RECHARGABLE BATTERY WITH INTERNAL CURRENT LIMITER AND INTERRUPTER
20170365840 · 2017-12-21
Assignee
Inventors
Cpc classification
H01M2010/4271
ELECTRICITY
Y02E60/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01M10/425
ELECTRICITY
H01M50/574
ELECTRICITY
H01M10/4235
ELECTRICITY
International classification
Abstract
A high energy density rechargeable (HEDR) battery employs a combined current limiter/current interrupter to prevent thermal runaway in the event of internal discharge or other disruption of the separator. The combined current limiter/current interrupter is interior to the battery.
Claims
1.-17. (canceled)
18. A battery, comprising: a current collector; and an electrode electrically coupled with the current collector, wherein the electrode is configured to cause, upon activation of at least a temperature trigger, formation of a nonconductive gap between the electrode and the current collector, wherein the formation of the nonconductive gap causes electrical decoupling of the electrode and the current collector, and wherein the electrical decoupling of the electrode and the current collector interrupts a current flow within the battery.
19. The battery of claim 18, wherein the electrode forms the nonconductive gap by at least generating, upon the activation of at least the temperature trigger, a gas, and wherein the gas forms the nonconductive gap by at least disengaging the electrode from the current collector.
20. The battery of claim 19, wherein the gas comprises a fire retardant gas.
21. The battery of claim 18, wherein the electrode forms the nonconductive gap by at least generating, upon the activation of at least the temperature trigger, a liquid that produces a gas, and wherein the gas forms the nonconductive gap by at least disengaging the electrode from the current collector.
22. The battery of claim 21, wherein the liquid produces the gas by at least vaporizing.
23. The battery of claim 21, wherein the liquid produces the gas by at least reacting with the current collector, a separator, and/or an electrolyte comprising the battery.
24. The battery of claim 18, further comprising a current limiter.
25. The battery of claim 24, wherein the current limiter is interposed between the electrode and the current collector.
26. The battery of claim 24, wherein a resistivity of the current limiter is greater than an internal resistivity of the electrode at temperatures above a temperature range for standard operation, and wherein the resistivity of the current limiter is less than the internal resistivity of the electrode at temperatures within the temperature range for standard operation.
27. The battery of claim 26, wherein the resistivity of the current limiter does not transition at temperatures within the temperature range for standard operation.
28. The battery of claim 18, wherein the electrode is further configured to cause the formation of the nonconductive gap upon activation of a voltage trigger.
29. The battery of claim 18, wherein the electrode is further configured to decompose upon the activation of at least the temperature trigger, and wherein the decomposition of the electrode further interrupts the current flow within the battery.
30. The battery of claim 18, wherein the electrode and the current collector are electrically coupled via a laminated connection, and wherein the formation of the nonconductive gap delaminates the laminated connection between the electrode and the current collector.
31. The battery of claim 18, wherein the temperature trigger is activated when temperature exceeds a temperature range for standard operation.
32. The battery of claim 18, wherein the electrode comprises an anode or a cathode of the battery.
33. The battery of claim 18, wherein the electrode comprises an electrochemically active material and a heat sensitive material, and wherein the heat sensitive material is configured to generate a gas and/or a liquid upon the activation of at least the temperature trigger.
34. The battery of claim 31, wherein the electrochemically active material comprises lithium (Li), aluminum (Al), potassium (K), sodium (Na), magnesium (Mg), and/or silicon (Si).
35. The battery of claim 31, wherein the heat sensitive material comprises an organic carbonate and/or an inorganic carbonate.
36. The battery of claim 31, wherein the heat sensitive material comprises a barium (Ba) carbonate, a calcium (Ca) carbonate, a cadmium (Cd) carbonate, a cobalt (Co) carbonate, a copper (Cu) carbonate, an iron (Fe) carbonate, a potassium (K) carbonate, a lithium (Li) carbonate, a magnesium (Mg) carbonate, a manganese (Mn) carbonate, a sodium (Na) carbonate, a nickel (Ni) carbonate, a lead (Pb) carbonate, a strontium (Sr) carbonate, and/or a zinc (Zn) carbonate.
37. A method, comprising: forming a nonconductive gap between an electrode and a current collector within a battery, wherein the electrode and the current collector are electrically coupled, wherein the formation of the nonconductive gap is caused by the electrode in response to an activation of least a temperature trigger, wherein the formation of the nonconductive gap electrically decouples the electrode and the current collector, and wherein the electrical decoupling of the electrode and the current collector interrupts a current flow within the battery.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0052] The present disclosure is described more fully herein with reference to the accompanying drawings, in which some exemplary embodiments of the present disclosure are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity.
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[0054] FIGS. 2 Aand 2B illustrate schematic representations of exemplary configurations of film-type lithium ion batteries having one or more layers serving as combined current limiters 6 and current interrupters 8, for protecting the battery against overheating in the event of an internal short circuit, combined with current interrupters 8 that are voltaicly activable by an increase in voltage, for irreversibly interrupting the self-discharge process in the event that the battery should become overcharged.
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DETAILED DESCRIPTION
[0095] Safe, long-term operation of high energy density rechargeable batteries, including lithium ion batteries, is a goal of battery manufacturers. One aspect of safe battery operation is controlling the heat generated by rechargeable batteries. As described above, many factors may cause the heat generated by a rechargeable battery to exceed its heat dissipation capacity, such as a battery defect, accident, or excessive internal current. When the heat generated by a battery exceeds its ability to dissipate heat, a rechargeable battery becomes susceptible to thermal runaway, overheating, and possibly even fire or violent explosion. Described below are apparatus and methods associated with a thermally activated internal current interrupter that can interrupt the internal circuit of a rechargeable battery, preventing thermal runaway.
[0096] Another aspect of safe battery operation is controlling the reactions at the electrodes of these rechargeable batteries during both battery charging and discharge. As described above, electrical current flows outside the battery, through an external circuit during use, while ions move from one electrode to another within the battery. In some cases, overcharge occurs and can lead to thermal runaway within the battery. Described below are apparatus and methods associated with an internal current limiter that limits the rate of internal discharge in a rechargeable battery when there is an internal short circuit.
[0097] A further aspect of safe battery operation is controlling the discharge of these rechargeable batteries. As described above, a separator, or barrier layer, is used to separate the negative and positive electrodes in rechargeable batteries in which ions can move through the battery, but electrical current is forced to flow outside the battery, through an external circuit. Many factors may cause the separator to be breached, and may cause a short-circuit to occur within a rechargeable battery. A short-circuit leads to rapid discharge and possibly overheating and thermal runaway. Described below are apparatus and methods associated with an internal current limiter that limits the rate of internal discharge in a rechargeable battery when there is an internal short circuit.
[0098] The terminology used herein is for the purpose of describing some particular exemplary embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0099] It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various members, elements, regions, layers and/or parts, these members, elements, regions, layers and/or parts should not be limited by these terms. These terms may be used merely to distinguish one member, element, region, layer and/or part from another member, element, region, layer and/or part. Thus, for example, a first member, element, region, layer and/or part discussed below could be termed a second member, element, region, layer and/or part without departing from the teachings of the present disclosure.
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Current Limiter
[0112] A first aspect of the disclosure is directed to an improved HEDR battery of a type including an anode energy layer 12, a cathode energy layer 14, a separator 2 between the anode energy layer 12 and the cathode energy layer 14 for preventing internal discharge thereof, and at least one current collector 4 for transferring electrons to and from either the anode or cathode energy layer. The anode and cathode energy layers each have an internal resistivity. The HEDR battery has a preferred temperature range for discharging electric current and an upper temperature safety limit. The improvement is employable, in the event of separator failure, for limiting the rate of internal discharge through the failed separator and the generation of joule heat resulting therefrom. More particularly, the improvement comprises a resistive layer 6 interposed between the separator and one of the current collectors 4 for limiting the rate of internal discharge through the failed separator in the event of separator failure. The resistive layer 6 has a fixed resistivity at temperatures between the preferred temperature range and the upper temperature safety limit. The fixed resistivity of the resistive layer 6 is greater than the internal resistivity of either energy layer. The resistive layer 6 helps the battery avoid temperatures in excess of the upper temperature safety limit in the event of separator failure.
[0113] Some embodiments of the present disclosure include an improved high energy density rechargeable battery are of a type including: [0114] 1. two electrodes (12 and 14) of opposite polarity, each electrode characterized by its resistivity, by its safe operating temperature range, and its safe charging voltage; the two electrodes being subject to a risk of overcharge above the safe charging voltage and the formation of the short circuit therefrom; the two electrodes being subject to a risk of thermal runaway above the safe operating temperature range. [0115] 2. a separator 2 for separating the two electrodes and preventing internal discharge therebetween; the separator being subject to a risk of forming a short circuit, the short circuit potentially allowing a rapid internal discharge between the two electrodes, the rapid internal discharge between the two electrodes potentially allowing a rapid production of joule heat therefrom, the rapid production of joule heat potentially allowing a thermal runaway. [0116] 3. at least one electrode employing a current collector 4 for transferring electrons. [0117] 4. a current limiter 6 forming an electrical coupling between one of the electrodes and its corresponding current collector, the current limiter having a resistivity for resistively impeding current therethrough and, in the event the separator forms the short circuit, for diverting current from the electrode current collector to which it is coupled, and for reducing the rate of the internal discharge between the two electrodes. [0118] 5. a current interrupter 8 having an engaged configuration, an disengaged configuration, and a gas generating component for transitioning the current interrupter from the engaged to the unengaged configuration, the gas generating component having a trigger for generating a gas, the trigger being selected from the group consisting of temperature triggers and voltage triggers, the temperature triggers being activatable above the safe operating temperature range; the voltage triggers being activatable above the safe charging voltage; in the engaged configuration, the current interrupter electrically coupling one of the electrodes and its corresponding current collector with a laminated connection, in the disengaged configuration, the laminated connection becoming delaminated and the current interrupter forming a nonconductive gap for interrupting the electrical coupling between the electrode and its corresponding current collector, the current interrupter transitioning from the engaged to the disengaged configuration by triggering the gas generating component responsive to the trigger, the generated gas delaminating the laminated connection for interrupting the electrical coupling between the electrode and its corresponding current collector, whereby the current limiter and the current interrupter, in combination, diminishing the risk of thermal runaway resulting from separator short circuit, electrode overcharge, and electrode overheating.
[0119] In some embodiments, the current interrupter is triggered by temperature.
[0120] In some embodiments, the current interrupter includes a layer containing a single gas generating component triggered by temperature.
[0121] In some embodiments, the current interrupter is triggered by voltage.
[0122] In some embodiments, the current interrupter includes a layer containing a single gas generating component triggered by voltage.
[0123] In some embodiments, the current interrupter is triggered by temperature and voltage.
[0124] In some embodiments, the current interrupter includes a layer containing a single gas generating component triggered by temperature and voltage.
[0125] In some embodiments, the current interrupter includes a layer containing two gas generating components, one triggered by temperature and the other triggered by voltage.
[0126] In some embodiments, the current interrupter may include a layer containing one or more inorganic gas generating compounds that generate gas at a specific temperature or voltage.
[0127] In some embodiments, the inorganic gas generating compounds are selected from the group consisting of CaCO.sub.3, La.sub.2(CO.sub.3).sub.3, Na.sub.2SO.sub.3, ZnCO.sub.3Zn(OH).sub.2, CuCO.sub.3Cu(OH).sub.2, and Cu(NO.sub.3).sub.2 as disclosed in
[0128] In some embodiments, the current interrupter may include a layer containing one or more organic gas generating compounds that generate gas at a specific temperature or voltage.
[0129] In some embodiments, the organic gas generating compounds are selected from the group consisting of Carbopol, Torlon® AI-50, CMC, and PVDF as disclosed in
[0130] In some embodiments, the current interrupter may include a layer containing a combination of inorganic and organic gas generating compounds that generate gas at a specific temperature or voltage.
[0131] In some embodiments of the improved high energy density rechargeable battery, the current limiter and the current interrupter are simultaneously incorporated into a protective layer interposed by lamination between the same electrode and current collector, as disclosed in
[0132] In some embodiments of the improved high energy density rechargeable battery, the current limiter and the current interrupter triggered by both temperature and voltage are simultaneously incorporated into a protective layer interposed by lamination between the same electrode and current collector, as disclosed in
[0133] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, the improvement further characterized wherein: [0134] the current limiter and the current interrupter are simultaneously incorporated into a first protective layer interposed by lamination between the first electrode and the first current collector; and [0135] the current limiter and the current interrupter are simultaneously incorporated into a second protective layer interposed by lamination between the second electrode and the second current collector,
as disclosed in
[0136] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, the improvement further characterized wherein: [0137] the current limiter and the current interrupter are simultaneously incorporated into a first protective layer interposed by lamination between the first electrode and the first current collector; and [0138] the current limiter and the current interrupter are simultaneously incorporated into a second protective layer interposed by lamination between the second electrode and the separator,
as disclosed in
[0139] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, the improvement further characterized wherein: [0140] the current limiter and the current interrupter are simultaneously incorporated into a first protective layer interposed by lamination between the first electrode and the separator; and [0141] the current limiter and the current interrupter are simultaneously incorporated into a second protective layer interposed by lamination between the second electrode and the second current collector,
as disclosed in
[0142] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the first electrode including a first portion and a second portion, the second portion of the first electrode interposed between the first portion of the first electrode and the first current collector, the improvement further characterized wherein: [0143] 1. the current limiter being layered between the first portion of the first electrode and the second portion of the first electrode; and [0144] 2. the current interrupter being layered between the second portion of the first electrode and the first current collector.
[0145] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the first electrode including a first portion and a second portion, the second portion of the first electrode interposed between the first portion of the first electrode and the first current collector, the improvement further characterized, wherein the current limiter and the current interrupter are simultaneously incorporated into a protective layer interposed by lamination between the first portion and the second portion of the first electrode, as disclosed in
[0146] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the first electrode including a first portion and a second portion, the second portion of the first electrode interposed between the first portion of the first electrode and the first current collector, the improvement further characterized, wherein the current limiter and the current interrupter triggered by both temperature and voltage are simultaneously incorporated into a protective layer interposed by lamination between the first portion and the second portion of the first electrode, as disclosed in
[0147] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the second electrode including a first portion and a second portion, the first portion of the second electrode interposed between the second portion of the second electrode and the second current collector, the improvement further characterized wherein: [0148] 1. the current limiter being layered between the first portion of the second electrode and the second portion of the second electrode; and [0149] 2. the current interrupter being layered between the second portion of the second electrode and the second current collector.
[0150] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the second electrode including a first portion and a second portion, the first portion of the second electrode interposed between the second portion of the second electrode and the second current collector, the improvement further characterized wherein: [0151] 1. the current interrupter being layered between the first portion of the second electrode and the second portion of the second electrode; and [0152] 2. the current limiter being layered between the second portion of the second electrode and the second current collector.
[0153] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the first electrode including a first portion and a second portion, the first portion of the second electrode interposed between the second portion of the second electrode and the second current collector, the improvement further characterized, wherein the current limiter and the current interrupter are simultaneously incorporated into a protective layer interposed by lamination between the first portion and the second portion of the second electrode, as disclosed in
[0154] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector, the two electrodes including a first electrode and a second electrode, and the first electrode including a first portion and a second portion, the second portion of the first electrode interposed between the first portion of the first electrode and the first current collector, the improvement further characterized wherein: [0155] 1. the current limiter being layered between the second portion of the first electrode and the first current collector; and [0156] 2. the current interrupter being layered between the first portion of the first electrode and the second portion of the first electrode.
[0157] In some embodiments, the improved high energy density rechargeable battery is of a type having two current collectors, including a first current collector and a second current collector and the two electrodes including a first electrode and a second electrode, the improvement further characterized, wherein: [0158] 1. the current limiter being layered between the first electrode and the first current collector; and [0159] 2. the current interrupter being layered between the second electrode and the second current collector.
[0160] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has a temperature range for safe operation and an internal resistivity therein, the improvement further characterized wherein the current limiter having a resistivity greater than the internal resistivity of the electrode with which the current limiter is layered within the temperature range for safe operation.
[0161] In some embodiments of the improved high energy density rechargeable battery, the improvement further characterized, wherein the current limiter lacking a resistivity transition switch at temperatures within the temperature range for safe operation.
[0162] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has a temperature range for standard operation, the improvement further characterized, wherein the current limiter having a resistivity transition with a resistivity less than the internal resistivity of the electrode within the temperature range for standard operation and a resistivity greater than the internal resistivity of the electrode above the temperature range for standard operation.
[0163] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has a temperature range for standard operation, the improvement further characterized, wherein the current interrupter is activated by temperature above the temperature range for standard operation.
[0164] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has a temperature range for standard operation and a temperature range for safe operation, the improvement further characterized, wherein the current interrupter is activated by temperature above the temperature range for standard operation and within the temperature range for safe operation.
[0165] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has an internal resistivity within the temperature range for safe operation, the improvement further characterized, wherein the current limiter having a resistivity greater than the internal resistivity of the electrode with which the current limiter is layered within the temperature range for safe operation.
[0166] In some embodiments of the improved high energy density rechargeable battery, the improvement further characterized, wherein the current limiter and the current interrupter are simultaneously incorporated into a protective layer interposed by lamination between the same electrode and current collector.
[0167] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has a voltage range for standard operation, the improvement further characterized, wherein the current interrupter is activated by voltage above the voltage range for standard operation.
[0168] In some embodiments, the improved high energy density rechargeable battery is of a type, wherein each electrode has a voltage range for standard operation and a voltage range for safe operation, the improvement further characterized, wherein the current interrupter is activated by voltage above the temperature range for standard operation and within the voltage range for safe operation.
[0169] In some embodiments of the improved high energy density rechargeable battery, the improvement further characterized, wherein the current limiter and the current interrupter are simultaneously incorporated into a protective layer interposed by lamination between the same electrode and current collector.
[0170] Other embodiments of the present disclosure include an improved high energy density rechargeable battery of a type including two electrodes of opposite polarity, a separator separating the two electrodes, and at least one current collector electrically coupled to one of the electrodes, the separator preventing internal discharge between the two electrodes, failure of the separator potentially causing an internal discharge between the two electrodes (as illustrated in
whereby, activation of either the thermally activated current interrupter or voltage activated current interrupter in the event of separator failure, slows the generation joule heat for diminishing the potential danger.
[0173] Some embodiments of the present disclosure include a process for avoiding thermal runaway within a high energy density rechargeable battery undergoing internal discharge due to separator failure, the process comprising delaminating an electrode within the battery from its current collector by generating a gas from a heat sensitive gas generating material within an interrupt layer interposed between the electrode and current collector, the delaminating electrically decoupling the electrode from its current collector for slowing the rate of internal discharge.
[0174] Some embodiments of the present disclosure include a process for avoiding thermal runaway within a high energy density rechargeable battery at risk of suffering from separator failure due to voltage overcharge (as illustrated in
[0175] The following abbreviations have the indicated meanings: [0176] Carbopol®-934=cross-linked polyacrylate polymer supplied by Lubrizol Advanced Materials, Inc. [0177] CMC=carboxymethyl cellulose [0178] CMC-DN-800H=CMC whose sodium salt of the carboxymethyl group had been replaced by ammonium (supplied by Daicel FineChem Ltd). [0179] MCMB=mesocarbon microbeads [0180] NMC=Nickel, Manganese and Cobalt [0181] NMP=N-methylpyrrolidone [0182] PTC=positive temperature coefficient [0183] PVDF=polyvinylidene fluoride [0184] SBR=styrene butadiene rubber [0185] Super P®=conductive carbon blacks supplied by Timcal [0186] Torlon AI-50=water soluble analog of Torlon 4000TF [0187] Torlon® 4000TF=neat resin polyamide-imide (PAI) fine powder
[0188] Preparation of the resistance layer and electrode active layer is described below, along with battery cell assembly.
[0189] The following is a generalized procedure for preparing a resistance layer (first layer): [0190] i. Dissovle the binder into an appropriate solvent. [0191] ii. Add the conductive additive and ceremic powder into the binder solution to form a slurry. [0192] iii. Coat the slurry made in Step ii. onto the surface of a metal foil, and then dry it to form a resistance layer on the surface of the foil.
[0193] The following is a generalized procedure for the electrode preparation (on the top of the first layer): [0194] i. Dissovle the binder into an appropriate solvent. [0195] ii. Add the conductive additive into the binder solution to form a slurry. [0196] iii. Put the cathode or anode material into the slurry made in the Step v. and mix it to form the slurry for the electrode coating. [0197] iv. Coat the electrode slurry made in the Step vi. onto the surface of the layer from Step iii. [0198] v. Compress the electrode into the design thickness.
[0199] The following is a generalized procedure for Cell assembly: [0200] i. Dry the positive electrode at 125° C. for 10 hr and negative electrode at 140° C. for 10 hr. [0201] ii. Punch the electrodes into the pieces with the electrode tab. [0202] iii. Laminate the positive and negative electrodes with the separator as the middle layer. [0203] iv. Put the flat jelly-roll made in the Step xi. into the Aluminium composite bag.
[0204] Below are the generalized steps for conducting an impact test, as shown in
[0213] Below are the generalized steps for performing an overcharge test. [0214] i. Charge the cell at 2 Aand 4.2V for 3 hr. [0215] ii. Put the charged cell into a room temperature oven. [0216] iii. Connect the cell to a power supply (manufactured by Hewlett-Packard). [0217] iv. Set the voltage and current on the power supply to 12V and 2 A. [0218] v. Turn on the power supply to start the overcharge test while recording the temperature and voltage. [0219] vi. Test ends when the cell temperature decreases and stablizes near room temperature.
[0220] Below are the generalized steps for performing the Resistance Measurement Test. [0221] i. Place one squared copper foil (4.2×2.8 cm) with the tab on to a metal plate (˜12ט8 cm). Then cut a piece of thermal tape and carefully cover the squared copper foil. [0222] ii. Cut a piece of the electrode that is slightly larger than the copper paper. Place the electrode on to the copper foil. [0223] iii. Place another copper foil (4.2×2.8 cm) with tab on the electrode surface, repeat steps i-ii with it. [0224] iv. At this point, carefully put them together and cover them using high temperature tape and get rid of any air bubble [0225] v. Cut a “V” shaped piece of metal off both tabs. [0226] vi. Attach the completed strip to the metal clamp and tighten the screws. Make sure the screws are really tight. [0227] vii. Attach the tabs to the connectors of Battery HiTester (produced by Hioki USA Corp.) to measure the resistance to make sure that a good sample has been made for the measurement. [0228] viii. Put the metal clamp inside the oven, connect the “V” shaped tabs to the connectors and then tightened the screw. Tape the thermocouple onto the metal clamp. [0229] ix. Attach the Battery HiTester to the wires from oven. Do not mix up the positive and the negative wires. [0230] x. Close the oven and set the temperature to 200° C. at 4° C. per minute, and start the test. Record data every 15 seconds. [0231] xi. Stop recording the data when the metal clamp and oven reach just a little over 200° C. [0232] xii. Turn off the oven and the Battery HiTester. [0233] xiii. End Test.
[0234] Below are the generalized steps for performing the Cycle Life procedure. [0235] i. Rest for 5 minutes. [0236] ii. Discharge to 2.8V at 1 A. [0237] iii. Rest for 20 minutes. [0238] iv. Charge to 4.2V at 0.7 A for 270 minutes. [0239] v. Rest for 10 minutes. [0240] vi. Discharge to 2.8V at 0.7 A. [0241] vii. Rest for 10 minutes. [0242] viii. Repeat Steps iii to vii 100 times. [0243] ix. End test.
[0244] Below are the generalized steps for testing a battery cell with a resistance layer for discharge at 1 A, 3 A, 6 A, and 10 A. In each test, the battery cell is tested in a chamber with controlled, constant temperature, for example 50° C. [0245] i. Rest for 5 1minutes. [0246] ii. Discharge to 2.8V at 1 12A. [0247] iii. Rest for 20 minutes. [0248] iv. Charge to 4.2V at 0.7 A for 270 minutes. [0249] v. Rest for 10 minutes. [0250] vi. Discharge to 2.8V at 1 A. [0251] vii. Rest for 10 minutes. [0252] viii. Charge to 4.2V at 0.7 A for 270 minutes. [0253] ix. Rest for 10 minutes. [0254] x. Discharge to 2.8V at 3 A. [0255] xi. Charge to 4.2V at 0.7 A for 270 minutes. [0256] xii. Rest for 10 minutes. [0257] xiii. Discharge to 2.8V at 6 A. [0258] xiv. Charge to 4.2V at 0.7 A for 270 minutes. [0259] xv. Rest for 10 minutes. [0260] xvi. Discharge to 2.8V at 10 A. [0261] xvii. Rest for 10 minutes. [0262] xviii. End Test.
[0263] Definitions
[0264] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this disclosure belongs. In the event that there is a plurality of definitions for a term herein, those in this section prevail unless stated otherwise.
[0265] As used herein, “high energy density rechargeable (HEDR) battery” means a battery capable of storing relatively large amounts of electrical energy per unit weight on the order of about 50 W-hr/kg or greater and is designed for reuse, and is capable of being recharged after repeated uses. Non-limiting examples of HEDR batteries include metal-ion batteries and metallic batteries.
[0266] As used herein, “metal-ion batteries” means any rechargeable battery types in which metal ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of metal-ion batteries include lithium-ion, aluminum-ion, potassium-ion, sodium-ion, magnesium-ion, and others.
[0267] As used herein, “metallic batteries” means any rechargeable battery types in which the anode is a metal or metal alloy. The anode can be solid or liquid. Metal ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of metallic batteries include M-S, M-NiCl.sub.2, M-V.sub.2O.sub.5, M-Ag.sub.2VP.sub.2O.sub.8, M-TiS.sub.2, M-TiO.sub.2, M-MnO.sub.2, M-Mo.sub.3S.sub.4, M-MoS.sub.6Se.sub.2, M-MoS.sub.2, M-MgCoSiO.sub.4, M-Mg.sub.1.03Mn.sub.0.97SiO.sub.4, and others, where M=Li, Na, K, Mg, Al, or Zn.
[0268] As used herein, “lithium-ion battery” means any rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of lithium-ion batteries include lithium cobalt oxide (LiCoO.sub.2), lithium iron phosphate (LiFePO.sub.4), lithium cobalt phosphate (LiCoPO.sub.4), lithium excess layered oxides such as (LiMnO.sub.3)x(LiMO.sub.2) (M=Ni, Co, Mn), olivines, LiMSiO.sub.4 (M=iron, Cobalt, Nickel and Vanadium); lithium manganese oxide (LiMn.sub.2O.sub.4), lithium nickel oxide (LiNiO.sub.2), lithium nickel manganese cobalt oxide (LiNiMnCoO.sub.2), lithium nickel cobalt aluminum oxide (LiNiCoAlO.sub.2), lithium titanate (Li.sub.4Ti.sub.5O.sub.12), lithium titanium dioxide, lithium/graphene, lithium/graphene oxide coated sulfur, lithium-sulfur, lithium-purpurin, and others. Lithium-ion batteries can also come with a variety of anodes including silicon-carbon nanocomposite anodes and others. Lithium-ion batteries can be in various shapes including small cylindrical (solid body without terminals), large cylindrical (solid body with large threaded terminals), prismatic (semi-hard plastic case with large threaded terminals), and pouch (soft, flat body). Lithium polymer batteries can be in a soft package or pouch. The electrolytes in these batteries can be a liquid electrolyte (such as carbonate based or ionic), a solid electrolyte, a polymer based electrolyte or a mixture of these electrolytes.
[0269] As used herein, “aluminum-ion battery” means any rechargeable battery types in which aluminum ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of aluminum-ion batteries include Al.sub.nM.sub.2 (XO.sub.4).sub.3, wherein X═Si, P, S, Mo, As, and others; and M=Fe, Ca, Mg, V, Cr and others; aluminum transition-metal oxides (Al.sub.xMO.sub.2 wherein M=Fe, Mn, Ni, Mo, Co, Cr, Ti, V and others) such as Al.sub.x (V.sub.4O.sub.8), Al.sub.xNiS.sub.2, Al.sub.xFeS.sub.2, Al.sub.xVS.sub.2 and Al.sub.xWS.sub.2 and others.
[0270] As used herein, “potassium-ion battery” means any rechargeable battery types in which potassium ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of potassium-ion batteries include K.sub.nM.sub.2(XO.sub.4).sub.3, wherein X═Si, P, S, Mo, As, and others; and M=Fe, Ca, Mg, V, Cr and others; potassium transition-metal oxides (KMO.sub.2 wherein M=Fe, Mn, Ni, Mo, Co, Cr, Ti, V and others), and others.
[0271] As used herein, “sodium-ion battery” means any rechargeable battery types in which sodium ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of sodium-ion batteries include Na.sub.nM.sub.2(XO.sub.4).sub.3, wherein X═Si, P, S, Mo, As, and others; and M=Fe, Ca, Mg, V, Cr and others; NaV.sub.1-xCr.sub.xPO.sub.4F, NaVPO.sub.4F, Na.sub.4Fe.sub.3(PO.sub.4).sub.2(P.sub.2O.sub.7), Na.sub.2FePO.sub.4F, Na.sub.2FeP.sub.2O.sub.7, Na.sub.2/3[Fe.sub.1/2Mn.sub.1/2]O.sub.2, Na(Ni.sub.1/3Fe.sub.1/3Mn.sub.1/3)O.sub.2, NaTiS.sub.2, NaFeF.sub.3; Sodium Transition-Metal Oxides (NaMO.sub.2 wherein M=Fe, Mn, Ni, Mo, Co, Cr, Ti, V and others) such as Na.sub.2/3[Fe.sub.1/2Mn.sub.1/2]O.sub.2, Na(Ni.sub.1/3Fe.sub.1/3Mn.sub.1/3)O.sub.2, Na.sub.xMo.sub.2O.sub.4, NaFeO.sub.2, Na.sub.0.7CoO.sub.2, NaCrO.sub.2, NaMnO.sub.2, Na.sub.0.44MnO.sub.2, Na.sub.0.7MnO.sub.2, Na.sub.0.7MnO.sub.2.25, Na.sub.2/3Mn.sub.2/3Ni.sub.1/3O.sub.2, Na.sub.0.61Ti.sub.0.48Mn.sub.0.52O.sub.2; Vanadium Oxides such as Na.sub.1+xV.sub.3O.sub.8, Na.sub.xV.sub.2O.sub.5, and Na.sub.xVO.sub.2 (x=0.7, 1); and others.
[0272] As used herein, “magnesium-ion battery” means any rechargeable battery types in which magnesium ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of magnesium-ion batteries include Mg.sub.nM.sub.2(XO.sub.4).sub.3, wherein X═Si, P, S, Mo, As, and others; and M=Fe, Ca, Mg, V, Cr and others; magnesium Transition-Metal Oxides (MgMO.sub.2 wherein M=Fe, Mn, Ni, Mo, Co, Cr, Ti, V and others), and others.
[0273] As used herein, “silicon-ion battery” means any rechargeable battery types in which silicon ions move from the negative electrode to the positive electrode during discharge and back when charging. Non-limiting examples of silicon-ion batteries include Si.sub.nM.sub.2(XO.sub.4).sub.3, wherein X═Si, P, S, Mo, As, and others; and M=Fe, Ca, Mg, V, Cr and others; Silicon Transition-Metal Oxides (SiMO.sub.2 wherein M=Fe, Mn, Ni, Mo, Co, Cr, Ti, V and others), and others.
[0274] As used herein, “binder” means any material that provides mechanical adhesion and ductility with inexhaustible tolerance of large volume change. Non-limiting examples of binders include styrene butadiene rubber (SBR)-based binders, polyvinylidene fluoride (PVDF)-based binders, carboxymethyl cellulose (CMC)-based binders, poly(acrylic acid) (PAA)-based binders, polyvinyl acids (PVA)-based binders, poly(vinylpyrrolidone) (PVP)-based binders, and others.
[0275] As used herein, “conductive additive” means any substance that increases the conductivity of the material. Non-limiting examples of conductive additives include carbon black additives, graphite nonaqueous ultrafine carbon (UFC) suspensions, carbon nanotube composite (CNT) additives (single and multi-wall), carbon nano-onion (CNO) additives, graphene-based additives, reduced graphene oxide (rGO), conductive acetylene black (AB), conductive poly(3-methylthiophene) (PMT), filamentary nickel powder additives, aluminum powder, electrochemically active oxides such as lithium nickel manganese cobalt oxide and others.
[0276] As used herein, “metal foil” means any metal foil that under high voltage is stable. Non-limiting examples of metal foils include aluminum foil, copper foil, titanium foil, steel foil, nano-carbon paper, graphene paper, carbon fiber sheet, and others.
[0277] As used herein, “ceramic powder” means any electrical insulator or electrical conductor that hasn't been fired. Non-limiting examples of ceramic powder materials include barium titanate (BaTiO.sub.3), zirconium barium titanate, strontium titanate (SrTiO.sub.3), calcium titanate (CaTiO.sub.3), magnesium titanate (MgTiO.sub.3), calcium magnesium titanate, zinc titanate (ZnTiO.sub.3), lanthanum titanate (LaTiO.sub.3), and neodymium titanate (Nd.sub.2Ti.sub.2O.sub.7), barium zirconate (BaZrO.sub.3), calcium zirconate (CaZrO.sub.3), lead magnesium niobate, lead zinc niobate, lithium niobate (LiNbO.sub.3), barium stannate (BaSnO.sub.3), calcium stannate (CaSnO.sub.3), magnesium aluminum silicate, sodium silicate (NaSiO.sub.3), magnesium silicate (MgSiO.sub.3), barium tantalate (BaTa.sub.2O.sub.6), niobium oxide, zirconium tin titanate, silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), titanium dioxide (TiO.sub.2), and others.
[0278] As used herein, “gas generator material” means any material which will decompose at the high temperature or high voltage to produce a gas either directing from the gas generator material or indirectly from reaction of the decomposition products produced from the gas generator material with other materials contained within the battery (e.g. the electrolyte and electrodes). Non-limiting examples of gas generator materials include inorganic carbonates such as M.sub.n(CO.sub.3).sub.m, M.sub.n(SO.sub.3).sub.m, M.sub.n(NO.sub.3).sub.m, .sup.1M.sub.n.sup.2M.sub.n(CO.sub.3).sub.m, NaSiO.sub.3*H.sub.2O, CuCO.sub.3CU(OH).sub.2, and others and organic carbonates such as polymethacrylic [—CH.sub.2—C(CH.sub.3)(COOM)-].sub.p and polyacrylate salts [—CH.sub.2—CH(COOM)-].sub.p, and others wherein M, .sup.1M, .sup.2M are independently selected from the group consisting of Ba, Ca, Cd, Co, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn; n is 1-3 and m is 1-4. In some embodiments, M is independently selected from the group consisting of an ammonium ion, pyridinium ion and a quaternary ammonium ion. In some embodiments, the gas generator material may decompose to produce a liquid (e.g. water). The liquid may react with other materials contained within the battery to form a gas and this gas will delaminate the electrode (e.g. water reacting with the electrolyte [LiFP.sub.6] to form gaseous HF and lithium in the negative to form hydrogen gas (H.sub.2)). If the temperature of the cell exceeds the vaporization temperature of the liquid, the liquid may also undergo a phase transition to form a gas and this gas will also delaminate the electrode.
[0279] Layers were coated onto metal foils by an automatic coating machine (compact coater, model number 3R250W-2D) produced by Thank-Metal Co., Ltd. Layers are then compressed to the desired thickness using a calender machine (model number X15-300-1-DZ) produced by Beijing Sevenstar Huachuang Electronics Co., Ltd.
EXAMPLES
[0280] The disclosure will be described more in detail below using examples, but the disclosure is not limited to the examples shown below.
Example 1
[0281] Preparation of baseline electrodes, positive and negative electrodes, and the completed Cell #1 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, and cycle life test are described below.
[0282] A) Preparation of POS1A as an Example of the Positive Electrode Preparation.
[0283] i) PVDF (21.6 g) was dissolved into NMP (250 g); ii) Carbon black (18 g) was added and mixed for 15 minutes at 6500 rpm; iii) LiNi.sub.0.5Mn.sub.0.3Co.sub.0.2O.sub.2 (NMC) (560.4 g) was added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto 15 μm aluminum foil using an automatic coating machine with the first heat zone set to about 80° C. and the second heat zone to about 130° C. to evaporate off the NMP. The final dried solid loading was about 15.55 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 117 μm. The electrode made here was considered as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature, and the dry for the cell assembly.
[0284] B) Preparation of NEG2A as an Example of the Negative Electrode Preparation
[0285] i) CMC (5.2 g) was dissolved into deionized water (˜300 g); ii) Carbon black (8.4 g) was added and mixed for 15 minutes at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (378.4 g in total) were added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (16.8 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 70° C. and the second heat zone to about 100° C. to evaporate off the water. The final dried solid loading was about 9.14 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 117 μm. The negative made was used for the dry for the cell assembly.
[0286] C) Preparation of Cell for the Evaluation
[0287] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The jelly-roll made in the Step iii was laid flat into an aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; ix) Rest for 16 hours; ix) The cell was charged to 4.2V at C/20 rate for 5 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0288]
Example 2
[0289] Preparation of CaCO.sub.3 based gas generator and resistive layer, positive and negative electrodes, and the completed Cell #3 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, over charge, and cycle life test are described below.
[0290] A) Positive POS3B as an Example of a Gas Generator and Resistive Layer (1.sup.st Layer) Preparation.
[0291] i) Torlon®4000TF (0.8 g) was dissolved into NMP (10 g); ii) PVDF (3.8 g) was dissolved into NMP (˜70 g); iii) The solutions prepared in Step i and ii were mixed, and then carbon black (0.32 g) was added and mixed for 10 minutes at 6500 rpm; iv) Nano CaCO.sub.3 powder (34.08 g) was added to the solution from Step iii and mixed for 20 minutes at 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 135° C. and the second heat zone to about 165° C. to evaporate off the NMP. The final dried solid loading was about 1 mg/cm.sup.2.
[0292] B) Preparation of POS3A as an Example of the Positive Electrode Preparation (2.sup.nd Layer).
[0293] i) PVDF (21.6 g) was dissolved into NMP (250 g); ii) Carbon black (18 g) was added and mixed for 15 minutes at 6500 rpm; iii) LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 (NMC) (560.4 g) was added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS3B (Example 2A) using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading was about 19.4 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 153 μm. The electrode made here was considered as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0294] C) Preparation of NEG3A as an Example of the Negative Electrode Preparation
[0295] i) CMC (13 g) was dissolved into deionized water (˜1000 g); ii) Carbon black (20 g) was added and mixed for 15 minutes at the rate of about 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (945.92 g in total) were added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (32 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 100° C. and the second heat zone to about 130° C. to evaporate off the water. The final dried solid loading was about 11.8 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 159 μm. The negative made was used for the dry for the cell assembly.
[0296] D) Preparation of Cell for the Evaluation
[0297] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The jelly-roll made in the Step iii was laid flat in an aluminum composite bag; v) The bag from Step iv was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate; x) Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0298]
Example 3
[0299] Preparation of 50% Al.sub.2O.sub.3 and 50% CaCO.sub.3 based gas generator and resistive layer, positive and negative electrodes, and the completed Cell #4 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, over charge and cycle life tests are described below.
[0300] A) Positive POS4B as an Example of a Gas Generator and Resistive Layer (1.sup.st Layer) Preparation.
[0301] i) Torlon®4000TF (0.8 g) was dissolved into NMP (10 g); ii) PVDF (3.8 g) was dissolved into NMP (˜70 g); iii) The solutions prepared in Step i and ii were mixed, and then carbon black (0.32 g) was added and mixed for 10 minutes at 6500 rpm; iv) Nano CaCO.sub.3 powder (17.04 g) and Al.sub.2O.sub.3 powder (17.04 g) were added to the solution from Step iii and mixed for 20 minutes at 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 135° C. and the second heat zone to about 165° C. to evaporate off the NMP. The final dried solid loading was about 1 mg/cm.sup.2.
[0302] B) Preparation of POS4A as an Example of the Positive Electrode Preparation (2.sup.nd Layer).
[0303] i) PVDF (21.6 g) was dissolved into NMP (250 g); ii) Carbon black (18 g) was added and mixed for 15 minutes at the rate of about 6500 rpm; iii) LiNi.sub.1/3CO.sub.1/3Mn.sub.1/3O.sub.2 (NMC) (560.4 g) was added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS4B (Example 3A) using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading was about 19.4 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 153 μm. The electrode made here was considered as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0304] C) Preparation of NEG4A as an Example of the Negative Electrode Preparation
[0305] i) CMC (13 g) was dissolved into deionized water (˜1000 g); ii) Carbon black (20 g) was added and mixed for 15 minutes at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (945.92 g in total) were added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (32 g) was added to the slurry formed in Step iii and mixed at about 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 100° C. and the second heat zone to about 130° C. to evaporate off the water. The final dried solid loading was about 11.8 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 159 μm. The negative made was used for the dry for the cell assembly.
[0306] D) Preparation of Cell for the Evaluation
[0307] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The jelly-roll made in the Step iii was laid flat in an aluminum composite bag; v) The bag from Step iv was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate; x) Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0308]
Example 4
[0309] Preparation of Al.sub.2O.sub.3 and Sodium trisilicate (NaSiO.sub.3) mixed based gas generator and resistive layer, positive and negative electrodes, and the completed Cell #5 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, over charge, and cycle life tests are described below.
[0310] A) Positive POS5B as an Example of a Gas Generator and Resistive Layer (1.sup.st Layer) Preparation.
[0311] i) Torlon®4000TF (0.8 g) was dissolved into NMP (˜10 g); ii) PVDF (3.8 g) was dissolved into NMP (60 g); iii) The solutions prepared in Step i and ii were mixed, and then carbon black (0.32 g) was added and mixed for 10 minutes at 6500 rpm; iv) Nano A1.sub.2O.sub.3 powder (17.04 g) and NaSiO.sub.3 (17.04 g) were added to the solution from Step iii and mixed for 20 minutes at 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 135° C. and the second heat zone to about 165° C. to evaporate off the NMP. The final dried solid loading was about 0.7 mg/cm.sup.2.
[0312] B) Preparation of POS5A as an Example of the Positive Electrode Preparation (2.sup.nd Layer).
[0313] i) PVDF (21.6 g) was dissolved into NMP (270 g); ii) Carbon black (18 g) was added and mixed for 15 minutes at the rate of about 6500 rpm; iii) LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 (NMC) (560.4 g) was added to the slurry from Step ii and mixed for 30 minutes at the rate of about 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS5B (Example 4A) using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading was about 19.4 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 153 μm. The electrode made here was considered as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0314] C) Preparation of NEG5A as an Example of the Negative Electrode Preparation
[0315] i) CMC (13 g) was dissolved into deionized water (˜1000 g); ii) Carbon black (20 g) was added and mixed for 15 minutes at the rate of about 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (945.92 g in total) were added to the slurry from Step ii and mix for 30 minutes at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (32 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 100° C. and the second heat zone to about 130° C. to evaporate off the water. The final dried solid loading was about 11.8 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 159 μm. The negative made is ready for the dry for the cell assembly.
[0316] D) Preparation of Cell for the Evaluation
[0317] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The jelly-roll made in the Step iii was laid flat in an aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. x) Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0318]
Example 5
[0319] Preparation of 52% CaCO.sub.3 and 48% PVDF based gas generator and resistive layer, positive and negative electrodes, and the completed Cell #6 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, over charge, and cycle life tests are discussed below.
[0320] A) Positive POS6B as an Example of a Gas Generator and Resistive Layer (1.sup.st Layer) Preparation.
[0321] i) PVDF (23.25 g) was dissolved into NMP (˜250 g); ii) The solution prepared in Step I was mixed, and then carbon black (1.85 g) was added and mixed for 10 minutes at the rate of about 6500 rpm; iv) Nano CaCO.sub.3 powder (24.9 g) was added to the solution from Step iii and mixed for 20 minutes at 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 135° C. and the second heat zone to about 165° C. to evaporate off the NMP. The final dried solid loading was about 1 mg/cm.sup.2.
[0322] B) Preparation of POS6A as an Example of the Positive Electrode Preparation (2.sup.nd Layer).
[0323] i) PVDF (24 g) was dissolved into NMP (300 g); ii) Carbon black (12 g) was added and mixed for 15 minutes at 6500 rpm; iii) LiNi.sub.0.4Co.sub.0.3Mn.sub.0.4Co.sub.0.3O.sub.2 (NMC) (558 g) was added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS6B (Example 5A) using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading was about 22 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 167 μm. The electrode made here was considered as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0324] C) Preparation of NEG6A as an Example of the Negative Electrode Preparation.
[0325] i) CMC (9 g) was dissolved into deionized water (˜530 g); ii) Carbon black (12 g) was added and mixed for 15 minutes at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) (564 g) were added to the slurry from Step ii and mixed for 30 minutes at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (30 g) was added to the slurry formed in Step iii and mixed at about 6500 rpm for 5 min; v) Some water was added to adjust the viscosity for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 95° C. and the second heat zone to about 125° C. to evaporate off the water. The final dried solid loading was about 12 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 170 μm. The negative made was used for the dry for the cell assembly.
[0326] D) Preparation of Cell for the Evaluation.
[0327] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The jelly-roll made in the Step iii was laid flat in an aluminum composite bag; v) The bag from Step iv was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. x) Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0328]
Example 6
[0329] Preparation of positive electrodes for chemical decomposition voltage measurements is described below.
[0330] POS7B was prepared as follows: (i) Deionized water (˜300 g) was mixed into Carbopol®-934 (19.64 g); (ii) Super-P® (160 mg) and LiOH (200 mg) were added into the slurry made in Step (i) and mixed for 30 minutes at 5000 rpm; (iii) An appropriate amount of deionized water was added to adjust the slurry to form a coatable slurry. (iv) The slurry was coated onto a 15 μm aluminum foil with the automatic coating machine with the drying temperatures set to 135° C. for zone 1 and 165° C. for zone 2. The final dried solid loading was about 0.7 mg/cm.sup.2.
[0331] POS8B was prepared as follows: (i) Deionized water (−100 g) was mixed into AI-50 (19.85 g); (ii) Super-P® (160 mg) was added into the slurry made in Step (i) and mixed for 30 minutes at 5000 rpm; (iii) An appropriate amount of deionized water was added to adjust the slurry to form a coatable slurry. (iv) The slurry was coated onto 15 μm aluminum foil with automatic coating machine with the drying temperatures set to 135 for zone 1 and 165° C. for zone 2. The final dried solid loading was about 0.7 mg/cm.sup.2.
[0332] POS9B was prepared as follows: (i) Deionized water (˜322 g) was mixed into 19.85 g CMC-DN-800H; (ii) Super-P® (160 mg) was added into the slurry made in Step (i) and mixed for 30 minutes at 5000 rpm; (iii) An appropriate amount of deionized water was added to adjust the slurry to form a coatable slurry. (iv) The slurry was coated onto 15 μm aluminum foil with automatic coating machine with the drying temperatures set to 135 for zone 1 and 165° C. for zone 2. The final dried solid loading was about 0.7 mg/cm.sup.2.
[0333] POS13B was prepared as follows: (i) Torlon® 4000TF (300 mg) was dissolved into NMP (3 g). (ii) PVDF-A (2.4 g) was dissolved into NMP (30 g). (iii) The two solutions were mixed and Super-P® (160 mg) was added, then mixed for 30 minutes at 5000 rpm. (iv) La.sub.2(CO.sub.3).sub.3 (17.04 g) or the salts listed in
Example 7
[0334] Electrochemical test for the positives electrodes coated with gas generator layers is described below.
[0335] The decomposition voltages of all resistive layers were measured with a three electrode configuration (resistive layer as the working electrode, and lithium metal as both reference electrode and count electrode) by Linear Sweep Voltammetry technology using a VMP2 multichannel potentiostat instrument at room temperature. A 0.3 cm×2.0 cm piece of the resistive layer was the working electrode, and 0.3 cm×2.0 cm piece of lithium metal was both reference electrode and counter electrode. These electrodes were put into a glass containing LiPF.sub.6 ethylene carbonate based electrolyte (5 g). The scan rate is 5 mV/second in the voltage range from 0 to 6V.
Example 8
[0336] Preparation of CaCO.sub.3 based gas generator layer, positive and negtaive electrodes, and the cell (#7) for the evaluation in the over charge test is described below. This gas generator layer could become a resitive layer if the conductive additive content is in the certain range such that the resistivity of the gas-generater layer is more resistive (50% more at least) than that of the energy layer or the layer that provide the majority (>50%) of the battery discharge energy. The gas generator content can be 2% to 99%.
[0337] A) Positive POS071A as an Example of a Gas Generator Layer (1.sup.st Layer) Preparation.
[0338] i) Torlon®4000TF (0.9 g) was dissolved into NMP (10 g); ii) PVDF (5.25 g) was dissolved into NMP (˜68 g); iii) The solutions prepared in Step i and ii were mixed, and then carbon black (1.8 g) was added and mixed for 10 min at the rate of about 6500 rpm; iv) Nano CaCO.sub.3 powder (7.11 g) and 134.94 g LiNi.sub.0.33Al.sub.0.33Co.sub.0.33O.sub.2 were added to the solution from Step iii and mixed for 20 min at the rate of about 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 90° C. and the second heat zone to about 140° C. to evaporate off the NMP. The final dried solid loading was about 4 mg/cm.sup.2.
[0339] B) Preparation of POS071B as an Example of the Positive Electrode Preparation (2nd Layer).
[0340] i) PVDF (25.2 g) was dissolved into NMP (327 g); ii) Carbon black (21 g) was added and mixed for 15 min at the rate of about 6500 rpm; iii) LiNi.sub.0.82Al.sub.0.03Co.sub.0.15O.sub.2 (NCA) (649 g) was added to the slurry from Step ii and mixed for 30 min at the rate of about 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS071A using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading is about 20.4 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 155 μm.
[0341] C) Preparation of NEG015B as an Example of the Negative Electrode Preparation
[0342] i) CMC (15 g) was dissolved into deionized water (˜951 g); ii) Carbon black (15 g) was added and mixed for 15 min at the rate of about 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) (945 g) was added to the slurry from Step ii and mixed for 30 min at the rate of about 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (50 g) was added to the slurry formed in Step iii and mixed at about 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 100° C. and the second heat zone to about 130° C. to evaporate off the water. The final dried solid loading was about 11 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 155 μm. The negative made is ready for the dry for the cell assembly.
[0343] D) Preparation of Cell for the Evaluation
[0344] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at ˜125° C. for 10 hr and negative electrode at ˜140° C. for 10 hr; iii)The positive and negative electrodes were laminated with the separator as the middle layer; iv)The jelly-roll made in the Step iii was laid flat in an aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vaccum oven; vi) The bag from Step v was filled with the carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. The cell made here was used for grading and other tests such as over chrage test.
[0345]
Example 9
[0346] Preparation of Al.sub.2O.sub.3 based resistive layer, positive and negative electrodes, and the completed Cell 3 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, and cycle life test are described below.
[0347] A) Positive POS3B as an Example of a Resistance Layer (1.sup.st Layer) Preparation.
[0348] i) Dissolve Torlon® 4000TF (1 g) into NMP (10 g); Dissolve PVDF (6 g) into NMP (70 g); iii) Mix solution prepared in Step i and ii, and then add carbon black (0.4 g) and mix for 10 min at 6500 rpm; iv) Add nano Al.sub.2O.sub.3 powder (32 g) to the solution from Step iii and mix for 20 min at the rate of 6500 rpm to form a flowable slurry; v) Coat this slurry onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 130° C. and the second heat zone to about 160° C. to evaporate off the NMP. The final dried solid loading is about 1 mg/cm.sup.2.
[0349] B) Preparation of POS3A as an Example of the Positive Electrode Preparation (2nd Layer).
[0350] i) PVDF (21.6 g) was dissolved into NMP (250 g); Carbon black (18 g) was added and mixed for 15 min at 6500 rpm; LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 (NMC) (560.4 g) was added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS3B using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading was about 19.4 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 153 μm. The electrode made here is called as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0351] C) Preparation of NEG3A as an Example of the Negative Electrode Preparation
[0352] i) CMC (13 g) was dissolved into deionized water (˜1000 g); ii) Carbon black (20 g) was added and mixed for 15 min at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (945.92 g in total) was added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (32 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 gm thick copper foil using an automatic coating machine with the first heat zone set to about 100° C. and the second heat zone to about 130° C. to evaporate off the water. The final dried solid loading was about 11.8 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 159 μm. The negative made was used for the dry for the cell assembly.
[0353] D) Preparation of Cell for the Evaluation
[0354] i) The electrodes were punched into the pieces with the electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The flat jelly-roll made in the Step iii. was laid flat into an aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rested for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0355]
Example 10
[0356] Preparation of 50% Polyacrylic latex and 50% Barium Tatanate (BaTiO2) based resistive layer, positive and negative electrodes, and the completed Cell 4 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, and cycle life test are described below.
[0357] A) Positive POS4B as an Example of a Resistance Layer (1.sup.st Layer) Preparation.
[0358] i) CMC (0.375 g) was dissolved into deionized water (˜30 g); ii) The solution prepared in Step i was mixed, and then carbon black (1.75 g) was added and mixed for several minutes; iii) nano BaTiO.sub.2 powder (25 g) was added to the solution from Step ii and mixed for 20 min at 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 90° C. and the second heat zone to about 140° C. to evaporate off the water. The final dried solid loading was about 0.7 mg/cm.sup.2.
[0359] B) Preparation of POS4A as an Example of the Positive Electrode Preparation (2.sup.nd Layer).
[0360] i) PVDF (14.4 g) was dissolved into NMP (˜160 g); ii) Carbon black (12 g) was added and mixed for 15 min at 6500 rpm; iii) LiNi.sub.0.5Mn.sub.0.3O.sub.0.2O.sub.2 (NMC) (373.6 g) was added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS4B (Example 2A) using an automatic coating machine with the first heat zone set to about 80° C. and the second heat zone to about 130° C. to evaporate off the NMP. The final dried solid loading was about 15.2 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 113 μm. The electrode made here was called as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0361] C) Preparation of NEG3A as an Example of the Negative Electrode Preparation
[0362] i) CMC (7.8 g) was dissolved into deionized water (˜800 g); ii) Carbon black (12 g) was added and mixed for 15 min at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (568.6 g in total) was added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (25.2 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 70° C. and the second heat zone to about 100° C. to evaporate off the water. The final dried solid loading was about 8.99 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 123 μm. The negative made was used for the dry for the cell assembly.
[0363] D) Preparation of Cell for the Evaluation
[0364] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The flat jelly-roll made in the Step iii. was laid flat into the aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0365]
Example 11
[0366] Preparation of resistive layer in negative electrodes, positive and negative electrodes, and the completed Cell 5 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, and cycle life test are described below.
[0367] A) Preparation of POS5A as an Example of the Positive Electrode Preparation.
[0368] i) PVDF (31.5 g) was dissolved into NMP (˜340 g); ii) Carbon black (13.5 g) was added and mixed for 15 min at 6500 rpm; iii) LiNi.sub.0.33Mn.sub.0.33Co.sub.0.33O.sub.2 (NMC) (855 g) was added to the slurry from Step ii and mix for 30 min at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was added onto 15 μm aluminum foil using an automatic coating machine with the first heat zone set to about 80° C. and the second heat zone to about 130° C. to evaporate off the NMP. The final dried solid loading was about 14.8 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 113 μm. The electrode made here was designated as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature, and the dry for the cell assembly.
[0369] B) Preparation of NEG5B as an Example of the Negative Electrode Preparation (1.sup.st Layer)
[0370] CMC (0.375 g) was dissolved into deionized water (˜90 g); ii) Carbon black (1.75 g) was added and mixed for 15 min; BaTiO.sub.2 (25 g in total) was added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (35.6 g) was added to the slurry formed in Step iii and mixed at about 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 90° C. and the second heat zone to about 140° C. to evaporate off the water.
[0371] C) Preparation of NEG5A as an Example of the Negative Electrode Preparation (2.sup.nd Layer)
[0372] i) CMC (3.9 g) was dissolved into deionized water (˜350 g); ii) Carbon black (6 g) was added and mixed for 15 min at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (283.8 g in total) were added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (25.2 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto NEG5B (Example 4B) using an automatic coating machine with the first heat zone set to about 70° C. and the second heat zone to about 100° C. to evaporate off the water. The final dried solid loading was about 9.8 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 114 μm. The negative made was used for the dry for the cell assembly.
[0373] D) Preparation of Cell for the Evaluation
[0374] i) The electrodes were punched into the pieces with the electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The flat jelly-roll made in the Step iii. was laid flat into the aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/20 rate for 5 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0375]
Example 12
[0376] Preparation of Al.sub.2O.sub.3 and Sodium trisilicate (NaSiO.sub.3) mixed based resistive layer, positive and negative electrodes, and the completed Cell 6 for the evaluation in the resistance measurement, discharge capability tests at 50° C., impact test, and cycle life test are described below.
[0377] A) Positive POS6B as an example of a resistance layer (1.sup.st layer) preparation.
[0378] i) Torlon® 4000TF (0.8 g) was dissolved into NMP (˜10 g); ii) PVDF (3.8 g) was dissolved into NMP (60 g); iii) The solutions prepared in Step i and ii were mixed, and then carbon black (0.32 g) was added and mixed for 10 min at 6500 rpm; iv) nano Al.sub.2O.sub.3 powder (17.04 g) and NaSiO.sub.3 (17.04 g) were added to the solution from Step iii and mixed for 20 min at 6500 rpm to form a flowable slurry; v) This slurry was coated onto 15 μm thick aluminum foil using an automatic coating machine with the first heat zone set to about 135° C. and the second heat zone to about 165° C. to evaporate off the NMP. The final dried solid loading was about 0.7 mg/cm.sup.2.
[0379] B) Preparation of POS6A as an Example of the Positive Electrode Preparation (2.sup.nd Layer).
[0380] i) PVDF (21.6 g) was dissolved into NMP (270 g); ii) Carbon black (18 g) was added and mixed for 15 min at 6500 rpm; iii) LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 (NMC) (560.4 g) was added to the slurry from Step ii and mixed for 30 min at 6500 rpm to form a flowable slurry; iv) Some NMP was added for the viscosity adjustment; v) This slurry was coated onto POS6B (Example 1A) using an automatic coating machine with the first heat zone set to about 85° C. and the second heat zone to about 135° C. to evaporate off the NMP. The final dried solid loading was about 19.4 mg/cm.sup.2. The positive layer was then compressed to a thickness of about 153 μm. The electrode made here was called as zero voltage against a standard graphite electrode and was used for the impedance measurement at 0 V in relation to the temperature.
[0381] C) Preparation of NEG6A as an Example of the Negative Electrode Preparation
[0382] i) CMC (13 g) was dissolved into deionized water (˜1000 g); ii) Carbon black (20 g) was added and mixed for 15 min at 6500 rpm; iii) Negative active graphite (JFE Chemical Corporation; Graphitized Mesophase Carbon Micro Bead (MCMB) and Synthetic Graphite (TIMCAL) (945.92 g in total) were added to the slurry from Step ii and mix for 30 min at 6500 rpm to form a flowable slurry; iv) SBR (solid content 50% suspended in water) (42 g) was added to the slurry formed in Step iii and mixed at 6500 rpm for 5 min; v) The viscosity was adjusted for a smooth coating; vi) This slurry was coated onto 9 μm thick copper foil using an automatic coating machine with the first heat zone set to about 100° C. and the second heat zone to about 130° C. to evaporate off the water. The final dried solid loading was about 11.8 mg/cm.sup.2. The negative electrode layer was then compressed to a thickness of about 159 μm. The negative made is ready for the dry for the cell assembly.
[0383] D) Preparation of Cell for the Evaluation
[0384] i) The electrodes were punched into the pieces with an electrode tab; ii) The positive electrode was dried at 125° C. for 10 hours and negative electrode at 140° C. for 10 hours; iii) The positive and negative electrodes were laminated with the separator as the middle layer; iv) The flat jelly-roll made in the Step iii. was put into an aluminum composite bag; v) The bag from Step iv. was dried in a 70° C. vacuum oven; vi) The bag from Step v was filled with the LiPF.sub.6 containing organic carbonate based electrolyte; vii) The bag from Step vi was sealed; viii) Rest for 16 hours; ix) The cell was charged to 4.2V at C/50 rate for 8 hours and then to 4.2V at 0.5 C rate for 2 hours, then rest for 20 minutes, then discharged to 2.8V at 0.5 C rate. Under vacuum, the cell was punctured to release any gases and then resealed. The cell made here was used for grading and other tests such as discharging capability test at 50° C., impact test, cycle life test and so on.
[0385]
[0386] In the descriptions above and in the claims, phrases such as “at least one of” or “one or more of” may occur followed by a conjunctive list of elements or features. The term “and/or” may also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases “at least one of A and B;” “one or more of A and B;” and “A and/or B” are each intended to mean “A alone, B alone, or A and B together.” A similar interpretation is also intended for lists including three or more items. For example, the phrases “at least one of A, B, and C;” “one or more of A, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together.” Use of the term “based on,” above and in the claims is intended to mean, “based at least in part on,” such that an unrecited feature or element is also permissible.
[0387] The subject matter described herein can be embodied in systems, apparatus, methods, and/or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims.