Electrochemical energy storage devices and housings

Abstract

The disclosure provides electrochemical batteries, electrochemical battery housings and methods for assembling electrochemical batteries. The battery housing can include a container, a container lid assembly and an electrical conductor. The container can include a cavity that extends into the container from a cavity aperture. The lid assembly can seal the cavity, and can include an electrically conductive container lid and an electrically conductive flange. The container lid can cover the cavity aperture and can include a conductor aperture that extends through the container lid. The flange can cover the conductor aperture and can be electrically isolated from the container lid. The conductor can be connected to the flange and can extend through the conductor aperture into the cavity. The conductor can be electrically isolated from the container lid.

Claims

1. An electrochemical battery, comprising: a container including a cavity that extends into the container from a cavity aperture; an electrochemical battery cell arranged within the cavity, wherein the electrochemical battery cell comprises an electrolyte arranged between a negative electrode and a positive electrode, and wherein at least one of the negative electrode and the positive electrode is liquid at an operating temperature of the electrochemical battery greater than 250 C.; a container lid assembly sealing the battery cell in the cavity, the container lid assembly including an electrically conductive container lid and an electrically conductive flange, wherein the container lid covers the cavity aperture and includes a conductor aperture that extends through the container lid, wherein the electrically conductive flange covers the conductor aperture and is electrically isolated from the container lid, and wherein the electrically conductive flange is in electrical communication with the negative metal electrode and the container lid is in electrical communication with the positive electrode; and an electrical conductor extending through the conductor aperture and electrically coupled to the electrochemical battery cell and the electrically conductive flange, wherein the conductor is electrically isolated from the container lid.

2. The battery of claim 1, further comprising a current collector electrically coupled to the negative electrode, wherein the current collector is connected to the conductor, and wherein the conductor is connected to the electrically conductive flange.

3. The battery of claim 1, further comprising a gasket arranged between and electrically isolating the electrically conductive flange and the container lid.

4. The battery of claim 3, wherein the gasket comprises dielectric material.

5. The battery of claim 1, wherein said container lid assembly hermetically seals said battery cell in said cavity.

6. The battery of claim 1, wherein the container is in electrical communication with an electrode of the electrochemical battery cell.

7. The battery of claim 1, wherein the electrochemical battery is capable of storing at least 25 Wh of energy.

8. The battery of claim 1, wherein a ratio of an area of the conductor aperture to an area of the container is less than 0.2.

9. The battery of claim 1, wherein the flange covers a portion of the conductor aperture.

10. The battery of claim 1, further comprising a current collector within the cavity and connected to the conductor.

11. The battery of claim 3, wherein the gasket comprises a ceramic material.

12. The battery of claim 3, wherein the gasket comprises aluminum nitride.

13. The battery of claim 3, wherein the gasket is annular.

14. The battery of claim 10, wherein the current collector is a metal foam or metal mesh.

15. The battery of claim 1, wherein the positive electrode comprises antimony.

16. The battery of claim 1, wherein the negative electrode comprises calcium.

17. The battery of claim 1, wherein the electrically conductive flange is connected to the container lid with a brazed ceramic.

18. The battery of claim 1, wherein the electrically conductive flange is connected to the container lid with a plurality of fasteners.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also Figure or FIG. herein), of which:

(2) FIG. 1 is a illustration of an electrochemical cell (A) and a compilation (i.e., battery) of electrochemical cells (B and C);

(3) FIG. 2 is a schematic cross sectional illustration of a battery housing having a conductor in electrical communication with a current collector pass through an aperture in the housing;

(4) FIG. 3 is a schematic cross sectional illustration of an electrochemical cell;

(5) FIG. 4 is a schematic cross sectional illustration of an embodiment of a cell lid assembly;

(6) FIG. 5 is a schematic cross sectional illustration of an electrochemical cell having feed-throughs that are electrically insulated from a housing with a dielectric seal components;

(7) FIG. 6, panels A & B, show that the current collector can be combined into a shared lid assembly and the invention can be used with cells of any size;

(8) FIG. 7 is a schematic sectional illustration of an embodiment of an electrochemical battery;

(9) FIG. 8 is a schematic perspective illustration of a first end of a container lid for the battery illustrated in FIG. 7;

(10) FIG. 9 is a schematic perspective illustration of a second end of the container lid for the battery illustrated in FIG. 7;

(11) FIG. 10 is a schematic perspective illustration of a first end of a flange for the battery illustrated in FIG. 7;

(12) FIG. 11 is a schematic perspective illustration of a second end of the flange for the battery illustrated in FIG. 7;

(13) FIG. 12 is a schematic exploded perspective illustration of a container lid assembly for the battery illustrated in FIG. 7;

(14) FIG. 13 is a schematic partially exploded perspective illustration of an alternate embodiment electrochemical battery housing;

(15) FIG. 14 is a schematic sectional illustration of the battery housing illustrated in FIG. 13;

(16) FIG. 15 is a schematic sectional illustration of an electrochemical battery stack that can include a plurality of alternate embodiment electrochemical battery housings;

(17) FIG. 16 is a schematic top view illustration of the battery stack illustrated in FIG. 15;

(18) FIG. 17, panels A & B, are a schematic illustration where the conductive feed-throughs of a one cell are connected to the base of another cell;

(19) FIG. 18 is a cross-sectional illustration of a seal of an electrochemical cell;

(20) FIG. 19 is an exploded view illustration of a sealed electrochemical cell;

(21) FIG. 20 is a top view illustration of the components of a seal of an electrochemical cell;

(22) FIG. 21 is a cross-sectional illustration of a seal of an electrochemical cell with a recessed conductive feed-through;

(23) FIG. 22 is an exploded view illustration of a seal of an electrochemical cell with a recessed conductive feed through; and

(24) FIG. 23 is a top view illustration of the components of a seal of an electrochemical cell with a recessed conductive feed through.

DETAILED DESCRIPTION

(25) While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.

(26) This disclosure provides electrochemical energy storage devices (or batteries) and electrochemical battery housings. An electrochemical battery can include an electrochemical battery cell sealed (e.g., hermetically sealed) within an electrochemical battery housing.

(27) Electrochemical Cells and Housings

(28) The term cell, as used herein, generally refers to an electrochemical cell. A cell can include a negative electrode of material A and a positive electrode of material B, denoted as AB. The positive and negative electrodes can be separated by an electrolyte.

(29) The term module, as used herein, generally refers to cells that are attached together in parallel by, for example, mechanically connecting the cell housing of one cell with the cell housing of an adjacent cell (e.g., cells that are connected together in an approximately horizontal packing plane). A module can include a plurality of cells in parallel. A module can comprise any number of cells (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more). In some cases, a module comprises 9, 12, or 16 cells. In some cases, a module is capable of storing about 700 Watt-hours of energy and/or delivering about 175 Watts of power.

(30) The term pack, as used herein, generally refers to modules that are attached through different electrical connections (e.g., vertically). A pack can comprise any number of modules (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more). In some cases, a pack comprises 3 modules. In some cases, a pack is capable of storing about 2 kilo-Watt-hours of energy and/or delivering about 0.5 kilo-Watts of power.

(31) The term core, as used herein generally refers to a plurality of modules or packs that are attached through different electrical connections (e.g., in series and/or parallel). A core can comprise any number of modules or packs (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more). In some cases, the core also comprises mechanical, electrical, and thermal systems that allow the core to efficiently store and return electrical energy in a controlled manner. In some cases, a core comprises 12 packs. In some cases, a core is capable of storing about 25 kilo-Watt-hours of energy and/or delivering about 6.25 kilo-Watts of power.

(32) The term pod, as used herein, generally refers to a plurality of cores that are attached through different electrical connections (e.g., in series and/or parallel). A pod can comprise any number of cores (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more). In some cases, the pod contains cores that are connected in parallel with appropriate by-pass electronic circuitry, thus enabling a core to be disconnected while continuing to allow the other cores to store and return energy. In some cases, a pod comprises 4 cores. In some cases, a pod is capable of storing about 100 kilo-Watt-hours of energy and/or delivering about 25 kilo-Watts of power.

(33) The term system, as used herein, generally refers to a plurality of cores or pods that are attached through different electrical connections (e.g., in series and/or parallel). A system can comprise any number of cores or pods (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more). In some cases, a system comprises 20 pods. In some cases, a system is capable of storing about 2 megawatt-hours of energy and/or delivering about 500 kilowatts of power.

(34) The term battery, as used herein, generally refers to one or more electrochemical cells connected in series and/or parallel. A battery can comprise any number of electrochemical cells, modules, packs, cores, pods or systems.

(35) Electrochemical cells of the disclosure may include an anode, an electrolyte adjacent to the anode, and a cathode adjacent to the electrolyte. In some examples, an electrochemical cell is a liquid metal battery cell. A liquid metal battery cell may include a liquid electrolyte separator arranged between a negative liquid (e.g., molten) metal electrode and a positive liquid metalloid electrode. In some embodiments, a liquid metal battery cell has a molten alkali metal (e.g., lithium) anode, an electrolyte, and a molten metal (e.g. lead, lead-antimony alloy) cathode.

(36) To maintain the electrodes in the liquid states, the battery cell may be heated to any suitable temperature. In some embodiments, the battery cell is heated to a temperature of about 200 C., about 250 C., about 300 C., about 350 C., about 400 C., about 450 C., about 500 C., about 550 C., about 600 C., about 650 C., or about 700 C. The battery cell may be heated to a temperature of at least about 200 C., at least about 250 C., at least about 300 C., at least about 350 C., at least about 400 C., at least about 450 C., at least about 500 C., at least about 550 C., at least about 600 C., at least about 650 C., or at least about 700 C. In some situations, the battery cell is heated to between 200 C. and about 500 C., between 200 C. and about 700 C. or between about 300 C. and 450 C.

(37) Electrochemical cells of the disclosure may be adapted to cycle between charged (or energy storage) modes and discharged (or energy depleted) modes. In some examples, an electrochemical cell can be fully charged, partially discharged, or fully discharged.

(38) In some implementations, during a charging mode, electrical current received from an external power source (e.g., a generator or an electrical grid) may cause metal atoms in the metalloid cathode to shed one or more electrons, dissolving into the electrolyte as a positively charged ion (i.e., cation). Simultaneously, cations of the same species can migrate through the electrolyte, and may accept electrons at the anode, causing them to transition to a neutral metal species, adding to the mass of the electrode. The removal of the active metal species from the cathode and the addition of the active metal to the anode stores electrical potential energy. During an energy discharge mode, an electrical load is coupled to the electrodes. The previously added metal species in the anode are released from the metal electrode (e.g. through melting), and pass through the electrolyte as ions. These ions in the electrolyte alloy with the cathode, with the flow of ions accompanied by the external and matching flow of electrons through the external circuit/load. This electrochemically facilitated metal alloying reaction discharges the previously stored electrical potential energy to the electrical load.

(39) In a charged state, the anode can include anode material and the cathode can include cathode material. During discharging (e.g., when the battery is coupled to a load), the anode material yields one or more electrons and cations of the anode material. The cations migrate through the electrolyte to the cathode material and react with the cathode material to form an metal or metal alloy. During charging, the alloy disassociates to yield cations of the anode material, which migrates to the anode.

(40) Electrochemical cells of the disclosure can include housings that may be suited for various uses and operations. A battery housing can be configured to electrically couple the electrodes to a switch, which is connected to the external power source and the electrical load. The battery cell housing may include, for example, an electrically conductive container that is electrically coupled to a first pole of the switch and/or another cell housing, and an electrically conductive container lid that is electrically coupled to a second pole of the switch and/or another cell housing. The container can be an electrode of the battery cell. The battery cell can be arranged within a cavity of the battery container. One of the electrodes contacts and/or is in electrical communication with an endwall of the battery container. A ceramic sheath may electrically insulate remaining portions of the battery cell from other portions of the battery container. A conductor electrically couples a second one of the electrodes to the container lid, which can seal (e.g., hermetically or non-hermetically) the battery cell within the cavity.

(41) Batteries and Housings

(42) A battery, as used herein can comprise a plurality of electrochemical cells. With reference to FIG. 1, an electrochemical cell (A) is a unit comprising an anode and a cathode. The cell may comprise an electrolyte and be sealed in a housing as described herein. In some cases, the electrochemical cells can be stacked (B) to form a battery (i.e., a compilation of electrochemical cells). The cells can be arranged in parallel, in series, or in both parallel and series (C). The cells can be made into different shapes and geometries that may differ from what is depicted.

(43) Electrochemical cells of the disclosure may be capable of storing (and/or taking in) a suitably large amount of energy. In some instances, a cell is capable of storing (and/or taking in) about 1 Wh, about 5 Wh, 25 Wh, about 50 Wh, about 100 Wh, about 500 Wh, about 1 kWh, about 1.5 kWh, about 2 kWh, about 3 kWh, or about 5 kWh. In some instances, the battery is capable of storing (and/or taking in) at least about 1 Wh, at least about 5 Wh, at least about 25 Wh, at least about 50 Wh, at least about 100 Wh, at least about 500 Wh, at least about 1 kWh, at least about 1.5 kWh, at least about 2 kWh, at least about 3 kWh, or at least about 5 kWh. It is recognized that the amount of energy stored in an electrochemical cell and/or battery may be less than the amount of energy taken into the electrochemical cell and/or battery (e.g., due to inefficiencies and losses).

(44) The compilation of cells (i.e., battery) can include any suitable number of cells, such as at least about 2, at least about 5, at least about 10, at least about 50, at least about 100, at least about 500, at least about 1000, at least about 5000, at least about 10000, and the like. In some examples, a battery includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 5000, 10,000, 20,000, 50,000, 100,000, 500,000, or 1,000,000 cells.

(45) Batteries of the disclosure may be capable of storing a suitably large amount of energy for use with a power grid (i.e., a grid-scale battery) or other loads or uses. In some instances, a battery is capable of storing (and/or taking in) about 5 kWh, 25 kWh, about 50 kWh, about 100 kWh, about 500 kWh, about 1 MWh, about 1.5 MWh, about 2 MWh, about 3 MWh, or about 5 MWh. In some instances, the battery is capable of storing (and/or taking in) at least about 5 kWh, at least about 25 kWh, at least about 50 kWh, at least about 100 kWh, at least about 500 kWh, at least about 1 MWh, at least about 1.5 MWh, at least about 2 MWh, at least about 3 MWh, or at least about 5 MWh.

(46) In some instances, the cells and cell housings are stackable. Any suitable number of cells can be stacked. Cells can be stacked side-by-side, on top of each other, or both. In some instances, at least about 10, 50, 100, or 500 cells are stacked. In some cases, a stack of 100 cells is capable of storing at least 50 kWh of energy. A first stack of cells (e.g., 10 cells) can be electrically connected to a second stack of cells (e.g., another 10 cells) to increase the number of cells in electrical communication (e.g., 20 in this instance). In some instances, the energy storage device comprises a stack of 1 to 10, 11 to 50, 51 to 100, or more electrochemical cells.

(47) Cell Lid Assemblies

(48) An electrochemical cell can be housed in a container, which can include a container lid. In some cases, the container is an electrode of the electrochemical cell. The container lid may utilize, for example, a seal or gasket (e.g., annular dielectric gasket) to electrically isolate the battery container from the container lid. Such a gasket may be constructed from a relatively hard electrically insulating material, such as, for example, glass, silicon oxide, aluminum oxide, boron nitride, aluminum nitride, or other oxides comprising of lithium oxide, calcium oxide, barium oxide, yttrium oxide, silicon oxide, aluminum oxide, lithium nitride, or other ceramics. The gasket may be subject to relatively high compressive forces (e.g., greater than 10,000 psi) between the container lid and the battery container in order to provide the seal in addition to the electrical isolation. In order to subject the dielectric gasket to such high compressive forces, the fasteners may have relatively large diameters and may be closely spaced together. Such large diameter fasteners may be expensive and, thus, may significantly increase the cost to build a relatively large diameter battery container. In addition, as the diameter of the dielectric gasket is increased to accommodate a large diameter battery container, the gasket may become more and more fragile and difficult to maneuver.

(49) With reference to FIG. 2, a battery comprises an electrically conductive housing 201 and a conductor 202 in electrical communication with a current collector 203. The conductor may be electrically isolated from the housing and may protrude through the housing through an aperture in the housing such that the conductor of a first cell contacts the housing of a second cell when the first and second cells are stacked.

(50) In an aspect, a cell housing comprises an electrically conductive container and a conductor in electrical communication with a current collector. The conductor may protrude through the housing through an aperture in the container and is electrically isolated from the container. The conductor of a first housing may contact the container of a second housing when the first and second housings are stacked.

(51) In some instances, the area of the aperture through which the conductor protrudes from the housing and/or container is small relative to the area of the housing and/or container. In some cases, the ratio of the area of the aperture to the area of the housing is about 0.001, about 0.005, about 0.01, about 0.05, about 0.1, about 0.15, about 0.2, about 0.3, about 0.4, or about 0.5. In some cases, the ratio of the area of the aperture to the area of the housing is less than 0.001, less than 0.005, less than 0.01, less than 0.05, less than 0.1, less than 0.15, less than 0.2, less than 0.3, less than 0.4, or less than 0.5.

(52) In an aspect, a cell comprises an electrically conductive housing and a conductor in electrical communication with a current collector. The conductor protrudes through the housing through an aperture in the housing and may be electrically isolated from the housing. The ratio of the area of the aperture to the area of the housing may be less than about 0.1.

(53) In an aspect, a cell housing comprises an electrically conductive container and a conductor in electrical communication with a current collector. The conductor protrudes through the container through an aperture in the container and is electrically isolated from the container. The ratio of the area of the aperture to the area of the container may be less than 0.1. The housing can be capable of enclosing a cell that is capable of storing and or taking in at least 25 Wh of energy.

(54) In some instances, the conductor is electrically isolated from the housing with a gasket or seal. FIG. 3 shows a cell lid assembly 301 that can be welded onto a container 305. At least one conductive feed-through (i.e., conductor) passes through the lid assembly and is in electrical communication with a liquid anode 302. In some embodiments, the current collector is an electrically conductive foam, wherein the anode comprises a liquid metal (e.g. lithium, magnesium, sodium). The anode is in contact with a molten salt electrolyte 304, which is in contact with a liquid metal cathode 303. In some embodiments the liquid metal cathode comprises lead and antimony.

(55) FIG. 4 shows a conductor 401, housing aperture and associated structures for electrically isolating the conductor from the housing 402 and sealing the electrochemical cell. In some embodiments, at least one bolt 403 holds the assembly in place. The bolt can be in electrical communication with the housing and electrically insulated from the conductive feed-through. In some embodiments, the bolt compresses a top flange 404 with a bottom flange 405. The bottom flange is welded to the cell lid in some instances. An electrically insulating washer or washer assembly 406 can insulate the bolt from the top flange. In some cases, a dielectric gasket 407 insulates the top flange from the bottom flange. A dielectric sheath (not shown) can be used to prevent the bolt from contacting the top flange in some cases. In some cases, the feed-through conductor has negative polarity (e.g., is in electrical communication with the anode) and the bolts and housing have positive polarity (e.g., is in electrical communication with the cathode).

(56) When sealed, the force applied to the gasket can be about 1,000 psi, about 2,000 psi, about 5,000 psi, about 10,000 psi, about 15,000 psi, or about 30,000 psi. In some instances, the force applied to the gasket is at least 1,000 psi, at least 2,000 psi, at least 5,000 psi, at least 10,000 psi, at least 15,000 psi, or at least 30,000 psi.

(57) In some cases, a cell comprises an electrically conductive housing and a conductor in electrical communication with a current collector. The conductor can protrude through the housing through an aperture in the housing and is electrically isolated from the housing with a gasket. The force on the gasket may be at least 1,000 psi, at least 5,000 psi, at least 10,000 psi, and the like.

(58) A cell housing can comprise an electrically conductive container and a conductor in electrical communication with a current collector. The conductor may protrude through the container through an aperture in the container and may be electrically isolated from the container with a gasket. The force on the gasket can be at least 1,000 psi, at least 5,000 psi, at least 10,000 psi, and the like.

(59) Few Bolts and Fasteners

(60) Bolts and fasteners can add to the cost of the battery and/or housing substantially. In some instances, the battery or battery housing comprises few bolts or fasteners. In some embodiments, the battery or housing comprises about 50, about 40, about 30, about 20, about 10, about 5, or about 2 bolts or fasteners. The battery or battery housing may comprise no bolts or fasteners. In some embodiments, the battery or housing comprises less than 50, less than 40, less than 30, less than 20, less than 10, less than 5, or less than 2 bolts or fasteners. In other embodiments, the dielectric sealing material may be mechanically and/or chemically adhered to the surfaces of the cell lid and the feed through leads, allowing the system to achieve a hermetic gas-tight seal without the need for any bolts or fasteners on the cell. Pressure may also be applied to the top of the feed-through, such as through cell stacking or adding a weight to the top of the cell, improving the performance and durability of the seal.

(61) A battery can comprise an anode, a cathode, an electrolyte, a positive current collector, and a negative current collector. The negative current collector can be in contact with the anode and the positive current collector is in contact with the cathode. The battery can be capable of storing and or taking in at least 25 Wh of energy and comprises less than 10 bolts or fasteners.

(62) In some cases, a compilation of cells is capable of storing at least 25 Wh, 200 Wh, 300 Wh, 400 Wh, 500 Wh, 600 Wh, 700 Wh, 800 Wh, 900 Wh, 1,000 Wh, 2,000 Wh, 3,000 Wh, 4,000 Wh, 4,000 Wh, 5,000 Wh, 6,000 Wh, 7,000 Wh, 8,000 Wh, 9,000 Wh, 10,000 Wh, 20,000 Wh, 30,000 Wh, 40,000 Wh, or 50,000 Wh of energy, and each of the cells comprises less than 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 bolt(s) or fastener(s). In some examples, cell components can be welded to one another.

(63) A cell housing can be capable of hermetically sealing a cell which is capable of storing and or taking in at least 25 Wh of energy. The housing comprises less than 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 bolt(s) or fastener(s).

(64) Cell lid assemblies can use adhesive seals instead of flanges and gaskets. In some cases, adhesive seals eliminate bolts from the electrochemical cell housing. As seen in FIG. 5, the conductive feed-through 501 is electrically isolated from the housing and the housing is sealed by an adhesive sealing material 502 disposed between the feed-through and the housing.

(65) In some cases, for cells that are sealed with adhesive dielectric seals that do not use bolts, a pressure of less than 1 psi may be all that is required to maintain a gas tight seal. In some cases, at least part of the pressure can be supplied by the weight of one or more electrochemical cells stacked upon each other in a battery. The adhesive seal material can comprise a glass seal or a brased ceramic, such as Alumina with CuAg braze alloy, or other ceramic-braze combination.

(66) Sealing the electrochemical cell with an adhesive material rather than bolts and flanges can reduce the height at which the lid assembly can extend above the housing (head space). In a stacked battery configuration, it may be desirable to reduce the head space so that relatively more of the volume of the battery can comprise anode and cathode material (i.e., a higher energy storage capacity). In some instances, the width of the head space (as measured from the top of the feed-through to the top surface of the anode) is a small fraction of the width of the battery (as measured from the top of the feed-through to the bottom surface of the housing). In some embodiments, the head space is about 5%, about 10%, about 15%, about 20%, or about 25% of the height of the battery. In some embodiments, the head space is at most about 5%, at most about 10%, at most about 15%, at most about 20%, or at most about 25% of the height of the battery.

(67) In some embodiments, the combined volume of anode and cathode material is about 50%, about 60%, about 70%, about 80%, about 90%, or about 95% of the volume of the battery (e.g., as defined by the outer-most housing of the battery, such as a shipping container). In some embodiments, the combined volume of anode and cathode material is at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 95% of the volume of the battery.

(68) In some situations, the use of a few or only a single conductive feed-through can result in uneven current distribution in the electrode. As described herein, a plurality of conductive feed-throughs can more evenly distribute the current in the electrode.

(69) In an aspect, an electrochemical energy storage device comprises a housing, a liquid metal electrode, a current collector in contact with the liquid metal electrode, and a plurality of conductors that are in electrical communication with the current collector and protrude through the housing through apertures in the housing. In some embodiments, current is distributed substantially evenly across the liquid metal electrode.

(70) In some embodiments, the liquid metal electrode is in contact with an electrolyte along a surface (and/or interface) and the current flowing across the surface (and/or interface) is uniform. The current flowing through any portion of the surface (and/or interface) does not deviate far from the average current. In some embodiments, the maximum density of current flowing across an area of the surface (and/or interface) is less than about 105%, less than about 115%, less than about 125%, less than about 150%, less than about 175%, less than about 200%, less than about 250%, or less than about 300% of the average density of current flowing across the surface (and/or interface). In some embodiments, the minimum density of current flowing across an area of the surface (and/or interface) is greater than about 50%, greater than about 60%, greater than about 70%, greater than about 80%, greater than about 90%, or greater than about 95% of the average density of current flowing across the surface (and/or interface).

(71) FIG. 6 shows multiple conductive feed-throughs. The electrochemical storage device and/or housings can comprise any number of conductive feed-throughs (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more). In some cases, the conductive feed-throughs are separate (panel A). In some cases, the conductive feed-throughs share a common upper portion (panel B).

(72) Hermetic Sealing of Cells

(73) A hermetically sealed battery or battery housing may prevent an unsuitable amount of air, oxygen and/or water into the battery (e.g., an amount such that the battery maintains at least 80% of its energy storage capacity for at least one year, at least 2 years, at least 5 years, at least 10 or at least 20 years).

(74) In some instances, the rate of oxygen, nitrogen, and water vapor transfer into the battery is less than about 0.25 mL per hour when the battery is contacted with air at a pressure of 1 bar and temperature of 400 to 700 C. In some embodiments, the number of moles of oxygen, nitrogen, or water vapor that leaks into the cell over a 10 year period is less than 10% of the number of moles of active metal material in the cell.

(75) In an aspect, a battery comprises an anode and a cathode. The battery is capable of storing at least 10 Wh of energy and is hermetically or non-hermetically sealed. At least one of the anode and the cathode can be a liquid metal. In some cases, the anode is a liquid metal (e.g. lithium, magnesium, sodium).

(76) In an aspect, a group of batteries is capable of storing at least 10 Wh of energy and each of the batteries are hermetically or non-hermetically sealed.

(77) In an aspect, a battery housing comprises an electrically conductive container, a container aperture and a conductor in electrical communication with a current collector. The conductor may pass through the container aperture and is electrically isolated from the electrically conductive container. The housing may be capable of hermetically sealing a battery which is capable of storing at least 100 kWh of energy.

(78) Embodiments of Electrochemical Cells, Batteries and Battery Housings

(79) FIG. 7 illustrates an electrochemical cell 20, in accordance with an embodiment of the invention. The cell 20 includes at least one electrochemical cell 22 sealed (e.g., hermetically sealed) within an electrochemical cell housing 24. The cell housing 24 includes a cell container 26, a container lid assembly 28 and one or more electrical conductors 30 (e.g., conductor rods). The cell housing 24 can also include a thermally and/or electrically insulating sheath 32, a first (e.g., negative) current collector 34 and a second (e.g., positive) current collector 36.

(80) The battery cell 22 may be configured as a liquid metal battery cell. The battery cell 22 may include, for example, a liquid separator 38 arranged axially between a liquid first (e.g., negative) electrode 40 and a liquid second (e.g., positive) electrode 42.

(81) In some instances, the electrochemical battery departs from that in FIG. 7. For example, the top electrode 40 can be contained within the top current collector (e.g., foam) 34. In this embodiment, the salt layer comes up in contact with the bottom and sides of the foam 34, and the top metal in the foam is held away from the sidewalls 32 or 26, thus allowing the cell to run without the insulating sheath 32. In some cases, a graphite sheath is used to prevent creeping of the cathode up the sidewall, which can prevent shorting of the cell.

(82) The separator 38 may be an ionically conducting liquid electrolyte. An example of a liquid electrolyte is a liquid solution of one or more ionically conductive molten salts such as, for example, fluoride salt, chloride salt, bromide salt, iodide salt, or a combination thereof. The first electrode 40 may be a liquid (e.g., molten) metal. Examples of materials that may be used as the first electrode 40 include, without limitation, sodium (Na), potassium (K), lithium (Li), calcium (Ca), barium (Ba), magnesium (Mg), or combinations thereof. The liquid metal of the first electrode 40 may contain one or more of the listed examples. The second electrode 42 may be a liquid metal or metalloid. Examples of materials that may be used as the second electrode 42 include, without limitation, antimony (Sb), lead (Pb), tin (Sn), bismuth (Bi), tellurium (Te), selenium (Se), or combinations thereof. The second electrode 42 may contain one or more of metals or metalloid metals listed above. Other examples of separator, first electrode and second electrode materials and/or configurations are disclosed in U.S. Patent Application Publication Nos. 2008/0044725, 2011/0014503, 2011/0014505 and 2012/0104990, each of which is entirely incorporated by reference herein. The present invention, however, is not limited to any particular battery cell configurations and/or materials.

(83) The battery container 26 can be constructed from an electrically conductive material such as, for example, steel, iron, stainless steel, graphite, nickel, nickel based alloys, titanium, aluminum, molybdenum, tungsten, or conductive glass. The cell container may also comprise of a structure component, and thinner lining component of a separate metal or electrically insulating coating, such as, for example, a steel container with a graphite lining, or a steel container with a boron nitride coating. The battery container 26 can have a cross-sectional geometry that can extend axially between a first container end (e.g., edge) 44 and a second container end (e.g., edge) 46. The cross-sectional geometry can be, for example, circular as illustrated in FIG. 13, rectangular (e.g., square) as illustrated in FIG. 16, or any other shape that may be selected based on design requirements for the battery 20. The battery container 26 includes a cell cavity 48 defined by a container (bottom) endwall 50 and a container sidewall 52. The cavity 48 can extend axially into the battery container 26 from a cavity aperture 54 that is located at the first container end 44 to the container endwall 50 that is located at the second container end 46. The cavity 48 can also extend laterally between opposing sides of the container sidewall 52.

(84) The container lid assembly 28 can include an electrically conductive container lid 56, one or more electrically conductive flanges 58, and one or more electrically insulating gaskets 60 (e.g., annular dielectric gaskets).

(85) Referring to FIGS. 8 and 9, the container lid 56 can be constructed from an electrically conductive material such as, for example, steel, iron, copper, stainless steel, graphite, nickel, nickel based alloys, titanium, aluminum, molybdenum, tungsten, or conductive glass. The container lid 56 can extend axially between a first lid end 62 and a second lid end 64. The container lid 56 can include an electrically conductive base 66 and one or more electrically conductive mounting rings 68 (also referred to as feed through flanges). The base can extend axially between the first lid end 62 and a base end 70, which is located axially between the first lid end 62 and the second lid end 64. The base 66 can include one or more mounting ring apertures 72 that can extend axially through the base 66 between the first lid end 62 and the base end 70. The mounting rings 68 are respectively mated with the mounting ring apertures 72, and connected (e.g., welded, adhered or otherwise fastened) to the base 66. The mounting rings 68 can extend axially between the first lid end 62 and the second lid end 64. Each of the mounting rings 68 includes a first conductor aperture 74 that can extend axially therethrough between the first lid end 62 and the second lid end 64. The first conductor aperture 74 has a diameter that is, for example, at least 2 (e.g., between about 2 and 6) times less than a diameter of the cavity aperture 54 (see FIG. 7). Each of the mounting rings 68 may also include one or more threaded fastener apertures 76 arranged circumferentially around the respective first conductor aperture 74. The fastener apertures 76 extend axially into the respective mounting ring 68 from the first lid end 62.

(86) Referring to FIGS. 10 and 11, each of the flanges 58 is constructed from an electrically conductive material such as, for example, steel, iron, stainless steel, graphite, nickel, nickel based alloys, titanium, aluminum, molybdenum, tungsten, or conductive glass. Each of the flanges 58 can extend axially from a first flange end 78 to a second flange end 80. Each of the flanges 58 may include an electrically conductive base 82 and an electrically conductive flange ring 84. The base 82 can extend axially between the first flange end 78 and the second flange end 80. The base 82 includes a threaded conductor aperture 86 that can extend axially into the base 82 from the second flange end 80 to a base endwall 88. The flange ring 84 can extend circumferentially around the base 82. The flange ring 84 can also extend axially between a first flange ring end 90 and a second flange ring end 92. The first flange ring end 90 may be offset from the first flange end 78 by a first axial distance, and/or the second flange ring end 92 may be offset from the second flange end 80 by a second axial distance. The flange ring 84 may include a plurality of fastener apertures 94 arranged circumferentially around the base 82. The fastener apertures 94 extend axially through the flange ring 84 between the first flange ring end 90 and the second flange ring end 92.

(87) Referring to FIGS. 7 and 12, the gaskets 60 are constructed from a dielectric material such as, for example, glass, brazed ceramic, thermiculite, aluminum nitride, mica and/or vermiculite. Each of the gaskets 60 includes a second conductor aperture 96 that can extend axially therethrough between a first gasket end 98 and a second gasket end 100. The second conductor aperture 96 has a diameter that is substantially equal to or less than the diameter of a respective one of the first conductor apertures 74.

(88) Referring to FIG. 7, the conductors 30 can be constructed from an electrically conductive material such as, for example, steel, iron, stainless steel, graphite, nickel, nickel based alloys, titanium, aluminum, molybdenum, or tungsten. The conductors 30 extend axially between a first conductor end 102 and a second conductor end 104. Each of the conductors 30 may include a threaded end region 106 adjacent the first conductor end 102.

(89) Referring to FIG. 7, the sheath 32 can be constructed from a thermally insulating and/or electrically insulating material such as, for example, alumina, titania, silica, magnesia, boron nitride, or a mixed oxide including calcium oxide, aluminum oxide, silicon oxide, lithium oxide, magnesium oxide, etc. The sheath 32 has an annular cross-sectional geometry that can extend axially between a first sheath end (top) 108 and a second sheath end (bottom) 110.

(90) As an alternative, the sheath can be used to prevent corrosion of the container and/or prevent wetting of the cathode material up the side wall, and may be constructed out of an electronically conductive material, such as steel, stainless steel, tungsten, molybdenum, nickel, nickel based alloys, graphite, or titanium. The sheath may be very thin and could be a coating. The coating can cover just the inside of the walls, and/or, can also cover the bottom of the inside of the container.

(91) Referring to FIG. 7 and FIG. 12, the first current collector 34 is constructed from an electrically conductive material such as, for example, nickel-iron (NiFe) foam, perforated steel disk, sheets of corrugated steel, sheets of expanded metal mesh, etc. The first current collector 34 may be configured as a plate that can extend axially between a first collector end 112 and a second collector end 114. The first current collector 34 has a collector diameter that is less than the diameter of the cavity aperture 54, and greater than the diameter of the first conductor aperture 74. Examples of other current collector configurations are disclosed in U.S. Patent Publication Nos. 2011/0014503, 2011/0014505, and 2012/0104990, which are entirely incorporated herein by reference. The present invention is not limited to any particular first current collector configurations.

(92) The second current collector 36 may be configured as a part of the cell container 26. In the embodiment illustrated in FIG. 7, for example, the container endwall 50 is configured as the second current collector 36. As an alternative, the current collector may be discrete from and, for example, electrically connected to, the battery container. Examples of such a current collector arrangement are disclosed in the aforementioned U.S. Patent Publication Nos. 2011/0014503, 2011/0014505, and 2012/0104990, which are entirely incorporated herein by reference. The present invention is not limited to any particular second current collector configurations.

(93) FIGS. 13 and 14 illustrate an alternative embodiment electrochemical battery housing 120. A sheath in such a case can in some cases be precluded. In contrast to the battery housing 24 of FIGS. 7 and 12, each of the flanges 58 of the battery housing 120 includes a flange ring 122 that is directly connected (e.g., welded, glued, fused, adhered and/or otherwise fastened) to a respective one of the conductors 30. Each of the gaskets 60 of the battery housing 120 may additionally include a plurality of fastener apertures 124, which receive the fasteners 116. Each of the fasteners 116 may be electrically isolated from the flange ring 122 via an electrically insulating sleeve 126 and an electrically insulating washer 128. The sleeve 126 and the washer 128 are each constructed from a dielectric such as, for example, mica or vermiculite. The battery housing 120 may also include one or more fluid ports 130 (e.g., quick connect gas fittings) that direct fluid (e.g., inert gas) into and/or out of the sealed cavity 48.

(94) FIGS. 15 and 16 illustrate another alternative embodiment electrochemical battery housing 132. In contrast to the battery housing 24 of FIGS. 7 and 12, each of the flanges 58 of the battery housing 132 includes a base 134 that can extend axially between the first flange ring end 90 and the second flange end 80. Each of the flanges 58 can also include a protrusion 136 (e.g., a boss) that is connected to the base 134 and/or the flange ring 84, and can extend axially to the first flange end 78. Such a protrusion 136 may be utilized for vertically stacking and/or electrically interconnecting a plurality of the battery housing 132 as illustrated in FIG. 15.

(95) FIG. 17 illustrates an embodiment that reduces the number of pieces of the electrochemical cells and/or batteries described herein (e.g., allows the assembly of a plurality of electrochemical cells using a single pre-assembled piece). In some cases, the conductors of a first electrochemical cell 1701 are connected to, and/or are formed from the same piece of metal as, the housing (e.g., positive current collector) of a second electrochemical cell 1702. In some cases, the top of a first electrochemical cell is directly connected to (e.g., welded or bolted) or formed from the same piece of metal as the bottom of a second electrochemical cell that is located on top of the first electrochemical cell. The cells can be assembled as shown in panel A in FIG. 17. As seen here, a plurality of pieces 1703 comprising a housing portion and a container lid assembly portion 1704 are put together (e.g., welded) one on top of another to form a plurality of electrochemical cells. The negative current collector 1705, positive electrode 1706 and electrolyte 1707 can be inserted and/or filled into the electrochemical cells as the cells are assembled from the pieces. The negative current collector 1705 can include (e.g., house, contain) the negative electrode. For example, the negative current collector 1705 can be a porous material that includes material of the negative electrode (e.g., lithium) in the pores of the negative current collector 1705.

(96) The electrochemical cell can be hermetically and/or electrically sealed by placing a sealant material between two surfaces.

(97) In an aspect, an electrochemical cell comprises an electrically conductive housing and a conductor in electrical communication with a current collector, wherein the conductor protrudes through the housing through an aperture in the housing and is electrically isolated from the housing with a seal that hermetically seals the electrochemical cell.

(98) With reference to FIG. 18, the sealant 1800 can be disposed and/or placed between the housing of the electrochemical cell 1801 and another article 1802 (e.g., a conductive feed through). FIG. 19 shows that the two surfaces 1900 can be metal. In some cases, the seal and/or sealant 1901 is a ceramic, glass, or glass-ceramic composite. FIG. 20 shows a top view for each layer of the assembly with the electrochemical cell housing on the left 2000, the seal in the center 2001 and the article 2002 (e.g., conductive feed through) on the right.

(99) In some cases, the surfaces are made of dissimilar materials (i.e., materials that are not the same, such as two different metal surfaces). The materials can have different coefficients of thermal expansion. The dissimilar materials can be inlaid and/or recessed into one another (e.g., one material surrounds the other on at least two planes, such as a flat surface and an edge). FIG. 21 shows an embodiment where a conductive feed-through 2100 is inlaid in the housing of the electrochemical cell 2101. In some cases, the feed-through is sealed from the housing along two planes including along a horizontal plane 2102 and along the edges 2103 (i.e., a vertical plane).

(100) In some instances, the feed-through is recessed in the housing and electrically insulated from the housing on all sides, but only sealed along one plane. For example, a horizontal shim (e.g., made of ceramic material) can be put between the feed through and the housing in the horizontal direction and the sealant can be disposed along the vertical direction. In some embodiments, a vertical ring (e.g., made of ceramic material) is placed between the feed through and the housing in the vertical direction (e.g., along the edges) and the sealant can be disposed along the horizontal direction. FIG. 22 shows a 3-dimensional exploded view of the feed-through, housing and seal, horizontal shim 2201 and/or vertical ring 2200 along two planes (e.g., vertical and horizontal).

(101) FIG. 23 shows a top view of each layer of the assembly including from left to right; the electrochemical cell housing 2300, the horizontal shim 2301, the conductive feed through 2302, and the vertical ring 2303 on the far right. In an embodiment, the layers of the assembly have relative dimensions as shown. In particular, the housing 2300 may have a hole with an inner diameter of one arbitrary unit (denoted by the symbol ) 1.00 with a second diameter of 1.5 and an outer diameter of 4.00 (e.g., 4 inches). The base of the housing 2300 can be made of metal and be about 0.5 thick. In some cases, the horizontal shim 2301 has an inner diameter of 0.6 and an outer diameter of 1.5 with a thickness of 0.05. In some embodiments, the conductive feed through 2302 has a diameter of 1.38 and a thickness of 0.2. In some instances, the vertical ring 2303 has an inner diameter of 1.38, an outer diameter of 1.5 and a thickness of 0.2.

(102) A compressive force can be established on the seal if the housing and feed-through are made of dissimilar materials that have a different coefficient of thermal expansion. In some embodiments, the housing has a greater coefficient of thermal expansion than the feed-through. The seal can be put between the materials when expanded at a high temperature. Upon cooling, the materials can shrink in volume (e.g., with the outer housing shrinking more than the inner feed-through) to establish a compressive force upon the seal. The force can be any suitable force (e.g., suitable for hermetically sealing the electrochemical cell). In some cases, the force is about 1,000 psi, about 2,000 psi, about 5,000 psi, about 10,000 psi, or about 20,000 psi. In some cases, the force is at least 1,000 psi, at least 2,000 psi, at least 5,000 psi, at least 10,000 psi, or at least 20,000 psi.

(103) In an aspect, a method for sealing an electrochemical cell comprises (a) applying a sealant material between a housing and an article recessed into the housing, wherein the sealant is applied at a temperature at which the sealant material is malleable, viscous, and/or flowable, and wherein the housing and the article have different coefficients of thermal expansion; and (b) lowering the temperature to a temperature at which the sealant material is not malleable, viscous, and/or flowable, i.e. solidifies or hardens, thereby creating a seal between the housing and the article that is under a compressive force. In some embodiments, the seal is under compression at the operating temperature of the electrochemical cell.

(104) The sealant can be any suitable material. In some instances, the seal is formed by brazing ceramic onto a metal substrate. In some embodiments, the seal is formed by solidifying ceramic and/or glass. In some embodiments, the seal is formed by mechanically and/or chemically bonded glass or glass-ceramic composite.

(105) In some cases, the sealant material is a re-flowable material such as borosilicate glass (or other seal-specific glass). In such an embodiment, a hermetic seal can be established by sliding a borosilicate glass tube around the cell top as a horizontal spacer. After insertion of the re-flowable material into the inlaid space, heating to a temperature of about, for example, 700 to 800 C. can allow flow of the borosilicate glass to form a glass seal. The seal can be stable at the temperatures of battery operation. In some instances, the glass seal is suitably thick to hermetically seal the cell and be resilient to shear stress. In some embodiments, the cell is slowly and evenly cooled following melting such that the seal forms evenly without cracks, delamination, and the like.

(106) In some cases, more than one sealant material can be used. In some embodiments, the seal is formed from at least two different materials, at least one of which is resistant to degradation from contact with materials contained in the electrochemical cell. In some embodiments, the seal is resistant to reactive metal vapors such as sodium (Na), lithium (Li) or magnesium (Mg). In some instances, the seal is a chalcogenide seal (e.g., comprises a chalgen such as CaAl.sub.2S.sub.4). In some embodiments, the sealant material is a chalcogenide based compound. In some cases, the chalcogenide has the chemical formula CaAl.sub.2S.sub.4.

(107) Systems, apparatuses and methods of the disclosure may be combined with or modified by other systems, apparatuses and/or methods, such as batteries and battery components described in U.S. Patent Publication No. 2012/0104990 (Alkali Metal Ion Battery with Bimetallic Electrode), which is entirely incorporated herein by reference.

(108) Energy storage devices of the disclosure may be used in grid-scale settings or stand-alone settings. Energy storage device of the disclosure can, in some cases, be used to power vehicles, such as scooters, motorcycles, cars, trucks, trains, helicopters, airplanes, and other mechanical devices, such as robots.

(109) A person of skill in the art will recognize that the battery housing components may be constructed from materials other than the examples provided above. One or more of the electrically conductive battery housing components, for example, may be constructed from metals other than steel and/or from one or more electrically conductive composites. In another example, one or more of the electrically insulating components may be constructed from dielectrics other than the aforementioned glass, mica and vermiculite. The present invention therefore is not limited to any particular battery housing materials.

(110) It is to be understood that the terminology used herein is used for the purpose of describing specific embodiments, and is not intended to limit the scope of the present invention. It should be noted that as used herein, the singular forms of a, an and the include plural references unless the context clearly dictates otherwise. In addition, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

(111) While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.