ALL-SOLID-STATE BATTERY WITH A PROTECTIVE LAYER INCLUDING A METAL SULFIDE AND A METHOD OF MANUFACTURING SAME
20230070626 · 2023-03-09
Assignee
Inventors
- Seung Ho Choi (Hanam-si, KR)
- Ga Hyeon Im (Gwangju, KR)
- Sang Heon Lee (Yongin-si, KR)
- Yun Sung Kim (Seoul, KR)
Cpc classification
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
Y02P70/50
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
H01M10/0525
ELECTRICITY
International classification
H01M4/62
ELECTRICITY
Abstract
An all-solid-state battery and a method of manufacturing such a battery are disclosed. The battery includes a protective layer including a metal sulfide and thus is capable of suppressing the growth of lithium dendrites and is improved in performance aspects such as lifespan, charge/discharge rate, and the like.
Claims
1. An all-solid-state battery comprising: a cathode layer; an anode current collector; a solid electrolyte layer interposed between the cathode layer and the anode current collector; and a protective layer interposed between the anode current collector and the solid electrolyte layer, wherein the protective layer comprises a metal.
2. The all-solid-state battery of claim 1, wherein the metal of the protective layer is capable of alloying with lithium, and wherein the protective layer further comprises a metal sulfide incapable of alloying with lithium.
3. The all-solid-state battery of claim 2, wherein the metal sulfide comprises a compound represented by chemical formula MS.sub.x, wherein M comprises molybdenum (Mo), tungsten (W), chromium (Cr), vanadium (V), titanium (Ti), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), or any combination thereof, and wherein x is an integer in a range of 1 to 3.
4. The all-solid-state battery of claim 2, wherein an average particle diameter (D50) of the metal sulfide is in a range of 10 nm to 500 nm.
5. The all-solid-state battery of claim 2, wherein the protective layer comprises: wt. % to 90 wt. % of the metal sulfide; and wt. % to 80 wt. % of the metal.
6. The all-solid-state battery of claim 2, wherein the protective layer further comprises a binder.
7. The all-solid-state battery of claim 6, wherein the binder comprises butadiene rubber (BR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), polyethylene oxide (PEO), or a combination thereof.
8. The all-solid-state battery of claim 6, wherein the protective layer comprises 1 part by weight to 20 parts by weight of the binder based on 100 parts by weight of the metal sulfide and the metal.
9. The all-solid-state battery of claim 1, wherein the metal comprises silver (Ag), tin (S.sub.n), zinc (Zn), magnesium (Mg), indium (In), bismuth (Bi), germanium (Ge), silicon (Si), or any combination thereof.
10. The all-solid-state battery of claim 1, wherein an average particle diameter (D50) of the metal is in a range of 10 nm to 500 nm.
11. The all-solid-state battery of claim 1, wherein the protective layer has a thickness in a range of 0.1 μm to 20 μm.
12. A method of manufacturing an all-solid-state battery, the method comprising: preparing a slurry comprising a metal sulfide incapable of alloying with lithium, a metal capable of alloying with lithium, and a solvent; forming a protective layer by applying the slurry on an anode current collector; forming a solid electrolyte layer on the protective layer; and forming a cathode layer on the solid electrolyte layer.
13. The method of claim 12, wherein the metal sulfide comprises a compound represented by chemical formula MS.sub.x, wherein M comprises molybdenum (Mo), tungsten (W), chromium (Cr), vanadium (V), titanium (Ti), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), or any combination thereof, and wherein x is an integer in a range of 1 to 3.
14. The method of claim 12, wherein an average particle diameter (D50) of the metal sulfide is in a range of 10 nm to 500 nm.
15. The method of claim 12, wherein the metal comprises silver (Ag), tin (S.sub.n), zinc (Zn), magnesium (Mg), indium (In), bismuth (Bi), germanium (Ge), silicon (Si), or any combination thereof.
16. The method of claim 12, wherein an average particle diameter (D50) of the metal is in a range of 10 nm to 500 nm.
17. The method of claim 12, wherein the solvent comprises N-methyl pyrrolidone (NMP), water, ethanol, isopropanol, dimethyl sulfoxide (DMSO), or a combination thereof.
18. The method of claim 12, wherein the slurry further comprises a binder, and wherein the binder comprises butadiene rubber (BR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), polyethylene oxide (PEO), or a combination thereof.
19. The method of claim 18, wherein the slurry comprises 1 part by weight to 20 parts by weight of the binder based on 100 parts by weight of the metal sulfide and the metal.
20. The method of claim 12, wherein the protective layer has a thickness is a range of 0.1 μm to 20 μm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above and other features of the present disclosure are described in detail with reference to certain embodiments thereof illustrated in the accompanying drawings, which are given hereinbelow by way of illustration only, and thus are not limitative of the present disclosure.
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
DETAILED DESCRIPTION
[0040] The above and other objects, features, and advantages of the present disclosure are more clearly understood from the following embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein and may be modified into different forms. These embodiments are provided to thoroughly explain the disclosure and to sufficiently transfer the spirit of the present disclosure to those of ordinary skill in the art.
[0041] Throughout the drawings, the same reference numerals refer to the same or like elements. For the sake of clarity of the present disclosure, the dimensions of structures are depicted as being larger than the actual sizes thereof. Although terms such as “first,” “second,” etc. may be used herein to describe various elements, these elements are not to be limited by these terms. These terms are only used to distinguish one element from another element. For instance, a “first” element discussed below could be termed a “second” element without departing from the scope of the present disclosure. Similarly, the “second” element could also be termed a “first” element. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.
[0042] The terms “comprise”, “include”, “have”, etc., when used in this specification, specify the presence of stated features, integers, acts, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, acts, operations, elements, components, or combinations thereof. Also, when an element such as a layer, film, area, or sheet is referred to as being “on” another element, it may be directly on the other element, or intervening elements may be present therebetween. Similarly, when an element such as a layer, film, area, or sheet is referred to as being “under” another element, it may be directly under the other element, or intervening elements may be present therebetween.
[0043] Unless otherwise specified, all numbers, values, and/or representations that express the amounts of components, reaction conditions, polymer compositions, and mixtures used herein are to be taken as approximations including various uncertainties affecting measurement that inherently occur in obtaining these values, among others, and thus should be understood to be modified by the term “about” in all cases. Furthermore, when a numerical range is disclosed in this specification, the range is continuous, and includes all values from the minimum value of said range to the maximum value thereof, unless otherwise indicated. Moreover, when such a range pertains to integer values, all integers including the minimum value to the maximum value are included, unless otherwise indicated.
[0044]
[0045] The cathode layer 10 may include a cathode active material, a solid electrolyte, a conductive material, a binder, and the like.
[0046] The cathode active material may include an oxide active material or a sulfide active material.
[0047] The oxide active material may include a rock-salt-layer-type active material such as LiCoO.sub.2, LiMnO.sub.2, LiNiO.sub.2, LiVO.sub.2, Li.sub.1+xNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2, or the like, a spinel-type active material such as LiMn.sub.2O.sub.4, Li(Ni.sub.0.5Mn.sub.1.5)O.sub.4, or the like, an inverse-spinel-type active material such as LiNiVO.sub.4, LiCoVO.sub.4, or the like, an olivine-type active material such as LiFePO.sub.4, LiMnPO.sub.4, LiCoPO.sub.4, LiNiPO.sub.4, or the like, a silicon-containing active material such as Li.sub.2FeSiO.sub.4, Li.sub.2MnSiO.sub.4, or the like, a rock-salt-layer-type active material in which a portion of a transition metal is substituted with a different metal, such as LiNi.sub.0.8Co.sub.(0.2−x)Al.sub.xO.sub.2 (0<x<0.2), a spinel-type active material in which a portion of a transition metal is substituted with a different metal, such as Li.sub.1+xMn.sub.2−x−yM.sub.yO.sub.4 (M being at least one of aluminum (Al), magnesium (Mg), cobalt (Co), iron (Fe), nickel (Ni), and zinc (Zn), 0<x+y<2), or lithium titanate such as Li.sub.4Ti.sub.5O.sub.12, or the like.
[0048] The sulfide active material may include copper chevrel, iron sulfide, cobalt sulfide, nickel sulfide, etc.
[0049] The cathode active material may be coated with an oxide such as LiNbO.sub.3. The oxide is configured to prevent a side reaction between the cathode active material and the solid electrolyte by preventing physical contact therebetween.
[0050] The solid electrolyte may include an oxide-based solid electrolyte or a sulfide-based solid electrolyte. In certain examples, the sulfide-based solid electrolyte has a high lithium-ion conductivity. The sulfide-based solid electrolyte is not particularly limited, but examples thereof may include Li.sub.2S—P.sub.2S.sub.5, Li.sub.2S—P.sub.2S.sub.5—LiI, Li.sub.2S—P.sub.2S.sub.5—LiCl, Li.sub.2S—P.sub.2S.sub.5—LiBr, Li.sub.2S—P.sub.2S.sub.5—Li.sub.2O, Li.sub.2S—P.sub.2S.sub.5—Li.sub.2O—LiI, Li.sub.2S—SiS.sub.2, Li.sub.2S—SiS.sub.2—LiI, Li.sub.2S—SiS.sub.2—LiBr, Li.sub.2S—SiS.sub.2—LiCl, Li.sub.2S—SiS.sub.2—B.sub.2S.sub.3—LiI, Li.sub.2S—SiS.sub.2—P.sub.2S.sub.5—LiI, Li.sub.2S—B.sub.2S.sub.3, Li.sub.2S—P.sub.2S.sub.5—Z.sub.mS.sub.n (in which m and n are positive numbers and Z is any one of Ge, Zn, and Ga), Li.sub.2S—GeS.sub.2, Li.sub.2S—SiS.sub.2—Li.sub.3PO.sub.4, Li.sub.2S—SiS.sub.2—Li.sub.xMO.sub.y (in which x and y are positive numbers and M is any one of P, Si, Ge, B, Al, Ga, and In), Li.sub.10GeP.sub.2S.sub.12, and the like.
[0051] Examples of the conductive material may include carbon black, conductive graphite, ethylene black, graphene, and the like.
[0052] Examples of the binder may include butadiene rubber (BR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), polyethylene oxide (PEO), and the like.
[0053] A cathode current collector 11 may be disposed on the cathode layer 10.
[0054] The cathode current collector 11 may be an electrically conductive plate-type substrate and may include aluminum foil.
[0055] The anode current collector 20 may be an electrically conductive plate-type substrate. The anode current collector 20 may include at least one of nickel (Ni), stainless steel (SUS), or any combination thereof.
[0056] The anode current collector 20 may be a high-density metal thin film having porosity of less than 1%.
[0057] The anode current collector 20 may have a thickness of 1 μm to 20 μm, or 5 μm to 15 μm.
[0058] The solid electrolyte layer 30 may be positioned between the cathode layer 10 and the anode current collector 20 so as to allow lithium ions to move therebetween.
[0059] The solid electrolyte layer 30 may include an oxide-based solid electrolyte or a sulfide-based solid electrolyte. In certain examples, the sulfide-based solid electrolyte has a high lithium-ion conductivity. The sulfide-based solid electrolyte is not particularly limited, but examples thereof may include Li.sub.2S—P.sub.2S.sub.5, Li.sub.2S—P.sub.2S.sub.5—LiI, Li.sub.2S—P.sub.2S.sub.5—LiCl, Li.sub.2S—P.sub.2S.sub.5—LiBr, Li.sub.2S—P.sub.2S.sub.5—Li.sub.2O, Li.sub.2S—P.sub.2S.sub.5—Li.sub.2O—LiI, Li.sub.2S—SiS.sub.2, Li.sub.2S—SiS.sub.2—LiI, Li.sub.2S—SiS.sub.2—LiBr, Li.sub.2S—SiS.sub.2—LiCl, Li.sub.2S—SiS.sub.2—B.sub.2S.sub.3—LiI, Li.sub.2S—SiS.sub.2—P.sub.2S.sub.5—LiI, Li.sub.2S—B.sub.2S.sub.3, Li.sub.2S—P.sub.2S.sub.5—Z.sub.mS.sub.n (in which m and n are positive numbers, and Z is any one of germanium (Ge), zinc (Zn), and gallium (Ga)), Li.sub.2S—GeS.sub.2, Li.sub.2S—SiS.sub.2—Li.sub.3PO.sub.4, Li.sub.2S—SiS.sub.2—Li.sub.xMO.sub.y (in which x and y are positive numbers and M is any one of phosphorous (P), silicon (Si), germanium (Ge), boron (B), aluminum (Al), gallium (Ga), and indium (In)), Li.sub.10GeP.sub.2S.sub.12, and the like.
[0060] The oxide-based solid electrolyte or sulfide-based solid electrolyte included in the solid electrolyte layer 30 may be the same as or different from the oxide-based solid electrolyte or sulfide-based solid electrolyte included in the cathode layer 10.
[0061] The protective layer 40 may include a metal sulfide incapable of alloying with lithium and a metal capable of alloying with lithium. The metal sulfide fills a space between the anode current collector 20 and the solid electrolyte layer 30 and is responsible for moving lithium ions therebetween. During charging of the all-solid-state battery, lithium ions, which are introduced into the protective layer 40 from the solid electrolyte layer 30, move through the metal sulfide and react with the metal capable of alloying with lithium. Accordingly, as shown in
[0062] The metal sulfide may include a compound represented by Chemical Formula 1 below.
[Chemical Formula 1]
MS.sub.x (1)
[0063] Here, M includes molybdenum (Mo), tungsten (W), chromium (Cr), vanadium (V), titanium (Ti), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), or any combination thereof, and x is an integer in a range of 1 to 3.
[0064] Specifically, the metal sulfide may include MoS.sub.2, WS.sub.2, CoS.sub.2, NiS, or any combination thereof.
[0065] The average particle diameter (D50) of the metal sulfide may range from 10 nm to 500 nm.
[0066] The metal may include silver (Ag), tin (S.sub.n), zinc (Zn), magnesium (Mg), indium (In), bismuth (Bi), germanium (Ge), silicon (Si), or any combination thereof.
[0067] The average particle diameter (D50) of the metal may range from 10 nm to 500 nm.
[0068] The protective layer 40 may include 20 wt. % to 90 wt. % of the metal sulfide and 10 wt. % to 80 wt. % of the metal. In other example, the protective layer 40 may include 50 wt. % to 90 wt. % of the metal sulfide and 10 wt. % to 50 wt. % of the metal. In yet another example, the protective layer 40 may include 70 wt. % to 90 wt. % of the metal sulfide and 10 wt. % to 30 wt. % of the metal. When the amounts of the metal sulfide and the metal fall within the above ranges, the growth of lithium dendrites may be suppressed and characteristics such as lifespan and the like may be improved.
[0069] The protective layer 40 may further include a small amount of a binder. The binder may include at least one of butadiene rubber (BR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), polyethylene oxide (PEO), or any combination thereof.
[0070] The protective layer 40 may include the binder in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight, which is the sum of the metal sulfide and the metal.
[0071] The protective layer 40 does not include a carbon material. This is in contrast with a conventional anodeless all-solid-state battery, which uses a carbon material in order to provide space for lithium deposition. In the present disclosure, a metal sulfide advantageously provides the path of movement of lithium ions in the protective layer 40, so reversible charge and discharge is possible without using a carbon material.
[0072] The thickness of the coating layer 40 may range from 0.1 μm to 20 μm. If the thickness of the coating layer 40 is less than 0.1 μm, the effects described above cannot be obtained due to the insufficient amounts of the metal sulfide and metal. Further, if the thickness of the coating layer 40 exceeds 20 μm, reversible charge and discharge may become difficult because the coating layer is too thick.
[0073] In addition, a method of manufacturing the all-solid-state battery may include preparing a slurry including a metal sulfide incapable of alloying with lithium, a metal capable of alloying with lithium, and a solvent; forming a protective layer by applying the slurry on an anode current collector; forming a solid electrolyte layer on the protective layer; and forming a cathode layer on the solid electrolyte layer.
[0074] The solvent is not particularly limited, and any solvent may be used, so long as it is capable of dispersing the metal sulfide, the metal, and the binder. For example, the solvent may include N-methyl pyrrolidone (NMP), water, ethanol, isopropanol, dimethyl sulfoxide (DMSO), or any combination thereof.
[0075] The slurry may further include a binder. The binder may include butadiene rubber (BR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), polyethylene oxide (PEO), or any combination thereof.
[0076] The slurry may include the binder in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight, which is the sum of the metal sulfide and the metal.
[0077] The solid electrolyte layer may be formed using a slurry including a solid electrolyte or by pressing a solid electrolyte in a powder phase. Moreover, the cathode layer may be formed using a slurry including a cathode active material or by pressing starting materials in a powder phase.
[0078] The acts of forming the coating layer, the solid electrolyte layer, and the cathode layer are not necessarily performed in the order in which they are mentioned, and individual layers may be formed at the same time or at different times. Moreover, variations in the manufacturing method described above may encompass not only directly forming a solid electrolyte layer on the coating layer, a cathode layer on the solid electrolyte layer, and a cathode current collector on the cathode layer, but also forming the individual layers separately and then stacking the same to realize the structure shown in
[0079] A better understanding of the present disclosure may be obtained through the following examples. However, these examples are merely set forth to illustrate the present disclosure and are not to be construed as limiting the scope of the present disclosure.
COMPARATIVE EXAMPLE
[0080] A protective layer including a metal sulfide was formed. A slurry was prepared by adding MoS.sub.2 (D50: 80 nm), which is the metal sulfide, to an NMP (N-methyl pyrrolidone), which is a solvent, and adding a small amount of a PVDF (polyvinylidene difluoride), which is a binder, thereto.
[0081] A protective layer was formed by applying the slurry on an anode current collector.
[0082] A half-cell was manufactured by forming a solid electrolyte layer on the protective layer and attaching a lithium thin film to the upper surface of the solid electrolyte layer.
[0083] The battery characteristics were evaluated by charging and discharging the half cell. Specifically, evaluation was carried out under conditions of a current density of 1.175 mA/cm.sup.2 and a deposition capacity of 3.52 mAh/cm.sup.2. The evaluation temperature was set to 60° C. Efficiency was determined by measuring the magnitude of charge after discharge for a predetermined period of time.
[0084]
[0085]
Example 1
[0086] A slurry was prepared by adding MoS.sub.2 (D50: 80 nm) as a metal sulfide and Ag (D50: 50 nm) as a metal to an NMP (N-methyl pyrrolidone), which is a solvent, and adding a small amount of a PVDF (polyvinylidene difluoride), which is a binder, thereto. The slurry includes 70 wt. % of the metal sulfide and 30 wt. % of the metal, excluding the binder.
[0087] A protective layer was formed by applying the slurry on an anode current collector.
[0088]
[0089] A half-cell was manufactured by forming a solid electrolyte layer on the protective layer and attaching a lithium thin film to the upper surface of the solid electrolyte layer.
[0090] The battery characteristics were evaluated by charging and discharging the half cell. Specifically, evaluation was carried out under conditions of a current density of 1.175 mA/cm.sup.2 and a deposition capacity of 3.52 mAh/cm.sup.2. The evaluation temperature was set to 60° C. Efficiency was determined by measuring the magnitude of charge after discharge for a predetermined period of time.
[0091]
[0092]
Example 2
[0093] The battery characteristics were evaluated by charging and discharging the half-cell of Example 1 at an evaluation temperature of 30° C.
[0094]
[0095]
[0096]
Example 3
[0097] A protective layer and a half cell were manufactured in the same manner as in Example 1, with the exception that 90 wt. % metal sulfide and 10 wt. % metal were used. The battery characteristics were evaluated through charge and discharge under the same conditions as Example 2 (an evaluation temperature of 30° C.).
[0098]
[0099] As is apparent from the above description, an all-solid-state battery capable of suppressing the formation of lithium dendrites can be obtained.
[0100] According to the present disclosure, an all-solid-state battery having improved battery characteristics such as lifespan, charge/discharge rate, and the like can be obtained.
[0101] According to the present disclosure, an all-solid-state battery capable of operating across a wide temperature range from low to high temperatures can be obtained.
[0102] The effects of the present disclosure are not limited to the above-mentioned effects. It should be understood that the effects of the present disclosure include all effects that can be inferred from the description of the present disclosure.
[0103] As described hereinbefore, the present disclosure has been described in detail with reference to test examples and embodiments. However, the scope of the present disclosure is not limited to the aforementioned test examples and examples, and various modifications and improved modes of the present disclosure using the basic concept of the present disclosure defined in the accompanying claims are also incorporated in the scope of the present disclosure.