All-solid-state battery

Abstract

The invention relates to an all-solid-state battery. An all-solid-state battery includes a laminate of a plurality of battery cells including a first current collector layer, an electrode layer, a second current collector layer, an electrode layer, and a first current collector layer in this order, the laminate including a battery cell X and a battery cell Y that are adjacent to each other, and a fixing portion that fixes the battery cell X and the battery cell Y. And the fixing parts are respectively connected with the electrode layer of the battery unit X and the electrode layer of the battery unit Y.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an all-solid battery. BACKGROUND

[0002] Development of an all-solid battery using a solid electrolyte instead of an electrolyte in which an electrolyte is dissolved in an organic solvent has been progressing.

[0003] As one example of a manufacturing method of an all-solid battery, there is a method of laminating a plurality of battery cells that are produced in advance. A battery obtained by laminating a plurality of battery cells is likely to generate a positional shift of the battery cells due to vibration at the time of use, expansion and contraction at the time of charge and discharge, and the like. The positional shift of the battery cells can become a cause of short circuit or the like.

[0004] As a countermeasure against the positional shift between the battery cells, an all-solid battery having an adhesive member for fixing the battery cells adjacent to each other with an adhesive is proposed in Japanese Patent Application Publication No. 2017-204377. SUMMARY

[0005] In the all-solid battery described in Japanese Patent Application Publication No. 2017-204377, the adhesive member is provided on the mutually facing surfaces of the battery cells adjacent to each other. Therefore, the number of battery cells that can be accommodated in the battery case is limited due to the adhesive member disposed between the plurality of battery cells, and the construction efficiency of the battery can be reduced.

[0006] An object of one embodiment of the present disclosure is to provide an all-solid battery that suppresses a positional shift of battery cells without reducing the construction efficiency of the battery.

[0007] Means for solving the above object include the following embodiments.

[0008] <1> An all-solid battery,

[0009] including a laminate of a plurality of battery cells that sequentially include a first current collector layer, an electrode layer, a second current collector layer, an electrode layer, and a first current collector layer,

[0010] the laminate including battery cells X and battery cells Y that are adjacent to each other, and a fixing portion that fixes the battery cells X and the battery cells Y,

[0011] the fixing portion respectively abutting on an end surface of the electrode layer of the battery cells X and an end surface of the electrode layer of the battery cells Y.

[0012] <2> The all-solid battery described in <1> includes

[0013] the fixing portion respectively abutting on an end surface of the first current collector layer of the battery cells X and an end surface of the first current collector layer of the battery cells Y.

[0014] <3> The all-solid-state battery according to <1> or <2>,

[0015] The electrode layer of the battery cell X and the electrode layer of the battery cell Y each include a first active material layer adjacent to the first current collector layer, a solid electrolyte layer, and a second active material layer adjacent to the second current collector layer,

[0016] The fixing portion is in contact with the first active material layer of the battery cell X and the first active material layer of the battery cell Y, respectively.

[0017] <4> The all-solid-state battery according to <1> or <2>,

[0018] The electrode layer of the battery cell X and the electrode layer of the battery cell Y each include a first active material layer adjacent to the first current collector layer, a solid electrolyte layer, and a second active material layer adjacent to the second current collector layer,

[0019] The fixing portion is in contact with the solid electrolyte layer of the battery cell X and the solid electrolyte layer of the battery cell Y, respectively.

[0020] <5> The all-solid-state battery according to any one of <1> to <4>,

[0021] The fixing portion contains a resin.

[0022] According to one embodiment of the present disclosure, there is provided an all-solid-state battery that suppresses positional displacement of battery cells without reducing the construction efficiency of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0023] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

[0024] Figure 1A is a cross-sectional view schematically showing one example of a structure of battery cells X and battery cells Y that are adjacent to each other among battery cells included in an all-solid-state battery.

[0025] Figure 1B is a plan view schematically showing a structure when the battery cell X shown in FIG. 1 is viewed from the main surface side of the first current collector layer 10. Figure 1A

[0026] Figure 2A is a cross-sectional view schematically showing one example of a structure of battery cells X and battery cells Y that are adjacent to each other among battery cells included in an all-solid-state battery.

[0027] Figure 2B is a plan view schematically showing a structure when the battery cell X shown in FIG. 1 is viewed from the main surface side of the first current collector layer 10. Figure 2A ​A plan view of the structure at the time of the battery cell X is shown. DETAILED DESCRIPTION

[0028] The all-solid battery of the present disclosure includes a laminate of a plurality of battery cells, the battery cells sequentially including a first current collector layer, an electrode layer, a second current collector layer, an electrode layer, and a first current collector layer.

[0029] The laminate includes battery cells X and battery cells Y that are adjacent to each other, and a fixing portion that fixes the battery cells X and the battery cells Y.

[0030] The fixing portion is in contact with the electrode layer of the battery cell X and the electrode layer of the battery cell Y, respectively.

[0031] The all-solid battery of the present disclosure is a so-called laminated battery that includes a laminate of a plurality of battery cells.

[0032] The laminate includes battery cells X and battery cells Y that are adjacent to each other, and a fixing portion that fixes the battery cells X and the battery cells Y.

[0033] That is, at least a part of the plurality of battery cells included in the laminate is fixed to the adjacent battery cell by the fixing portion.

[0034] In the all-solid battery of the present disclosure, the fixing portion is in contact with the electrode layer of the battery cell X and the electrode layer of the battery cell Y, respectively. That is, the point of difference from the existing all-solid battery is that the place where the fixing portion is disposed is not between the first electrode layer of the battery cell X and the first electrode layer of the battery cell Y.

[0035] The all-solid battery of the present disclosure reduces the influence of the thickness of the fixing portion in the dimension of the stacking direction of the battery cells, compared to the case where the fixing portion is disposed between the first electrode layer of the battery cell X and the first electrode layer of the battery cell Y. As a result, the number of battery cells that can be accommodated in the battery case is sufficiently ensured, and the reduction in the construction efficiency of the battery is suppressed.

[0036] In the following description, the battery cell X and the battery cell Y are sometimes referred to as "battery cell" without distinction.

[0037] The battery cell constituting the laminate sequentially includes a first current collector layer, an electrode layer, a second current collector layer, an electrode layer, and a first current collector layer.

[0038] The first current collector layer and the second current collector layer are in a relationship of being opposite to each other. That is, the second current collector layer is a positive electrode current collector layer in the case where the first current collector layer is a negative electrode current collector layer, and the second current collector layer is a negative electrode current collector layer in the case where the first current collector layer is a positive electrode current collector layer.

[0039] From the viewpoint of more reliably suppressing positional displacement of the battery cells, the fixing portions that fix the battery cell X and the battery cell Y are preferably in contact with the end surface of the 1st current collector layer of the battery cell X and the end surface of the 1st current collector layer of the battery cell Y, respectively.

[0040] From the viewpoint of effectively suppressing reduction in construction efficiency of the all-solid battery, when the stack of the battery cells is viewed from above in the stacking direction, the fixing portion is preferably disposed at a portion that is more inward than the outer periphery of the stack.

[0041] Among the plurality of battery cells included in the stack, the conditions of the battery cell X and the battery cell Y can be satisfied by all or some of the plurality of battery cells.

[0042] That is, among the plurality of battery cells included in the stack, the plurality of battery cells can be fixed to the adjacent battery cells by the fixing portion or some of the plurality of battery cells can be fixed to the adjacent battery cells by the fixing portion.

[0043] From the viewpoint of effectively suppressing positional displacement of the battery cells, it is preferable that, among the plurality of battery cells included in the stack, the conditions of the battery cell X and the battery cell Y are satisfied by 50% to 100% of the number. It is preferable that, among the plurality of battery cells included in the stack, the conditions of the battery cell X and the battery cell Y are satisfied by 70% to 100% of the number. It is more preferable that, among the plurality of battery cells included in the stack, the conditions of the battery cell X and the battery cell Y are satisfied by 80% to 100% of the number.

[0044] The electrode layer included in the battery cell can include a 1st active material layer adjacent to the 1st current collector layer, a solid electrolyte layer, and a 2nd active material layer adjacent to the 2nd current collector layer.

[0045] The 1st active material layer is a layer including a negative electrode active material when the 1st current collector layer is a negative electrode current collector layer, and is a layer including a positive electrode active material when the 1st current collector layer is a positive electrode current collector layer.

[0046] The 2nd active material layer is a layer including a negative electrode active material when the 2nd current collector layer is a negative electrode current collector layer, and is a layer including a positive electrode active material when the 2nd current collector layer is a positive electrode current collector layer.

[0047] Hereinafter, the 1st active material layer and the 2nd active material layer are sometimes referred to as "active material layers" without distinction.

[0048] The active material layer is a layer including at least an active material, and the solid electrolyte layer is a layer including at least a solid electrolyte. The active material layer can include the solid electrolyte together with the active material.

[0049] The fixing portion of the fixed battery cell X and the fixed battery cell Y can also be in contact with any one of the layers included in the electrode layer. For example, the following three modes 1 to 3 are exemplified. In the three modes 1 to 3, the fixing portion can also be in contact with other layers included in the electrode layer.

[0050] Mode 1: A mode in which the fixing portion is in contact with the first active material layer of the battery cell X and the first active material layer of the battery cell Y, respectively

[0051] Mode 2: A mode in which the fixing portion is in contact with the first active material layer of the battery cell X and the first active material layer of the battery cell Y, respectively

[0052] Mode 3: A mode in which the fixing portion is in contact with the second active material layer of the battery cell X and the second active material layer of the battery cell Y, respectively

[0053] The material of the fixing portion is not particularly limited as long as it can fix the battery cell X and the battery cell Y.

[0054] From the viewpoint of more reliably fixing the battery cell X and the battery cell Y, the fixing portion is preferably in a state of being adhered to the electrode layer of the battery cell X and the electrode layer of the battery cell Y.

[0055] As the fixing portion in a state of being adhered to the electrode layer of the battery cell X and the electrode layer of the battery cell Y, a fixing portion including a resin can be given. The fixing portion including a resin is, for example, formed by applying a material including a resin such as a solution obtained by dissolving a hot-melt adhesive, an adhesive, to a solvent, to a predetermined site of at least one of the electrode layer of the battery cell X or the electrode layer of the battery cell Y.

[0056] In the case where the fixing portion includes a resin, the kind of the resin is not particularly limited. As the resin, specifically, polyethylene (PE), polypropylene (PP), or the like polyolefin, ethylene-vinyl acetate copolymer (EVA), styrene-isoprene-styrene block copolymer (SIS), polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), acrylic resin, polyurethane, polyester, polyamide, or the like can be given.

[0057] The method of applying the material of the fixing portion to the electrode layer of the battery cell is not particularly limited, and can be selected from known methods such as coating, printing, transfer, inkjet, or the like. If necessary, after the material of the fixing portion is applied to the electrode layer of the battery cell, a process such as heating, pressurization, or the like can be performed.

[0058] From the viewpoint of more reliably suppressing the positional deviation of the battery cell, the site to which the material of the fixing portion is applied is preferably a site that is in contact with the end surface of the first current collector layer disposed on the electrode layer to which the material of the fixing portion is applied.

[0059] From the viewpoint of effectively suppressing a decrease in the construction efficiency of the all-solid-state battery, the portion of the material to which the fixing portion is imparted is preferably a portion that is more inside than the outer periphery of the battery cell when the battery cell is viewed from above in the stacking direction.

[0060] Hereinafter, one example of the structure of the all-solid-state battery of the present disclosure will be described with reference to the drawings. The dimensions and shapes of the components shown in the following drawings are conceptual structures, and the actual structures are not limited to these.

[0061] Figure 1A is a cross-sectional view schematically showing one example of the structure of mutually adjacent battery cell X and battery cell Y among the battery cells included in the all-solid-state battery of the present disclosure.

[0062] Figure 1A The battery cell X and the battery cell Y shown are in a state in which the first current collector layer 10, the electrode layer 20, the second current collector layer 30, the electrode layer 20, and the first current collector layer 10 are sequentially stacked.

[0063] On both sides of the first current collector layer 10, the electrode layer 20 is disposed. The electrode layer 20 is in a state in which the first active material layer 22 adjacent to the first current collector layer 10, the solid electrolyte layer 24, and the second active material layer 26 adjacent to the second current collector layer 30 are sequentially stacked.

[0064] As shown in Figure 1A , the first current collector layer 10 and the second current collector layer 20 included in the battery cell X and the battery cell Y are in a state of protruding in mutually different directions.

[0065] In Figure 1A , the region in which the first current collector layer protrudes is referred to as the first protruding region R1, the region in which the second current collector layer protrudes is referred to as the second protruding region R2, and the region between the first protruding region R1 and the second protruding region R2 is referred to as the intermediate region R3.

[0066] In the first protruding region R1 and the second protruding region R2, the first current collector layer 10 is in a state of not overlapping the second current collector layer 30 in the stacking direction LD.

[0067] As shown in Figure 1A , the end surface of the first protruding region R1 side of the second current collector layer 30 included in the battery cell X and the battery cell Y is covered by the insulating portion 50. The insulating portion 50 prevents the second current collector layer 30 from coming into contact with the first current collector layer 10 (short circuit).

[0068] As shown in Figure 1AAs shown, the battery cell X and the battery cell Y have a portion (hereinafter referred to as a gap) where the electrode layer 20 and the first collector layer 10 do not overlap in the stacking direction LD. The fixing portion 40 is arranged in the gap between the battery cell X and the battery cell Y, and is respectively connected to the electrode layer 20 of the battery cell X (in Figure 1A The first active material layer 22) and the electrode layer 20 of the battery cell Y (in Figure 1A The first active material layer 22 is in contact with the substrate.

[0069] Figure 1A The illustrated fixing portion 40 is arranged near the boundary between the intermediate region R3 and the second protruding region R2.

[0070] Figure 1B The diagram schematically shows the first current collector layer 10 viewed from the main surface side. Figure 1A The structure of the battery cell X is shown in the top view.

[0071] like Figure 1B As shown, the first current collector layer 10 of the battery cell X has a protruding shape corresponding to the first protruding region R1. The fixing portion 40 is arranged in the portion (gap) where the first active material layer 22 included in the electrode layer 20 is exposed. The gap is provided on one side of the first current collector layer 10 having the protruding portion and on the side opposite to the protruding portion.

[0072] Figure 1B The fixing portion 40 shown is arranged in the gap on the side of the first current collector layer 10 opposite to the side having the protruding portion.

[0073] Figure 2A This is a cross-sectional view schematically showing an example of the structure of a battery cell X and a battery cell Y adjacent to each other among the battery cells included in the all-solid-state battery of the present disclosure.

[0074] exist Figure 2A In the structure shown, the fixing portion 40 is arranged near the boundary between the middle region R3 and the second protruding region R2 of the battery cell (see Figure 1A ), the fixing portion 40 is arranged near the boundary between the middle region R2 and the first protruding region R1 of the battery cell.

[0075] Figure 2B The diagram schematically shows the first current collector layer 10 viewed from the main surface side. Figure 2A The structure of the battery cell X is shown in the top view.

[0076] exist Figure 2B In the structure shown, the fixing portion 40 is arranged in the gap on the side opposite to the side having the protruding portion of the first current collector layer 10 (see FIG. Figure 1B) different, the fixing portion 40 is arranged at the gap of the side of the first current collector layer 10 having the protruding portion.

[0077] In the above-described drawings, the fixing portion 40 is in contact with the first active material layer 22 included in the electrode layer 20 of the battery cell X and the battery cell Y, but the embodiment of the present disclosure is not limited thereto. For example, the fixing portion 40 can also be in contact with the solid electrolyte layer 24 or the second active material layer 26 included in the electrode layer 20 of the battery cell X and the battery cell Y.

[0078] In the above-described drawings, the number of the fixing portion 40 included in the battery cell X and the battery cell Y is two per one battery cell, but the embodiment of the present disclosure is not limited thereto. For example, the number of the fixing portion 40 per one battery cell can also be one, and can also be three or more.

[0079] As shown in the above-described drawings, the fixing portion 40 can be arranged at the side of the first current collector layer of the battery cell where the first current collector layer does not protrude (refer to Figure 1A and Figure 1B ), or can be arranged at the side of the first current collector layer of the battery cell where the first current collector layer protrudes (refer to Figure 2A and Figure 2B ).

[0080] From the viewpoint of suppressing the occurrence of short circuit due to expansion and contraction of the battery cell while suppressing the positional displacement of the battery cell, the fixing portion is preferably arranged at the side of the first current collector layer of the battery cell where the first current collector layer does not protrude.

[0081] The amount of change in size due to the expansion of the battery cell is proportional to the size of the battery cell from the position where the fixing portion is arranged. Therefore, the positional displacement due to the expansion of the battery cell is more likely to occur at the side of the battery cell where the fixing portion is not arranged.

[0082] In the structure shown in Figure 1A and Figure 1B , the degree of expansion of the battery cell in the side where the fixing portion is not arranged, that is, the side where the second current collector layer protrudes, is relatively large. On the other hand, with respect to the end surface of the side where the second current collector layer does not protrude, insulation treatment such as covering with an insulating portion can be performed at the time of manufacturing the battery cell. Therefore, with respect to the side where the second current collector layer protrudes, even if the expansion of the battery cell occurs, it is easy to reduce the risk of short circuit.

[0083] Hereinafter, the constituent elements of the battery cell included in the all-solid-state battery of the present disclosure will be described. However, the all-solid-state battery of the present disclosure is not limited thereto.

[0084] The battery cell sequentially includes a first current collector layer, an electrode layer, a second current collector layer, an electrode layer, and a first current collector layer.

[0085] The second current collector layer is a positive electrode current collector layer when the first current collector layer is a negative electrode current collector layer, and the second current collector layer is a negative electrode current collector layer when the first current collector layer is a positive electrode current collector layer.

[0086] As the material of the negative electrode current collector layer or the positive electrode current collector layer, for example, a metal of Ag, Cu, Au, Al, Ni, Fe, Ti or an alloy containing these metals can be given.

[0087] As the material of the negative electrode current collector layer, Cu and Ni are preferable, and as the material of the positive electrode current collector layer, Al is preferable.

[0088] The electrode layer included in the battery cell includes a first active material layer adjacent to the first current collector layer, a solid electrolyte layer, and a second active material layer adjacent to the second current collector layer.

[0089] The first active material layer is a layer containing a negative electrode active material when the first current collector layer is a negative electrode current collector layer, and the first active material layer is a layer containing a positive electrode active material when the first current collector layer is a positive electrode current collector layer.

[0090] The second active material layer is a layer containing a negative electrode active material when the second current collector layer is a negative electrode current collector layer, and the second active material layer is a layer containing a positive electrode active material when the second current collector layer is a positive electrode current collector layer.

[0091] The negative electrode active material can be selected from a material capable of occluding and releasing metal ions such as lithium ions.

[0092] As the negative electrode active material, specifically, metal lithium, lithium alloy, carbon materials such as graphite and hard carbon, silicon materials such as metal alloy and silicon alloy, Li4Ti5O12 (LTO), and the like can be given. 12 (LTO), and the like can be given.

[0093] As the positive electrode active material, specifically, metal oxides containing transition metals such as manganese, cobalt, nickel, and titanium, and lithium can be given. Specifically, lithium cobaltate, lithium nickelate, lithium manganate, lithium nickel cobalt manganate, hetero-element-substituted Li-Mn spinel, lithium titanate, metal lithium phosphate, and the like can be given.

[0094] As the solid electrolyte, sulfide-based amorphous solid electrolyte, oxide-based amorphous solid electrolyte, sulfide-based crystalline solid electrolyte, oxide-based crystalline solid electrolyte, iodide-based crystalline solid electrolyte, nitride-based solid electrolyte, and the like can be given.

[0095] As needed, each layer constituting the electrode layer can also contain a component other than the active material or the solid electrolyte. As the component other than the active material or the solid electrolyte, a binder, a conductive material, and the like can be given.

[0096] The thickness of the stack composed of a plurality of battery cells is not particularly limited and can be set according to the use and performance of the all-solid battery.

[0097] For example, the thickness of the stack can be selected from the range of 1 mm to 100 mm.

[0098] The stack composed of a plurality of battery cells can also be in a state of being housed in an outer body. The material of the outer body housing the stack is not particularly limited and can be set according to the use and performance of the all-solid battery. In an embodiment, the outer body can also be an outer body (laminate film) including a base material layer and a barrier layer.

[0099] The material of the base material layer is not particularly limited and examples include thermoplastic resins, metals, and the like. As the barrier layer, examples include metal foils, vapor-deposited layers, and the like.

[0100] The number of battery cells included in the stack is not particularly limited and can be selected according to the size and performance of the all-solid battery, and the like.

[0101] For example, the number of battery cells included in the stack can also be selected from the range of 10 to 100.

[0102] The thickness of the all-solid battery including the stack of battery cells is not particularly limited and can be set according to the use and performance of the all-solid battery.

[0103] For example, the thickness of the all-solid battery can be selected from the range of 1 mm to 100 mm.

Claims

1. A full solid battery, a laminate including a plurality of battery cells, the battery cells including, in order, a first current collector layer, an electrode layer, a second current collector layer, an electrode layer, and a first current collector layer, the laminate including battery cell X and battery cell Y which are adjacent to each other, and a fixing portion which fixes battery cell X and battery cell Y, the fixing portion being in contact with the electrode layer of battery cell X and the electrode layer of battery cell Y, respectively.

2. The full solid battery according to claim 1, wherein the fixing portion is in contact with an end surface of the first current collector layer of battery cell X and an end surface of the first current collector layer of battery cell Y, respectively.

3. The full solid battery according to claim 1, wherein the electrode layer of battery cell X and the electrode layer of battery cell Y each include a first active material layer adjacent to the first current collector layer, a solid electrolyte layer, and a second active material layer adjacent to the second current collector layer, the fixing portion is in contact with the first active material layer of battery cell X and the first active material layer of battery cell Y, respectively.

4. The full solid battery according to claim 1, wherein the electrode layer of battery cell X and the electrode layer of battery cell Y each include a first active material layer adjacent to the first current collector layer, a solid electrolyte layer, and a second active material layer adjacent to the second current collector layer, the fixing portion is in contact with the solid electrolyte layer of battery cell X and the solid electrolyte layer of battery cell Y, respectively.

5. The full solid battery according to any one of claims 1 to 4, wherein the fixing portion contains a resin.

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