Solid-state batteries and solid-state battery cells

Abstract

The problem to be solved by the present invention is to provide a solid-state battery or a solid-state battery unit, wherein the solid-state battery has a laminate, the laminate is covered by an outer resin part, the solid-state battery can suppress damage to the outer resin part due to volume changes of the laminate, and can ensure higher mechanical strength. In order to solve the above-mentioned problem, the present invention provides a solid-state battery (1), comprising: a solid-state battery cell (100), a laminate (110) and a first elastic component (140), wherein the laminate (110) has: at least one positive electrode (10), having a positive electrode collector (11) and a positive electrode active material layer (12); at least one negative electrode (20), having a negative electrode collector (21) and a negative electrode active material layer (22); and a solid electrolyte (30) between the positive electrode (10) and the negative electrode (20); and the first elastic component (140) is at least arranged on both sides of the laminate (110) in a lamination direction C; and an outer resin part (300) comprises a thermosetting resin or a thermoplastic resin, which tightly covers the solid-state battery cell (100).

Description

Technical Field

[0001] The invention relates to a solid-state battery and a solid-state battery unit. Background Art

[0002] In recent years, with the popularization of electrical and electronic devices of various sizes such as automobiles, personal computers and mobile phones, the demand for high-capacity and high-output batteries has rapidly expanded. As such a battery, a solid-state battery having a laminate body in which a flame-retardant solid electrolyte is interposed between a positive electrode and a negative electrode can be cited. As such a solid-state battery, a solid-state battery is known in which a laminate body or the like is covered with a resin.

[0003] For example, Patent Document 1 describes a solid-state battery in which a solid-state battery element is coated with a thermosetting resin or a thermoplastic resin. In addition, Patent Document 2 describes a solid-state battery in which at least the side of the entire laminate of the solid-state battery is covered, and a gap portion exists between the side of the negative electrode active material layer and the outer resin portion.

[0004] [Prior Technical Literature]

[0005] (Patent Document)

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-106154

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-121532 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] In addition, as described in Patent Document 1, in a solid-state battery in which a laminate is covered with a resin, the volume of the negative electrode active material layer in the laminate changes due to charge and discharge, and cracks may occur in the outer resin portion. In contrast, in the solid-state battery of Patent Document 2, since there is a gap between the side of the negative electrode active material layer and the outer resin portion, even if the volume of the negative electrode active material layer changes, the negative electrode active material layer can be expanded in a direction orthogonal to the lamination direction, and cracks in the outer resin portion can be suppressed.

[0010] However, in the solid-state battery of Patent Document 2, since there is a gap between the side of the negative electrode active material layer and the outer resin part, the side orthogonal to the lamination direction of the laminate and the collector ear when the collector ear is formed on the side cannot be fully protected, and further improvement is needed to ensure higher mechanical strength.

[0011] The object of the present invention is to provide a solid-state battery and a solid-state battery unit, wherein the solid-state battery has a laminate, the laminate is covered with an exterior resin part, the solid-state battery can suppress damage to the exterior resin part due to volume changes of the laminate, and can ensure higher mechanical strength.

[0012] [Technical means to solve the problem]

[0013] The present invention relates to a solid-state battery, comprising: a solid-state battery cell, comprising a laminate and a first elastic component, wherein the laminate has: at least one positive electrode, comprising a positive electrode collector and a positive electrode active material layer; at least one negative electrode, comprising a negative electrode collector and a negative electrode active material layer; and a solid electrolyte, disposed between the positive electrode and the negative electrode; and the first elastic component is at least arranged on both sides of the lamination direction of the laminate; and an outer resin portion, comprising a thermosetting resin or a thermoplastic resin, which tightly covers the solid-state battery cell.

[0014] The aforementioned solid-state battery cell also comprises: a positive electrode collector tab, extending from the end of the aforementioned positive electrode collector in a direction orthogonal to the aforementioned lamination direction in a direction away from the aforementioned laminate; and, a negative electrode collector tab, extending from the end of the aforementioned negative electrode collector in a direction orthogonal to the aforementioned lamination direction in a direction away from the aforementioned laminate; and the aforementioned outer resin portion tightly covers the aforementioned positive electrode collector tab and the aforementioned negative electrode collector tab.

[0015] Alternatively, the area of ​​a surface of the first elastic member that contacts the laminate is greater than or equal to the area of ​​a surface perpendicular to the lamination direction of the negative electrode active material layers.

[0016] Alternatively, the sum of the maximum compression amounts in the thickness direction of the first elastic members disposed on both sides of the laminate in the lamination direction is greater than the maximum expansion amount of the laminate.

[0017] Optionally, the negative electrode active material constituting the negative electrode active material layer is hard carbon.

[0018] Optionally, the negative electrode active material constituting the negative electrode active material layer is a graphite active material, and the capacity ratio of the negative electrode to the positive electrode (negative electrode capacity / positive electrode capacity) is greater than 1.1.

[0019] In addition, the present invention also relates to a solid-state battery unit, comprising: a fixed battery module, comprising a laminate group and a second elastic component, wherein the laminate group is composed of a plurality of laminates laminated in a lamination direction of the laminate, and the laminate has: at least one positive electrode having a positive electrode collector and a positive electrode active material layer; at least one negative electrode having a negative electrode collector and a negative electrode active material layer; and a solid electrolyte between the positive electrode and the negative electrode; and the second elastic component is at least arranged on both sides of the laminate group in the lamination direction; and a module exterior resin portion comprising a thermosetting resin or a thermoplastic resin, which tightly covers the solid-state battery module.

[0020] Optionally, the second elastic component is disposed on both sides of each of the plurality of laminated bodies in the lamination direction.

[0021] (Effects of the Invention)

[0022] According to the present invention, a solid-state battery or a solid-state battery unit can be provided, wherein the solid-state battery has a laminate, and the laminate is covered with an exterior resin portion. The solid-state battery can suppress damage to the exterior resin portion due to volume changes of the laminate and can ensure higher mechanical strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a perspective view showing a solid-state battery according to one embodiment of the present invention.

[0024] Figure 2 yes Figure 1 AA line section view in.

[0025] Figure 3 This is a perspective view showing a solid-state battery cell according to one embodiment of the present invention.

[0026] Figure 4 yes Figure 3 BB line cross section in. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are for illustrating the present invention, and the present invention is not limited to the following embodiments.

[0028] <Solid-state battery>

[0029] Reference Figure 1 and Figure 2 The solid-state battery 1 of this embodiment will be described. Figure 1 It is a three-dimensional diagram of the solid-state battery 1. Figure 2 yes Figure 1 AA line cross-sectional view of the solid-state battery 1 in FIG. Figure 1In the figure, the outer resin portion 300 is represented by two chain lines. Figure 2 In order to avoid complicating the drawing, hatching of the lead terminal 200 and the exterior resin portion 300 is omitted.

[0030] like Figure 1 and Figure 2 As shown, the solid-state battery 1 of the present embodiment includes a solid-state battery cell 100 , a lead terminal 200 , and an exterior resin portion 300 .

[0031] (Solid-state battery cells)

[0032] The solid-state battery cell 100 includes a laminate 110 , a positive electrode current collector tab 120 , a negative electrode current collector tab 130 , and a first elastic member 140 .

[0033] [Laminate]

[0034] The laminate 110 includes at least one positive electrode 10, at least one negative electrode 20, and a solid electrolyte 30 interposed between the positive electrode 10 and the negative electrode 20. Figure 2 As shown in FIG. 1 , the laminate 110 is in a generally rectangular parallelepiped shape, and is laminated with three positive electrodes 10, namely positive electrodes 10a, 10b, and 10c, four negative electrodes 20, namely negative electrodes 20a, 20b, 20c, and 20d, and six solid electrolytes 30, namely solid electrolytes 30a, 30b, 30c, 30d, 30e, and 30f. Specifically, from one side of the laminate direction C of the laminate 110 (at Figure 2 The negative electrode 20a, the solid electrolyte 30a, the positive electrode 10a, the solid electrolyte 30b, the negative electrode 20b, the solid electrolyte 30c, the positive electrode 10b, the solid electrolyte 30d, the negative electrode 20c, the solid electrolyte 30e, the positive electrode 10c, the solid electrolyte 30f, and the negative electrode 20d are stacked in this order. In addition, the stacking direction C is Figure 2 The direction is indicated by the arrows on both sides.

[0035] [positive electrode]

[0036] The three positive electrodes 10 respectively include a plate-shaped positive electrode current collector 11 and a plate-shaped positive electrode active material layer 12. Figure 2 As shown, the positive electrode active material layer 12 is disposed on both sides of the positive electrode current collector 11 in the lamination direction C.

[0037] [Positive electrode current collector]

[0038] The positive electrode current collector 11 is not particularly limited, and a known current collector that can be used in a positive electrode of a solid-state battery can be applied, for example, a metal foil such as a stainless steel (SUS) foil and an aluminum (Al) foil.

[0039] On one side of the positive electrode current collector 11 that is orthogonal to the lamination direction C (at Figure 2 The positive electrode collector tab 120 is formed at the end 111 (left side in the figure). Specifically, the positive electrode collector tab 120 of the positive electrodes 10a to 10d extends from the end 111 of each positive electrode collector 11 of the positive electrodes 10a to 10c in a direction away from the laminate 110.

[0040] Each positive electrode collector tab 120 of the positive electrodes 10a to 10c is bonded to a lead terminal 200 described later while being bound at the end opposite to the laminate 110. The bonding method is not particularly limited, and a known method such as welding such as vibration welding and ultrasonic welding or welding can be used.

[0041] The positive electrode collector tab 120 may be integrally formed with the positive electrode collector 11, or may be a component different from the positive electrode collector 11, and is electrically connected to the end 111 of the positive electrode collector 11 by welding or the like. The positive electrode collector tab 120 of the present embodiment is integrally formed with the positive electrode collector 11. In the present embodiment, the positive electrode collector 11 is a portion that contacts the positive electrode active material layer 12 in one metal foil and is rolled by the pressure from the lamination direction C, and the positive electrode collector tab 120 is a portion that is not in contact with the positive electrode active material layer 12 in the one metal foil and is not rolled. Therefore, a weaker fragile portion 121 is formed at the boundary between the rolled positive electrode collector 11 and the non-rolled positive electrode collector tab 120.

[0042] The width of the positive electrode collector tab 120 is appropriately set to a value that maximizes the width of the composite material and reduces the resistance according to the purpose of use, but is preferably 1 mm to 1000 mm, more preferably 2 mm to 300 mm. The thickness is generally about 5 to 50 μm, and the length is about 5 to 50 mm.

[0043] [Positive electrode active material layer]

[0044] There is no particular limitation on the material constituting the positive electrode active material layer 12, and known materials can be used as positive electrode active materials for solid-state batteries. There is no particular limitation on its composition, and in addition to the positive electrode active material, it may also contain a solid electrolyte, a conductive additive, and a binder.

[0045] Examples of positive electrode active materials include transition metal chalcogenides such as titanium disulfide, molybdenum disulfide, and niobium selenide, and transition metal oxides such as lithium nickelate (LiNiO2), lithium manganate (LiMnO2, LiMn2O4), and lithium cobaltate (LiCoO2).

[0046] [negative electrode]

[0047] The four negative electrodes 20 each include a plate-shaped negative electrode current collector 21 and a plate-shaped negative electrode active material layer 22. Figure 2 As shown, the negative electrode active material layer 22 is disposed on one or both sides of the negative electrode current collector 21 in the lamination direction C.

[0048] [Negative electrode current collector]

[0049] The negative electrode current collector 21 is not particularly limited, and a known current collector that can be used in a negative electrode of a solid-state battery can be applied, for example, metal foil such as stainless steel (SUS) foil and copper (Cu) foil.

[0050] On the other side orthogonal to the lamination direction C of the negative electrode current collector 21 (at Figure 2 The negative electrode collector tab 130 is formed at the end 211 of the negative electrode 20a to 20d (right side). Specifically, the negative electrode collector tab 130 of the negative electrodes 20a to 20d extends from the end 211 of each negative electrode collector 21 of the negative electrodes 20a to 20d in a direction away from the laminate 110.

[0051] The negative electrode current collector tabs 130 of the negative electrodes 20a to 20d are bonded to the lead terminal 200 described later with the ends opposite to the laminate 110 being bound. The bonding method is not particularly limited, and a known method such as welding such as vibration welding and ultrasonic welding or welding can be used.

[0052] The negative electrode collector tab 130 may be integrally formed with the negative electrode collector 21, or may be a component different from the negative electrode collector 21, and is electrically connected to the end 211 of the negative electrode collector 21 by welding or the like. The negative electrode collector tab 130 of the present embodiment is integrally formed with the negative electrode collector 21. In the present embodiment, the negative electrode collector 21 is a portion that is in contact with the negative electrode active material layer 22 in one metal foil and is rolled by the pressure from the lamination direction C, and the negative electrode collector tab 130 is a portion that is not in contact with the negative electrode active material layer 22 in the one metal foil and is not rolled. Therefore, a weaker fragile portion 131 is formed at the boundary between the rolled negative electrode collector 21 and the unrolled negative electrode collector tab 130.

[0053] The width of the negative electrode collector tab 130 is appropriately set to a value that maximizes the width of the composite material and reduces the resistance according to the purpose of use, but is preferably 1 mm to 1000 mm, more preferably 2 mm to 300 mm. Generally, the thickness is generally about 5 to 50 μm and the length is about 5 to 50 mm.

[0054] [Negative Electrode Active Material Layer]

[0055] There is no particular limitation on the material constituting the negative electrode active material layer 22, and known materials can be used as negative electrode active materials for solid-state batteries. There is no particular limitation on its composition, and in addition to the negative electrode active material, it may also contain a solid electrolyte, a conductive additive, a binder, and the like.

[0056] The negative electrode active material is not particularly limited as long as it can absorb / release lithium ions. For example, as the negative electrode active material, metal lithium, lithium alloys, metal oxides, metal sulfides, metal nitrides, Si, SiO, and carbon materials such as graphite, hard carbon, and soft carbon can be listed. From the viewpoint that the volume change of the negative electrode 20 is small, it is preferred to use hard carbon with a small volume change due to charge and discharge as the negative electrode active material. In addition, similar to hard carbon, from the viewpoint that the volume change of the negative electrode 20 is small, it is preferred to use graphite as the negative electrode active material, and the capacity ratio (negative electrode capacity / positive electrode capacity) of the negative electrode 20 to the positive electrode 10 is set to 1.1 or more.

[0057] [Solid Electrolyte]

[0058] The solid electrolyte 30 is laminated between the positive electrode 10 and the negative electrode 20 and is formed in a layered form, for example. The solid electrolyte 30 is a layer containing at least a solid electrolyte material. The solid electrolyte material enables charge transfer between the positive electrode active material and the negative electrode active material.

[0059] The solid electrolyte material is not particularly limited, and examples thereof include sulfide solid electrolyte materials, oxide solid electrolyte materials, nitride solid electrolyte materials, and halide solid electrolyte materials.

[0060] [First elastic member]

[0061] The first elastic member 140 is a plate-shaped member with high elasticity. Examples of the first elastic member 140 include natural rubber, diene rubber, non-diene rubber, etc. In this embodiment, a styrene-butadiene rubber plate is used as the first elastic member 140 .

[0062] The first elastic member 140 is disposed at least on both sides of the laminate 110 in the lamination direction C. Figure 1 and Figure 2 As shown, two first elastic members 140 , namely a first elastic member 140 a and a first elastic member 140 b , are arranged on both sides of the lamination direction C of the laminate 110 .

[0063] The first elastic member 140a is disposed on one side of the laminated body 110 in the lamination direction C (at Figure 2 The first elastic member 140b is disposed on the other side of the lamination direction C of the laminate 110 (in Figure 2Specifically, the first elastic member 140a is disposed on one side of the negative electrode collector 21 of the negative electrode 20a in the lamination direction C (in Figure 2 The first elastic member 140b is configured to be in surface contact with the other side (in the lamination direction C) of the negative electrode collector 21 of the negative electrode 20d. Figure 2 With this structure, for example, even if the negative electrode active material layer 22 expands due to charging of the solid-state battery 1 and the volume of the laminate 110 increases, the first elastic component 140 can be compressed in the lamination direction C according to the increase in volume. That is, even if the volume of the laminate 110 increases, the volume of the entire solid-state battery cell 100 can be kept constant by compressing the first elastic component 140.

[0064] The area of ​​the surface of the first elastic member 140a in contact with the laminate 110 is greater than or equal to the area of ​​the surface perpendicular to the lamination direction C of the negative electrode active material layers 22 of the negative electrode 20. Similarly, the area of ​​the surface of the first elastic member 140b in contact with the laminate 110 is greater than or equal to the area of ​​the surface perpendicular to the lamination direction C of the negative electrode active material layers 22 of the negative electrode 20.

[0065] In addition, the solid-state battery cell 100 is configured such that the sum of the maximum compression amounts in the thickness direction of the first elastic members 140 disposed on both sides of the laminated body 110 in the lamination direction C is greater than the maximum expansion amount of the laminated body 110. Specifically, the sum of the maximum compression amounts in the thickness direction of the first elastic members 140a and 140b is greater than the sum of the maximum expansion amounts of all the negative electrode active material layers 22 included in the laminated body 110. In addition, the dimensions and materials of the first elastic members 140a and 140b, such as thickness, length, and width, may be the same or different from each other.

[0066] (Lead terminal)

[0067] like Figure 2 As shown, one side of the lead terminal 200 (at Figure 2 The end 201 of the laminate 110 side is electrically connected to the plurality of positive electrode collector tabs 120 or the plurality of negative electrode collector tabs 130 by welding or the like, and the other side (on the laminate 110 side) ... Figure 2 The end portion 202 (the opposite side to the laminate 110) extends outward from the outer resin portion 300 to form an electrode portion of the solid-state battery cell 100. The material of the lead terminal 200 can be the same as the collector ear lead used in existing solid-state batteries, without particular limitation.

[0068] like Figure 2As shown, two lead terminals 200 , ie, lead terminals 200 a and 200 b , are connected to the solid-state battery cell 100 of this embodiment. Specifically, the lead terminal 200 a is connected to a plurality of positive electrode collector tabs 120 , and the lead terminal 200 b is connected to a plurality of negative electrode collector tabs 130 .

[0069] (Exterior resin part)

[0070] The outer resin portion 300 includes a thermosetting resin or a thermoplastic resin. As a resin used as the outer resin portion 300, its melting point is preferably lower than 200°C, which is a temperature that affects the positive electrode active material, the negative electrode active material, and the solid electrolyte of the solid-state battery 1. As the type of resin, for example, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polystyrene (PS), acrylonitrile-styrene resin (AS), acrylonitrile-butadiene-styrene resin (ABS), polyethylene (PE), ethylene vinyl acetate (EVA), polypropylene (PP), polyacetal (POM), acrylic resin (PMMA), methyl methacrylate-styrene copolymer (MS), polycarbonate (PC), polyurethane (PU), polyvinylidene fluoride (PVDF), etc. can be listed.

[0071] The outer resin part 300 tightly covers the entire solid-state battery cell 100. That is, the outer resin part 300 tightly covers the four side surfaces orthogonal to the lamination direction C of the laminate 110, the four side surfaces orthogonal to the lamination direction C of the first elastic member 140, the surface opposite to the surface in contact with the laminate 110 in the lamination direction C, the positive electrode collector tab 120, and the negative electrode collector tab 130. In addition, the outer resin part 300 tightly covers each end 201 of the lead terminal 200a connected to the plurality of positive electrode collector tabs 120 and the lead terminal 200b connected to the plurality of negative electrode collector tabs 130.

[0072] The method for forming the outer resin part 300 is not particularly limited, and a known method can be used. For example, the outer resin part 300 is formed by placing the solid-state battery cell 100 connected with the lead terminals 200a, 200b on a mold, and filling the mold with a liquid thermosetting resin or thermoplastic resin below the melting point, and then solidifying it. At this time, each end 202 of the lead terminals 200a, 200b is arranged outside the mold, and each end 201 of the lead terminals 200a, 200b is arranged to be located inside the mold.

[0073] According to the solid-state battery 1 provided in this embodiment, the following effects are achieved.

[0074] The solid-state battery 1 of this embodiment comprises: a solid-state battery cell 100, a laminate 110 and a first elastic member 140, wherein the laminate 110 comprises: at least one positive electrode 10 having a positive electrode collector 11 and a positive electrode active material layer 12; at least one negative electrode 20 having a negative electrode collector 21 and a negative electrode active material layer 22; and a solid electrolyte 30 interposed between the positive electrode 10 and the negative electrode 20; and the first elastic member 140 is disposed at least on both sides of the laminate 110 in the lamination direction C; and an outer resin portion 300 comprising a thermosetting resin or a thermoplastic resin, which closely covers the solid-state battery cell 100. Thus, the entire solid-state battery cell 100 including the laminate 110 is closely covered on the outer resin portion 300, and the entire solid-state battery cell 100 can be more reliably protected. In addition, even when the entire solid-state battery cell 100 is covered with the outer resin part 300 without a gap, the first elastic component 140 between the laminate 110 and the outer resin part 300 is compressed according to the volume change of the laminate 110 caused by the expansion of the negative electrode active material layer 22 due to charging and discharging. That is, even if the volume of the laminate 110 in the lamination direction C changes, the generation of cracks in the outer resin part 300 can be suppressed by compressing the first elastic component 140. Therefore, it is possible to suppress damage to the outer resin part 300 due to the volume change of the laminate 110, and it is possible to ensure a higher mechanical strength of the solid-state battery 1.

[0075] In addition, the solid-state battery cell 100 of the solid-state battery 1 provided in the present embodiment further comprises: a positive electrode collector tab 120 extending from an end 111 in a direction orthogonal to the lamination direction C of the positive electrode collector 11 in a direction away from the laminate 110; and a negative electrode collector tab 130 extending from an end 211 in a direction orthogonal to the lamination direction C of the negative electrode collector 21 in a direction away from the laminate 110; and an outer resin portion 300 closely covers the positive electrode collector tab 120 and the negative electrode collector tab 130. Thus, the entire positive electrode collector tab 120 including the weaker fragile portion 121 and the entire negative electrode collector tab 130 including the weaker fragile portion 131 are protected by the outer resin portion 300. Therefore, the first elastic member 140 that can expand and contract according to the volume change of the laminate 110 can suppress the occurrence of cracks in the exterior resin portion 300 and improve the strength of the positive electrode collector tab 120 and the negative electrode collector tab 130 .

[0076] In addition, in the solid-state battery cell 100 of the solid-state battery 1 provided in the present embodiment, the area of ​​the surface of the first elastic member 140 on the side in contact with the laminate 110 is greater than the area of ​​the surface orthogonal to the lamination direction C of the negative electrode active material layer 22. Thus, the first elastic member 140 can be expanded and contracted according to the volume change of the entire surface orthogonal to the lamination direction C of the negative electrode active material layer 22. Therefore, it is possible to more reliably suppress damage to the exterior resin portion 300 due to the volume change of the laminate 110.

[0077] In addition, in the solid-state battery 1 provided in the present embodiment, the sum of the maximum compression amounts in the thickness direction of the first elastic members 140 disposed on both sides of the laminate 110 in the lamination direction C is greater than the maximum expansion amount of the laminate 110. Thus, even if all the negative electrode active material layers 22 in the laminate 110 expand to the maximum extent in the lamination direction C, the first elastic members 140 disposed in the laminate 110 are compressed according to the expansion, and therefore, damage to the exterior resin portion 300 due to a volume change of the laminate 110 can be more reliably suppressed.

[0078] In addition, the negative electrode active material constituting the negative electrode active material layer 22 of the solid-state battery 1 provided in this embodiment is hard carbon. This can reduce the volume change of the laminate 110 caused by expansion and contraction of the negative electrode active material layer 22 during charge and discharge.

[0079] In addition, the negative electrode active material constituting the negative electrode active material layer 22 of the solid-state battery 1 provided in this embodiment is a graphite active material, and the capacity ratio (negative electrode capacity / positive electrode capacity) of the negative electrode 20 to the positive electrode 10 is greater than 1.1. As a result, the volume change of the laminate 110 caused by the expansion and contraction of the negative electrode active material layer 22 due to charge and discharge can be reduced.

[0080] <Solid-state battery cell>

[0081] Next, refer to Figure 3 and Figure 4 A solid-state battery cell 1A according to the present embodiment will be described. Figure 3 It is a perspective view of the solid-state battery unit 1A. Figure 4 yes Figure 3 BB line cross-sectional view of the solid-state battery cell 1A. Figure 3 In FIG. 4 , the module exterior resin portion 400 is represented by two chain lines. Figure 4 In order to avoid complication of the drawing, hatching of the lead terminal 200A and the module exterior resin portion 400 is omitted. In addition, the same reference numerals are given to the same components as those of the solid-state battery 1 and their description is omitted.

[0082] like Figure 3 and Figure 4As shown, the solid-state battery unit 1A includes a solid-state battery module 100A, a lead terminal 200A, and a module exterior resin portion 400 .

[0083] (Solid-state battery module)

[0084] The solid-state battery module 100A includes a laminate group 110A, a positive electrode current collector tab 120 , a negative electrode current collector tab 130 , and a second elastic member 150 .

[0085] [Laminate group]

[0086] The laminate group 110A is formed by laminating a plurality of laminates 110 in the lamination direction C. In this embodiment, Figure 3 and Figure 4 As shown, the laminate group 110A has a substantially rectangular parallelepiped shape as a whole, and is composed of three laminates 110, namely, laminates 110a, 110b, and 110c laminated in sequence.

[0087] [Second elastic member]

[0088] The second elastic member 150 is a plate-shaped member with high elasticity. Examples of the second elastic member 150 include natural rubber, diene rubber, non-diene rubber, and the like. In the present embodiment, a styrene-butadiene rubber plate is used as the second elastic member 150 .

[0089] The second elastic member 150 is disposed at least on both sides of the laminate group 110A in the lamination direction C. Figure 3 and Figure 4 As shown, four second elastic members 150, namely, second elastic members 150a, 150b, 150c, and 150d are arranged on the laminate group 110A.

[0090] The second elastic member 150a is disposed on one side (at the side of the stacking direction C) of the stacking body group 110A. Figure 4 Specifically, the second elastic member 150a is disposed on one side (in the lamination direction C) of the negative electrode current collector 21 of the negative electrode 20a of the laminate 110a. Figure 4 The entire surface (upper side) is in contact.

[0091] The second elastic member 150d is arranged on the other side of the lamination direction C of the laminate group 110A (at Figure 4 Specifically, the second elastic member 150b is arranged on the other side (at the bottom) of the negative electrode collector 21 of the negative electrode 20d of the laminate 110c in the lamination direction C. Figure 4 The entire surface (lower side in the middle) is in contact with each other.

[0092] The second elastic member 150b is disposed between the laminate 110a and the laminate 110b. Specifically, the second elastic member 150b is disposed on the other side (at the same direction) of the lamination direction C of the negative electrode current collector 21 of the negative electrode 20d of the laminate 110a. Figure 4 The entire surface of the negative electrode collector 21 of the negative electrode 20a of the laminate 110b is in surface contact with the negative electrode collector 21 of the negative electrode 20a of the laminate 110b (in the lamination direction C). Figure 4 The entire surface (upper side) is in contact.

[0093] The second elastic member 150c is disposed between the laminate 110b and the laminate 110c. Specifically, the second elastic member 150c is disposed on the other side of the negative electrode collector 21 of the negative electrode 20d of the laminate 110b in the lamination direction C (at Figure 4 At the same time, the other side of the negative electrode collector 21 of the negative electrode 20a of the laminate 110c (in the lamination direction C) Figure 4 The entire surface (upper side) is in contact.

[0094] The area of ​​the surface of each of the second elastic members 150a to 150d in contact with the laminate 110 is greater than the area of ​​the surface of the laminate 110 perpendicular to the lamination direction C of the negative electrode active material layer 22. Thus, the second elastic member 150 can expand and contract according to the volume change of the entire surface perpendicular to the lamination direction C of the negative electrode active material layer 22.

[0095] In addition, the solid-state battery module 100A is configured so that the sum of the maximum compression amounts of all the second elastic members 150 arranged on the laminate group 110A in the thickness direction is greater than the maximum expansion amount of the laminate group 110A. Specifically, the sum of the maximum compression amounts of the second elastic members 150a to 150d in the thickness direction is greater than the sum of the maximum expansion amounts of all the negative electrode active material layers 22 contained in the laminate group 110A. Thus, even if all the negative electrode active material layers 22 in the laminate group 110A expand to the maximum extent in the lamination direction C, the second elastic member 150 arranged on the laminate group 110A can be compressed according to the expansion. In addition, the dimensions and materials of the second elastic members 150a to 150d, such as thickness, length, width, etc., can be the same or different from each other.

[0096] (Lead terminal)

[0097] like Figure 4 As shown, one side of the lead terminal 200A (at Figure 4 The end 201 of the laminate group 110A side is electrically connected to the plurality of positive electrode collector tabs 120 or the plurality of negative electrode collector tabs 130 by welding or the like, and the other side (on the laminate group 110A side) is electrically connected to the plurality of positive electrode collector tabs 120 or the plurality of negative electrode collector tabs 130 by welding or the like. Figure 4The end portion 202 (in the opposite side to the laminate group 110A) extends outward from the module exterior resin portion 400 to form an electrode portion of the solid-state battery unit 1A. The material of the lead terminal 200A is the same as that of the lead terminal 200, and the same material as the collector ear lead used in the existing solid-state battery can be used without any particular limitation.

[0098] like Figure 4 As shown, six lead terminals 200A, namely, lead terminals 200c, 200d, 200e, 200f, 200g, and 200h, are electrically connected on the solid-state battery module 100A by welding or the like. Specifically, the lead terminal 200c is connected to a plurality of positive electrode collector tabs 120 extending from the laminate 110a, the lead terminal 200d is connected to a plurality of negative electrode collector tabs 130 extending from the laminate 110a, the lead terminal 200e is connected to a plurality of positive electrode collector tabs 120 extending from the laminate 110b, the lead terminal 200f is connected to a plurality of negative electrode collector tabs 130 extending from the laminate 110b, the lead terminal 200g is connected to a plurality of positive electrode collector tabs 120 extending from the laminate 110c, and the lead terminal 200h is connected to a plurality of negative electrode collector tabs 130 extending from the laminate 110c.

[0099] (Module exterior resin part)

[0100] The module exterior resin portion 400 includes a thermosetting resin or a thermoplastic resin. As the module exterior resin portion 400, the same type of resin as that of the exterior resin portion 300 can be used.

[0101] The module exterior resin part 400 tightly covers the entire solid-state battery module 100A. That is, the module exterior resin part 400 tightly covers the four side surfaces orthogonal to the lamination direction C of the laminate group 110A, the four side surfaces orthogonal to the lamination direction C of the second elastic members 150a to 150d, the surface opposite to the surface in contact with the laminate group 110A in the lamination direction C of the second elastic members 150a, 150d, the positive electrode collector tab 120, and the negative electrode collector tab 130. In addition, the module exterior resin part 400 tightly covers at least the end 201 of the lead terminals 200c to 200h connected to the positive electrode collector tab 120 or the negative electrode collector tab 130.

[0102] The method for forming the module exterior resin part 400 is not particularly limited, and a known method can be used. For example, the module exterior resin part 400 is formed by placing the solid-state battery module 100A connected to the lead terminal 200A on a mold, and filling the mold with a liquid thermosetting resin or thermoplastic resin below the melting point, and then solidifying it. At this time, the end 202 of the lead terminal 200A is arranged outside the mold, and the end 201 of the lead terminal 200A is arranged to be located inside the mold.

[0103] According to the solid-state battery cell 1A of the present embodiment, the following effects are achieved.

[0104] The solid-state battery unit 1A of this embodiment comprises: a fixed battery module 100A, a laminate group 110A and a second elastic component 150, wherein the laminate group 110A is formed by laminating the laminate 110 in the lamination direction C; and the second elastic component 150 is at least arranged on both sides of the lamination direction C of the laminate group 110A; and a module exterior resin portion 400, comprising a thermosetting resin or a thermoplastic resin, which tightly covers the solid-state battery module 100A. Thus, a solid-state battery module 100A having a plurality of laminates 110 arranged in parallel can be protected by a single module exterior resin portion 400, so there is no need to provide an exterior body on each laminate 110, and the miniaturization of the solid-state battery unit 1A can be achieved. In addition, since the entire solid-state battery module 100A including the laminate group 110A is tightly covered on the module exterior resin portion 400, the entire solid-state battery module 100A can be more reliably protected. Furthermore, even when the entire solid-state battery module 100A is covered with the module exterior resin portion 400 without a gap, the second elastic member 150 between the laminate group 110A and the module exterior resin portion 400 is compressed according to the volume change of the laminate group 110A caused by the expansion and contraction of the negative electrode active material layer 22 due to charge and discharge. Therefore, it is possible to suppress damage to the module exterior resin portion 400 due to the volume change of the laminate group 110A, and at the same time, it is possible to achieve miniaturization and improvement of mechanical strength of the solid-state battery unit 1A.

[0105] In addition, the second elastic member 150 of the solid-state battery cell 1A of the present embodiment is arranged on both sides of each of the plurality of laminates 110 in the lamination direction C. Thus, since the second elastic member 150 is arranged on both sides of the lamination direction C of each laminate 110 included in the laminate group 110A, the second elastic member 150 can be compressed more reliably according to the volume change of each laminate 110.

[0106] In addition, the second elastic member 150 of the solid-state battery unit 1A of the present embodiment has insulating properties. Therefore, even when the laminates 110 of the solid-state battery module 100A are connected in series, insulation between the laminates 110 can be ensured.

[0107] As mentioned above, although embodiment of this invention was demonstrated, this invention is not limited to the said embodiment, It is possible to make appropriate changes.

[0108] In the above embodiment, the laminate 110 of the solid-state battery 1 has three positive electrodes 10, four negative electrodes 20, and six solid electrolytes 30, but as long as the solid electrolyte 30 is interposed between the positive electrode 10 and the negative electrode 20 and laminated, the number of positive electrodes 10, negative electrodes 20, and solid electrolytes 30 in the laminate 110 is not particularly limited. For example, the number of positive electrodes 10 may be 2 or less, or 4 or more. In addition, the number of negative electrodes 20 may be 3 or less, or 5 or more. In addition, the number of solid electrolytes 30 may be 5 or less, or 7 or more.

[0109] In the above embodiment, the first elastic member 140 is arranged on both sides of the laminate 110 of the solid-state battery 1 in the lamination direction C. Alternatively, the first elastic member 140 may be arranged on the side surfaces of the laminate 110 orthogonal to the lamination direction C of the negative electrode active material layer 22 .

[0110] In the above embodiment, the solid-state battery module 100A of the solid-state battery unit 1A has three laminates 110, but the number of laminates 110 is not particularly limited as long as it is two or more. For example, the number of laminates 110 of the solid-state battery module 100A may be two or four or more.

[0111] In the above embodiment, the second elastic member 150 of the solid-state battery unit 1A is arranged on both sides of the lamination direction C of all the laminates 110 of the solid-state battery module 100A, but it can also be arranged only on both sides of the laminate group 110A. In addition, in addition to this, the second elastic member 150 can also be arranged on the side of the laminate 110 that is orthogonal to the lamination direction C of the negative electrode active material layer 22. In addition, when the connection method of each laminate 110 in the solid-state battery module 100A is a series connection, the insulating member is interposed between each laminate 110.

[0112] Reference numerals

[0113] 1. Solid-state batteries

[0114] 10,10a,10b,10c Positive electrode

[0115] 11. Positive electrode current collector

[0116] 12 Positive electrode active material layer

[0117] 20,20a,20b,20c,20d negative electrode

[0118] 21. Negative electrode current collector

[0119] 22 Negative electrode active material layer

[0120] 30,30a,30b,30c,30d,30e,30f Solid electrolyte

[0121] 100 solid-state battery cells

[0122] 110 Laminate

[0123] 140, 140a, 140b first elastic member

[0124] 300 Exterior resin part

Claims

1. A solid-state battery having: A solid-state battery cell, comprising a laminate and a first elastic component, wherein the laminate comprises: at least one positive electrode having a positive electrode collector and a positive electrode active material layer; at least one negative electrode having a negative electrode collector and a negative electrode active material layer; and a solid electrolyte disposed between the positive electrode and the negative electrode; and the first elastic component is disposed at least on both sides of the laminate in a lamination direction of the laminate; and, The outer resin portion includes a thermosetting resin or a thermoplastic resin, and closely covers the solid-state battery cell. The first elastic member is configured to maintain a constant volume of the solid-state battery cell by compressing the first elastic member.

2. The solid-state battery according to claim 1, wherein: The aforementioned solid-state battery monomer also has: A positive electrode collector tab extending from an end of the positive electrode collector in a direction perpendicular to the lamination direction in a direction away from the laminate; and A negative electrode collector tab extends from an end of the negative electrode collector in a direction perpendicular to the lamination direction in a direction away from the laminate; and The exterior resin portion closely covers the positive electrode current collector tab and the negative electrode current collector tab.

3. The solid-state battery according to claim 1 or 2, wherein: The area of ​​the surface of the first elastic member that contacts the laminate is greater than or equal to the area of ​​a surface perpendicular to the lamination direction of the negative electrode active material layers.

4. The solid-state battery according to claim 1 or 2, wherein: The sum of the maximum compression amounts of the first elastic members disposed on both sides of the laminate in the lamination direction in the thickness direction is greater than the maximum expansion amount of the laminate.

5. The solid-state battery according to claim 1 or 2, wherein: The negative electrode active material constituting the negative electrode active material layer is hard carbon.

6. The solid-state battery according to claim 1 or 2, wherein: The negative electrode active material constituting the negative electrode active material layer is a graphite active material, and the capacity ratio of the negative electrode to the positive electrode (negative electrode capacity / positive electrode capacity) is greater than 1.

1.

7. A solid-state battery cell comprising: A fixed battery module, comprising a laminate group and a second elastic component, wherein the laminate group is formed by laminating a plurality of laminates in a lamination direction of the laminates, wherein the laminates have: at least one positive electrode having a positive electrode collector and a positive electrode active material layer; at least one negative electrode having a negative electrode collector and a negative electrode active material layer; and a solid electrolyte disposed between the positive electrode and the negative electrode; and the second elastic component is disposed at least on both sides of the laminate group in the lamination direction; and, The module outer resin portion includes a thermosetting resin or a thermoplastic resin, which closely covers the solid-state battery module. The second elastic member is configured to maintain a constant volume of the solid-state battery cell by compressing the second elastic member.

8. The solid-state battery cell according to claim 7, wherein: The second elastic member is disposed on both sides of each of the plurality of laminated bodies in the lamination direction.

9. The solid-state battery cell according to claim 7 or 8, wherein: The second elastic member has insulating properties.

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