All-solid-state battery

Abstract

To provide an all-solid-state battery capable of preventing cracking of an insulating layer arranged on the outside of one electrode layer.SOLUTION: The all-solid-state battery includes a first current collecting foil, a first electrode layer arranged on the first current collecting foil, an insulating layer arranged on the first current collecting foil and arranged on the outer side of the first electrode layer in a surface direction, a solid electrolyte layer arranged on the first electrode layer, a second electrode layer arranged on the solid electrolyte layer, a second current collecting foil arranged on the second electrode layer, and a shock absorbing member for absorbing shock applied to the insulating layer. The shock absorbing member is arranged at a position opposing the insulating layer in a stacking direction and supported by the second current collecting foil.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an all-solid-state battery. [Background technology]

[0002] An all-solid-state battery is a secondary battery in which all components, including an electrolyte layer, are substantially made of solids. Known all-solid-state batteries include a solid electrolyte layer, a pair of electrode layers (a positive electrode layer and a negative electrode layer) sandwiching the solid electrolyte layer, and current collector foils (a positive electrode current collector foil and a negative electrode current collector foil) disposed on each of the pair of electrode layers.

[0003] For various reasons, some structure may be provided around the electrode layer. For example, Patent Document 1 (International Publication No. WO 2020 / 137388) discloses an all-solid-state battery provided with a sealing layer having a specific glass transition temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 137388 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have been studying an all-solid-state battery in which an insulating layer is disposed on the outer side of one of a pair of electrode layers (hereinafter, sometimes referred to as the first electrode layer). By disposing the insulating layer in such a position, it is expected that short circuits can be prevented.

[0006] However, when the above-mentioned configuration is adopted, the insulating layer is easily subjected to external impact during transportation, manufacturing, etc. As a result, the insulating layer may crack. Therefore, an object of the present invention is to provide a technology that can prevent cracking of the insulating layer disposed on the outer side of one of the electrode layers. [Means for solving the problem]

[0007] In one aspect, the all-solid-state battery according to the present invention includes a first current collecting foil, a first electrode layer disposed on the first current collecting foil, an insulating layer disposed on the first current collecting foil and disposed outside the first electrode layer in a surface direction, a solid electrolyte layer disposed on the first electrode layer, a second electrode layer disposed on the solid electrolyte layer, a second current collecting foil disposed on the second electrode layer, and a shock absorbing member that absorbs shock applied to the insulating layer. The shock absorbing member is disposed at a position facing the insulating layer in the stacking direction and is supported by the second current collecting foil. Effect of the Invention

[0008] According to the present invention, a technique is provided that can prevent cracks in an insulating layer disposed on the outer side of one of the electrode layers. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery according to a first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an all-solid-state battery according to the second embodiment. [Diagram 3] FIG. 3 is a plan view illustrating a schematic diagram of an all-solid-state battery according to a third embodiment. [Figure 4] FIG. 4 is a plan view that illustrates a schematic diagram of an all-solid-state battery according to a fourth embodiment. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing an all-solid-state battery according to the fifth embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view showing an all-solid-state battery according to the sixth embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an all-solid-state battery according to the seventh embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view showing an all-solid-state battery according to the eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] In this specification, an "all-solid-state battery" refers to a secondary battery in which the electrolyte layer, the positive electrode layer, and the negative electrode layer are all substantially solid. Each layer may be "substantially" solid, and may contain a small amount of liquid material.

[0012] (1) First embodiment FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment.

[0013] (Summary) 1, the all-solid-state battery 1 has a first current collecting foil 2, a first electrode layer 3, a solid electrolyte layer 5, a second electrode layer 6, a second current collecting foil 7, an insulating layer 4, and an impact absorbing member 8. The first electrode layer 3 is disposed on the first current collecting foil 2. The solid electrolyte layer 5 is disposed on the first electrode layer 3. The second electrode layer 6 is disposed on the solid electrolyte layer 5. The second current collecting foil 7 is disposed on the second electrode layer 6.

[0014] The first electrode layer 3, the solid electrolyte layer 5, and the second electrode layer 6 are parts that realize a power generation function. In the following description, a stacked structure consisting of the first electrode layer 3, the solid electrolyte layer 5, and the second electrode layer 6 may be referred to as a unit 11. The sizes of the first electrode layer 3, the solid electrolyte layer 5, and the second electrode layer 6 are approximately equal when viewed along the stacking direction.

[0015] The insulating layer 4 is provided for the purpose of preventing short circuits, etc. The insulating layer 4 is disposed on the first current collecting foil 2. The insulating layer 4 is disposed on the outer side of the first electrode layer 3 in the planar direction. Specifically, the insulating layer 4 is disposed so as to surround the first electrode layer 3. The inner peripheral edge of the insulating layer 4 contacts the outer peripheral edge of the first electrode layer 3.

[0016] The shock absorbing member 8 is provided to absorb shock applied to the insulating layer 4. The shock absorbing member 8 is disposed at a position facing the insulating layer 4 in the stacking direction. The shock absorbing member 8 is supported by the second current collector foil 7.

[0017] According to the configuration described above, the shock absorbing member 8 is provided, and therefore absorbs the shock when the insulating layer 4 comes into contact with the second current collecting foil 7. This makes it possible to prevent the insulating layer 4 from being damaged.

[0018] The above is an outline of the present embodiment. Next, the details of the all-solid-state battery 1 according to the present embodiment will be described.

[0019] (Electrode layer and solid electrolyte layer) As described above, the unit 11 (the first electrode layer 3, the solid electrolyte layer 5, and the second electrode layer 6) are the parts that realize the function of a battery. One of the first electrode layer 3 and the second electrode layer 6 is a positive electrode layer, and the other is a negative electrode layer. The positive electrode layer is a layer containing a positive electrode active material. The negative electrode layer is a layer containing a negative electrode active material. During charging, ions (lithium ions) of the negative electrode layer are conducted from the positive electrode layer via the solid electrolyte layer 5. Conversely, during discharging, ions are conducted from the negative electrode layer via the solid electrolyte layer 5 to the positive electrode layer.

[0020] In the example shown in FIG. 1, a plurality of units 11 (two in the example shown in FIG. 1) are stacked with current collecting foils interposed between them. In other words, the unit 11 is sandwiched between the first current collecting foil 2 and the second current collecting foil 7. The unit 11 is sandwiched between the first current collecting foil 2 and the second current collecting foil 7 such that the first current collecting foil 2 side faces the first electrode layer 3 side. However, the all-solid-state battery 1 does not necessarily need to include a plurality of units 11. There may be a single unit 11. Conversely, the all-solid-state battery 1 may have a configuration in which three or more units 11 are stacked.

[0021] As described above, the first electrode layer 3, the solid electrolyte layer 5, and the second electrode layer 6 are approximately equal in size when viewed along the stacking direction. However, in the example shown in FIG. 1, the outer peripheral edge of the solid electrolyte layer 5 is located slightly outside the outer peripheral edges of each electrode layer (the first electrode layer 3 and the second electrode layer 6). In the all-solid-state battery 1, lithium dendrites may precipitate so as to wrap around the edges. If the outer peripheral edge of the solid electrolyte layer 5 is located outside the outer peripheral edges of each electrode layer, it is possible to prevent short circuits caused by such lithium dendrites.

[0022] (current collecting foil) The first current collecting foil 2 and the second current collecting foil 7 are provided to electrically connect the unit 11 to an external device. The size of each current collecting foil (the first current collecting foil 2 and the second current collecting foil 7) is larger than the size of the unit 11. That is, when viewed along the stacking direction, the outer peripheral edge of each current collecting foil (the first current collecting foil 2 and the second current collecting foil 7) is located outside the outer peripheral edges of the first electrode layer 3, the solid electrolyte layer 5, and the second electrode layer 6. Each current collecting foil (the first current collecting foil 2 and the second current collecting foil 7) is connected to a tab 9 on the side of the unit 11. The tab 9 is connected to a lead 10. Note that in the example shown in FIG. 1, a plurality of (two) second current collecting foils 7 are depicted. A plurality of tabs 9 are also provided corresponding to the plurality of second current collecting foils 7. A plurality of tabs 9 corresponding to the plurality of second current collecting foils 7 are gathered together on the side of the unit 11 and connected to the lead 10.

[0023] 1 illustrates only one first current collecting foil 2. However, when multiple first current collecting foils 2 are provided, similarly to the second current collecting foils 7, multiple tabs 9 connected to the multiple first current collecting foils 2 are gathered together on the side of the unit 11 and connected to a lead 10.

[0024] (insulating layer) As described above, the insulating layer 4 is disposed on the first current collecting foil 2. When viewed along the stacking direction, the insulating layer 4 is disposed so as to surround the first electrode layer 3. The provision of the insulating layer 4 prevents short circuits.

[0025] In addition, when the outer peripheral end of the solid electrolyte layer 5 is located outside the outer peripheral ends of each electrode layer (first electrode layer 3 and second electrode layer 6), the insulating layer 4 can be provided to support the end of the solid electrolyte layer 5. If the insulating layer 4 were not present, the end of the solid electrolyte layer 5 would not be supported. As a result, when an impact is applied for some reason, the end of the solid electrolyte layer 5 is easily damaged. In response to this, the insulating layer 4 can be provided to support the end of the solid electrolyte layer 5. This makes it possible to prevent the end of the solid electrolyte layer 5 from cracking.

[0026] The insulating layer 4 may have any insulating properties. Preferably, the insulating layer 4 is made of the same material as the solid electrolyte layer 5 or a material having lower electronic conductivity than the solid electrolyte layer 5. If the insulating layer 4 is made of such a material, a short circuit between the first electrode layer 3 and the second electrode layer 6 can be more reliably prevented.

[0027] (shock absorbing material) As described above, the shock absorbing member 8 is provided to absorb the shock when the insulating layer 4 and the second current collecting foil 7 come into contact with each other. As described above, the size of the solid electrolyte layer 5 and the second electrode layer 6 is approximately equal to the size of the first electrode layer 3. Therefore, the solid electrolyte layer 5 and the second electrode layer 6 do not exist on the insulating layer 4. That is, the insulating layer 4 faces the second current collecting foil 7 in most parts without sandwiching the solid electrolyte layer 5 and the second electrode layer 6. Here, during manufacturing or transportation, the second current collecting foil 7 may come into contact with the insulating layer 4 for some reason. If the shock absorbing member 8 does not exist, the insulating layer 4 may be damaged by the shock at the time of contact. However, according to this embodiment, the shock is absorbed by the shock absorbing member 8, so that the insulating layer 4 is prevented from being damaged.

[0028] The shock absorbing member 8 may be formed of a material having a function of absorbing shock. For example, a material that deforms itself when it comes into contact with the insulating layer 4 may be used as the shock absorbing member 8. In other words, a material that is softer than the insulating layer 4 may be used as the shock absorbing member 8. For example, an insulating elastic body made of resin may be used as the shock absorbing member 8. For example, an elastomer such as rubber may be used as the shock absorbing member 8.

[0029] In a preferred embodiment, the shock absorbing member 8 is configured to adsorb or absorb fragments of the insulating layer 4. By adopting such a configuration, even if the insulating layer 4 is damaged, the fragments of the insulating layer 4 are adsorbed or absorbed by the shock absorbing member 8. This can prevent the fragments of the insulating layer 4 from scattering. In particular, it is preferable that the fragments of the insulating layer 4 can be prevented from penetrating into the electrode layer. For example, if the shock absorbing member 8 is formed of a resin having a certain degree of viscoelasticity, the shock absorbing member 8 can have a function of adsorbing the fragments of the insulating layer 4. Alternatively, if the shock absorbing member 8 is formed of a sponge (porous elastic body), the shock absorbing member 8 can have a function of absorbing the fragments of the insulating layer 4.

[0030] The shock absorbing member 8 is preferably disposed at a distance from the insulating layer 4. In other words, a gap is preferably provided between the shock absorbing member 8 and the insulating layer 4. The electrode layer may expand and contract as the battery is charged and discharged. If a gap exists between the shock absorbing member 8 and the insulating layer 4, the electrode layer is allowed to expand and contract as the battery is charged and discharged. When the thickness of the unit 11 changes as the battery is charged and discharged, the gap may be formed when the unit 11 is at its thickest.

[0031] Moreover, the shock absorbing member 8 is disposed on the outer side of the second electrode layer 6 when viewed along the stacking direction. The shock absorbing member 8 is preferably formed from a material softer than the second electrode layer 6 (a material that is more easily deformed than the second electrode layer 6). The second electrode layer 6 may also expand and contract in the planar direction. If the shock absorbing member 8 is softer than the second electrode layer 6, expansion and contraction in the planar direction of the second electrode layer 6 is also permitted.

[0032] The shock absorbing member 8 is preferably formed from a material having a lower density than the insulating layer 4. By using such a shock absorbing member 8, the weight can be reduced and a decrease in energy density can be suppressed.

[0033] It is preferable that the shock absorbing member 8 has a degree of flexibility that enables it to conform to the second current collecting foil 7. As in the example shown in Fig. 1, a plurality of tabs 9 may be grouped together at the end of the all-solid-state battery 1. Therefore, the second current collecting foil 7 may be bent depending on the direction in which the tab 9 stretches. If the shock absorbing member 8 has a degree of flexibility that enables it to conform to the second current collecting foil 7, the shock absorbing member 8 does not become an obstacle when the second current collecting foil 7 is bent.

[0034] (others) Next, the materials used for each part and other points will be described.

[0035] The material of the solid electrolyte layer 5 is not particularly limited. The solid electrolyte layer 5 may be made of a material that is solid and functions as an electrolyte layer in a secondary battery. For example, the solid electrolyte layer 5 includes a resin binder and a solid electrolyte dispersed in the resin binder. The solid electrolyte preferably includes a sulfide solid electrolyte. The thickness of the solid electrolyte layer 5 is, for example, 5 to 100 μm.

[0036] The material of the positive electrode layer (one of the first electrode layer 3 and the second electrode layer 6) is not particularly limited. The positive electrode layer may be made of a material that can release lithium ions during charging and absorb lithium ions during discharging. For example, the positive electrode layer is formed of a material containing a resin binder and a positive electrode active material dispersed in the resin binder. The positive electrode active material is not particularly limited, but for example, an NMC-based positive electrode active material can be used. The thickness of the positive electrode layer is, for example, 10 to 1000 μm, preferably 30 to 500 μm.

[0037] The negative electrode layer (the other of the first electrode layer 3 and the second electrode layer 6) may be configured to absorb lithium during charging and release lithium as lithium ions during discharging. For example, the negative electrode layer may be formed from a material containing a resin binder and a negative electrode active material dispersed in the resin binder.

[0038] Alternatively, the negative electrode layer may be realized by metallic lithium that is precipitated between the solid electrolyte layer 5 and the negative electrode current collector foil during charging. That is, the all-solid-state battery 1 may be a so-called precipitation-type secondary battery. In this case, it is preferable that the first electrode layer 3 is the positive electrode layer and the second electrode layer 6 is the negative electrode layer. In such a precipitation-type secondary battery, there may be almost no metallic lithium as the negative electrode active material in a fully discharged state. However, at least the metallic lithium that is precipitated during charging functions as a negative electrode layer containing a negative electrode active material, and therefore is included in the all-solid-state battery 1 according to this embodiment.

[0039] When the all-solid-state battery 1 is a precipitation-type all-solid-state battery, an anode protective layer may be provided between the solid electrolyte layer 5 and the anode layer. The anode protective layer is provided to prevent the solid electrolyte layer 5 from being damaged by metallic lithium precipitated during charging. As the anode protective layer, for example, a layer containing Ag and C is used.

[0040] Next, a description will be given of a method for manufacturing the all-solid-state battery 1. The method for manufacturing the all-solid-state battery 1 according to this embodiment is not particularly limited. For example, the following method can be adopted.

[0041] First, the first current collecting foil 2 is prepared. Then, the first electrode layer 3 and the insulating layer 4 are formed on the first current collecting foil 2. The first electrode layer 3 can be formed, for example, by applying a slurry containing the constituent material of the first electrode layer 3 onto the first current collecting foil 2 and drying it. Similarly, the insulating layer 4 can be formed, for example, by applying a slurry and drying it. Next, the solid electrolyte layer 5 is formed on the first electrode layer 3. The solid electrolyte layer 5 can be formed, for example, by applying a slurry containing a solid electrolyte and drying it. Meanwhile, the second current collecting foil 7 is prepared, and the second electrode layer 6 and the shock absorbing member 8 are formed on the second current collecting foil 7. Then, the second current collecting foil 7 provided with the second electrode layer 6 and the shock absorbing member 8 is attached onto the solid electrolyte layer 5. Thereafter, necessary members such as a tab 9 and a lead 10 are attached. In this manner, the all-solid-state battery 1 is obtained.

[0042] (2) Second embodiment Next, a second embodiment will be described. Note that detailed description of the second embodiment will be omitted for the points where the same configuration as the first embodiment can be adopted.

[0043] 2 is a schematic cross-sectional view showing the all-solid-state battery 1 according to this embodiment. In this embodiment, the insulating layer 4 is formed integrally with the solid electrolyte layer 5. By adopting such a configuration, it is not necessary to separately prepare materials for forming the insulating layer 4 and materials for forming the solid electrolyte layer 5. This is preferable because the management of materials is not complicated.

[0044] In this embodiment, the insulating layer 4 and the solid electrolyte layer 5 can be obtained, for example, by applying a slurry containing the constituent materials of the insulating layer 4 and the solid electrolyte layer 5 so as to cover the first electrode layer 3. Alternatively, a solid electrolyte layer 5 larger than the first electrode layer 3 is placed on the first electrode layer 3, and isostatic pressing, roll pressing, or the like is performed. This makes it possible to obtain a configuration in which the portion of the solid electrolyte layer 5 protruding from the first electrode layer 3 covers the side of the first electrode layer 3. Since the insulating layer 4 and the solid electrolyte layer 5 can be formed in one step, the manufacturing cost can be reduced.

[0045] (3) Third embodiment Next, a third embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as in the above-described embodiments can be adopted.

[0046] Fig. 3 is a plan view showing a schematic diagram of the all-solid-state battery 1 according to this embodiment. That is, it is a diagram showing the all-solid-state battery 1 viewed along the stacking direction. Fig. 3 shows a schematic diagram of the positional relationship between the tab 9, the current collecting foils (the first current collecting foil 2 and the second current collecting foil 7), the unit 11 (the first electrode layer 3, the solid electrolyte layer 5, the second electrode layer 6), the insulating layer 4, and the impact absorbing member 8.

[0047] First, the shape of each current collecting foil (2, 7) will be described. Each current collecting foil (2, 7) has a shape that includes a tab side 12. The tab side 12 is the side to which the tab 9 is connected. In the example shown in FIG. 3, each current collecting foil (2, 7) is rectangular. Each current collecting foil (2, 7) is connected to the tab 9 at its short side. In other words, the tab side 12 is the short side of each current collecting foil (2, 7). No tab is connected to the long side of each current collecting foil (2, 7).

[0048] When viewed along the stacking direction, the shock absorbing member 8 is disposed between the tab side 12 and the first electrode layer 3. Specifically, the shape of the unit 11 corresponds to the shape of each current collecting foil (2, 7). That is, in the example shown in FIG. 3, it is rectangular. Then, when viewed from the stacking direction, the insulating layer 4 and the shock absorbing member 8 are provided between the unit 11 and the tab side 12. That is, the shock absorbing member 8 is provided along the tab side 12.

[0049] According to this embodiment, cracking of the insulating layer 4 is more reliably prevented. In the all-solid-state battery 1, vibrations are easily transmitted through the tab 9. As described above, since the multiple tabs 9 are grouped together at the end, the current collecting foil is pulled by the tab 9 in the vicinity of the tab 9 and is easily brought into contact with the insulating layer 4. That is, in the vicinity of the tab 9, the insulating layer 4 is easily subjected to impact from the second current collecting foil 7. However, according to this embodiment, the impact absorbing member 8 is provided along the tab side 12. That is, the impact absorbing member 8 is disposed in a position where the insulating layer 4 is easily cracked. Therefore, cracking of the insulating layer 4 can be effectively prevented.

[0050] (4) Fourth embodiment Next, a fourth embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as in the above-described embodiments can be adopted.

[0051] Fig. 4 is a plan view showing a schematic diagram of the all-solid-state battery 1 according to the present embodiment. That is, it is a diagram showing the all-solid-state battery 1 as viewed along the stacking direction. As in Fig. 3, Fig. 4 also shows the positional relationship between the tab 9, the current collecting foils (the first current collecting foil 2 and the second current collecting foil 7), the unit 11 (the first electrode layer 3, the solid electrolyte layer 5, the second electrode layer 6), the insulating layer 4, and the shock absorbing member 8.

[0052] In this embodiment, the shock absorbing member 8 is arranged in a frame shape so as to surround the entire periphery of the first electrode layer 3 when viewed along the stacking direction. Specifically, the shock absorbing member 8 is arranged so as to surround the unit 11.

[0053] According to this embodiment, since the shock absorbing member 8 is arranged in a frame shape, the height of the all-solid-state battery 1 is maintained uniform. The all-solid-state battery 1 is usually constrained so as to be compressed along the stacking direction. If the shock absorbing member 8 is provided only on a specific side, the height of the all-solid-state battery 1 may become non-uniform. As a result, the all-solid-state battery may be distorted. However, according to this embodiment, since the shock absorbing member 8 is arranged so as to surround the entire periphery of the first electrode layer 3, distortion during constraining can be avoided. This makes it possible to prevent pressure from being concentrated at one point on the insulating layer 4, and to prevent the insulating layer 4 from being locally destroyed.

[0054] (5) Fifth embodiment Next, a fifth embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as in the above-described embodiments can be adopted.

[0055] 5 is a schematic cross-sectional view showing the all-solid-state battery 1 according to this embodiment. In this embodiment, the shapes of the opposing surfaces of the insulating layer 4 and the impact absorbing member 8 are devised.

[0056] The surface of the impact absorbing member 8 facing the insulating layer 4 is defined as the impact absorbing member facing surface 14. The surface of the insulating layer 4 facing the impact absorbing member 8 is defined as the insulating layer facing surface 15. The impact absorbing member facing surface 14 and the insulating layer facing surface 15 are non-flat. The impact absorbing member facing surface 14 has a shape corresponding to the insulating layer facing surface 15. In the example shown in FIG. 5, the insulating layer facing surface 15 has a shape such that the insulating layer 4 becomes thinner toward the outside. Conversely, the impact absorbing member facing surface 14 has a shape such that the impact absorbing member 8 becomes thicker toward the outside.

[0057] According to this embodiment, the shock-absorbing member opposing surface 14 has a shape corresponding to the insulating layer opposing surface 15, so even if the insulating layer 4 has a variation in thickness, the thickness of the all-solid-state battery 1 can be made uniform.

[0058] (6) Sixth embodiment Next, a sixth embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as in the above-described embodiments can be adopted.

[0059] 6 is a schematic cross-sectional view showing the all-solid-state battery 1 according to this embodiment. In this embodiment, the size of the impact absorbing member 8 is devised.

[0060] First, for convenience, an end region 16 and an inner region 17 are defined in the insulating layer 4. The end region 16 is a region including an outer end in the surface direction. On the other hand, the inner region 17 is a region on the inner side of the end region 16.

[0061] The shock absorbing members 8 are disposed in positions facing the end regions 16. On the other hand, the shock absorbing members 8 are not disposed in positions facing the inner region 17. In other words, the shock absorbing members 8 are provided only in positions corresponding to the vicinity of the ends of the insulating layer 4.

[0062] According to this embodiment, it is possible to effectively protect the easily cracked portions of the insulating layer 4. That is, the insulating layer 4 is more easily cracked near the ends. Therefore, by arranging the shock absorbing member 8 so as to face the end region 16, the easily cracked portions of the insulating layer 4 are protected. On the other hand, the shock absorbing member 8 is not present in a position facing the inner region 17. Therefore, the cost of materials required for the shock absorbing member 8 can be reduced.

[0063] (7) Seventh embodiment Next, a seventh embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as in the above-described embodiments can be adopted.

[0064] 7 is a schematic cross-sectional view showing the all-solid-state battery 1 according to this embodiment. In this embodiment, the size of the impact absorbing member 8 is designed. Specifically, the outer end of the impact absorbing member 8 is located outside the outer end of the insulating layer 4 when viewed along the stacking direction.

[0065] Such a configuration can more reliably absorb the impact caused when the insulating layer 4 and the second current collector foil 7 come into contact with each other. Furthermore, if the impact absorbing member 8 is insulating, it can more reliably prevent short circuits.

[0066] Furthermore, in the all-solid-state battery 1, lithium dendrites may occur during charging and discharging. If lithium dendrites precipitate so as to wrap around the end of the solid electrolyte layer 5, the electrode layers will be short-circuited. However, according to this embodiment, the outer end of the shock absorbing member 8 is located outside the outer end of the insulating layer 4, so that wrapping around of lithium dendrites is prevented.

[0067] (8) Eighth embodiment Next, an eighth embodiment will be described. Note that detailed description will be omitted for those points in which the same configuration as in the above-described embodiments can be adopted.

[0068] 8 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment. In this embodiment, a frame material 18 is provided on the second current collector foil 7. The frame material 18 is disposed at a position facing the insulating layer 4. The frame material 18 is disposed so as to surround the second electrode layer 6. The impact absorbing member 8 is disposed on the frame material 18.

[0069] By providing the frame material 18, a short circuit between the first electrode layer 3 and the second electrode layer 6 is prevented. As described above, the second electrode layer 6 may expand in the planar direction due to the confining pressure. If the frame material 18 were not provided, when the second electrode layer 6 expands in the planar direction, there is a possibility that the first electrode layer 3 and the second electrode layer 6 may be short-circuited at the end portions. In contrast, according to the present embodiment, since the frame material 18 is provided, a short circuit is prevented even if the second electrode layer 6 expands.

[0070] A relatively hard material is often used as the above-mentioned frame material 18. For example, a ceramic material is used as the frame material 18.

[0071] However, if the frame material 18 comes into direct contact with the insulating layer 4, there is a possibility that the insulating layer 4 may crack due to the impact. In contrast, according to the present embodiment, since the impact absorbing member 8 is provided on the frame material 18, the impact caused by the contact between the frame material 18 and the insulating layer 4 is absorbed.

[0072] The present invention has been described above with reference to the first to eighth embodiments. Note that these embodiments are not independent of each other, and can be used in combination as long as there is no contradiction.

[0073] The main embodiments of the present invention and their effects are summarized below as supplementary notes.

[0074] (Appendix 1) An all-solid-state battery comprising: a first current collecting foil 2, a first electrode layer 3 arranged on the first current collecting foil, an insulating layer 4 arranged on the first current collecting foil and arranged outside the first electrode layer in a surface direction, a solid electrolyte layer 5 arranged on the first electrode layer, a second electrode layer 6 arranged on the solid electrolyte layer, a second current collecting foil 7 arranged on the second electrode layer, and a shock absorbing member 8 that absorbs shock applied to the insulating layer, wherein the shock absorbing member is arranged at a position facing the insulating layer in the stacking direction and is supported by the second current collecting foil 7.

[0075] According to such a configuration, the shock absorbing member 8 absorbs the shock applied to the insulating layer 4. Therefore, damage to the insulating layer 4 can be prevented.

[0076] (Appendix 2) 2. The all-solid-state battery according to claim 1, wherein the shock-absorbing member is spaced from the insulating layer.

[0077] With such a configuration, the electrode layer is allowed to expand and contract during charging and discharging.

[0078] (Appendix 3) 3. The all-solid-state battery according to claim 1 or 2, wherein the insulating layer is formed of the same material as the solid electrolyte layer or is formed of a material having lower electronic conductivity than the solid electrolyte layer.

[0079] According to such a configuration, a short circuit between the first electrode layer 3 and the second electrode layer 6 is more reliably prevented.

[0080] (Appendix 4) 4. The all-solid-state battery according to any one of claims 1 to 3, wherein the insulating layer and the solid electrolyte layer are integrally formed.

[0081] With this configuration, costs can be reduced.

[0082] (Appendix 5) 5. The all-solid-state battery according to any one of Appendices 1 to 4, wherein, when viewed along the stacking direction, the first current collector foil 2 and the second current collector foil 7 have a tab side 12 that is a side to which the tab 9 is connected, and the shock absorbing member 8 is disposed between the tab side 12 and the first electrode layer 3, when viewed along the stacking direction.

[0083] According to such a configuration, the impact is absorbed in the vicinity of the tab 9 where the impact is likely to be applied to the insulating layer 4, so that the insulating layer 4 is effectively protected.

[0084] (Appendix 6) 6. The all-solid-state battery according to any one of claims 1 to 5, wherein the impact absorbing member is arranged in a frame shape so as to surround the entire periphery of the first electrode layer when viewed along the stacking direction.

[0085] According to such a configuration, the variation in thickness due to the presence of the shock absorbing member is suppressed, and distortion of the all-solid-state battery is prevented.

[0086] (Appendix 7) An all-solid-state battery according to any one of Appendices 1 to 6, wherein a surface of the shock absorbing member facing the insulating layer is defined as a shock absorbing member facing surface 14, a surface of the insulating layer facing the shock absorbing member is defined as an insulating layer facing surface 15, the shock absorbing member facing surface 14 and the insulating layer facing surface 15 are non-planar, and the shock absorbing member facing surface 14 has a shape corresponding to the insulating layer facing surface 15.

[0087] According to this configuration, even if the insulating layer has a varying thickness, the variation in thickness is absorbed by the shock absorbing member, and as a result, the variation in thickness of the all-solid-state battery can be suppressed.

[0088] (Appendix 8) 8. The all-solid-state battery according to any one of appendices 1 to 7, wherein the insulating layer has an end region 16 including an outer end in a surface direction and an inner region 17 which is a region on the inside of the end region, and the impact absorbing member is disposed at a position facing the end region and is not disposed at a position facing the inner region.

[0089] According to this configuration, the end regions, which are prone to cracking, of the insulating layer are protected by the shock absorbing material, while the shock absorbing material is omitted in the position corresponding to the inner region, thereby reducing the cost spent on the shock absorbing material.

[0090] (Appendix 9) 9. The all-solid-state battery according to any one of claims 1 to 8, wherein an outer end of the impact absorbing member is located outer than an outer end of the insulating layer when viewed along the stacking direction.

[0091] With this configuration, the impact applied to the insulating layer 4 is absorbed more reliably.

[0092] (Appendix 10) The all-solid-state battery according to any one of Appendices 1 to 9, further comprising a frame material 18 disposed on the second current collector foil, the frame material being disposed in a position facing the insulating layer, and the impact absorbing member being disposed on the frame material.

[0093] According to such a configuration, the frame material can suppress the second electrode layer 6 from spreading in the planar direction, thereby preventing a short circuit. Meanwhile, the impact when the frame material comes into contact with the insulating layer is absorbed by the impact absorbing member, so that cracks in the insulating layer 4 can be prevented.

[0094] (Appendix 11) 11. The all-solid-state battery according to any one of claims 1 to 10, wherein the shock-absorbing member is configured to adsorb or absorb fragments of the insulating layer.

[0095] With this configuration, even if the insulating layer 4 is damaged, the fragments are prevented from scattering, and therefore the fragments of the insulating layer are prevented from entering the electrode layer. [Explanation of symbols]

[0096] Reference Signs List 1 all-solid-state battery, 2 first current collecting foil, 3 first electrode layer, 4 insulating layer, 5 solid electrolyte layer, 6 second electrode layer, 7 second current collecting foil, 8 shock absorbing member, 9 tab, 10 lead, 11 unit, 12 tab side, 14 shock absorbing member facing surface, 15 insulating layer facing surface, 16 end region, 17 inner region, 18 frame material

Claims

1. A first current collecting foil; a first electrode layer disposed on the first current collecting foil; an insulating layer disposed on the first current collecting foil and disposed outside the first electrode layer in a surface direction; a solid electrolyte layer disposed on the first electrode layer; a second electrode layer disposed on the solid electrolyte layer; a second current collecting foil disposed on the second electrode layer; a shock absorbing member that absorbs a shock applied to the insulating layer; Equipped with the impact absorbing member is disposed at a position facing the insulating layer in the stacking direction and is supported by the second current collecting foil. All-solid-state battery.

2. The all-solid-state battery according to claim 1 , The shock absorbing member is spaced from the insulating layer. All-solid-state battery.

3. The all-solid-state battery according to claim 1 or 2, The insulating layer is formed of the same material as the solid electrolyte layer or is formed of a material having lower electronic conductivity than the solid electrolyte layer. All-solid-state battery.

4. The all-solid-state battery according to claim 1 or 2, The insulating layer and the solid electrolyte layer are integrally formed. All-solid-state battery.

5. The all-solid-state battery according to claim 1 or 2, When viewed along the lamination direction, the first current collecting foil and the second current collecting foil have a tab side which is a side to which a tab is connected, The impact absorbing member is disposed between the tab side and the first electrode layer when viewed along the stacking direction. All-solid-state battery.

6. The all-solid-state battery according to claim 1 or 2, The impact absorbing member is disposed in a frame shape so as to surround the entire periphery of the first electrode layer when viewed along the stacking direction. All-solid-state battery.

7. The all-solid-state battery according to claim 1 or 2, A surface of the impact absorbing member facing the insulating layer is defined as an impact absorbing member facing surface, A surface of the insulating layer facing the impact absorbing member is defined as an insulating layer facing surface, the impact absorbing member facing surface and the insulating layer facing surface are non-flat, The impact absorbing member facing surface has a shape corresponding to the insulating layer facing surface. All-solid-state battery.

8. The all-solid-state battery according to claim 1 or 2, the insulating layer has an end region including an outer end in a surface direction and an inner region that is a region on the inner side of the end region, The shock absorbing member is disposed at a position facing the end region and is not disposed at a position facing the inner region. All-solid-state battery.

9. The all-solid-state battery according to claim 1 or 2, When viewed along the stacking direction, an outer end of the impact absorbing member is located outside an outer end of the insulating layer. All-solid-state battery.

10. The all-solid-state battery according to claim 1 or 2, Furthermore, a frame material disposed on the second current collecting foil; Equipped with The frame material is disposed in a position facing the insulating layer, The shock absorbing member is disposed on the frame material. All-solid-state battery.

11. The all-solid-state battery according to claim 1 or 2, The shock absorbing member is configured to adsorb or absorb fragments of the insulating layer. All-solid-state battery.

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