All solid state battery cell

Abstract

The purpose of the present invention is to provide an all solid state battery cell in which lithium does not leak to the outside even if the lithium has melted.　An all solid state battery cell according to the present invention comprises an electrode laminate, an exterior body that accommodates the electrode laminate, and a pair of insulating shape maintenance materials that maintain the shape of the exterior body such that a space between the exterior body and the electrode laminate is secured even when the area inside of the exterior body is in a depressurized state, wherein: each of the pair of shape maintenance materials has a flat plate-shaped flat plate part and a side surface part which is bonded to an end of the flat plate part; the flat plate part is located at the outermost part of the electrode laminate in the lamination direction; the outer shape of the flat plate part, when viewed along the lamination direction, is larger than the outer shape of the electrode laminate; and the tip end surface of the side surface part of one of the shape maintenance materials faces the tip end surface of the side surface part of the other of the shape maintenance materials.

Description

All-solid-state battery cells

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

[0002] All-solid-state batteries having a configuration in which an electrode stack is housed in an outer casing are known. Patent Document 1 (JP2017-117696A) describes an invention relating to a manufacturing method of such an all-solid-state battery. Patent Document 1 describes a manufacturing method of an all-solid-state battery that can improve volumetric energy density while suppressing the occurrence of wrinkles in the outer casing at a portion in contact with the stacking direction surface of the stack. This document describes a manufacturing method including a step of placing the stack inside the outer casing, a step of sealing the peripheral portion of the stack placed inside the outer casing in a reduced pressure atmosphere, a step of pressing the outer casing against the stacking direction surface using a pressure member while maintaining the reduced pressure atmosphere after the sealing step, and a step of changing the atmosphere from the reduced pressure atmosphere to an atmospheric pressure atmosphere while maintaining the pressure applied by the pressure member.

[0003] In the all-solid-state battery described in Patent Document 1, the laminate disposed within the exterior body is sealed in a reduced pressure atmosphere, so that the exterior body is in close contact with the laminate body, i.e., substantially no space is formed between the exterior body and the laminate body.

[0004] Incidentally, a battery using metallic lithium as a negative electrode active material is known as an all-solid-state battery. In such an all-solid-state battery, for example, in the event of a malfunction (such as a short circuit), the temperature may become high enough to melt the metallic lithium. As a result, the molten lithium may leak out. As described in Patent Document 1, if there is no space between the exterior body and the laminate, the molten lithium may leak out.

[0005] Even if the lithium melts, it is desirable that the molten lithium does not leak to the outside. Therefore, an object of the present invention is to provide an all-solid-state battery cell that does not leak lithium to the outside even if the lithium melts.

[0006] The all-solid-state battery cell according to the present invention includes an electrode laminate, an exterior body, and a pair of shape-retaining materials. The electrode laminate includes a positive electrode, a solid electrolyte layer, and a negative electrode, and is configured to use metallic lithium as the negative electrode active material. The exterior body is flexible and houses the electrode laminate. The pair of shape-retaining materials are provided within the exterior body so as to be located at both ends of the electrode laminate in the stacking direction. The pair of shape-retaining materials retain the shape of the exterior body so that a space is secured between the exterior body and the electrode laminate even when the internal region of the exterior body is depressurized. Each of the pair of shape-retaining materials has a flat plate portion and a side portion joined to an end of the flat plate portion. The flat plate portion is located at an end of the electrode laminate in the stacking direction. When viewed along the stacking direction, the outer shape of the flat plate portion is larger than the outer shape of the electrode laminate. An end surface of the side surface portion of one shape-retaining material faces an end surface of the other shape-retaining material.

[0007] Fig. 1 is a schematic cross-sectional view showing an all-solid-state battery module according to a first embodiment. Fig. 2 is a cross-sectional view and a top view showing a schematic configuration of a battery cell. Fig. 3 is a cross-sectional view showing a schematic configuration of a battery cell when metallic lithium is melted. Fig. 4 is a cross-sectional view showing a battery cell according to a second embodiment. Fig. 5 is a cross-sectional view showing a battery cell according to a third embodiment. Fig. 6 is a cross-sectional view and a top view showing a battery cell according to a fourth embodiment.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] First Embodiment Fig. 1 is a schematic cross-sectional view showing an all-solid-state battery module 9 using an all-solid-state battery cell 1 (hereinafter, sometimes simply referred to as battery cell 1) according to this embodiment. As shown in Fig. 1, the all-solid-state battery module 9 has a plurality of battery cells 1 and a pair of end plates 8. The plurality of battery cells 1 are stacked. The pair of end plates 8 are arranged to sandwich the stacked plurality of battery cells 1 in the stacking direction. The pair of end plates 8 are compressed by a compression mechanism (not shown). As a result, a compressive load is applied to the plurality of battery cells 1.

[0010] In this embodiment, the configuration of each battery cell 1 is devised. The configuration of the battery cell 1 will be described below.

[0011] Fig. 2 is a cross-sectional view (a) and a top view (b) that schematically show the configuration of the battery cell 1. Fig. 3 is a cross-sectional view that schematically shows the configuration of the battery cell 1 when lithium has melted.

[0012] As shown in FIG. 2 , the battery cell 1 includes an electrode stack 2, an exterior body 3, a pair of shape-retaining materials (4a and 4b), and current collecting tabs (6-1 and 6-2). The electrode stack 2 is disposed within the exterior body 3. The electrode stack 2 is configured to use metallic lithium as the negative electrode active material. The pair of shape-retaining materials (4a and 4b) are also disposed within the exterior body 3. The pair of shape-retaining materials (4a and 4b) maintain the shape of the exterior body 3 so that the exterior body 3 does not come into close contact with the electrode stack 2 even if the internal region of the exterior body 3 is depressurized. In other words, a space is secured between the exterior body 3 and the electrode stack 2. Specifically, a space is secured on both sides of the electrode stack 2 in the direction connecting the current collecting tabs 6-1 and 6-2.

[0013] With the above-described configuration, even if the metallic lithium contained in the electrode stack 2 melts, the molten lithium is contained in the space between the exterior body 3 and the electrode stack 2 (see FIG. 3 ). Therefore, the molten lithium is prevented from leaking out of the exterior body 3.

[0014] Each part of the battery cell 1 will be described in detail below.

[0015] The electrode stack 2 has a structure in which a plurality of units are stacked. Each unit has a positive electrode, a solid electrolyte layer, and a negative electrode. The solid electrolyte layer is sandwiched between the positive electrode and the negative electrode. As described above, the electrode stack 2 is configured to use metallic lithium as the negative electrode active material. In such an electrode stack 2, as described above, if the temperature becomes extremely high, lithium may melt and leak from the electrode stack 2.

[0016] The "electrode laminate" in the present invention also includes an electrode laminate configured such that no negative electrode is present during discharge and a negative electrode is generated during charge. That is, the electrode laminate 2 may be configured such that no lithium is present on the negative electrode side during discharge and that lithium migrates from the positive electrode side to the negative electrode side and deposits thereon during charge, thereby forming a negative electrode.

[0017] In the electrode stack 2, a current collector (5-1 or 5-2) is sandwiched between adjacent units. One of the current collectors 5-1 and 5-2 is a positive electrode current collector, and the other is a negative electrode current collector. A plurality of current collectors (5-1 and 5-2) are provided. The current collectors (5-1 and 5-2) protrude from the side surfaces of the electrode stack 2, and are joined at their ends and connected to current collecting tabs (6-1 and 6-2).

[0018] The current collecting tabs 6-1 and 6-2 are provided to electrically connect the electrode stack 2 to the outside. One end of each current collecting tab (6-1 and 6-2) is disposed inside the exterior body 3, and the other end is disposed outside the exterior body 3.

[0019] The exterior body 3 is provided for the purpose of protecting the electrode stack 2. The exterior body 3 is flexible and houses the electrode stack 2. Specifically, the exterior body 3 is composed of a pair of sheets. The pair of sheets are arranged on the upper and lower sides of the electrode stack 2 and are bonded at seal portions 7 on the sides of the electrode stack 2. Note that the exterior body 3 partially sandwiches the current collecting tabs 6-1 and 6-2. In the portions where the current collecting tabs 6-1 and 6-2 are provided, the exterior body 3 is sealed to the current collecting tabs 6-1 and 6-2.

[0020] The material of the exterior body 3 is not particularly limited, but for example, an aluminum film or the like can be used.

[0021] As described above, the pair of shape-retaining members (4a and 4b) are provided to ensure a space between the exterior body 3 and the electrode stack 2 even when the internal region of the exterior body 3 is depressurized. The pair of shape-retaining members (4a and 4b) are provided so as to be located at both outermost portions (top and bottom) of the electrode stack 2 in the stacking direction.

[0022] Specifically, each of the pair of shape-retaining members (4a and 4b) has a flat plate portion (4a-1, 4b-1) and a side surface portion (4a-2, 4b-2).

[0023] Each flat plate portion (4a-1, 4b-1) has a flat plate shape. The flat plate portions (4a-1 and 4b-1) are disposed on the upper and lower surfaces of the electrode stack 2. When viewed along the stacking direction, the outer shape of each flat plate portion (4a-1, 4b-1) is larger than the outer shape of the electrode stack 2. Note that the outer shape of the electrode stack 2 here refers to the outer shape of the portion (active area) where the positive electrode, solid electrolyte layer, and negative electrode overlap.

[0024] Specifically, each flat plate portion (4a-1, 4b-1) has a generally rectangular shape and is larger in its longitudinal direction (the direction connecting the current collecting tab 6-1 and the current collecting tab 6-2) than the electrode stack 2. Note that in the lateral direction, the outer shape of each flat plate portion (4a-1, 4b-1) may be larger than or the same as the electrode stack 2.

[0025] Each side surface portion (4a-2, 4b-2) is connected to an end of each flat plate portion (4a-1, 4b-1) and extends upright from the corresponding flat plate portion (4a-1, 4b-1). The side surface portion 4a-2 and the side surface portion 4b-2 are arranged so that their tip surfaces face each other. In other words, the tip surface of the side surface portion 4a-2 and the tip surface of the side surface portion 4b-2 overlap in the stacking direction.

[0026] Each shape-retaining member (4a and 4b) is made of an insulating material. Each shape-retaining member (4a and 4b) is made of a material strong enough to withstand pressure reduction inside the exterior body 3. Each shape-retaining member (4a and 4b) is also made of a heat-resistant material that will not be damaged even if the temperature rises to a level high enough to melt metallic lithium. Examples of such materials include heat-resistant resins.

[0027] As described above, in this embodiment, the pair of shape-retaining members (4 a and 4 b) ensures a space on the side of the electrode stack 2. As a result, even if the metallic lithium melts, the molten lithium is contained in the space. Therefore, the molten lithium is less likely to leak to the outside of the exterior body 3.

[0028] Next, an example of a method for manufacturing a battery cell 1 according to this embodiment will be described. When manufacturing the battery cell 1 described above, first, an electrode laminate 2 is fabricated, and current collectors (5-1 and 5-2) are connected to current collecting tabs (6-1 and 6-2). Next, a pair of shape-retaining bodies (4a and 4b) are arranged above and below the electrode laminate 2. Furthermore, a pair of sheets for forming the exterior body 3 are arranged to cover the pair of shape-retaining bodies (4a and 4b). Next, while reducing the pressure inside the pair of sheets, the pair of sheets are pressurized and sealed at the seal portion 7. This results in a battery cell 1. Here, during the reduction in pressure, the sheets for forming the exterior body 3 are drawn inward. This eliminates excess space, allowing the size of the battery cell 1 to be reduced. Meanwhile, the pair of shape-retaining bodies (4a and 4b) ensures space on the sides of the electrode laminate 2.

[0029] In this embodiment, a space is formed on the side of the electrode laminate 2. Preferably, the space is formed on the side of the electrode laminate 2 where the current collecting tabs 6-1 and 6-2 are provided. Here, the volumetric energy density of the battery cell 1 is reduced by the amount of this space. However, as shown in FIG. 1 , an all-solid-state battery is usually provided as an all-solid-state battery module 9 in which a plurality of battery cells 1 are stacked. In the all-solid-state battery module 9, a current collecting tab or the like is usually disposed in the region on the side of each battery cell 1, resulting in dead space. Therefore, even if a space is formed on the side of the battery cell 1 (particularly on the current collecting tab side), the volumetric energy density of the all-solid-state battery module 9 does not substantially change. In other words, there is no disadvantage due to the formation of excess space.

[0030] Incidentally, in order to efficiently promote the battery reaction in an all-solid-state battery, a load must be applied to the electrode stack 2. Therefore, preferably, the lengths of the side portions (4a-2 and 4b-2) are designed so that pressure (load) is applied to the electrode stack 2. Specifically, the sum of the lengths (a1 and a2 in FIG. 2 ) of the side portions (4a-2 and 4b-2) along the stacking direction is set to be equal to or less than the thickness of the electrode stack 2 when the SOC (State of Charge) is 0%. "SOC" is a parameter that represents the state of charge of the electrode stack 2. A 0% SOC state means a fully discharged state. An electrode stack 2 using metallic lithium as the negative electrode active material expands during charging and contracts during discharging. That is, the thickness of the electrode stack 2 is smallest in a fully discharged state. Because the total length (a1 + a2) of the side portions (4a-2 and 4b-2) is set to be equal to or less than the thickness of the electrode stack 2 when the SOC is 0%, a gap is formed between one side portion 4a-2 and the other side portion 4b-2 except during full discharge (see FIG. 2). Therefore, one shape-retaining material 4a and the other shape-retaining material 4b do not interfere with each other. Pressure applied to the battery cell 1 is applied to the electrode stack 2 via each shape-retaining material (4a and 4b). Because the shape-retaining materials (4a and 4b) do not prevent pressure from being applied, the battery reaction is not hindered.

[0031] More preferably, the sum (a1 + a2) of the lengths of the side portions (4a-2 and 4b-2) is set to be equal to the thickness of the electrode stack 2 when the SOC is 0%. Note that "same" here includes the concept of "approximately same." By adopting such a configuration, it is possible to more reliably prevent molten lithium from leaking out of the exterior case 3. That is, when lithium melts and leaks from the electrode stack 2, the thickness of the electrode stack 2 decreases. If the sum (a1 + a2) of the lengths of the side portions (4a-2 and 4b-2) is equal to the thickness of the electrode stack 2 when the SOC is 0%, the gap between the side portions (4a-2) and (4b-2) is closed when the thickness of the electrode stack 2 decreases due to melted lithium (see FIG. 3 ). As a result, it becomes difficult for molten lithium to reach the seal portion 7, which is prone to leakage, and lithium leakage can be more reliably prevented.

[0032] Preferably, the size of the surplus space formed inside the exterior body 3 is larger than the volume of the metallic lithium present in the fully charged state when it melts. By adopting such a configuration, even if all of the metallic lithium melts, all of the molten lithium is accommodated in the space inside the exterior body 3. Note that the volume V of the molten metallic lithium Ｌｉ (cm ３ ) can be calculated by the following formula:

[0033] In the above formula, Q is the cell capacity (Ah), r is the A / C ratio, and F is Faraday's constant, 9.65 x 10 ４ [C / mol]. M is the molar mass of lithium, 6.94 [g / mol]. d1 is the density of molten lithium, 0.512 [g / cm ３ ]

[0034] The first embodiment has been described above. Representative configurations and effects of this embodiment will now be summarized.

[0035] The battery cell 1 according to this embodiment includes an electrode stack 2, an exterior body 3, and a pair of insulating shape-retaining materials (4a and 4b). The electrode stack includes a positive electrode, a solid electrolyte layer, and a negative electrode, and is configured to use metallic lithium as the negative electrode active material. The exterior body 3 is flexible and houses the electrode stack 2. The pair of shape-retaining materials (4a and 4b) are disposed within the exterior body 3 so as to be positioned at both outermost portions of the electrode stack 2 in the stacking direction. The pair of shape-retaining materials (4a and 4b) maintain the shape of the exterior body 3 so that a space is maintained between the exterior body 3 and the electrode stack 2 even when the internal region of the exterior body 3 is depressurized. Each of the pair of shape-retaining materials (4a and 4b) includes a flat plate portion (4a-1, 4b-1) and a side portion (4a-2, 4b-2) joined to the end of the flat plate portion (4a-1, 4b-1). The flat plate portions (4a-1, 4b-1) are located at the outermost positions of the electrode stack 2 in the stacking direction. When viewed along the stacking direction, the outer shapes of the flat plate portions (4a-1, 4b-1) are larger than the outer shape of the electrode stack 2. The tip surface of the side surface portion (4a-2) of one shape-retaining member 4a faces the tip surface of the other shape-retaining member 4b. With this configuration, a space is formed between the exterior body 3 and the electrode stack 2. Therefore, even if the metallic lithium melts, the lithium is accommodated in this space and does not leak out of the exterior body 3.

[0036] In a preferred embodiment, the total length along the stacking direction of the side portions (4a-2, 4b-2) of the pair of shape-retaining materials (4a and 4b) is equal to or less than the thickness of the electrode stack 2 when the SOC is 0%. By adopting such a configuration, the pair of shape-retaining materials (4a and 4b) do not interfere with each other. The pressure for pressing the battery cell 1 is not impeded by the pair of shape-retaining materials (4a and 4b) and is also applied to the electrode stack 2. Therefore, the progress of the battery reaction is not impeded.

[0037] In a preferred embodiment, the total length of the side portions (4a-2, 4b-2) of the pair of shape-retaining members (4a and 4b) along the stacking direction is equal to the thickness of the electrode stack 2 when the SOC is 0%. By adopting such a configuration, when molten metallic lithium leaks from the electrode stack 2, the gap between the side portions (4a-2 and 4b-2) is closed. Therefore, the molten metallic lithium is less likely to leak outside the exterior body 3.

[0038] In a preferred embodiment, an excess space larger than the volume of the metallic lithium present in a fully charged state when it is melted is formed inside the exterior case 3. By adopting such a configuration, even if all of the metallic lithium contained in the electrode stack 2 melts, all of the molten lithium can be accommodated in the excess space. Therefore, it is possible to more reliably prevent the molten metallic lithium from leaking outside the exterior case 3.

[0039] Second Embodiment Next, a second embodiment will be described. In the following description, detailed description of the same configuration as the first embodiment will be omitted.

[0040] Fig. 4 is a schematic cross-sectional view showing a battery cell 1 according to a second embodiment. In this embodiment, the exterior body 3 and each flat plate portion (4a-1 and 4b-1) are bonded together. In Fig. 4, the bonded portions are shown as bonded portions (10a-1 and 10b-1). With this configuration, even when pressure is applied to the battery cell 1, the exterior body 3 and the flat plate portions (4a-1 and 4b-1) do not slip. This makes it less likely for wrinkles to form in the exterior body 3.

[0041] Each of the flat plate portions (4a-1 and 4b-1) may be bonded to the exterior body 3 over the entire surface thereof, or only part thereof.

[0042] In a preferred embodiment, the exterior body 3 is bonded to each of the flat plate portions (4a-1 and 4b-1), but is not bonded to each of the side surface portions (4a-2 and 4b-2). With this configuration, when the electrode stack 2 contracts, the exterior body 3 can bend outward on the sides of the electrode stack 2. This makes it easier for the exterior body 3 to follow the expansion and contraction of the electrode stack 2.

[0043] 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 previously described embodiments can be adopted.

[0044] 5 is a schematic cross-sectional view showing a battery cell 1 according to a third embodiment. In this embodiment, a gap is provided between the side surface portion 4 a-2 and the side surface portion 4 b-2 (the gap may be closed during full discharge). That is, the total length of the side surface portions (4 a-2 and 4 b-2) along the stacking direction is equal to or less than the thickness of the electrode stack 2 when the SOC is 0%.

[0045] The exterior body 3 is adhered to the tip surfaces of the side portions (4a-2 and 4b-2). In FIG. 5, this adhered portion is shown as an adhered portion 12.

[0046] As a result of the exterior body 3 being adhered to the tip end surfaces of the side portions (4a-2, 4b-2), the exterior body 3 has a shape that is recessed inward between the side portions (4a-2, 4b-2) and the seal portion 7. In other words, the exterior body 3 is adhered to the pair of shape-retaining members (4a and 4b) so as to wrap around the side portions (4a-2, 4b-2).

[0047] According to this embodiment, the exterior body 3 can flex between the side surface portion 4 a-2 and the side surface portion 4 b-2. This allows the exterior body 3 to easily follow the expansion and contraction of the electrode stack 2. Here, when the electrode stack 2 contracts, the exterior body 3 flexes inward rather than outward. Therefore, when contracting, the area of ​​the battery cell 1 does not increase when viewed along the stacking direction. This is therefore preferable from the standpoint of space saving.

[0048] In this embodiment, the exterior body 3 may or may not be bonded to the flat plate portions (4a-1 and 4b-1). In a preferred embodiment, the exterior body 3 is bonded to the flat plate portions (4a-1 and 4b-1).

[0049] The exterior body 3 may or may not be bonded to the outer surfaces of the side surface portions (4a-2 and 4b-2). In a preferred embodiment, the exterior body 3 is not bonded to the outer surfaces of the side surface portions (4a-2 and 4b-2).

[0050] Fourth Embodiment Next, a fourth embodiment will be described. Note that detailed description will be omitted for the fact that the same configuration as in the previously described embodiments can be adopted.

[0051] 6A is a cross-sectional view of a battery cell 1 according to a fourth embodiment, and FIG. 6B is a top view showing the shape of the flat plate portion 4a-1. In this embodiment, an opening 11 is provided in each flat plate portion (4a-1 and 4b-1).

[0052] According to this embodiment, the weight of each shape-retaining member (4a and 4b) can be reduced by providing the openings 11. This allows the weight energy density of the battery cell 1 to be improved.

[0053] The position of the opening 11 is not particularly limited. However, preferably, the opening 11 has an outer shape larger than the outer shape of the electrode stack 2 when viewed along the stacking direction. In other words, the outer shape of the opening 11 is located outside the outer shape of the electrode stack 2 when viewed along the stacking direction.

[0054] As described above, because the outer shape of the opening 11 is larger than that of the electrode stack 2, the shape-retaining materials (4a and 4b) do not interfere with the electrode stack 2. The upper and lower surfaces of the electrode stack 2 are in direct contact with the exterior body 3. The positions of the outer surfaces of the shape-retaining materials (4a and 4b) in the thickness direction are aligned with the positions of the upper and lower surfaces of the electrode stack 2. Therefore, despite the provision of a pair of shape-retaining materials (4a and 4b), the thickness of the battery cell 1 in the stacking direction does not increase. Therefore, the volumetric energy density is not impaired.

[0055] If the outer shape of the opening 11 is larger than that of the electrode stack 2, the pair of shape-retaining materials (4a and 4b) cannot be supported by the electrode stack 2. However, by adhering the flat plate portions (4a-1 and 4b-1) to the exterior body 3, the exterior body 3 can support the pair of shape-retaining materials (4a and 4b).

[0056] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0057] This application claims priority based on Japanese Patent Application No. 2022-100726, filed with the Japan Patent Office on June 22, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. An electrode laminate including a positive electrode, a solid electrolyte layer, and a negative electrode, wherein metallic lithium is used as a negative electrode active material; A flexible exterior body housing the electrode laminate; A current collecting tab having one end disposed inside the exterior body and the other end disposed outside the exterior body; A pair of insulating shape-retaining members provided so as to be positioned at both outermost portions of the electrode laminate in the stacking direction within the exterior body, and maintaining the shape of the exterior body so as to secure a space between the exterior body and the electrode laminate even when the interior region of the exterior body is depressurized; Each of the pair of shape-retaining members has: A flat plate portion in a flat plate shape; Side surface portions coupled to ends of the flat plate portion; The flat plate portion is positioned at the outermost portion of the electrode laminate in the stacking direction; When viewed along the stacking direction, the outer shape of the flat plate portion is larger than the outer shape of the electrode laminate; The tip surfaces of the side surface portions of one of the shape-retaining members face the tip surfaces of the side surface portions of the other shape-retaining member and are spaced apart from the current collecting tab; An all-solid-state battery cell.

2. The all-solid-state battery cell according to Claim 1, wherein an opening is provided in the flat plate portion. An all-solid-state battery cell.

3. The all-solid-state battery cell according to Claim 2, wherein when viewed along the stacking direction, the outer shape of the opening is positioned outside the outer shape of the electrode laminate. An all-solid-state battery cell.

4. The all-solid-state battery cell according to Claim 1 or 2, wherein the exterior body is adhered to the flat plate portion. An all-solid-state battery cell.

5. The all-solid-state battery cell according to Claim 4, wherein the exterior body is not adhered to the side surface portion. An all-solid-state battery cell.

6. An electrode laminate including a positive electrode, a solid electrolyte layer, and a negative electrode, wherein metallic lithium is used as a negative electrode active material; A flexible exterior body housing the electrode laminate; A pair of insulating shape-retaining members provided so as to be positioned at both outermost portions of the electrode laminate in the stacking direction within the exterior body, and maintaining the shape of the exterior body so as to secure a space between the exterior body and the electrode laminate even when the interior region of the exterior body is depressurized; Each of the pair of shape-retaining members has: A flat plate portion in a flat plate shape; Side surface portions coupled to ends of the flat plate portion; The flat plate portion is positioned at the outermost portion of the electrode laminate in the stacking direction; When viewed along the stacking direction, the outer shape of the flat plate portion is larger than the outer shape of the electrode laminate, The tip surfaces of the side portions of one of the shape retainers and the tip surfaces of the side portions of the other shape retainer face each other, The exterior body is adhered to the tip surface of the side portion, All-solid-state battery cell.

7. The all-solid-state battery cell according to claim 1 or 2, The sum of the lengths of the side portions of the pair of shape retainers along the stacking direction is equal to or less than the thickness of the electrode laminate when the state of charge (SOC) is 0%, All-solid-state battery cell.

8. The all-solid-state battery cell according to claim 1 or 2, The sum of the lengths of the side portions of the pair of shape retainers along the stacking direction is the same as the thickness of the electrode laminate when the state of charge (SOC) is 0%, All-solid-state battery cell.

9. An electrode laminate including a positive electrode, a solid electrolyte layer, and a negative electrode, with metallic lithium used as a negative electrode active material, A flexible exterior body that houses the electrode laminate, A pair of insulating shape retainers provided at both outermost portions of the electrode laminate in the stacking direction within the exterior body, and configured to maintain the shape of the exterior body so that a space is ensured between the exterior body and the electrode laminate even when the internal region of the exterior body is depressurized, The pair of shape retainers each have, A flat plate portion in the shape of a flat plate, A side portion joined to an end of the flat plate portion, The flat plate portion is located at the outermost portion of the electrode laminate in the stacking direction, When viewed along the stacking direction, the outer shape of the flat plate portion is larger than the outer shape of the electrode laminate, The tip surfaces of the side portions of one of the shape retainers and the tip surfaces of the side portions of the other shape retainer face each other, An excess space larger than the volume when the metallic lithium present in the fully charged state melts is formed inside the exterior body, All-solid-state battery cell.

10. The all-solid-state battery cell according to claim 1 or 2, A space exists between the side portion and the electrode laminate, All-solid-state battery cell.

11. The all-solid-state battery cell according to claim 1 or 2, Pressurized by a pressurizing mechanism, All-solid-state battery cell.