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

Technical Field

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

Background Art

[0002] An all-solid-state battery having a configuration in which an electrode laminate is housed in an exterior body is known. An invention regarding a manufacturing method of such an all-solid-state battery is described in Patent Document 1 (JP2017-117696A). Patent Document 1 describes a manufacturing method of an all-solid-state battery capable of improving the volume energy density while suppressing the generation of wrinkles on the exterior body in a portion contacting the surface in the lamination direction of the laminate. This document describes a step of disposing a laminate in an exterior body, a step of sealing the peripheral portion of the laminate disposed in the exterior body in a reduced-pressure atmosphere, a step of pressing the exterior body against the surface in the lamination direction of the laminate using a pressing member while maintaining the reduced-pressure atmosphere after the sealing step, and a releasing step of changing the atmosphere from the reduced-pressure atmosphere to the atmospheric pressure atmosphere while maintaining the pressing by the pressing member.

Summary of the Invention

[0003] In the all-solid-state battery described in Patent Document 1, since the laminate disposed in the exterior body is sealed in a reduced-pressure atmosphere, the exterior body adheres closely to the laminate. That is, substantially no space is formed between the exterior body and the laminate.

[0004] By the way, as an all-solid-state battery, a battery using metallic lithium as a negative electrode active material is known. In such an all-solid-state battery, for example, in the event of a failure (such as a short circuit), the temperature may rise to such an extent that metallic lithium melts. As a result, there is a possibility that the melted lithium may flow out. As described in Patent Document 1, when there is no space between the exterior body and the laminate, there is a possibility that the melted lithium may leak to the outside.

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

[0006] The all-solid-state battery cell according to the present invention comprises an electrode stack, an outer casing, and a pair of shape-retaining members. 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 outer casing is flexible and houses the electrode stack. The pair of shape-retaining members are provided inside the outer casing so as to be located at both ends of the electrode stack in the stacking direction. The pair of shape-retaining members maintain the shape of the outer casing so that a space is maintained between the outer casing and the electrode stack even when the internal region of the outer casing is depressurized. Each of the pair of shape-retaining members has a flat plate portion and a side portion connected to the end of the flat plate portion. The flat plate portion is located at the end of the electrode stack 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 stack. The tip surface of the side portion of one shape-retaining member and the tip surface of the other shape-retaining member face each other. [Brief explanation of the drawing]

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

[0008] Embodiments of the present invention will be described below with reference to the drawings.

[0009] (First Embodiment) Figure 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 Figure 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 pressurized to compress by a pressurizing 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 has been carefully designed. The configuration of the battery cell 1 will be described below.

[0011] Figure 2 shows a schematic cross-sectional view (a) and a top view (b) of the battery cell 1. Figure 3 is a schematic cross-sectional view showing the battery cell 1 when lithium is melted.

[0012] As shown in Figure 2, the battery cell 1 comprises an electrode stack 2, an outer casing 3, a pair of shape-retaining materials (4a and 4b), and current-collecting tabs (6-1 and 6-2). The electrode stack 2 is located inside the outer casing 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 located inside the outer casing 3. The pair of shape-retaining materials (4a and 4b) maintain the shape of the outer casing 3 so that it does not come into close contact with the electrode stack 2 even when the internal region of the outer casing 3 is depressurized. In other words, a space is maintained between the outer casing 3 and the electrode stack 2. Specifically, a space is maintained on both sides of the electrode stack 2 in the direction connecting 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 were to melt, the molten lithium would be contained in the space between the outer casing 3 and the electrode stack 2 (see Figure 3). Therefore, it is prevented that the molten lithium will leak out to the outside of the outer casing 3.

[0014] The following describes each part of battery cell 1 in detail.

[0015] The electrode stack 2 has a structure in which multiple 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 and negative electrodes. Furthermore, as previously described, the electrode stack 2 is configured to use metallic lithium as the negative electrode active material. In such an electrode stack 2, as previously described, if the temperature becomes extremely high, lithium may melt and leak out of the electrode stack 2.

[0016] Furthermore, the "electrode stack" in this invention also includes those configured such that there is no negative electrode during discharge, but a negative electrode is generated during charging. That is, the electrode stack 2 may be configured such that lithium is not present on the negative electrode side in the discharge state, and a negative electrode is formed when lithium moves from the positive electrode side to the negative electrode side and deposits during charging.

[0017] In the electrode stack 2, current collectors (5-1 or 5-2) are 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. Multiple current collectors (5-1 and 5-2) are provided. Each of the current collectors (5-1 and 5-2) protrudes from the side of the electrode stack 2, is joined together at its end, and is connected to current collector tabs (6-1 and 6-2).

[0018] Current collector tabs 6-1 and 6-2 are provided to electrically connect the electrode stack 2 to the outside. One end of each current collector tab (6-1 and 6-2) is located inside the outer casing 3, and the other end is located outside the outer casing 3.

[0019] The exterior body 3 is provided for the purpose of protecting the electrode laminate 2. The exterior body 3 has flexibility and houses the electrode laminate 2. Specifically, the exterior body 3 is composed of a pair of sheets. The pair of sheets are arranged on the upper side and the lower side of the electrode laminate 2 and are adhered at the seal portion 7 on the side of the electrode laminate 2. Note that the exterior body 3 sandwiches the current collecting tabs 6-1 and 6-2 at a part. At the portion 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, and 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 secure a space between the exterior body 3 and the electrode laminate 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 (uppermost and lowermost portions) of the electrode laminate 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) is flat. The flat plate portions (4a-1 and 4b-1) are arranged on the upper surface and the lower surface of the electrode laminate 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 laminate 2. Here, the outer shape of the electrode laminate 2 means the outer shape of the portion where the positive electrode, the solid electrolyte layer, and the negative electrode overlap (active area).

[0024] Specifically, each flat plate portion (4a-1, 4b-1) is generally rectangular in shape. Furthermore, in its longitudinal direction (the direction connecting current collection tabs 6-1 and 6-2), it is larger than the electrode stack 2. In the transverse 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 section (4a-2, 4b-2) is connected to the end of each flat section (4a-1, 4b-1) and extends upward from each flat section (4a-1, 4b-1). The side sections 4a-2 and 4b-2 are positioned so that their tip surfaces face each other. In other words, the tip surface of side section 4a-2 and the tip surface of side section 4b-2 overlap in the stacking direction.

[0026] Each shape-retaining material (4a and 4b) is made of an insulating material. Furthermore, each shape-retaining material (4a and 4b) is made of a material with sufficient strength to prevent deformation even when the internal region of the outer casing 3 is reduced in pressure. Additionally, each shape-retaining material (4a and 4b) is made of a heat-resistant material that will not be damaged even when exposed to temperatures high enough to melt metallic lithium. For example, a heat-resistant resin can be used as such a material.

[0027] As described above, in this embodiment, a space is secured on the side of the electrode stack 2 by a pair of shape-retaining materials (4a and 4b). As a result, even if metallic lithium melts, the molten lithium will be contained in this space. Therefore, it becomes difficult for the molten lithium to leak to the outside of the outer casing 3.

[0028] Next, an example of a method for manufacturing the battery cell 1 according to this embodiment will be described. When manufacturing the battery cell 1 described above, first, an electrode stack 2 is made and current collectors (5-1 and 5-2) are connected to current collector tabs (6-1 and 6-2). Next, a pair of shape retainers (4a and 4b) are placed above and below the electrode stack 2. Furthermore, a pair of sheets for forming the outer casing 3 are placed so as to cover the pair of shape retainers (4a and 4b). Next, the pair of sheets are pressurized while the area inside the pair of sheets is depressurized, and the pair of sheets are sealed at the seal portion 7. This gives rise to the battery cell 1. Here, when the pressure is reduced, the sheets for forming the outer casing 3 are drawn inward. Therefore, excess space can be eliminated, and the size of the battery cell 1 can be reduced. On the other hand, since a pair of shape retainers (4a and 4b) are provided, space is secured on the sides of the electrode stack 2.

[0029] In this embodiment, a space is formed on the side of the electrode stack 2. Preferably, the space is formed on the side of the electrode stack 2 where the current collector tabs 6-1 and 6-2 are provided. Here, the volumetric energy density of the battery cell 1 decreases by the amount of this space. However, as shown in Figure 1, all-solid-state batteries are usually provided as all-solid-state battery modules 9 in which multiple battery cells 1 are stacked. In the all-solid-state battery module 9, current collector tabs and the like are usually placed in the area 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 (especially on the current collector 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 for the battery reaction to proceed efficiently in an all-solid-state battery, a load must be applied to the electrode stack 2. Therefore, preferably, the length of the side portions (4a-2 and 4b-2) is designed so that pressure (load) is applied to the electrode stack 2. Specifically, the sum of the lengths of the side portions (4a-2 and 4b-2) along the stacking direction (a1 and a2 in Figure 2) is set to be less than or equal to the thickness of the electrode stack 2 when the SOC (State of Charge) is 0%. "SOC" is a parameter that represents the charge state of the electrode stack 2. An SOC of 0% means a completely discharged state. The electrode stack 2, which uses metallic lithium as the negative electrode active material, expands during charging and contracts during discharge. That is, the thickness of the electrode stack 2 is smallest in the completely discharged state. The total length of the side portions (4a-2 and 4b-2) (a1 + a2) is set to be less than or equal to the thickness of the electrode stack 2 when the SOC is 0%, so that a gap is formed between one side portion 4a-2 and the other side portion 4b-2, except during complete discharge (see Figure 2). Therefore, one shape-retaining material 4a and the other shape-retaining material 4b do not interfere with each other. The pressure applied to the battery cell 1 is applied to the electrode stack 2 via each shape-retaining material (4a and 4b). Since the application of pressure is not hindered by each shape-retaining material (4a and 4b), the battery reaction is also not hindered.

[0031] More preferably, the sum of the lengths of the side portions (4a-2 and 4b-2) (a1 + a2) is set to be the same as the thickness of the electrode stack 2 when the SOC is 0%. Here, "same" includes the concept of being approximately the same. By adopting such a configuration, it is possible to more reliably prevent molten lithium from leaking out of the outer casing 3. That is, when lithium melts and leaks from the electrode stack 2, the thickness of the electrode stack 2 decreases. If the sum of the lengths of the side portions (4a-2 and 4b-2) (a1 + a2) is equal to the thickness of the electrode stack 2 when the SOC is 0%, then when the thickness of the electrode stack 2 decreases due to the melting of lithium, the gap between the side portions (4a-2) and (4b-2) is closed (see Figure 3). As a result, it becomes more 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 excess space formed inside the outer casing 3 is larger than the volume of the molten metallic lithium present in the fully charged state. By adopting such a configuration, even if all the metallic lithium melts, all of the molten lithium will be contained in the space inside the outer casing 3. Note that the volume V of the molten metallic lithium is Li (cm 3 ) can be calculated using the following formula.

number

[0033] In the above equation, Q is the cell capacity (Ah), r is the A / C ratio, and F is the Faraday constant, which is 9.65 × 10⁻⁶. 4 The value is [C / mol]. M is the molar mass of lithium, which is 6.94 [g / mol]. d1 is the density of molten lithium, which is 0.512 [g / cm³]. 3 ]

[0034] The first embodiment has been described above. Below, we will summarize some representative configurations and effects of this embodiment.

[0035] The battery cell 1 according to this embodiment comprises an electrode stack 2, an outer casing 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 outer casing 3 is flexible and houses the electrode stack 2. The pair of shape-retaining materials (4a and 4b) are provided within the outer casing 3 so as to be located on both outermost surfaces of the electrode stack 2 in the stacking direction. The pair of shape-retaining materials (4a and 4b) also maintain the shape of the outer casing 3 so that a space is maintained between the outer casing 3 and the electrode stack 2 even when the internal region of the outer casing 3 is depressurized. Each of the pair of shape-retaining materials (4a and 4b) has a flat plate portion (4a-1, 4b-1) and a side portion (4a-2, 4b-2) connected to the ends of the flat plate portion (4a-1, 4b-1). The flat plate portions (4a-1, 4b-1) are located on the outermost edges of the electrode stack 2 in the stacking direction. When viewed along the stacking direction, the outer shape of the flat plate portions (4a-1, 4b-1) is larger than the outer shape of the electrode stack 2. The tip surface of the side portion (4a-2) of one shape-retaining material 4a and the tip surface of the other shape-retaining material 4b face each other. With this configuration, a space is formed between the outer casing 3 and the electrode stack 2, so even if metallic lithium melts, the lithium will be contained in this space and will not leak to the outside of the outer casing 3.

[0036] In a preferred embodiment, the sum of the lengths of the side portions (4a-2, 4b-2) of the pair of shape-retaining materials (4a and 4b) along the stacking direction is less than or equal to 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 pressurizing the battery cell 1 is not hindered 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 hindered.

[0037] In a preferred embodiment, the sum of the lengths of the side portions (4a-2, 4b-2) of the pair of shape-retaining materials (4a and 4b) along the stacking direction is equal to the thickness of the electrode stack 2 when the SOC is 0%. By adopting this configuration, the gap between the side portions (4a-2 and 4b-2) is closed when molten metallic lithium leaks out of the electrode stack 2. Therefore, molten metallic lithium is less likely to leak outside the outer casing 3.

[0038] In one preferred embodiment, an excess space larger than the volume of molten metallic lithium present in a fully charged state is formed inside the outer casing 3. By adopting this configuration, even if all the metallic lithium contained in the electrode stack 2 melts, all of the molten lithium can be contained in the excess space. Therefore, leakage of molten metallic lithium to the outside of the outer casing 3 can be prevented more reliably.

[0039] (Second embodiment) Next, a second embodiment will be described. Note that detailed explanations will be omitted regarding aspects where the same configuration as the first embodiment can be adopted.

[0040] Figure 4 is a schematic cross-sectional view showing a battery cell 1 according to a second embodiment. In this embodiment, the outer casing 3 and each flat plate portion (4a-1 and 4b-1) are bonded together. In Figure 4, the bonded portion is shown as the bonded portion (10a-1 and 10b-1). With this configuration, even when the battery cell 1 is pressurized, the outer casing 3 and the flat plate portions (4a-1 and 4b-1) do not slip. Therefore, wrinkles are less likely to form on the outer casing 3.

[0041] Each flat plate portion (4a-1 and 4b-1) may be bonded to the outer casing 3 over its entire surface, or it may be bonded to the outer casing 3 only in part.

[0042] In a preferred embodiment, the outer casing 3 is bonded to each flat plate portion (4a-1 and 4b-1) but not to each side portion (4a-2 and 4b-2). With this configuration, when the electrode stack 2 shrinks, the outer casing 3 can bend outward on the side of the electrode stack 2. Therefore, the outer casing 3 can be made to follow the expansion and contraction of the electrode stack 2.

[0043] (Third embodiment) Next, a third embodiment will be described. Note that detailed explanations will be omitted regarding the fact that the same configuration as the previously described embodiments can be adopted.

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

[0045] The outer casing 3 is then bonded to the leading edges of the side sections (4a-2 and 4b-2). In Figure 5, this bonded portion is shown as the bonded portion 12.

[0046] As a result of the outer casing 3 being bonded to the leading edges of each side portion (4a-2, 4b-2), the outer casing 3 has a shape that is recessed inward between each side portion (4a-2, 4b-2) and the sealing portion 7. In other words, the outer casing 3 is bonded to the pair of shape-retaining materials (4a and 4b) in such a way that it wraps around each side portion (4a-2, 4b-2).

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

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

[0049] Furthermore, the outer casing 3 may or may not be adhered to the outer surfaces of each side portion (4a-2 and 4b-2). In a preferred embodiment, it is not adhered.

[0050] (Fourth embodiment) Next, we will describe the fourth embodiment. Note that we will omit detailed explanations regarding the fact that the same configuration as the previously described embodiments can be adopted.

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

[0052] According to this embodiment, the presence of the opening 11 makes it possible to reduce the weight of each shape-retaining material (4a and 4b). This makes it possible to improve the gravimetric energy density of the battery cell 1.

[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, when viewed along the stacking direction, the outer shape of the opening 11 is located outside the outer shape of the electrode stack 2.

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

[0055] Furthermore, if the outer diameter of the opening 11 is larger than that of the electrode stack 2, the electrode stack 2 cannot support the pair of shape-retaining members (4a and 4b). However, by bonding the flat plate portions (4a-1 and 4b-1) to the outer casing 3, the outer casing 3 can support the pair of shape-retaining members (4a and 4b).

[0056] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

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

Claims

1. An electrode laminate comprising a positive electrode, a solid electrolyte layer, and a negative electrode, wherein metallic lithium is used as the negative electrode active material, An outer casing that is flexible and houses the electrode stack, A current collector tab, one end of which is positioned inside the outer casing and the other end of which is positioned outside the outer casing, Within the outer casing, a pair of insulating shape-retaining materials are provided so as to be located at the outermost edges of the electrode stack in the stacking direction, and maintain the shape of the outer casing so as to ensure a space between the outer casing and the electrode stack even when the internal region of the outer casing is depressurized. The pair of shape-retaining members are, A flat plate-shaped part, It has a side portion attached to the end of the flat plate portion, The flat plate portion is located at the outermost edge of the electrode stack 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 stack. The leading edge of the side surface of one of the shape-retaining materials and the leading edge of the side surface of the other shape-retaining material face each other and are separated from the current-collecting tab. The sum of the lengths of the side surfaces of the pair of shape-retaining materials along the lamination direction is less than or equal to the thickness of the electrode laminate when the SOC is 0%. All-solid-state battery cell.

2. A solid-state battery cell according to claim 1, The flat plate portion is provided with an opening. All-solid-state battery cell.

3. A solid-state battery cell as described in claim 2, When viewed along the stacking direction, the outer shape of the opening is located outside the outer shape of the electrode stack. All-solid-state battery cell.

4. A solid-state battery cell according to claim 1 or 2, The exterior body is bonded to the flat plate portion. All-solid-state battery cell.

5. A solid-state battery cell according to claim 4, The exterior body is not adhered to the side portion. All-solid-state battery cell.

6. An electrode laminate comprising a positive electrode, a solid electrolyte layer, and a negative electrode, wherein metallic lithium is used as the negative electrode active material, An outer casing that is flexible and houses the electrode stack, Within the outer casing, a pair of insulating shape-retaining materials are provided so as to be located at the outermost edges of the electrode stack in the stacking direction, and maintain the shape of the outer casing so as to ensure a space between the outer casing and the electrode stack even when the internal region of the outer casing is depressurized. The pair of shape-retaining members are, A flat plate-shaped part, It has a side portion attached to the end of the flat plate portion, The flat plate portion is located at the outermost edge of the electrode stack 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 stack. The tip surface of the side portion of one of the shape-retaining materials and the tip surface of the side portion of the other shape-retaining material are facing each other. The exterior body is adhered to the tip surface of the side portion, All-solid-state battery cell.

7. A solid-state battery cell according to claim 1 or 2, The sum of the lengths of the side surfaces of the pair of shape-retaining materials along the lamination direction is the same as the thickness of the electrode laminate when the SOC is 0%. All-solid-state battery cell.

8. An electrode laminate comprising a positive electrode, a solid electrolyte layer, and a negative electrode, wherein metallic lithium is used as the negative electrode active material, An outer casing that is flexible and houses the electrode stack, Within the outer casing, a pair of insulating shape-retaining materials are provided so as to be located at the outermost edges of the electrode stack in the stacking direction, and maintain the shape of the outer casing so as to ensure a space between the outer casing and the electrode stack even when the internal region of the outer casing is depressurized. The pair of shape-retaining members are, A flat plate-shaped part, It has a side portion attached to the end of the flat plate portion, The flat plate portion is located at the outermost edge of the electrode stack 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 stack. The tip surface of the side portion of one of the shape-retaining materials and the tip surface of the side portion of the other shape-retaining material are facing each other. Inside the aforementioned outer casing, an excess space larger than the volume of the metallic lithium present in a fully charged state if it were to melt is formed. All-solid-state battery cell.

9. A solid-state battery cell according to claim 1 or 2, A space exists between the aforementioned side portion and the electrode stack. All-solid-state battery cell.

10. A solid-state battery cell according to claim 1 or 2, Pressurized by a pressurizing mechanism, All-solid-state battery cell.

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