All-solid-state battery and method for manufacturing the same

Abstract

The X-direction end of the housing portion of the outer film is made less susceptible to deformation in both the X-direction and the Z-direction. [Solution] The all-solid-state battery comprises an electrode stack in which multiple layers are stacked in the Z direction, and an outer film. The inside of the outer film is under reduced pressure compared to the outside. The outer film has an intermediate section between a housing section and a sealing section. The intermediate section has an intermediate section base end as the end on the housing section side and an intermediate section tip end as the end on the sealing section side. In the natural state before the inside of the outer film is depressurized, the magnitude in the X direction from the electrode stack to the intermediate section base end is smaller than the magnitude in the X direction from the intermediate section base end to the intermediate section tip.

Description

Technical Field

[0001] The present invention relates to an all-solid-state battery mounted on a vehicle or the like.

Background Art

[0002] In recent years, research and development on all-solid-state batteries that contribute to energy efficiency have been carried out to ensure that more people can access affordable, reliable, sustainable and advanced energy.

[0003] Some all-solid-state batteries include an electrode laminate and an exterior film. In the electrode laminate, a plurality of layers extending in predetermined X and Y directions are stacked in the Z direction. The exterior film has a housing portion that houses the electrode laminate inside, and a sealing portion provided around the housing portion when viewed in the Z direction.

[0004] The electrode laminate includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer as the aforementioned layers. The positive electrode layer and the negative electrode layer each have a current collecting portion. These current collecting portions are electrically connected to the corresponding tab leads respectively. Each tab lead passes through the sealing portion of the exterior film in the X direction and is drawn out to the outside of the exterior film.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0006] In such all-solid-state batteries, the electrode stack expands in the Z direction due to the deposition of lithium and other elements in the negative electrode layer during charging. On the other hand, during discharge, the electrode stack contracts in the Z direction due to the dissolution of lithium and other elements in the negative electrode layer. To prevent the current collector from breaking due to such expansion and contraction, an excess length is provided in the current collector. As a result, the current collector is housed in a slightly bent state in the space between the X-direction end of the electrode stack and the outer film.

[0007] During the manufacturing process of such all-solid-state batteries, the inside of the outer film is often depressurized. This depressurization can cause the X-direction end face of the housing portion of the outer film to deform inward in the X-direction, resulting in the portion of the tab lead welded to the sealing portion of the outer film being pulled inward in the X-direction. This can damage the tab lead or current collector, or cause the tab lead or current collector to become embedded in the electrode stack.

[0008] Furthermore, such deformation of the outer film in the X direction may cause the current collector to become trapped between the electrode laminate and the outer film. In that case, the current collector may not be able to move properly and could be damaged when the electrode laminate expands outward or contracts inward in the Z direction.

[0009] On the other hand, if the space between the X-direction end of the electrode laminate and the outer film is made too large in the X direction to prevent the current collector from being pinched, that space will collapse, making the X-direction end of the housing portion of the outer film more prone to deformation in the Z direction.

[0010] This invention has been made in view of the above circumstances, and aims to make the end portion of the outer film housing difficult to deform in either the inward direction in the X direction or the inward direction in the Z direction. [Means for solving the problem]

[0011] The inventors of the present invention discovered that the above objective can be achieved by providing a predetermined structure at the X-direction end of the outer film, and thus arrived at the present invention. The present invention comprises (1) to (7) all-solid-state batteries and (8) a method for manufacturing all-solid-state batteries.

[0012] (1) An electrode laminate comprising a plurality of layers extending in a predetermined X direction and a predetermined Y direction perpendicular to the X direction, stacked in a Z direction perpendicular to the X direction and the Y direction, and an outer film, The outer film has a housing portion that houses the electrode laminate on the inside, and a sealing portion that is provided around the housing portion when viewed in the Z direction. The inside of the aforementioned outer film is under reduced pressure compared to the outside. The electrode laminate comprises, as layers, at least a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The positive electrode layer and the negative electrode layer each have a current collector, The current collector is electrically connected to a tab lead that passes through the sealing portion in the X direction and is drawn out to the outside of the outer film. All-solid-state battery, The outer film has an intermediate portion between the housing portion and the portion welded to the tab lead in the sealing portion, The intermediate portion has an intermediate base end as the end on the housing side and an intermediate tip end as the end on the sealing side. A space is formed between the electrode stack and the intermediate base end. The length in the X direction from the electrode stack to the base end of the intermediate portion is smaller than the length in the X direction from the base end of the intermediate portion to the tip of the intermediate portion. All-solid-state battery.

[0013] According to this configuration, by providing an intermediate section between the housing section and the sealing section, the rigidity of the housing section's end in the X direction and its surrounding area in the X direction can be improved, making it difficult for the housing section to deform inward in the X direction. Furthermore, by making the X-direction size from the electrode stack to the base end of the intermediate section smaller than the X-direction size from the base end to the tip of the intermediate section, the space between the electrode stack and the base end of the intermediate section can be reduced in the X direction. As a result, the X-direction end of the housing section can also be made difficult to deform inward in the Z direction.

[0014] As described above, this configuration makes it difficult for the X-direction end of the housing portion of the outer film to deform in either the X-direction inward or the Z-direction inward.

[0015] (2) In the housing portion, a protruding portion is formed in the portion between the end face of the electrode stack in the Z direction and the base end of the intermediate portion, which protrudes outward in the Z direction from the portion that is in contact with the end face of the electrode stack in the Z direction in the housing portion. The all-solid-state battery described in (1) above.

[0016] With this configuration, deformation in the X direction can be efficiently suppressed by bending the outer film outward in the Z direction.

[0017] (3) The intermediate base end is located within the central region of the three regions obtained by dividing the outer film from the Z-direction end to the tab lead into three equal parts in the Z-direction. The all-solid-state battery described in (1) or (2) above.

[0018] With this configuration, the intermediate portion protrudes outward in the X direction from within the central region in the Z direction, thereby efficiently improving the rigidity of the X-direction edge of the outer film.

[0019] (4) When viewed in its natural state before the inside of the outer film is depressurized, the intermediate portion has a parallel portion between the base end of the intermediate portion and the tip of the intermediate portion that extends substantially parallel to the sealing portion in the X direction and the Y direction, The all-solid-state battery according to any one of the above (1) to (3).

[0020] According to this configuration, the stepped shape can be efficiently provided. The stepped shape can efficiently improve the rigidity of the end portion in the X direction of the exterior film.

[0021] (5) When viewed in the Y direction, the intermediate portion has an inclined portion extending in a direction oblique to the X direction between the intermediate portion base end and the intermediate portion tip end. The all-solid-state battery according to any one of the above (1) to (3).

[0022] According to this configuration, the force that would otherwise be applied inward in the X direction to the end portion in the X direction of the exterior film can be deflected by the inclined portion in a direction oblique to the inner side in the X direction. Thereby, the inward deformation of the exterior film in the X direction can be efficiently suppressed.

[0023] (6) The length of the intermediate portion tip end in the Y direction is smaller than the length of the intermediate portion base end in the Y direction. When viewed in the Z direction, an angle of a virtual straight line connecting the intermediate portion base end and the intermediate portion tip end at the Y-direction end of the intermediate portion with respect to the X direction is greater than 45°. The all-solid-state battery according to any one of the above (1) to (5).

[0024] According to this configuration, the intermediate portion and its peripheral portion can be easily formed.

[0025] (7) At the Y-direction side end of the intermediate portion, a predetermined base end side section is provided in a portion located closer to the intermediate portion base end than a predetermined portion, and a predetermined tip end side section is provided in a portion located closer to the intermediate portion tip end than the predetermined portion. When viewed in the Z direction, the angle of the extending direction of the tip end side section with respect to the X direction is larger than the angle of the extending direction of the base end side section with respect to the X direction. The all-solid-state battery according to any one of the above (1) to (6).

[0026] This configuration allows for an improvement in the rigidity of the X-direction end of the outer film by reducing the angle of the extension direction of the base end section with respect to the X direction, thereby bringing the extension direction of the base end section closer to the X direction. Furthermore, increasing the angle of the extension direction of the tip end section with respect to the X direction makes it easier to form the intermediate section and its surrounding area.

[0027] (8) An electrode laminate comprising a plurality of layers extending in a predetermined X direction and a predetermined Y direction perpendicular to the X direction, stacked in a Z direction perpendicular to the X direction and the Y direction, and an outer film, The outer film has a housing portion that houses the electrode laminate on the inside, and a sealing portion that is provided around the housing portion when viewed in the Z direction. The inside of the aforementioned outer film is under reduced pressure compared to the outside. The electrode laminate comprises, as layers, at least a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The positive electrode layer and the negative electrode layer each have a current collector, The current collector is electrically connected to a tab lead that passes through the sealing portion in the X direction and is drawn out to the outside of the outer film. all-solid-state battery, A method for manufacturing an all-solid-state battery, In the pre-depressurization stage before reducing the pressure inside the outer film, The outer film has an intermediate portion between the housing portion and the portion welded to the tab lead in the sealing portion, The intermediate portion has an intermediate base end as the end on the housing side and an intermediate tip end as the end on the sealing side. A space is formed between the electrode stack and the intermediate base end. The size in the X direction from the electrode stack to the base end of the intermediate portion is smaller than the size in the X direction from the base end of the intermediate portion to the tip of the intermediate portion. From the state before the depressurization stage, the inside of the outer film is depressurized. All-solid-state battery manufacturing method.

[0028] This manufacturing method also yields the same effects as in case (1) above. [Effects of the Invention]

[0029] As described above, according to the all-solid-state battery of (1) and the manufacturing method of (8), the X-direction end of the housing portion of the outer film can be made difficult to deform in either the X-direction inward or the Z-direction inward. Furthermore, according to the configurations of (2) to (7) which refer to (1), each additional effect can be obtained. [Brief explanation of the drawing]

[0030] [Figure 1] This is a perspective view showing the all-solid-state battery of the first embodiment before depressurization. [Figure 2] This is a plan view showing the all-solid-state battery before depressurization. [Figure 3] This is an enlarged view of the fg3 portion in Figure 2. [Figure 4] This figure shows a cross-section of the line fg4-fg4 in Figure 2. [Figure 5] This figure shows a cross-section of the line fg5-fg5 in Figure 3. [Figure 6] This is a plan view showing the state of a solid-state battery after depressurization. [Figure 7] This is a cross-section of the line fg7-fg7 in Figure 6. [Figure 8] This is a plan view showing the reduced pressure of a comparative all-solid-state battery. [Figure 9] This figure shows a cross-section of the line fg9-fg9, as shown in Figure 8. [Figure 10] This is a perspective view showing the all-solid-state battery of the second embodiment before depressurization. [Figure 11] This is a cross-sectional view of the all-solid-state battery before depressurization, viewed in the Y direction. [Figure 12] This is a cross-sectional view of the all-solid-state battery after depressurization, viewed in the Y direction. [Figure 13] This is a perspective view showing the all-solid-state battery of the third embodiment before depressurization. [Figure 14]This is a perspective view showing the all-solid-state battery of the fourth embodiment before depressurization. [Modes for carrying out the invention]

[0031] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited in any way to the following embodiments and can be implemented with appropriate modifications without departing from the spirit of the invention.

[0032] [First Embodiment] Hereinafter, as shown in Figure 1, three predetermined mutually orthogonal directions are referred to as the "X direction," "Y direction," and "Z direction." In this embodiment, the Z direction is the vertical direction, and the X and Y directions are the horizontal directions. However, instead, for example, the Z direction may be oblique to the vertical direction, and the X and Y directions may be orthogonal to the direction oblique to the vertical direction. Alternatively, for example, one of the X and Y directions may be the vertical direction, and the other X and Y direction and the Z direction may be the horizontal direction.

[0033] As shown in Figure 7, the all-solid-state battery 101 comprises an electrode stack 30 and an outer film 50. The inside of the outer film 50 is under reduced pressure compared to the outside. Hereinafter, the state before such reduced pressure is referred to as "pre-reduced pressure," and the state after such reduced pressure is referred to as "post-reduced pressure." Furthermore, the stage before reduced pressure is referred to as the "pre-reduced pressure stage," and the stage after reduced pressure is referred to as the "post-reduced pressure stage." Also, the state before reduced pressure is referred to as the "natural state," and the state after reduced pressure is referred to as the "product state."

[0034] Figures 1 to 5 show the all-solid-state battery 101 before depressurization. On the other hand, Figures 6 and 7 show the all-solid-state battery 101 after depressurization.

[0035] First, we will describe the all-solid-state battery 101 in the pre-depressurization stage shown in Figures 1 to 5, that is, the all-solid-state battery 101 in its natural state with the outer film 50.

[0036] As shown in Figure 5, the outer film 50 consists of a first film 50u and a second film 50d arranged side by side in the Z direction. However, the outer film 50 may instead consist of a single folded film.

[0037] The first film 50u and the second film 50d each have a housing portion 53 and a sealing portion 54. The housing portion 53 houses the electrode stack 30 inside. As shown in Figure 2, the sealing portion 54 is provided around the housing portion 53 when viewed in the Z direction. Note that in this pre-depressurization stage, a part of the sealing portion 54 is open. The all-solid-state battery 101 has a positive electrode tab lead 40 on one side in the X direction and a negative electrode tab lead 40 on the other side in the X direction.

[0038] As shown in Figure 5, the electrode stack 30 is constructed by stacking multiple layers extending in the X and Y directions in the Z direction. The electrode stack 30 includes a positive electrode layer 31, a solid electrolyte layer 32, and a negative electrode layer 33.

[0039] The positive electrode layer 31 has a positive electrode current collector 31c, and the negative electrode layer 33 has a negative electrode current collector 33c. The negative electrode current collector 33c protrudes toward the negative electrode tab lead 40 and is electrically connected to the tab lead 40. The positive electrode current collector 31c protrudes toward the positive electrode tab lead 40 as shown in Figure 2 and is electrically connected to the tab lead 40. Hereinafter, the positive electrode current collector 31c and the negative electrode current collector 33c will be collectively referred to as "current collectors 31c, 33c".

[0040] As shown in Figure 2, the tab leads 40 on the positive and negative electrode sides are drawn out to the outside of the outer film 50 by passing through the sealing portion 54 in the X direction. As shown in Figure 5, the tab leads 40 are located in the center of the all-solid-state battery 101 in the Z direction. However, instead, the tab leads 40 may be located at one end of the all-solid-state battery 101 in the Z direction. Furthermore, one of the first film 50u and the second film 50d may be provided in a planar shape extending in the X and Y directions, different from the shape shown in Figure 5.

[0041] As shown in Figure 5, each of the first film 50u and the second film 50d has an intermediate portion 60 between the housing portion 53 and the portion welded to the tab lead 40 in the sealing portion 54. The intermediate portion 60 has an intermediate portion base end 61 as the end on the housing portion 53 side and an intermediate portion tip end 65 as the end on the sealing portion 54 side.

[0042] As shown in Figure 4, when viewed in the X direction, the intermediate base end 61 is located between the Z-direction end of the outer film 50 and the tab lead 40. More specifically, the intermediate base end 61 is located within the central region Rg2 of the three regions Rg1, Rg2, and Rg3 obtained by dividing the distance from the Z-direction end of the outer film 50 to the tab lead 40 into three equal parts in the Z direction.

[0043] As shown in Figure 5, a space Sp is formed between the electrode stack 30 and the intermediate base end 61. The intermediate portion 60 extends from the intermediate base end 61 to a bent portion 63 located outward in the X direction from the intermediate base end 61, and then extends to the intermediate tip 65.

[0044] As shown in Figure 1, the intermediate portion 60 has a parallel portion 62 between the base end 61 and the bent portion 63 that extends in the X and Y directions parallel or substantially parallel to the sealing portion 54. The intermediate portion 60 also has a vertical portion 64 between the bent portion 63 and the tip 65 of the intermediate portion that extends in the Z direction perpendicular or substantially perpendicular to the sealing portion 54.

[0045] As shown in Figure 5, the size xA in the X direction from the electrode stack 30 to the intermediate base end 61 is smaller than the size xB2 in the X direction from the intermediate base end 61 to the intermediate tip 65, and further smaller than the size xB1 in the X direction from the intermediate base end 61 to the bent portion 63.

[0046] As shown in Figure 2, the length yB1 of the base end 61 of the intermediate section in the Y direction is smaller than the length yA of the housing section 53 in the Y direction. Specifically, the length yB1 of the base end 61 of the intermediate section in the Y direction is 30-80% of the length yA of the housing section 53 in the Y direction. Therefore, the intermediate section 60 protrudes outward in the X direction from between the two ends of the housing section 53 in the Y direction. The length yB2 of the tip 65 of the intermediate section in the Y direction is smaller than the length yB1 of the base end 61 of the intermediate section in the Y direction. Therefore, as shown in Figure 3, when viewed in the Z direction, the imaginary line vL connecting the base end 61 and the tip 65 of the intermediate section at the Y-side end 68 of the intermediate section 60 is oblique to the X direction. That is, this imaginary line vL extends inward in the Y direction as it moves outward in the X direction.

[0047] More specifically, as shown in Figure 3, when viewed in the Z direction, the angle θb of this virtual line vL with respect to the X direction is greater than 45°. At the Y-direction end 68 of the intermediate portion 60, a predetermined base-end section 682 is provided in the portion located closer to the base end 61 of the intermediate portion than a predetermined portion 683. Also, at the same end 68, a predetermined tip-end section 684 is provided in the portion located closer to the tip 65 of the intermediate portion than the predetermined portion 683. Thus, when viewed in the Z direction, the angle θb2 of the tip-end section 684 with respect to the X direction is greater than the angle θb1 of the base-end section 682 with respect to the X direction.

[0048] The above is a description of the all-solid-state battery 101 in the pre-depressurization stage, that is, a description of the all-solid-state battery 101 in its natural state with the outer film 50.

[0049] Next, the manufacturing method of the all-solid-state battery 101 of this embodiment, that is, the manufacturing method of the all-solid-state battery 101 in its product state, will be described. In this manufacturing method, from the state before depressurization described above, the inside of the outer film 50 is depressurized to completely seal the sealing portion 54. This completes the all-solid-state battery 101 in the post-depressurization stage shown in Figures 6 and 7, that is, the all-solid-state battery 101 in its product state.

[0050] The following describes the all-solid-state battery 101 in its product state.

[0051] As shown in Figure 7, even in the product state, the intermediate base end 61 is located inward in the Z direction from the Z-direction edge of the outer film 50 and outward in the Z direction from the tab lead 40. Therefore, even in the product state, as in the natural state shown in Figure 4, the intermediate base end 61 is located between the Z-direction edge of the outer film 50 and the tab lead 40 when viewed in the X direction. More specifically, even in the product state, as in the natural state shown in Figure 4, the intermediate base end 61 is located within the central region Rg2 of the three regions Rg1, Rg2, and Rg3 obtained by dividing the distance from the Z-direction edge of the outer film 50 to the tab lead 40 into three equal parts in the Z direction.

[0052] As shown in Figure 7, even in the product state, the intermediate portion 60 extends from the intermediate portion base end 61 to the bent portion 63 which is located outward in the X direction from the intermediate portion base end 61, and then extends to the intermediate portion tip 65. Even in the product state, similar to the natural state shown in Figure 5, the size xA in the X direction from the electrode stack 30 to the intermediate portion base end 61 is smaller than the size xB2 in the X direction from the intermediate portion base end 61 to the intermediate portion tip 65, and further smaller than the size xB1 in the X direction from the intermediate portion base end 61 to the bent portion 63.

[0053] Even in the product state, similar to the natural state shown in Figure 2, the length yB1 of the base end 61 in the Y direction is smaller than the length yA of the housing section 53, and the length yB1 of the base end 61 in the Y direction is 30-80% of the length yA of the housing section 53. Therefore, even in the product state, the intermediate section 60 protrudes in the X direction from between the two ends of the housing section 53 in the Y direction. Even in the product state, the length yB2 of the tip 65 of the intermediate section in the Y direction is smaller than the length yB1 of the base end 61 in the Y direction. Therefore, even in the product state, similar to the natural state shown in Figure 3, the aforementioned virtual line vL is oblique to the X direction when viewed in the Z direction. More specifically, even in the product state, similar to the natural state shown in Figure 3, the angle θb of the virtual line vL with respect to the X direction when viewed in the Z direction is greater than 45°. Furthermore, even in the product state, similar to the case viewed in the natural state shown in Figure 3, when viewed in the Z direction, the angle θb2 of the extending direction of the tip-side section 684 relative to the X direction is greater than the angle θb1 of the extending direction of the base-side section 682 relative to the X direction.

[0054] As shown in Figure 7, in the product state, a protruding portion 536 is formed in the portion of the housing 53 between the electrode stack 30 and the intermediate base end 61, which protrudes outward in the Z direction from the portion that abuts the Z-direction end face of the electrode stack 30 in the housing 53.

[0055] The above is a description of the all-solid-state battery 101 in its product state, that is, a description of the all-solid-state battery 101 in the post-depressurization stage.

[0056] The embodiment will now be described in more detail.

[0057] The positive electrode layer 31 shown in Figure 5 comprises a positive electrode active material layer. The negative electrode layer 33 comprises a negative electrode active material layer. The solid electrolyte layer 32 is provided between the positive electrode layer 31 and the negative electrode layer 33. During charging of the all-solid-state battery 101, the electrode stack 30 expands outward in the Z direction due to the deposition of lithium and other elements in the negative electrode layer 33. On the other hand, during discharge, the electrode stack 30 contracts inward in the Z direction due to the dissolution of lithium and other elements in the negative electrode layer 33. To prevent the current collectors 31c and 33c from breaking due to such expansion and contraction, excess length is provided in the current collectors 31c and 33c. As a result, the current collectors 31c and 33c are stored in a slightly bent state in the space Sp between the X-direction end of the electrode stack 30 and the outer film 50.

[0058] The first film 50u and the second film 50d of the outer film 50 are both laminate films. In this embodiment, the first film 50u and the second film 50d are arranged substantially symmetrically in the Z direction. However, as described above, instead, a tab lead 40 may be provided at one end of the all-solid-state battery 101 in the Z direction, and one of the first film 50u and the second film 50d may be made into a planar shape extending in the X and Y directions.

[0059] The dimension xA in the X direction from the electrode stack 30 to the intermediate base end 61 shown in Figure 5 is approximately 2 mm. On the other hand, the dimension xB2 in the X direction from the intermediate base end 61 to the intermediate tip end 65 is approximately 4 mm. The dimension in the Z direction from the Z-direction edge of the outer film 50 to the tab lead 40 is approximately 4 mm.

[0060] Hereinafter, as shown in Figures 8 and 9, a comparative form is provided in which the intermediate section 60 is omitted from this embodiment.

[0061] As shown in Figure 9, in this comparative configuration, the reduced pressure inside the outer film 50 causes the end face of the housing portion 53 of the outer film 50 to deform in the X direction, causing the portion of the tab lead 40 welded to the sealing portion 54 to be pulled inward in the X direction. This may result in damage to the tab lead 40 or the current collector portion 33c, or the tab lead 40 or the current collector portion 33c becoming embedded in the electrode laminate 30.

[0062] Furthermore, the deformation of the outer film 50 in the X direction due to such depressurization may cause the current collector 33c to become trapped between the electrode laminate 30 and the outer film 50. In that case, the current collector 33c may not be able to move properly and could be damaged when the electrode laminate 30 expands outward in the Z direction or contracts inward in the Z direction.

[0063] The configuration and effects of this embodiment are summarized below, in comparison with the comparative form.

[0064] As shown in Figure 4, the intermediate base end 61 is located between the Z-direction end of the outer film 50 and the tab lead 40 when viewed in the X direction. As shown in Figure 5, the intermediate portion 60 extends from its intermediate base end 61 to the bent portion 63 which is further outward in the X direction, and then extends to the intermediate tip 65. Thus, as shown in Figure 4, the X-direction end face Es of the outer film 50 can be divided in the Z direction. Specifically, a first dividing surface Es1 is formed outward in the Z direction from the intermediate base end 61, and a second dividing surface Es2 is formed inward in the Z direction from the bent portion 63.

[0065] Furthermore, as shown in Figure 2, the intermediate portion 60 protrudes outward in the X direction from between the two ends in the Y direction of the housing portion 53. Therefore, as shown in Figure 4, the X-direction end face of the outer film 50 can also be divided in the Y direction. Specifically, a third dividing surface Es3 is formed on one side in the Y direction from the intermediate portion 60, and a fourth dividing surface Es4 is formed on the other side in the Y direction from the intermediate portion 60. In addition, as mentioned above, a first dividing surface Es1 and a second dividing surface Es2 are formed side by side in the Z direction between the third dividing surface Es3 and the fourth dividing surface Es4.

[0066] From the above, the end face Es in the X direction of the outer film 50, that is, the surface of the outer film 50 that receives the external air pressure inward in the X direction, can be divided in the Y and Z directions. This improves the rigidity of the end face in the X direction of the outer film 50 and suppresses deformation of the outer film 50 inward in the X direction due to the decrease in pressure inside the outer film 50.

[0067] As a result, compared to the comparative configuration shown in Figure 9, the retraction of the tab lead 40 due to the deformation can be suppressed, as shown in Figure 7. This prevents damage to the tab lead 40 and the current collectors 31c and 33c, and prevents the tab lead 40 and the current collectors 31c and 33c from becoming embedded in the electrode stack 30.

[0068] Furthermore, since deformation of the outer film 50 inward in the X direction can be suppressed in this way, it is possible to prevent the current collectors 31c and 33c from being pinched between the electrode laminate 30 and the outer film 50. Therefore, when the electrode laminate 30 expands outward in the Z direction or contracts inward in the Z direction, the current collectors 31c and 33c become more mobile and less likely to be damaged.

[0069] As shown in Figure 4, the intermediate base end 61 is located within the central region Rg2 of the three regions Rg1, Rg2, and Rg3 obtained by dividing the electrode laminate 30 from the Z-direction end to the tab lead 40 into three equal parts in the Z-direction. By having the intermediate portion 60 protrude outward in the X-direction from this central region Rg2 in the Z-direction, the X-direction end face of the outer film 50 is divided in a balanced manner in the Z-direction, thereby efficiently improving the rigidity of the X-direction end of the outer film 50.

[0070] The length yB1 in the Y direction of the intermediate base end 61 shown in Figure 2 is 30-80% of the length yA in the Y direction of the housing 53. This allows the end face in the X direction of the outer film 50 to be divided in a balanced manner in the Y direction, thereby efficiently improving the rigidity of the end face in the X direction of the outer film 50.

[0071] As shown in Figure 1, in its natural state, the intermediate portion 60 has a parallel portion 62 extending in the X and Y directions substantially parallel to the sealing portion 54 between the intermediate portion base end 61 and the bent portion 63. This allows for the efficient creation of a stepped shape. This stepped shape allows for the efficient improvement of the rigidity of the X-direction end of the outer film 50.

[0072] As shown in Figure 2, when viewed in the Z direction, the length of the tip 65 of the intermediate section in the Y direction is smaller than the length of the base 61 of the intermediate section in the Y direction. Therefore, as shown in Figure 3, when viewed in the Z direction in the natural state, the angle that the imaginary line vL connecting the base 61 and the tip 65 of the intermediate section makes with respect to the X direction at the Y-side end 68 of the intermediate section 60 is greater than 45°. This makes it easier to form the intermediate section 60 and its surrounding area.

[0073] As shown in Figure 3, at the Y-direction end 68 of the intermediate portion 60, a predetermined base-end section 682 is provided in the portion located closer to the base end 61 of the intermediate portion than a predetermined portion 683. Furthermore, at the same end 68, a predetermined tip-end section 684 is provided in the portion located closer to the tip 65 of the intermediate portion than the predetermined portion 683. As shown in Figure 3, in the natural state, when viewed in the Z direction, the angle θb2 of the extending direction of the tip-end section 684 in the X direction is greater than the angle θb1 of the extending direction of the base-end section 682 in the X direction.

[0074] In this way, by reducing the angle θb1 in the extending direction of the base end section 682 with respect to the X direction, the rigidity of the end of the outer film 50 in the X direction can be efficiently improved. On the other hand, by increasing the angle θb2 in the extending direction of the tip end section 684 with respect to the X direction, it is possible to easily form the intermediate section 60 and its surrounding area.

[0075] As shown in Figure 5, in its natural state, the size xA in the X direction from the electrode stack 30 to the intermediate base end 61 is smaller than the size xB2 in the X direction from the intermediate base end 61 to the intermediate tip 65, and further smaller than the size xB1 in the X direction from the intermediate base end 61 to the bent portion 63. This makes it possible to reduce the space Sp between the electrode stack 30 and the intermediate base end 61 in the X direction. This makes it possible to make the X-direction end of the housing portion 53 of the outer film 50 less prone to deformation not only in the X direction but also in the Z direction.

[0076] As shown in Figure 7, in the product state, a protruding portion 536 is formed in the portion of the housing 53 between the electrode stack 30 and the intermediate base end 61, which protrudes outward in the Z direction from the portion that abuts the Z-direction end face of the electrode stack 30 in the housing 53. By bending the outer film 50 outward in the Z direction in this way, deformation inward in the X direction can be efficiently suppressed.

[0077] [Second Embodiment] Next, the all-solid-state battery 102 of the second embodiment will be described with reference to Figures 10 to 12. This embodiment will be described based on the first embodiment, focusing on the differences, and explanations of the same or similar aspects as the first embodiment will be omitted as appropriate.

[0078] As shown in Figure 10, the intermediate portion 60 has an inclined portion 63s between the intermediate portion base end 61 and the intermediate portion tip 65, instead of the parallel portion 62, bent portion 63, and vertical portion 64 of the first embodiment. As shown in Figure 11, the inclined portion 63s extends in a direction oblique to the X direction when viewed in the Y direction in its natural state. That is, the inclined portion 63s extends inward in the Z direction as it moves outward in the X direction. Specifically, when viewed in the Y direction in its natural state, the angle θs of the direction of extension of the inclined portion 63s with respect to the X direction is 7° to 35°. As shown in Figure 12, this inclined portion 63s is also present in the product state. Even in the product state, when viewed in the Y direction, the angle of the direction of extension of the inclined portion 63s with respect to the X direction is 7° to 35°.

[0079] According to this embodiment, by providing such an inclined portion 63s, when the pressure inside the outer film 50 is reduced, the force that would normally be applied to the outer film 50 inward in the X direction can be deflected in a direction oblique to the inward direction in the X direction. As a result, as shown in Figure 12, deformation of the housing portion 53 of the outer film 50 inward in the X direction can be efficiently suppressed.

[0080] [Third Embodiment] Next, the all-solid-state battery 103 of the third embodiment will be described with reference to Figure 13. This embodiment will be described based on the second embodiment, focusing on the differences, and explanations of points that are the same as or similar to the second embodiment will be omitted as appropriate.

[0081] A base-side inclined portion 62s is provided on the base end 61 side of the intermediate portion 60, relative to the inclined portion 63s. In its natural state, viewed in the Y direction, the angle of the base-side inclined portion 62s in the direction of extension with respect to the X direction is greater than the angle of the inclined portion 63s in the direction of extension with respect to the X direction. This embodiment is effective when it is desired to make the inclined portion 63s gentler.

[0082] [Fourth Embodiment] Next, the fourth embodiment will be described with reference to Figure 14. This embodiment will be described based on the second embodiment, focusing on the differences, and explanations of points that are the same as or similar to the second embodiment will be omitted as appropriate.

[0083] The intermediate base end 61 is provided at the Z-direction end of the X-direction end face of the housing portion 53. The inclined portion 63s extends from the intermediate base end 61 to the intermediate tip end 65. This embodiment is effective when a simpler shape of the intermediate portion 60 is desired.

[0084] [Other embodiments] The embodiments described above can be modified as follows, for example. In each embodiment, for example, the end in the Y direction of the intermediate portion 60 shown in Figure 3 may be made to extend straight in the X direction. Alternatively, only the end on the X side of the Y direction end may be inclined so that it moves outward in the Y direction as it moves inward in the X direction. [Explanation of Symbols]

[0085] 30 Electrode Stack 31 Positive electrode layer 31c Positive electrode current collector (current collector) 32 Solid electrolyte layer 33 Negative electrode layer 33c Negative electrode current collector (current collector) 40 Tabread 50 Exterior film 53 Accommodation 536 Protrusion 54 Sealing part 60 Middle section 61 Intermediate base 62 Parallel section 63s slope section 65 Middle section tip 68 End in the Y direction in the intermediate section 682 Base end section 683 Predetermined part 684 Front end section 101 All-solid-state battery 102 All-solid-state battery 103 All-solid-state battery 104 All-solid-state battery Rg1 is the edge region of the three regions. Rg2 is the central region of the three regions. Rg3 is the edge region of the three regions. Sp space vL virtual line xA: Size in the X direction from the electrode stack to the intermediate base. xB2: The size in the X direction from the base end to the tip end of the intermediate section. yB1 Length in the Y direction of the base of the intermediate section yB2 Length in the Y direction of the tip of the intermediate section θa Angle of a virtual line relative to the X direction θb1 Angle in the extension direction of the base end section with respect to the X direction θb2 Angle in the extension direction of the tip-side section with respect to the X direction

Claims

1. The electrode laminate comprises a plurality of layers extending in a predetermined X direction and a predetermined Y direction perpendicular to the X direction, stacked in a Z direction perpendicular to the X direction and the Y direction, and an outer film. The outer film has a housing portion that houses the electrode laminate on the inside, and a sealing portion that is provided around the housing portion when viewed in the Z direction. The inside of the aforementioned outer film is under reduced pressure compared to the outside. The electrode laminate comprises, as layers, at least a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The positive electrode layer and the negative electrode layer each have a current collector, The current collector is electrically connected to a tab lead that passes through the sealing portion in the X direction and is drawn out to the outside of the outer film. All-solid-state battery, The outer film has an intermediate portion between the housing portion and the portion welded to the tab lead in the sealing portion, The intermediate portion has an intermediate base end as the receiving end and an intermediate tip end as the sealing end, A space is formed between the electrode stack and the intermediate base end. The length in the X direction from the electrode stack to the base end of the intermediate portion is smaller than the length in the X direction from the base end of the intermediate portion to the tip of the intermediate portion. All-solid-state battery.

2. In the housing portion, a protruding portion is formed in the portion of the electrode stack in the housing portion between the end face in the Z direction and the base end of the intermediate portion, which protrudes outward in the Z direction from the portion that abuts the end face in the Z direction of the electrode stack in the housing portion. The all-solid-state battery according to claim 1.

3. The aforementioned intermediate base end is located within the central region of the three regions obtained by dividing the outer film from the Z-direction end to the tab lead into three equal parts in the Z-direction. The all-solid-state battery according to claim 1 or 2.

4. When viewed in its natural state before the inside of the outer film is depressurized, the intermediate portion has a parallel portion between the base end and the tip of the intermediate portion that extends substantially parallel to the sealing portion in the X and Y directions. The all-solid-state battery according to claim 1 or 2.

5. Viewed in the Y direction, the intermediate portion has an inclined portion extending in a direction oblique to the X direction between the base end and the tip end of the intermediate portion. The all-solid-state battery according to claim 1 or 2.

6. The length of the tip of the intermediate portion in the Y direction is smaller than the length of the base of the intermediate portion in the Y direction. Viewed in the Z direction, the angle of the imaginary line connecting the base end and the tip end of the intermediate portion with respect to the X direction at the Y-direction end of the intermediate portion is greater than 45°. The all-solid-state battery according to claim 1 or 2.

7. At the end of the intermediate portion on the Y-direction side, a predetermined base-end section is provided in the portion located closer to the base end of the intermediate portion than a predetermined portion, and a predetermined tip-end section is provided in the portion located closer to the tip of the intermediate portion than the predetermined portion. When viewed in the Z direction, the angle of the extension direction of the tip section with respect to the X direction is greater than the angle of the extension direction of the base section with respect to the X direction. The all-solid-state battery according to claim 1 or 2.

8. The electrode laminate comprises a plurality of layers extending in a predetermined X direction and a predetermined Y direction perpendicular to the X direction, stacked in a Z direction perpendicular to the X direction and the Y direction, and an outer film. The outer film has a housing portion that houses the electrode laminate on the inside, and a sealing portion that is provided around the housing portion when viewed in the Z direction. The inside of the aforementioned outer film is under reduced pressure compared to the outside. The electrode laminate comprises, as layers, at least a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The positive electrode layer and the negative electrode layer each have a current collector, The current collector is electrically connected to a tab lead that passes through the sealing portion in the X direction and is drawn out to the outside of the outer film. all-solid-state battery, A method for manufacturing an all-solid-state battery, In the pre-depressurization stage before reducing the pressure inside the outer film, The outer film has an intermediate portion between the housing portion and the portion welded to the tab lead in the sealing portion, The intermediate portion has an intermediate base end as the end on the housing side and an intermediate tip end as the end on the sealing side. A space is formed between the electrode stack and the intermediate base end. The size in the X direction from the electrode stack to the base end of the intermediate portion is smaller than the size in the X direction from the base end of the intermediate portion to the tip of the intermediate portion. From the state before the depressurization stage, the inside of the outer film is depressurized. All-solid-state battery manufacturing method.

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