Battery, battery manufacturing apparatus, and battery manufacturing method

Abstract

To provide a battery, a battery manufacturing apparatus, and a battery manufacturing method that can improve the quality of a battery and thereby contribute to the efficiency of volumetric energy density.SOLUTION: An all-solid-state battery cell 1 includes an electrode laminate 2, an exterior body 3, and a bent portion 55. The bent portion 55 includes a first extending portion 57, a second extending portion 58 folded back from a tip portion 57a of the first extending portion 57, and a third extending portion 59 folded back from a tip portion 58a of the second extending portion 58. A length L between the tip portion 57a of the first extending portion 57 and the tip portion 58a of the second extending portion 58 is longer than a thickness H of the electrode laminate 2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a battery, a battery manufacturing apparatus, and a battery manufacturing method. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transportation systems have been gaining momentum. Toward this goal, development of all-solid-state battery cells, for example, as batteries, is underway. An all-solid-state battery cell has an electrode stack in which a positive electrode layer, a negative electrode layer facing the positive electrode layer in the thickness direction, and a solid electrolyte layer placed between the positive electrode layer and the negative electrode layer are stacked. The electrode stack is covered with an exterior body such as a laminate film. An all-solid-state battery module is formed by stacking multiple such all-solid-state battery cells.

[0003] Here, a peripheral edge portion is formed on the outer periphery of the electrode laminate in order to seal the electrode laminate. The peripheral edge portion is formed by overlapping the outer peripheries of the electrode laminate and heat-welding them. For example, when two laminate films are overlapped in the thickness direction of the electrode laminate and the peripheries are heat-welded, peripheral edges are formed on all four sides. For example, when one laminate film is folded to cover both sides in the thickness direction of the electrode laminate, three sides excluding the folded portion are heat-welded, and peripheral edges are formed on those three sides. When all-solid-state battery cells having such peripheral edges that are not processed in any way are stacked to form an all-solid-state battery module, the volumetric energy density of the all-solid-state battery is significantly reduced.

[0004] For this reason, a technique has been disclosed for improving the volumetric efficiency of an all-solid-state battery by folding the peripheral edge portions to reduce the size of the all-solid-state battery cell or all-solid-state battery module (see, for example, Patent Document 1). One method for bending the peripheral portion of the outer casing includes a step of abutting a pressure plate against the starting point of the bending of the peripheral portion, and a step of bending the peripheral portion by pressing the peripheral portion against the pressure plate using a pressing plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6935784 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-mentioned conventional technology, since the pressing plate is simply abutted against the starting point of the folding of the peripheral edge portion, the load when bending the peripheral edge portion is transmitted to the electrode laminate, which may result in damage to the electrode laminate. In particular, if the peripheral edge portion is folded multiple times rather than simply folded in half, there is a possibility that an additional load will be applied to the electrode laminate. In such cases, there is a problem that the quality of the all-solid-state battery will be deteriorated. Furthermore, if the pressing load when folding the peripheral edge portion is reduced in order to improve the quality of the all-solid-state battery cell, there is a problem in that it becomes difficult to reduce the size of the all-solid-state battery cell or all-solid-state battery module.

[0007] Therefore, the present invention provides a battery, a battery manufacturing apparatus, and a battery manufacturing method that can improve quality and ultimately contribute to more efficient volumetric energy density. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. (1) A battery according to the present invention (e.g., the all-solid-state battery cell 1 of the embodiments) includes an electrode laminate (e.g., the electrode laminate 2 of the embodiments), an outer periphery of the electrode laminate (e.g., the outer periphery 2a of the embodiments) overlapped to form a peripheral edge portion (e.g., the peripheral edge portion 52 of the embodiments), thereby forming an exterior body (e.g., the exterior body 3 of the embodiments) that covers the entire electrode laminate, and a bent portion (e.g., the bent portion 55 of the embodiments) formed by folding the peripheral edge portion along one side of the outer periphery of the electrode laminate, the bent portion including a first extension portion (e.g., the first extension portion 57 of the embodiments) bent in a first direction in the thickness direction of the electrode laminate from a root portion (e.g., the root portion 56 of the embodiments) of the peripheral edge portion closer to the outer periphery, The electrode laminate includes a second extension portion (e.g., second extension portion 58 in the embodiment) that is folded from the tip end of the first extension portion (e.g., tip end 57a in the embodiment) in a second direction opposite to the first direction in the thickness direction of the electrode laminate, and a third extension portion (e.g., third extension portion 59 in the embodiment) that is bent from the tip end of the second extension portion (e.g., tip end 58a in the embodiment) in the same direction as the first extension portion and extends toward the base portion in the first direction, and the length between the tip end of the first extension portion and the tip end of the second extension portion (e.g., length L in the embodiment) is longer than the thickness of the electrode laminate (e.g., thickness H in the embodiment).

[0009] By forming the bent portions in this way, the battery can be made smaller and the volumetric energy density can be made more efficient. Here, the load required for bending tends to be large at the tip of the folded first extension portion and the tip of the second extension portion among the bent portions. By positioning these portions on the outer side of the electrode stack in the thickness direction when viewed from the surface direction of the electrode stack, it is possible to reliably prevent the load of the pressing portion when folding the peripheral edge portion from being transmitted to the electrode stack. This improves the quality of the battery.

[0010] (2) A battery manufacturing apparatus according to the present invention (e.g., battery manufacturing apparatus 100 in the embodiment) is a battery manufacturing apparatus that folds the peripheral portion of an outer casing that entirely covers the electrode stack by covering the electrode stack from both sides in the thickness direction and overlapping the outer periphery of the electrode stack to form a peripheral portion, and is equipped with a clamping portion (e.g., clamping portion 101 in the embodiment) that grips the base portion of the peripheral portion of the electrode stack near the outer periphery so as to avoid gripping both sides in the thickness direction of the electrode stack in the outer casing, and a pressing portion (e.g., pressing portion 102 in the embodiment) that presses the excess portion of the peripheral portion that protrudes from the clamping portion toward the clamping portion and bends the excess portion of the peripheral portion.

[0011] This configuration allows the clamp portion to reliably bear the load of the pressing portion when folding the peripheral edge portion. The clamp portion grips the peripheral edge portion while avoiding gripping both sides of the electrode stack in the thickness direction of the outer casing, thereby preventing the load received by the clamp portion from being transmitted to the electrode stack. Moreover, the clamp portion grips the base portion of the peripheral edge portion near the outer periphery of the electrode stack, allowing the excess portion of the peripheral edge portion to be reliably folded. This improves the quality of the battery and ultimately contributes to more efficient volumetric energy density.

[0012] (3) In the above configuration, the excess peripheral edge portion may include a first extension portion bent from the base portion in a first direction in the thickness direction of the electrode stack, and a second extension portion bent from the tip of the first extension portion in a second direction opposite to the first direction in the thickness direction of the electrode stack.

[0013] By using the first and second extensions configured in this manner, it is possible to ensure contact between the exterior body and the heat transfer member, for example. This makes it possible to efficiently adjust the temperature of the electrode stack via the heat transfer member. As a result, it is possible to improve the performance of the battery and extend its lifespan.

[0014] (4) In the above configuration, the excess peripheral portion may include a third extension portion that is bent from the tip of the second extension portion in the same direction as the first extension portion and extends toward the first direction to the base portion.

[0015] This configuration makes it easier to form the curved portion of the periphery flat, thereby reducing unevenness at the curved portion of the periphery and enabling, for example, close contact between the exterior body and the heat transfer member.

[0016] (5) In the above configuration, at least one of the tip end of the first extension portion and the tip end of the second extension portion may be located outside the electrode stack in the thickness direction when viewed from a surface direction of the electrode stack that is perpendicular to the thickness direction of the electrode stack.

[0017] Here, the load from the pressing portion tends to be large at the portion where the peripheral portion is bent (the folded portion). By positioning such a portion on the outer side of the electrode stack in the thickness direction when viewed from the surface direction of the electrode stack, it is possible to reliably prevent the load from the pressing portion when the peripheral portion is folded from being transmitted to the electrode stack.

[0018] (6) In the above configuration, the clamp portion may have a base portion (e.g., base portion 105 in the embodiment) provided at a position overlapping the tip portion of the first extension portion and the tip portion of the second extension portion when viewed from the surface direction of the electrode stack.

[0019] This configuration ensures that the load from the pressing portion applied to the bent portion (folded portion) of the peripheral edge portion can be reliably transmitted to the base portion of the clamping portion. This more reliably prevents damage to the electrode stack. Furthermore, because the pressing portion and the base portion can reliably bend the peripheral edge portion, the bending properties of the bent portion can be improved.

[0020] (7) A battery manufacturing method according to the present invention is a battery manufacturing method in which the peripheral portion of an outer casing that entirely covers the electrode stack is folded by covering the electrode stack from both sides in the thickness direction and overlapping the outer periphery of the electrode stack to form a peripheral portion, and includes a gripping step of gripping a base portion of the peripheral portion of the electrode stack near the outer periphery so as to avoid gripping both sides of the electrode stack in the thickness direction of the outer casing, and a pressing step of pressing an excess portion of the peripheral portion that protrudes on the opposite side of the electrode stack from the gripped portion toward the electrode stack, thereby bending the excess portion of the peripheral portion.

[0021] This method prevents the load applied when folding the peripheral edge from being transmitted to the electrode stack. Furthermore, in the gripping process, the base of the peripheral edge near the outer periphery of the electrode stack is gripped, ensuring that the excess portion of the outer periphery is folded. This improves the quality of the battery and ultimately contributes to more efficient volumetric energy density.

[0022] (8) The pressing step of the above method may include a first extension portion forming step of bending the excess peripheral edge portion from the base portion in a first direction in the thickness direction of the electrode stack to form a first extension portion, and a second extension portion forming step of folding back the excess peripheral edge portion from the tip portion of the first extension portion in a second direction opposite to the first direction in the thickness direction of the electrode stack to form a second extension portion.

[0023] This method allows the formation of a first extension portion and a second extension portion. Using the first extension portion and the second extension portion, for example, the exterior body and the heat transfer member can be reliably contacted. This makes it possible to efficiently adjust the temperature of the electrode stack via the heat transfer member. As a result, it is possible to improve the performance of the battery and extend its lifespan.

[0024] (9) The pressing step of the above method may include a third extension portion forming step of forming a third extension portion that bends from the tip of the second extension portion in the same direction as the first extension portion and extends toward the first direction to the base portion.

[0025] This method makes it easier to form the curved portion of the periphery flat, thereby reducing unevenness at the curved portion of the periphery and enabling, for example, close contact between the exterior body and the heat transfer member.

[0026] (10) In the above method, in at least one of the second extension portion forming process and the third extension portion forming process, at least one of the tip end of the first extension portion and the tip end of the second extension portion may be bent so as to be positioned outside the electrode laminate in the thickness direction when viewed from a surface direction of the electrode laminate that is perpendicular to the thickness direction of the electrode laminate.

[0027] Here, the load from the pressing portion tends to be large at the portion where the peripheral portion is bent (the folded portion). By positioning such a portion on the outer side of the electrode stack in the thickness direction when viewed from the surface direction of the electrode stack, it is possible to reliably prevent the load from the pressing portion when the peripheral portion is folded from being transmitted to the electrode stack. [Effects of the Invention]

[0028] According to the present invention, the quality of the battery can be improved, which in turn can contribute to the efficiency of the volumetric energy density. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a plan view of an all-solid-state battery according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a plan view of an all-solid-state battery according to an embodiment of the present invention before a bent portion is formed. [Figure 5] 5A to 5C are explanatory diagrams showing a manufacturing process of a bent portion in the embodiment of the present invention. [Figure 6] 5A to 5C are explanatory diagrams showing a manufacturing process of a bent portion in the embodiment of the present invention. [Figure 7] 5A to 5C are explanatory diagrams showing a manufacturing process of a bent portion in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] Next, an embodiment of the present invention will be described with reference to the drawings.

[0031] <All-solid-state battery cell> Fig. 1 is a plan view of an all-solid-state battery cell 1. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. In Fig. 1 and Fig. 2, the scale of each part has been changed as appropriate to make the explanation easier to understand. As shown in FIGS. 1 and 2, the all-solid-state battery cell 1 includes an electrode laminate 2, an exterior body 3 that covers the electrode laminate 2, and two lead tabs 4, 5 (a positive electrode lead tab 4 and a negative electrode lead tab 5) that are drawn out from the electrode laminate 2 via the exterior body 3.

[0032] <Electrode laminate> The electrode stack 2 is formed into a rectangular parallelepiped shape as a whole. The electrode stack 2 mainly comprises two plate-shaped positive electrode layers 6, 7 (first positive electrode layer 6, second positive electrode layer 7), two negative electrode layers 8, 9 (first negative electrode layer 8, second negative electrode layer 9) arranged opposite the positive electrode layers 6, 7 in the thickness direction, and solid electrolyte layers 11, 12 (first solid electrolyte layer 11, second solid electrolyte layer 12) arranged between the positive electrode layers 6, 7 and the negative electrode layers 8, 9, respectively.

[0033] The two positive electrode layers 6, 7 each have a positive electrode active material layer 13. The two positive electrode layers 6, 7 have a common positive electrode current collector 14. The positive electrode active material layers 13 are laminated on both sides of the positive electrode current collector 14. Examples of active materials that constitute the positive electrode active material layers 13 include lithium cobalt oxide, lithium nickel oxide, lithium manganate, lithium metal phosphate, lithium nickel cobalt manganate, and lithium nickel cobalt aluminate.

[0034] The positive electrode current collector 14 is drawn out from the positive electrode active material layers 13 in a direction perpendicular to the stacking direction (hereinafter simply referred to as the stacking direction) of these positive electrode active material layers 13. The positive electrode current collector 14 is formed of a metal foil, a metal sheet, or a metal plate made of, for example, aluminum, copper, stainless steel, or the like. In the following description, the direction perpendicular to the stacking direction will be referred to as the “plane direction.” The stacking direction is also the thickness direction of the electrode stack 2.

[0035] The first negative electrode layer 8 of the two negative electrode layers 8, 9 is disposed opposite the first positive electrode layer 6 of the two positive electrode layers 6, 7 in the stacking direction. The second negative electrode layer 9 of the two negative electrode layers 8, 9 is disposed opposite the second positive electrode layer 7 of the two positive electrode layers 6, 7 in the stacking direction. More specifically, the first negative electrode layer 8 is disposed on the side of the first positive electrode layer 6 opposite the second positive electrode layer 7. The second negative electrode layer 9 is disposed on the side of the second positive electrode layer 7 opposite the first positive electrode layer 6.

[0036] The two negative electrode layers 8, 9 each have a negative electrode active material layer 15. The area of ​​the negative electrode active material layer 15 is larger than the area of ​​the positive electrode active material layer 13. Therefore, the negative electrode active material layer 15 protrudes in the planar direction more than the positive electrode active material layer 13. As a result, a gap G1 is formed between the two negative electrode layers 8, 9 at the outer peripheries of the two negative electrode layers 8, 9. This gap G1 can also be said to be formed at the outer peripheries of the two positive electrode layers 6, 7. In other words, the gap G1 is formed between the positive electrode layers 6, 7 and the negative electrode layers 8, 9.

[0037] Examples of the active material constituting the negative electrode active material layer 15 include lithium-based materials and silicon-based materials. Examples of the lithium-based materials include Li metal and Li alloys. Examples of the silicon-based materials include Si and SiO. Other examples of the active material constituting the negative electrode active material layer 15 include carbon materials such as graphite, soft carbon, and hard carbon, tin-based materials (Sn, SnO, etc.), and lithium titanate.

[0038] A negative electrode current collector 16 is laminated on the opposite side of each negative electrode active material layer 15 from the positive electrode layers 6, 7. The negative electrode current collector 16 is formed of the same material as the positive electrode current collector 14. Each negative electrode current collector 16 is pulled out in the planar direction from the corresponding negative electrode active material layer 15. For example, this pulling direction is opposite to the pulling direction of the positive electrode current collector 14. A tip end 16a of each negative electrode current collector 16 in the pulling direction is bent toward the center in the stacking direction.

[0039] Of the solid electrolyte layers 11, 12, the first solid electrolyte layer 11 is disposed between the first positive electrode layer 6 and the first negative electrode layer 8. Of the solid electrolyte layers 11, 12, the second solid electrolyte layer 12 is disposed between the second positive electrode layer 7 and the second negative electrode layer 9. The area of ​​each of the solid electrolyte layers 11, 12 is equal to the area of ​​the negative electrode active material layer 15. Each of the solid electrolyte layers 11 and 12 is formed of, for example, a solid electrolyte having ion conductivity. Examples of the material of the solid electrolyte layers 11 and 12 include a sulfide-based solid electrolyte material, an oxide-based solid electrolyte material, a nitride-based solid electrolyte material, and a halide-based solid electrolyte material.

[0040] The solid electrolyte layers 11 and 12, the positive electrode active material layer 13, and the negative electrode active material layer 15 may be formed by binding particles of the materials that make them up with an organic polymer compound binder.

[0041] <Exterior body> The exterior body 3 is formed, for example, by folding the laminate film 21 that forms this exterior body 3 in half. The laminate film 21 is formed, for example, by covering the front and back surfaces of a metal layer with a resin layer (insulating layer). By forming the exterior body 3 with the laminate film 21, the exterior body 3 has flexibility that can follow the expansion and contraction of the electrode stack 2. The flexibility that can follow the expansion and contraction of the electrode stack 2 can be obtained by the way in which the exterior body 3 wraps around the electrode stack 2, its shape, structure, etc.

[0042] The exterior housing 3 is integrally formed with a covering portion 51 that covers the entire electrode stack 2 and a peripheral portion 52 that is formed around the covering portion 51. The covering portion 51 is formed in a rectangular parallelepiped shape to correspond to the shape of the electrode stack 2. That is, the covering portion 51 is integrally formed with a pair of end surface covering portions 53 that cover the negative electrode current collector 16a from the outside in the stacking direction, and a side surface covering portion 54 that is joined to the outer edges of these end surface covering portions 53 and covers the outer peripheral portion 2a of the electrode stack 2. The outer peripheral portion 2a of the electrode stack 2 is the outer side surface in the surface direction. Therefore, the side surface covering portion 54 has a long side surface covering portion 54a that faces each other in the short direction when viewed from the stacking direction, and a pair of short side surface covering portions 54b that face each other in the longitudinal direction.

[0043] The peripheral edge portion 52 is formed by overlapping the peripheral edges of the side surface covering portions 54 on the opposite side from the end surface covering portions 53 in the stacking direction. Therefore, the peripheral edge portion 52 has a pair of long peripheral edge portions 52a formed on the long side surface covering portion 54a side and a pair of short peripheral edge portions 52b formed on the short side surface covering portion 54b side. Each peripheral edge portion 52a, 52b is formed in the center of each side surface covering portion 54a, 54b in the stacking direction. One of the pair of long peripheral edges 52a has a large excess portion 50. A bent portion 55 is formed by folding this excess portion 50 (excess portion of long peripheral edge 52a).

[0044] The bent portion 55 will be described in detail with reference to FIG. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. In the following description, one of the stacking directions (downward in Fig. 3) is referred to as a first direction, and the opposite direction (upward in Fig. 3) is referred to as a second direction. As shown in Figures 1 and 3, the bent portion 55 has a first extension portion 57 bent from a root portion 56 of the excess portion 50 near the outer peripheral portion 2a of the electrode stack 2, a second extension portion 58 bent from a tip portion 57a ​​of the first extension portion 57 opposite the root portion 56, and a third extension portion 59 bent from a tip portion 58a of the second extension portion 58 opposite the first extension portion 57.

[0045] The first extending portion 57 extends from the base portion 56 in the first direction. The first extending portion 57 is formed flat along the stacking direction. A small gap G2 is formed between the first extending portion 57 and the long side surface covering portion 54a. The first extending portion 57 extends outward in the stacking direction beyond the negative electrode current collector 16 as viewed in the surface direction. In other words, the tip portion 57a ​​of the first extending portion 57 is located outward in the stacking direction of the electrode stack 2 as viewed in the surface direction.

[0046] The second extension portion 58 is formed by folding back the tip portion 57a ​​of the first extension portion 57 to the side opposite the electrode stack 2 and then extending in the second direction. The second extension portion 58 is formed flat along the stacking direction. The second extension portion 58 is superimposed on the surface of the first extension portion 57 opposite the electrode stack 2. The second extension portion 58 extends outward in the stacking direction beyond the negative electrode current collector 16 as viewed in the planar direction. In other words, the tip portion 58a of the second extension portion 58 is located outside the side opposite to the tip portion 57a ​​of the first extension portion 57 of the electrode stack 2 as viewed in the planar direction. That is, the length L between the tip 57 a of the first extending portion 57 and the tip 58 a of the second extending portion 58 is longer than the thickness H of the electrode stack 2 .

[0047] The third extension portion 59 is formed by folding back the tip portion 58a of the second extension portion 58 toward the electrode stack 2 and then extending in the first direction. The third extension portion 59 is formed flat along the stacking direction. The third extension portion 59 is superimposed on the surface of the second extension portion 58 facing the electrode stack 2. In other words, the third extension portion 59 is located on the same plane as the first extension portion 57 in the stacking direction. The third extension portion 59 extends to just before the base portion 56. In other words, the tip portion 59a of the third extension portion 59 is located close to the base portion 56.

[0048] <Lead Tab> 1 and 2, of the two lead tabs 4, 5, one end of the positive electrode lead tab 4 is connected to the tip portion 14a of the positive electrode current collector 14. The positive electrode lead tab 4 extends in the planar direction. The other end of the positive electrode lead tab 4 is drawn out to the outside of the exterior body 3 via the short peripheral edge portion 52b of the exterior body 3. Of the two lead tabs 4, 5, one end of the negative electrode lead tab 5 is connected to a tip portion 16a of a negative electrode current collector 16 on each of both sides. The negative electrode lead tab 5 extends in the planar direction. The extending direction of the negative electrode lead tab 5 is, for example, the opposite side to the positive electrode lead tab 4. The other end of the negative electrode lead tab 5 is drawn out of the exterior body 3 via a short peripheral edge portion 52b of the exterior body 3.

[0049] The two lead tabs 4 and 5 are formed, for example, from a conductive metal sheet or plate. Such an all-solid-state battery cell 1 is connected to a charger or an electrical load via two lead tabs 4, 5, thereby charging or discharging the electrode stack 2.

[0050] <Battery manufacturing device and battery manufacturing method> Next, a battery manufacturing apparatus 100 for forming the bent portion 55 of the all-solid-state battery cell 1 and a battery manufacturing method for the bent portion 55 using the battery manufacturing apparatus 100 will be described with reference to FIGS. Fig. 4 is a plan view of the all-solid-state battery cell 1 before forming the bent portion 55. Fig. 4 corresponds to the above-mentioned Fig. 1. Figs. 5 to 7 are explanatory views showing the manufacturing process of the bent portion 55. Figs. 5 to 7 correspond to the above-mentioned Fig. 3.

[0051] As shown in FIGS. 4 and 5, in the all-solid-state battery cell 1 before the bent portion 55 is formed, the excess portion 50 protrudes in the planar direction. The battery manufacturing apparatus 100 includes a clamping portion 101 that grips the excess portion 50 from both sides in the stacking direction, and a pressing portion 102 that presses the excess portion 50 protruding from the clamping portion 101 toward the clamping portion 101.

[0052] The clamp unit 101 includes a pair of gripping portions 103 and 104. The pair of gripping portions 103 and 104 (first gripping portion 103 and second gripping portion 104) are arranged symmetrically with respect to the electrode stack 2. For this reason, in the following description, only the first gripping portion 103 of the pair of gripping portions 103 and 104 will be described. The second gripping portion 104 of the pair of gripping portions 103 and 104 will be denoted by the same reference numeral as the first gripping portion 103 and will not be described again.

[0053] The first gripping portion 103 includes a base portion 105 disposed opposite the end surface covering portion 53 at a predetermined distance G3 in the stacking direction, and claw portions 106 provided at the end portions of the base portion 105 in the surface direction. The claw portions 106 protrude in directions facing each other from the base portion 105. The gripping portions 103, 104 are arranged so that they can move toward and away from each other.

[0054] The pressing portion 102 is disposed on the opposite side of the claw portion 106 from the all-solid-state battery cell 1. The pressing portion 102 has a flat surface 102a that faces the outer periphery 2a of the electrode stack 2 in the planar direction. The flat surface 102a is aligned with the stacking direction. The pressing portion 102 is provided so as to be able to approach and move away from the claw portion 106.

[0055] With this configuration, as shown in FIG. 5, first, the gripping portions 103 and 104 are brought close to each other, and the base portion 56 of the excess portion 50 is gripped by the claw portions 106 (gripping step). At this time, the base portion 105 is disposed opposite the end surface covering portion 53 with a predetermined gap G3 in the stacking direction, thereby avoiding contact between the base portion 105 and the end surface covering portion 53. In other words, the clamp portion 101 grips the root portion 56 while avoiding gripping the end surface covering portion 53.

[0056] 6, using a jig (not shown), the excess portion of the excess portion 50 that protrudes from the clamp portion 101 to the opposite side from the electrode stack 2 is pressed by the pressing portion 102 (pressing step). The pressing portion 102 presses the excess portion 50 toward the clamp portion 101. As a result, a bent portion 55 is formed.

[0057] In this pressing step, first, using a jig (not shown), the excess portion 50 is bent in the first direction starting from the claw portion 106. This roughly forms the first extending portion 57 (first extending portion forming step). The tip end 57a of the first extension portion 57 is folded back in the second direction, away from the electrode stack 2. This forms the second extension portion 58 (second extension portion forming step). The tip end 58a of the second extending portion 58 is folded back toward the electrode stack 2 in the first direction, thereby forming a third extending portion 59 (third extending portion forming step).

[0058] 7, the pressing portion 102 presses the extension portions 57, 58, and 59 until the extension portions 57, 58, and 59 are sandwiched between the pressing portion 102 and the claw portion 106. This completely folds the excess portion 50, completing the manufacture of the bent portion 55. At this time, a gap G2 is formed between the first extension portion 57 and the long side surface covering portion 54a, the gap being equal to the thickness of the claw portion 106.

[0059] Incidentally, a tip 57a of the first extending portion 57, which is the folding point from the first extending portion 57 to the second extending portion 58, and a tip 58a of the second extending portion 58, which is the folding point from the second extending portion 58 to the third extending portion 59, are located outside in the stacking direction of the electrode stack 2 when viewed from the surface direction. The positions of these tip portions 57a, 58a are positions that overlap with the base portion 105 when viewed from the surface direction.

[0060] Here, the load applied to the bent portion 55 by the pressing portion 102 tends to be large at the folded portion of the bent portion 55. By positioning such a portion further outward in the stacking direction than the electrode stack 2 when viewed from the surface direction, it is possible to prevent the load F of the pressing portion 102, which is applied to the folded portion when forming the bent portion 55, from being transmitted to the electrode stack 2. Moreover, the avoided load F is reliably borne by the base portion 105.

[0061] In this way, the all-solid-state battery cell 1 described above has the excess portion 50 folded to form the bent portion 55. This allows the all-solid-state battery cell 1 to be miniaturized, and the volumetric energy density can be efficiently improved. The bent portion 55 has a first extending portion 57, a second extending portion 58, and a third extending portion 59. The length L between the tip end 57a of the first extending portion 57 and the tip end 58a of the second extending portion 58 is longer than the thickness H of the electrode stack 2. This makes it possible to prevent the load F of the pressing portion 102 applied to the folded portion when forming the bent portion 55 from being transmitted to the electrode stack 2. This makes it possible to prevent damage to the electrode stack 2 and improve the quality of the all-solid-state battery cell 1.

[0062] The above-described battery manufacturing apparatus 100 includes a clamping unit 101 and a pressing unit 102. Therefore, the clamping unit 101 can reliably bear the load of the pressing unit 102 when forming the bent portion 55, that is, the load of the pressing unit 102 when folding the surplus portion 50. The clamping unit 101 grips the surplus portion 50 (long peripheral edge portion 52a) while avoiding gripping the end surface covering portion 53, that is, while avoiding gripping both sides of the exterior body 3 in the stacking direction of the electrode stack 2. This prevents the load received by the clamping unit 101 from being transmitted to the electrode stack 2. Moreover, because the clamping unit 101 grips the base portion 56 of the surplus portion 50, the surplus portion 50 can be reliably folded. This improves the quality of the all-solid-state battery cell 1, which in turn contributes to improving the efficiency of volumetric energy density.

[0063] The bent portion 55 has a first extending portion 57 and a second extending portion 58, and thus the first extending portion 57 and the second extending portion 58 can be used to ensure contact between, for example, the exterior body 3 and a heat transfer member (not shown). A heat transfer member is a member that easily transfers heat. Examples include aluminum alloys and copper alloys. This makes it possible to efficiently adjust the temperature of the electrode stack 2 via the heat transfer member. More specifically, the electrode stack 2 can be easily heated or cooled. As a result, it is possible to improve the performance of the all-solid-state battery cell 1 and extend its lifespan.

[0064] Bent portion 55 further has third extending portion 59, which makes it easier to form bent portion 55 flat. As a result, irregularities in bent portion 55 can be reduced, and it becomes possible to bring exterior body 3 and a heat transfer member (not shown) into close contact with each other, for example. The tip 57a of the first extending portion 57 and the tip 58a of the second extending portion 58 are located outside in the stacking direction of the electrode stack 2. This prevents the load F of the pressing portion 102, which is applied to the folded portion when forming the bent portion 55, from being transmitted to the electrode stack 2. This prevents damage to the electrode stack 2.

[0065] The positions of the tip 57a of the first extending portion 57 and the tip 58a of the second extending portion 58 are such that they overlap the base portion 105 when viewed from the surface direction. Therefore, the load F of the pressing portion 102 that is applied to the folded portion when forming the bent portion 55 can be reliably received by the base portion 105. This can effectively prevent the load F from being transmitted to the electrode stack 2. Therefore, damage to the electrode stack 2 can be more reliably prevented. Furthermore, because the bent portion 55 can be reliably formed by the base portion 105 and the pressing portion 102, the bending properties of the bent portion 55 can be improved.

[0066] The method for manufacturing the bent portion 55 includes a gripping step and a pressing step. By using such a method, it is possible to prevent the load applied when folding the surplus portion 50 from being transmitted to the electrode stack 2. Moreover, since the base portion 56 of the surplus portion 50 is gripped in the gripping step, the surplus portion 50 can be folded reliably. This improves the quality of the all-solid-state battery cell 1, which in turn contributes to more efficient volumetric energy density.

[0067] The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.

[0068] For example, in the above-described embodiment, the area of ​​the negative electrode active material layer 15 is larger than the area of ​​the positive electrode active material layer 13. The area of ​​each of the solid electrolyte layers 11, 12 is equal to the area of ​​the negative electrode active material layer 15. However, this is not limited thereto, and the area of ​​the positive electrode active material layer 13, the area of ​​the negative electrode active material layer 15, and the area of ​​each of the solid electrolyte layers 11, 12 can be determined arbitrarily. For example, the area of ​​each of the solid electrolyte layers 11, 12 may be smaller than the area of ​​the positive electrode active material layer 13 or the area of ​​the negative electrode active material layer 15. The area of ​​the positive electrode active material layer 13 may be larger than the area of ​​the negative electrode active material layer 15.

[0069] In the above-described embodiment, the battery is described as having two positive electrode layers 6, 7 and two negative electrode layers 8, 9. However, the present invention is not limited to this, and the number of positive electrode layers and negative electrode layers may be one layer or three or more layers. The solid electrolyte layers 11, 12 may be disposed between the positive electrode layers and the negative electrode layers.

[0070] In the above-described embodiment, the first negative electrode layer 8 is disposed on the opposite side of the first positive electrode layer 6 from the second positive electrode layer 7. The second negative electrode layer 9 is disposed on the opposite side of the second positive electrode layer 7 from the first positive electrode layer 6. However, this is not limiting, and the positions of the positive electrode layers 6, 7 and the negative electrode layers 8, 9 may be reversed.

[0071] In the above embodiment, the third extending portion 59 is bent and formed at the tip end 58a of the second extending portion 58 in the bending portion 55. However, the present invention is not limited to this, and the bending portion 55 may have at least the first extending portion 57 and the second extending portion 58.

[0072] In the above-described embodiment, the case where the tip 57a of the first extending portion 57 and the tip 58a of the second extending portion 58 are each located outside in the stacking direction of the electrode stack 2 as viewed from the surface direction has been described. However, this is not limited to this, and it is sufficient that at least one of the tip 57a of the first extending portion 57 or the tip 58a of the second extending portion 58 is located outside in the stacking direction of the electrode stack 2 as viewed from the surface direction. Even in this configuration, damage to the electrode stack 2 when forming the bent portion 55 can be suppressed compared to a case where the tip portions 57a, 58a are not located outside in the stacking direction of the electrode stack 2 as viewed from the surface direction. [Explanation of symbols]

[0073] 1...All-solid-state battery cell (battery) 2...Electrode laminate 2a…Outer periphery 3...Exterior body 50...Excess part (surplus) 51...Covering part (exterior body) 52...periphery 52a...Long peripheral portion (periphery) 52b...short peripheral part (peripheral part) 53…End face covering part (exterior body) 54...Side covering part (exterior body) 54a... Long side covering part (exterior body) 54b…Short side covering part (exterior body) 55...Bend 57...First extension part 57a...Tip 58…Second extension part 58a...Tip 59...Third extension part 58a...Tip 100...Battery manufacturing equipment 101...Clamp section 102...Pressing part 105...Base H: Thickness L...length

Claims

1. an electrode stack; an exterior body that covers the entire electrode stack by overlapping the outer periphery of the electrode stack to form a peripheral edge portion; a bent portion formed by folding the peripheral edge portion along one side of the outer periphery of the electrode stack; Equipped with The bent portion is a first extending portion bent from a base portion of the peripheral edge portion closer to the outer periphery in a first direction in the thickness direction of the electrode stack; a second extension portion folded back from a tip end of the first extension portion in a second direction opposite to the first direction in the thickness direction of the electrode stack; a third extending portion bent from a tip end of the second extending portion in the same direction as the first extending portion and extending in the first direction to the root portion; Including, a length between the tip end of the first extension portion and the tip end of the second extension portion is longer than a thickness of the electrode stack; A battery characterized by:

2. A battery manufacturing apparatus that covers an electrode laminate from both sides in a thickness direction, overlaps an outer periphery of the electrode laminate to form a peripheral edge portion, and folds the peripheral edge portion of an exterior body that covers the entire electrode laminate, a clamping portion configured to hold a base portion of the electrode stack near the outer periphery of the peripheral edge portion of the electrode stack in a manner to avoid holding both sides of the electrode stack in a thickness direction of the exterior body; a pressing portion that presses an excess portion of the peripheral edge portion that protrudes from the clamping portion toward the opposite side of the electrode stack toward the clamping portion, thereby bending the excess portion of the peripheral edge portion; Equipped with A battery manufacturing apparatus characterized by:

3. The excess peripheral portion is a first extending portion bent from the base portion in a first direction in the thickness direction of the electrode stack; a second extension portion folded back from a tip end of the first extension portion in a second direction opposite to the first direction in the thickness direction of the electrode stack; Including, 3. The battery manufacturing apparatus according to claim 2.

4. The surplus peripheral edge portion includes a third extension portion that is bent from a tip end of the second extension portion in the same direction as the first extension portion and extends in the first direction to the base portion.

4. The battery manufacturing apparatus according to claim 3.

5. At least one of the tip end of the first extension portion and the tip end of the second extension portion is located on the outer side of the electrode stack in the thickness direction when viewed from a surface direction of the electrode stack that is perpendicular to the thickness direction of the electrode stack.

5. The battery manufacturing apparatus according to claim 4.

6. the clamping portion has a base portion provided at a position overlapping the tip end portion of the first extending portion and the tip end portion of the second extending portion when viewed from the surface direction of the electrode stack; 6. The battery manufacturing apparatus according to claim 5.

7. A battery manufacturing method including: covering an electrode laminate from both sides in a thickness direction; overlapping an outer periphery of the electrode laminate to form a peripheral edge portion; and folding the peripheral edge portion of an exterior body that entirely covers the electrode laminate, a gripping step of gripping a base portion of the electrode stack near the outer periphery of the peripheral edge portion of the electrode stack in the outer casing so as to avoid gripping both sides of the electrode stack in the thickness direction of the outer casing; a pressing step of pressing an excess portion of the peripheral edge portion protruding on the opposite side of the electrode stack from the gripped portion toward the electrode stack to bend the excess portion of the peripheral edge portion; having A battery manufacturing method comprising:

8. In the pressing step, a first extension portion forming step of bending the excess peripheral edge portion from the base portion in a first direction in the thickness direction of the electrode stack to form a first extension portion; a second extension portion forming step of folding back the first extension portion from a tip end portion thereof in a second direction opposite to the first direction in the thickness direction of the electrode stack to form a second extension portion; having 8. The battery manufacturing method according to claim 7.

9. In the pressing step, a third extending portion forming step of forming a third extending portion that is bent from a tip end of the second extending portion in the same direction as the first extending portion and extends in the first direction to the root end, 9. The battery manufacturing method according to claim 8.

10. In at least one of the second extension portion forming step and the third extension portion forming step, at least one of the tip end portion of the first extension portion and the tip end portion of the second extension portion is bent so as to be positioned outward in the thickness direction from the electrode stack when viewed from a surface direction of the electrode stack that is perpendicular to the thickness direction of the electrode stack.

10. The battery manufacturing method according to claim 9.

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