Battery case and battery

Abstract

To provide a battery case capable of obtaining a satisfactory volume energy density.SOLUTION: A battery case for storing an electrode body has a hollow structure, and the hollow structure includes a first face, a second face opposed to the first face, a third face connecting the first face and the second face, and a fourth face opposed to the third face. The battery case includes a projected structure in which when a boundary part between the third face and the first face is defined as B1, a boundary part between the third face and the second face is defined as B2, and a line segment connecting B1 and B2 is defined as L12 in a side face view of the hollow structure in an axial direction, the third face has an apex at a position closer to the fourth face than L12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to battery cases and batteries. [Background technology]

[0002] A battery comprises an electrode body and an outer casing that houses the electrode body. For example, Patent Document 1 discloses a stacked battery having a laminated outer casing. Patent Document 1 also discloses that a pressing member is placed on at least one of the circumferential surfaces of the stacked electrode body to press the stacked electrode body inward towards the battery. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-181897 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] For example, when a pressing member is arranged as in Patent Document 1, the volumetric energy density of the battery tends to decrease. This disclosure has been made in view of the above circumstances, and its main objective is to provide a battery case that can obtain a good volumetric energy density. [Means for solving the problem]

[0005] In this disclosure, a battery case for housing an electrode body is provided, the battery case having a hollow structure, the hollow structure having a first surface, a second surface opposite the first surface, a third surface connecting the first surface and the second surface, and a fourth surface opposite the third surface, and in an axial side view of the hollow structure, the boundary between the third surface and the first surface is denoted as B1, the boundary between the third surface and the second surface is denoted as B2, and the line segment connecting B1 and B2 is denoted as L 12 In that case, the third surface is L 12Provide a battery case including a convex structure having a top at a position closer to the fourth surface side than the above.

[0006] According to the present disclosure, since the third surface includes a predetermined convex structure, a battery case with a good volumetric energy density can be obtained.

[0007] In the above disclosure, the electrode body has a fifth surface, a sixth surface facing the fifth surface, a seventh surface connecting the fifth surface and the sixth surface, and an eighth surface facing the seventh surface. The fifth surface, the sixth surface, the seventh surface, and the eighth surface may each have a positional relationship corresponding to the first surface, the second surface, the third surface, and the fourth surface, respectively.

[0008] In the above disclosure, the distance between the position on the third surface closest to the fourth surface and the fourth surface is H C1 Let the distance between the seventh surface and the eighth surface be H E In the case of, the above H C1 And the above H E Are, H C1 ≦H E May be satisfied.

[0009] In the above disclosure, the distance between the position on the third surface farthest from the fourth surface and the fourth surface is H C2 Let the distance between the seventh surface and the eighth surface be H E In the case of, the above H C2 And the above H E Are, H C2 ≧H E May be satisfied.

[0010] In the above disclosure, the distance between the first surface and the second surface is W C Let the distance between the fifth surface and the sixth surface be W E In the case of, the above W C And the above W E Are, W C ≦W E May be satisfied.

[0011] In the above disclosure, a battery comprising an electrode body and a battery case housing the electrode body, wherein the battery case has a hollow structure, the hollow structure having a first surface, a second surface facing the first surface, a third surface connecting the first surface and the second surface, and a fourth surface facing the third surface, and in an axial side view of the hollow structure, the boundary between the third surface and the first surface is denoted as B1, the boundary between the third surface and the second surface is denoted as B2, and the line segment connecting B1 and B2 is denoted as L 12 In that case, the third surface is L 12 The present invention provides a battery that includes a convex structure having its apex at a position closer to the fourth surface than the electrode body, the electrode body having a fifth surface, a sixth surface facing the fifth surface, a seventh surface connecting the fifth surface and the sixth surface, and an eighth surface facing the seventh surface, the fifth surface, the sixth surface, the seventh surface and the eighth surface being in a positional relationship corresponding to the first surface, the second surface, the third surface and the fourth surface, respectively, the fourth surface of the battery case and the eighth surface of the electrode body being in contact, and the apex of the third surface of the battery case and the seventh surface of the electrode body being in contact.

[0012] According to this disclosure, the fourth surface of the battery case is in contact with the eighth surface of the electrode body, and the top of the third surface of the battery case is in contact with the seventh surface of the electrode body, resulting in a battery with good volumetric energy density.

[0013] In the above disclosure, the first surface of the battery case and the fifth surface of the electrode body may be in contact, and the second surface of the battery case and the sixth surface of the electrode body may be in contact.

[0014] In the above disclosure, the battery may include a side case disposed on the side of the battery case.

[0015] In the above disclosure, the side case may include a concave shape corresponding to the convex structure. [Effects of the Invention]

[0016] This disclosure offers the advantage of providing a battery case that can achieve a good volumetric energy density. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic perspective view illustrating a battery case in this disclosure. [Figure 2] This is a schematic side view illustrating a battery case in this disclosure. [Figure 3] This is a schematic perspective view illustrating the battery in this disclosure. [Figure 4] This is a schematic side view illustrating the battery case and battery in this disclosure. [Figure 5] This is a schematic side view illustrating the battery case and electrode assembly in this disclosure. [Figure 6] This is a schematic side view illustrating a battery case in this disclosure. [Figure 7] This is a schematic side view illustrating a battery case in this disclosure. [Figure 8] This is a schematic side view illustrating a battery case in this disclosure. [Figure 9] This is a schematic side view illustrating a battery in this disclosure. [Figure 10] This is a schematic cross-sectional view illustrating an example of an electrode body in this disclosure. [Figure 11] This is a schematic plan view illustrating a side case in this disclosure. [Modes for carrying out the invention]

[0018] The battery case and battery in this disclosure will be described in detail below. The following figures are schematic representations, and the size and shape of each part have been exaggerated as appropriate for ease of understanding. In addition, hatching indicating the cross-section of the components has been omitted as appropriate in each figure.

[0019] A. Battery case Figure 1 is a schematic perspective view illustrating a battery case in this disclosure. The battery case 10 shown in Figure 1 has a hollow structure. This hollow structure has a first surface S1, a second surface S2 opposite to the first surface S1, a third surface S3 connecting the first surface S1 and the second surface S2, and a fourth surface S4 opposite to the third surface S3. In Figure 1, the first surface S1 and the second surface S2 are opposite each other in the x-axis direction, and the third surface S3 and the fourth surface S4 are opposite each other in the z-axis direction. On the other hand, the sides P and Q of the battery case 10 correspond to openings in the hollow structure, and these two sides are opposite each other in the y-axis direction. That is, the hollow structure shown in Figure 1 has the y-axis direction as its axial direction.

[0020] Figure 2 is a schematic side view illustrating a battery case in this disclosure, and is a schematic side view of the hollow structure in the axial direction. As shown in Figure 2, the boundary between the third surface S3 and the first surface S1 is denoted as B1, the boundary between the third surface S3 and the second surface S2 is denoted as B2, and the line segment connecting B1 and B2 is denoted as L 12 Let's assume that the third surface S3 is L 12 The top C is located on the fourth surface S4 side. T It includes a convex structure having

[0021] According to this disclosure, since the third surface includes a predetermined convex structure, a battery case with good volumetric energy density is obtained. Here, a battery equipped with the battery case according to this disclosure will be explained with reference to Figure 3. In Figure 3, the fourth surface S4 of the battery case 10 is a surface S extending from the first surface S1. 4a And, the surface S extending from the second surface S2 4b It has the following: Surface S 4a and surface S 4b These are arranged so that they overlap each other when viewed from a planar perspective in the height direction (z-axis direction). For example, surface S 4a While moving in the +x direction, surface S 4b By moving it in the -x direction, the battery case 10 flexes, and the surface S in the x-axis direction 4a and surface S 4b A space is created between them. Through this space, the electrode body 20 is placed inside the battery case 10 (within the hollow structure). Surface S 4a and surface S4b After joining the electrodes, a pair of side cases 30 are placed on side P and side Q of the battery case 10, respectively, to seal the electrode body 20.

[0022] As shown in Figure 4(a), the third surface S3 has a top C T It includes a convex structure having C. As shown in Figure 4(b), when the electrode body 20 is placed inside the battery case 10, the electrode body 20 has a convex structure having a convex top C. T The position of the electrode is pushed out in a direction away from the fourth surface S4. As a result, pressure indicated by the black arrow is applied to the electrode body 20, and the position of the electrode body 20 is fixed. In this way, the convex structure on the third surface S3 can fix the position of the electrode body 20, so there is no need to arrange other pressing members. As a result, a battery case with good volumetric energy density is obtained. In addition, laminate-type casings are known as casings used for batteries. In laminate-type casings, a seal portion created by heat-sealing the laminates together is provided so as to surround the main surface of the electrode body in a plan view. In this case, the seal portion becomes a factor that reduces the volumetric energy density. In contrast, as described above, the battery case in this disclosure can have a side case arranged on the side of the battery case. Therefore, there is no need to provide a seal portion so as to surround the main surface of the electrode body. In this respect as well, a battery case with good volumetric energy density is obtained.

[0023] The battery case in this disclosure will be described in more detail below. The battery case in this disclosure has a hollow structure. As shown in Figure 1, the hollow structure has a first surface S1, a second surface S2 facing the first surface S1, a third surface S3 connecting the first surface S1 and the second surface S2, and a fourth surface S4 facing the third surface S3.

[0024] The planar shape of each surface (first, second, third, or fourth surface) of the battery case is not particularly limited, but examples include squares, rectangles, and other rectangular shapes. Furthermore, each surface may be planar, curved, or a combination of two or more planes. The planar shape of the first surface and the planar shape of the second surface may be the same. Similarly, the planar shape of the fourth surface and the planar shape of the third surface may be the same. The area of ​​the first surface is preferably larger than the area of ​​the third surface. Similarly, the area of ​​the first surface is preferably larger than the area of ​​the fourth surface. Furthermore, the first and second surfaces are preferably the surfaces that face the main surface of the electrode body (the surface whose direction of stacking is normal to the stacking direction if the electrode body has a stacked structure) when the electrode body is placed inside the battery case.

[0025] Furthermore, the battery case in this disclosure is used to house the electrode body. As shown in Figure 4(b), the electrode body 20 has a fifth surface S5, a sixth surface S6 opposite the fifth surface S5, a seventh surface S7 connecting the fifth surface S5 and the sixth surface S6, and an eighth surface S8 opposite the seventh surface S7. The fifth surface S5, the sixth surface S6, the seventh surface S7, and the eighth surface S8 are in a positional relationship corresponding to the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4, respectively. Specifically, when the electrode body is placed inside the battery case, the fifth surface S5 becomes the surface opposite the first surface S1. The same applies to the other surfaces.

[0026] The dimensions of the battery case are defined as follows: As shown in Figure 5(a), the distance between the position on the third surface S3 closest to the fourth surface S4 and the fourth surface S4 is H. C1 Let's assume that. H C1 This is typically the distance in the direction connecting the third surface S3 and the fourth surface S4 (the z-axis direction in Figure 2), and is the inner diameter excluding the thickness of the third surface S3 and the fourth surface S4. The position on the third surface S3 closest to the fourth surface S4 is typically the apex C. T This is the position. Also, as shown in Figure 5(a), the distance between the position on the third surface S3 furthest from the fourth surface S4 and the fourth surface S4 is H. C2 Let's assume that. H C2This is typically the distance in the direction connecting the third surface S3 and the fourth surface S4 (the z-axis direction in Figure 2), and is the inner diameter excluding the thickness of the third surface S3 and the fourth surface S4. The position on the third surface S3 furthest from the fourth surface S4 is, for example, the position of boundary B1 or boundary B2. Also, as shown in Figure 5(a), the distance between the first surface S1 and the second surface S2 is W. C Let's assume that. W C This is typically the distance in the direction connecting the first surface S1 and the second surface S2 (the x-axis direction in Figure 2), and is the inner diameter excluding the thickness of the first surface S1 and the second surface S2.

[0027] The dimensions of the electrode body are defined as follows: As shown in Figure 5(b), the distance between the 7th surface S7 and the 8th surface S8 is H. E Let's assume that. H E This is typically the distance in the direction connecting the 7th face S7 and the 8th face S8 (the z-axis direction in Figure 2). Also, as shown in Figure 5(b), the distance between the 5th face S5 and the 6th face S6 is W. E Let's assume that. W E This is typically the distance in the direction connecting the 5th face S5 and the 6th face S6 (the x-axis direction in Figure 2).

[0028] H C1 and H E H C1 ≤H E It is preferable that the following conditions be met. In particular, H C1 <H E In this case, the electrodes are more likely to be fixed in place when they are placed inside the battery case. E H for C1 The proportion (H C1 / H E ) is, for example, 0.90 or higher. On the other hand, H C1 / H E For example, it may be 1.00 or less, 0.99 or less, or 0.97 or less.

[0029] H C2 and H E H C2 ≥H E It is preferable that the following conditions be met. In particular, H C2 >HE In the case where it is [specific condition], when the electrode body is disposed inside the battery case, the electrode body is likely to be fixed. H E For H C2 The ratio (H C2 / H E ) is, for example, 1.00 or more, may be 1.01 or more, or may be 1.03 or more. On the other hand, H C2 / H E is, for example, 1.10 or less.

[0030] W C and W E are preferably such that W C ≦W E is satisfied. In particular, when W C <W E is [specific condition], when the electrode body is disposed inside the battery case, the electrode body is likely to be fixed. W E The ratio of W C to W C / W E ) is, for example, 0.90 or more. On the other hand, W C / W E is, for example, 1.00 or less, may be 0.99 or less, or may be 0.97 or less.

[0031] H C2 and H C1 The difference between them (H C2 -H C1 ) is, for example, 1 mm or more and 3 mm or less. Also, the ratio of H C to W C2 (H C2 / W C ) is, for example, 1 or more, and may be 5 or more. On the other hand, the upper limit of H C2 / W C is not particularly limited.

[0032] The third surface in the present disclosure includes a convex structure having a top at a position closer to the fourth surface than the line segment L 12 . As shown in FIG. 6(a), the top C T may be a point (vertex) in a side view. Also, as shown in FIG. 6(b), the top C TThe top C may be curved in side view. Also, as shown in Figure 6(c), T The surface may be flat in a side view. Also, as shown in Figure 6(d), the convex structure has two or more vertices C T It may have.

[0033] As shown in Figure 7, the thickness of the third surface may be greater than the thickness of the first surface and the thickness of the second surface. Increasing the thickness of the third surface allows for greater pressure on the electrode body. The ratio of the thickness of the third surface to the thickness of the first surface is, for example, 1.1 times, may be 1.5 or more, or 2.0 times or more. On the other hand, the above ratio is, for example, 5.0 times or less. Furthermore, the preferred range for the ratio of the thickness of the third surface to the thickness of the second surface is the same as the preferred range for the ratio of the thickness of the third surface to the thickness of the first surface. The thickness of each surface refers to the average thickness of each surface. One method for increasing the thickness of the third surface is, for example, to join a reinforcing metal sheet to it.

[0034] In this disclosure, the fourth surface is a surface positioned opposite the third surface in the hollow structure. As shown in Figure 8(a), the fourth surface S4 is a surface S extending from the first surface S1. 4a And, the surface S extending from the second surface S2 4b It may have the following. In Figure 8(a), surface S 4a and surface S 4b The overlapping portion is positioned to face the third surface (not shown). Also, as shown in Figure 8(b), the fourth surface S4 is a surface S extending from the first surface S1. 4a It has a surface and does not have to have a surface extending from the second surface S2. In Figure 8(b), surface S 4a The end of is positioned to overlap with the second surface S2. As shown in Figure 8(c), the fourth surface S4 is a surface S extending from the first surface S1. 4a And, the surface S extending from the second surface S2 4b It has and surface S 4a and surface S 4b They do not need to overlap. In this case, surface S 4a and surface S 4bIt is preferable to seal the opening between them using another member. As shown in Figures 8(a) and (b), the hollow structure may have a closed cross section when cut perpendicular to the axial direction. On the other hand, as shown in Figure 8(c), the hollow structure may have an open cross section when cut perpendicular to the axial direction.

[0035] The battery case may or may not have a heat-sealable resin layer on the inner surface of the hollow structure (the side where the electrodes are housed). The material of the battery case is not particularly limited, but examples include metals such as aluminum and stainless steel. Preferably, each surface constituting the hollow structure (first surface, second surface, third surface, and fourth surface) is made from a single metal plate. The thickness of the battery case is not particularly limited, but may be, for example, 0.05 mm or more, or 0.10 mm or more. On the other hand, the thickness of the battery case may be, for example, 0.50 mm or less, or 0.30 mm or less.

[0036] B.Battery Figure 9 is a schematic side view illustrating a battery in this disclosure. The battery 100 shown in Figure 9 comprises an electrode body 20 and a battery case 10 housing the electrode body 20. The fourth surface S4 of the battery case 10 and the eighth surface S8 of the electrode body 20 are in contact. Also, the top C of the third surface S3 of the battery case 10 T The seventh surface S7 of the electrode body 20 is in contact with it.

[0037] According to this disclosure, the fourth surface of the battery case is in contact with the eighth surface of the electrode body, and the top of the third surface of the battery case is in contact with the seventh surface of the electrode body, resulting in a battery with good volumetric energy density.

[0038] 1. Battery case In this disclosure, the battery case is a component that houses the electrode body. The battery case is the same as described in "A. Battery Case" above, so a description is omitted here.

[0039] As shown in Figure 9, the fourth surface S4 of the battery case 10 and the eighth surface S8 of the electrode body 20 are in contact. The fourth surface S4 and the eighth surface S8 may be in point contact or surface contact in a side view in the axial direction of the hollow structure. Also, in Figure 9, the top C of the third surface S3 of the battery case 10. T The seventh surface S7 of the electrode body 20 is in contact with the third surface S3. As shown in Figure 5(a) above, the distance between the position on the third surface S3 closest to the fourth surface S4 and the fourth surface S4 is H C1 Similarly, the distance between the position on the third face S3 that is furthest from the fourth face S4 and the fourth face S4 is H. C2 Let's assume that... Also, as shown in Figure 5(b) above, the distance between the 7th face S7 and the 8th face S8 is H E In the battery described herein, H C1 and H E However, usually, H C1 =H E The following conditions are met. Similarly, in the battery of this disclosure, H C2 and H E However, usually, H C2 >H E It satisfies the condition.

[0040] As shown in Figure 9, it is preferable that the first surface S1 of the battery case 10 and the fifth surface S5 of the electrode body 20 are in contact. The first surface S1 and the fifth surface S5 may be in point contact or surface contact in an axial side view of the hollow structure, but the latter is preferred. It is also preferable that the second surface S2 of the battery case 10 and the sixth surface S6 of the electrode body 20 are in contact. The second surface S2 and the sixth surface S6 may be in point contact or surface contact in an axial side view of the hollow structure, but the latter is preferred. As shown in Figure 5(a) above, the distance between the first surface S1 and the second surface S2 is W C Let's assume that... Also, as shown in Figure 5(b) above, the distance between the fifth face S5 and the sixth face S6 is W E In the battery described herein, W C and W E However, usually, W C =W E It satisfies the condition.

[0041] 2. Electrode body The electrode body in this disclosure is a component that generates a battery reaction. The electrode body 20 shown in Figure 10 has a positive electrode active material layer 21, a negative electrode active material layer 22, and an electrolyte layer 23 disposed between the positive electrode active material layer 21 and the negative electrode active material layer 22. The set of the positive electrode active material layer 21, the electrolyte layer 23, and the negative electrode active material layer 22 may be referred to as a power generation unit X. The electrode body 20 also has a positive electrode current collector 24 on the side of the positive electrode active material layer 21 opposite to the electrolyte layer 23, and a negative electrode current collector 25 on the side of the negative electrode active material layer 22 opposite to the electrolyte layer 23. The set of one or more power generation units X and two or more current collectors (positive electrode current collectors and negative electrode current collectors) may be referred to as a power generation element Y.

[0042] Furthermore, as shown in Figure 10, the electrode body 20 may also include a first protective layer 26a that protects the side surface of the power generation element Y. In Figure 10, the first protective layer 26a is provided on both sides of the power generation element Y. Although not specifically shown, the first protective layer may be provided on only one side of the power generation element Y. Also, in Figure 10, on the side surface of the power generation element Y, the thickness direction D T The first protective layer 26a is placed over the entire area. Although not shown in particular, the first protective layer may be placed only over a portion of the thickness direction on the side surface of the power generation element Y.

[0043] Furthermore, as shown in Figure 10, the electrode body 20 is the main surface (thickness direction D) of the power generation element Y. T A second protective layer 26b may be provided to protect the surface (with the normal direction to the element). In Figure 10, the second protective layer 26b is provided on both main surfaces of the power generation element Y. Although not specifically shown, the second protective layer may be provided on only one main surface of the power generation element Y. Furthermore, when viewed in plan in the thickness direction, the second protective layer may be provided so as to overlap at least a part of the power generation element Y. In addition, the second protective layer may be provided so as to encompass the entire power generation element Y.

[0044] The positive electrode active material layer contains at least a positive electrode active material and may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of positive electrode active materials include LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 Examples of oxide active materials include O2. Examples of conductive materials include carbon materials. Examples of electrolytes include solid electrolytes and liquid electrolytes (electrolytes). Examples of solid electrolytes include inorganic solid electrolytes such as sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes, as well as gel electrolytes and polymer electrolytes. Examples of electrolytes include electrolytes obtained by dissolving Li salts such as LiPF6 in a carbonate-based solvent. Examples of binders include fluorine-based binders such as PVDF. Examples of positive electrode current collectors include Al, SUS, and Ni.

[0045] The negative electrode active material layer contains at least a negative electrode active material and may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of negative electrode active materials include Si-based active materials such as elemental Si, Si alloys, and Si oxides, graphite-based active materials such as graphite, and oxide-based active materials such as lithium titanate. The conductive material, electrolyte, and binder in the negative electrode active material layer are the same as those described for the positive electrode active material layer. Examples of negative electrode current collectors include Cu, SUS, and Ni.

[0046] The electrolyte layer contains at least an electrolyte and may further contain a binder. The electrolyte and binder are the same as those described above for the positive electrode active material layer. When the electrolyte layer contains a solid electrolyte, such a battery is generally referred to as an all-solid-state battery. The battery in this disclosure may be an all-solid-state battery. When the electrolyte layer contains a liquid electrolyte, the electrolyte layer may be a layer in which a separator is impregnated with a liquid electrolyte.

[0047] When the electrode body has multiple power generation units, they may be connected in series or in parallel. Furthermore, the power generation elements in the electrode body usually have a laminated structure in which the aforementioned layers are stacked. The power generation elements may have a single-leaf laminated structure or a wound laminated structure. The protective layer is preferably an insulating layer, as this prevents short circuits. Examples of materials for the protective layer include resin.

[0048] 3. Side case The battery in this disclosure may include a side case positioned on the side of the battery case. As described above, the side of the battery case corresponds to an opening in the hollow structure. The battery in this disclosure may have a side case on only one of the two sides of the battery case, or it may have a side case on both sides. Depending on the size of the battery case, the side case may not be positioned on the side of the battery case, and the battery case may be sealed using a sealing material such as resin.

[0049] As shown in Figure 11(a), the electrode body 20 is placed inside the battery case 10 (within the hollow structure), and then the side case 30 is placed on the side of the battery case 10. At this time, an adhesive resin layer 31 is placed around the side case 30. As a result, as shown in Figure 11(b), the side of the battery case 10 is sealed by the side case 30 and the resin layer 31. The planar shape of the side case is not particularly limited, but it is preferable that it is similar in shape to the side shape of the battery case 10, as shown in Figure 11(a).

[0050] As shown in Figure 11(a), the side case 30 may include a concave shape corresponding to the convex structure of the battery case 10. The side case 30 shown in Figure 11(a) has, in plan view, a first side s1, a second side s2 opposite the first side s1, a third side s3 connecting the first side s1 and the second side s2, and a fourth side s4 opposite the third side s3. The first side s1, the second side s2, the third side s3, and the fourth side s4 are in a positional relationship corresponding to the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4 of the battery case 10, respectively. In the side case 30, the intersection of the third side s3 and the first side s1 is C1, the intersection of the third side s3 and the second side s2 is C2, and the line segment connecting C1 and C2 is l 12 Let's assume that the third side s3 is the line segment l 12 The base C is located closer to the fourth side s4 than the fourth side s4. B It may include a concave shape having the following characteristics.

[0051] The side case may have notches for arranging current collection terminals (positive and negative terminals). Alternatively, the side case itself may function as a current collection terminal. The material and thickness of the side case are not particularly limited, but are similar to those of the battery case described above.

[0052] 4.Battery The battery in this disclosure preferably comprises at least an electrode body and a battery case, and further preferably a side case. On the other hand, the battery in this disclosure preferably does not have a spacer inside the battery case.

[0053] The battery in this disclosure is typically a lithium-ion secondary battery. The application of the battery is not particularly limited, but examples include powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline cars, and diesel cars. It is particularly preferable that the battery be used as a power source for hybrid electric vehicles, plug-in hybrid electric vehicles, or electric cars. The battery in this disclosure may also be used as a power source for mobile devices other than vehicles (e.g., railways, ships, aircraft), or as a power source for electrical products such as information processing devices.

[0054] The battery manufacturing method described herein is not particularly limited, but examples include a placement step of arranging electrode bodies inside a battery case (within a hollow structure) and a side sealing step of sealing the sides of the battery case.

[0055] In the arrangement process, as shown in Figure 3 above, for example, surface S 4a While moving in the +x direction, surface S 4b By moving it in the -x direction, the battery case 10 is bent, and the surface S in the x-axis direction 4a and surface S 4b A space is created between them. The electrode body 20 is placed inside the battery case 10 (within the hollow structure) through this space.

[0056] In the arrangement process, it is preferable that the battery case and electrode body have the following dimensional relationship. Note that the following dimensional relationship is the relationship before the electrode body is placed inside the battery case. Here, as shown in Figure 5(a) above, the dimensions of the battery case are H C1 H C2 and W C Defines the same thing. Similarly, as shown in Figure 5(b) above, the dimensions of the electrode body are defined as H E and W E This defines the dimensions of the battery case and the electrode body. Furthermore, the dimensions of the battery case and electrode body typically have manufacturing tolerances. The upper limit of these tolerances is expressed as MAX, and the lower limit as MIN. C1-MAX and H E-MIN H C1-MAX ≤H E-MIN It is preferable that the following conditions be met. Also, H C2-MIN and H E-MAX H C2-MIN ≥H E-MAX It is preferable that the following conditions be met. Also, W C-MAX and W E-MIN is, W C-MAX ≤W E-MIN It is preferable that the following conditions be met.

[0057] In the side sealing process, as shown in Figure 11(b) above, the side of the battery case 10 may be sealed with the side case 30 and the resin layer 31.

[0058] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Explanation of Symbols]

[0059] 10… Battery case 20 … Electrode body 30… Side case 100…Battery

Claims

[Claim 1] A battery case for housing electrode bodies, The aforementioned battery case has a hollow structure, The hollow structure has a first surface, a second surface facing the first surface, a third surface connecting the first and second surfaces, and a fourth surface facing the third surface. In the axial side view of the hollow structure, the boundary between the third surface and the first surface is B １ The boundary between the third surface and the second surface is B ２ The above B1 and the above B ２ The line segment connecting them is L １２ In that case, the third surface is L １２ It includes a convex structure having its apex at a position closer to the fourth surface than the above-mentioned fourth surface, The first and second surfaces are, respectively, surfaces that face the main surface of the electrode when the electrode is housed therein. The aforementioned battery case satisfies any of the following conditions (i) to (iii): (i) The fourth surface has a surface S4a extending from the first surface and a surface S4b extending from the second surface, and has an overlapping portion where the surfaces S4a and S4b overlap. (ii) The fourth surface has a surface S 4a extending from the first surface, and the end of the surface S 4a is located on the second surface. (iii) A battery case in which the fourth surface has a surface S4a extending from the first surface and a surface S4b extending from the second surface, and the surfaces S4a and S4b do not overlap.

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