Battery

Abstract

To suppress generation of wrinkles at corners of a junction of an outer package and suppress generation of breakage of the outer package.SOLUTION: Provided is a battery in which an electrode body that is square in a plan view is housed in an outer package. The outer package has a junction 11a at least at three sides of its outer peripheral end part. Spacers 15 are arranged between corners of the electrode body and an inner surface of the outer package. Each spacer 15 has a projection 17 extending toward the junction of the outer package.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a battery having an electrode assembly and an exterior body that seals the electrode assembly. [Background technology]

[0002] Patent Document 1 discloses a battery in which a rectangular electrode body is sealed with a laminate film (exterior body), and a spacer is disposed between the corners of the rectangular electrode body and the laminate film. It is described that this suppresses the occurrence of wrinkles concentrated in the laminate film, particularly at the corners, and prevents damage to the metal foil layer in the laminate film, thereby preventing deterioration of battery performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-39271 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, even when the spacers as described in Patent Document 1 are disposed, the phenomenon of wrinkles occurring at the corners has been confirmed, and damage to the laminate film has occurred.

[0005] In view of the above background technology, an object of the present disclosure is to prevent the occurrence of wrinkles at corners of joints of an exterior body and to prevent the occurrence of damage to the exterior body. [Means for solving the problem]

[0006] After careful consideration, the inventors discovered that in conventional spacers, as shown in a portion of the cross-sectional view in Figure 17, at the corners of the laminate films (exterior body), there is a space S between the laminate films due to unjoined parts, as indicated by S in Figure 17, between the spacer and the joints between the laminate films, and that this is the cause of wrinkles, and thus completed the present invention.

[0007] The present application discloses a battery in which an electrode body that is rectangular in plan view is housed in an outer casing, the outer casing has joints on at least three sides of its outer circumferential edge, and a spacer is disposed between the corners of the electrode body and the inner surface of the outer casing, the spacer having a protrusion extending toward the joints of the outer casing.

[0008] The projections may be configured to taper towards their tips.

[0009] The projection may be configured to have a surface that is inclined in the thickness direction of the electrode assembly toward the joint.

[0010] The protrusion may be configured to have a concave surface. Effect of the Invention

[0011] According to the battery of the present disclosure, by positioning the spacer protrusions in the spaces formed at the corners of the joints of the exterior body where deformation is concentrated, it is possible to suppress the occurrence of wrinkles and prevent damage to the exterior body. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an external perspective view of an all-solid-state battery 10. [Diagram 2] FIG. 2 is a plan view of the all-solid-state battery 10. [Diagram 3] FIG. 3 is a front view of the all-solid-state battery 10. [Figure 4] FIG. 4 is an exploded perspective view of the all-solid-state battery 10. [Diagram 5] FIG. 5 is an enlarged view of a portion of FIG. [Figure 6]FIG. 6 is a cross-sectional view taken along line VI-VI. [Figure 7] FIG. 7 is a perspective view of the appearance of the spacer 15. As shown in FIG. [Figure 8] FIG. 8 is a plan view of the spacer 15. As shown in FIG. [Figure 9] FIG. 9 is a bottom view of the spacer 15. As shown in FIG. [Figure 10] FIG. 10 is a front view of the spacer 15. [Figure 11] FIG. 11 is a rear view of the spacer 15. FIG. [Figure 12] FIG. 12 is a side view of the spacer 15. [Figure 13] FIG. 13 is a cross-sectional view of the spacer 15. [Figure 14] FIG. 14 is a diagram illustrating another type of all-solid-state battery. [Figure 15] FIG. 15 is a diagram showing the results of the comparative example. [Figure 16] FIG. 16 shows the results of the example. [Figure 17] FIG. 17 is a diagram for explaining a conventional example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1.Battery 1 to 4 show diagrams for explaining an all-solid-state battery 10 according to one embodiment. Here, an all-solid-state battery is explained as one typical example, but the present disclosure is not necessarily applicable to an all-solid-state battery, and is applicable to a battery having an electrode body and an exterior body that seals it. Fig. 1 is an external perspective view, Fig. 2 is a plan view (viewed from the direction of arrow II in Fig. 1), Fig. 3 is a front view (viewed from the direction of arrow III in Fig. 1), and Fig. 4 is an exploded perspective view. 2. This figure focuses on one corner 10a of the all-solid-state battery 10. In FIG. 5, the spacer 15 arranged inside the exterior body 11 is shown in a see-through manner. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5.

[0014] 1 to 6, the all-solid-state battery 10 of this embodiment has an exterior body 11 (first exterior body 12, second exterior body 13), an electrode body 14, and a spacer 15. The electrode body 14 is a rectangular parallelepiped and generally rectangular in plan view, and a spacer 15 is disposed at each of the four corners of the electrode body 14, and the electrode body 14 to which the spacers 15 are attached is contained in the exterior body 11. At this time, a positive electrode terminal 14a and a negative electrode terminal 14b extend from the electrode body 14, and are disposed so that their tips protrude from the exterior body 11. Each component and the relationship between them will be described below.

[0015] 1.1.Exterior body In this embodiment, the exterior body 11 is made of a sheet-like member that is rectangular in plan view, and includes a first exterior body 12 and a second exterior body 13. An electrode body 14 and a spacer 15 are contained between the first exterior body 12 and the second exterior body 13, and an outer circumferential end of the first exterior body 12 and an outer circumferential end of the second exterior body 13 are joined to form a joint 11a. Thus, this exterior body 11 is bag-shaped, and contains and seals the electrode body 14 and the spacer 15 inside.

[0016] First exterior body 12 is rectangular in plan view and has rectangular recess 12a in plan view (the opening of recess 12a is on the lower side of the paper in FIG. 4 and cannot be seen in a blind spot), and electrode body 14 and spacer 15 are housed inside recess 12a. Protruding portion 12b is provided on the outer circumferential edge of recess 12a so as to protrude from said edge, and protruding portion 12b and the outer circumferential end of the surface of second exterior body 13 are joined to form joint 11a.

[0017] Second exterior body 13 has a rectangular sheet shape in a plan view. As described above, the outer circumferential end of the surface of second exterior body 13 facing protruding portion 12b of first exterior body 12 is overlapped and joined to protruding portion 12b of first exterior body 12, forming joint portion 11a.

[0018] In this embodiment, the first exterior body 12 and the second exterior body 13 are composed of a laminate film. Here, the laminate film is a film having a metal layer and a sealant material layer. Metals used for the metal layer of the laminate film include aluminum and stainless steel, and materials used for the sealant material layer include thermoplastic resins such as polypropylene, polyethylene, polystyrene, and polyvinyl chloride. The method for joining the first exterior body 12 and the second exterior body 13, i.e., the method for joining the laminate film, is not particularly limited, and a known method can be used. Specific examples include a method of welding the sealant material layers of the laminate film together (for example, a hot plate welding method, an ultrasonic welding method, a vibration welding method, a laser welding method, or the like) and adhesion using an adhesive.

[0019] 1.2. Electrode body The electrode body 14 has a positive electrode current collecting layer, a positive electrode composite layer, a separator layer, a negative electrode composite layer, a negative electrode current collecting layer, a positive electrode terminal 14a, and a negative electrode terminal 14b. In this embodiment, the electrode body 14 is formed by stacking a plurality of unit elements in this order, each of which includes a positive electrode current collecting layer, a positive electrode composite layer, a separator layer, a negative electrode composite layer, a negative electrode current collecting layer, a negative electrode composite layer, a separator layer, a positive electrode composite layer, and a positive electrode current collecting layer (sometimes referred to as a "stack 14c"). The positive electrode terminal 14a is electrically connected to the positive electrode current collecting layer of the stack 14c, and the negative electrode terminal 14b is electrically connected to the negative electrode current collecting layer of the stack 14c. The laminate 14c is also rectangular and quadrangular in plan view.

[0020] 1.2a. Positive electrode current collecting layer The positive electrode current collecting layer is laminated on the positive electrode mixture layer to collect current from the positive electrode mixture layer. The positive electrode current collecting layer is a rectangular foil in plan view, and in this embodiment, is made up of a positive electrode current collecting foil, which is a metal foil, and a carbon layer laminated on the positive electrode current collecting foil. The carbon layer is laminated on the positive electrode mixture layer, thereby laminating the positive electrode current collecting layer on the positive electrode mixture layer. Examples of materials that can be used to form the positive electrode current collector foil include stainless steel, aluminum, nickel, iron, and titanium, and the carbon layer is made of a material that contains carbon.

[0021] 1.2b. Positive electrode composite layer The positive electrode mixture layer has the positive electrode current collecting layer on one surface and a separator layer on the other surface. The positive electrode mixture layer has a rectangular sheet shape in a plan view.

[0022] The positive electrode mixture layer is a layer containing a positive electrode active material, and may further contain at least one of a solid electrolyte material, a conductive material, and a binder, as necessary. The positive electrode active material may be a known active material. For example, cobalt-based (LiCoO2, etc.), nickel-based (LiNiO2, etc.), manganese-based (LiMn2O4, Li2Mn2O3, etc.), iron phosphate-based (LiFePO4, Li2FeP2O7, etc.), NCA-based (nickel, cobalt, aluminum compound), NMC-based (nickel, manganese, cobalt compound), etc. are listed. More specifically, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc. The surface of the positive electrode active material may be covered with an oxide layer such as a lithium niobate layer, a lithium titanate layer, or a lithium phosphate layer.

[0023] The solid electrolyte is preferably an inorganic solid electrolyte, since it has higher ionic conductivity and superior heat resistance compared to organic polymer electrolytes. Examples of inorganic solid electrolytes include sulfide solid electrolytes and oxide solid electrolytes. Examples of sulfide solid electrolyte materials having Li ion conductivity include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-ZmSn (where m and n are positive numbers, and Z is Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y(wherein x and y are positive numbers; M is any of P, Si, Ge, B, Al, Ga, and In.) The above description of "Li2S-P2S5" means a sulfide solid electrolyte material obtained by using a raw material composition containing Li2S and P2S5, and the same applies to other descriptions.

[0024] On the other hand, examples of oxide solid electrolyte materials having Li ion conductivity include compounds having a NASICON structure. An example of a compound having a NASICON structure is a compound represented by the general formula Li 1+x Al x Ge 2-x Compounds represented by the formula (PO4)3 (0≦x≦2) (LAGP), general formula Li 1+x Al x Ti 2-x (PO4)3 (0≦x≦2) (LATP) and the like. Another example of the oxide solid electrolyte material is LiLaTiO (for example, Li 0.34 La 0.51 TiO3), LiPON (e.g., Li 2.9 PO 3.3 N 0.46 ), LiLaZrO (e.g., Li7La3Zr2O 12 ) etc.

[0025] The binder is not particularly limited as long as it is chemically and electrically stable, and examples thereof include fluorine-based binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), rubber-based binders such as styrene butadiene rubber (SBR), olefin-based binders such as polypropylene (PP) and polyethylene (PE), and cellulose-based binders such as carboxymethylcellulose (CMC). As the conductive material, carbon materials such as acetylene black (AB), ketjen black, and carbon fiber, and metal materials such as nickel, aluminum, and stainless steel can be used.

[0026] The content of each component in the positive electrode mixture layer may be the same as in the past. The thickness of the positive electrode mixture layer is, for example, preferably 0.1 μm to 1 mm, more preferably 1 μm to 150 μm.

[0027] 1.2c. Separator layer The separator layer (solid electrolyte layer) is a rectangular sheet-like layer in plan view, disposed between the positive electrode composite layer and the negative electrode composite layer, and includes a solid electrolyte material, which can be considered to be the same as the solid electrolyte material described for the positive electrode composite layer.

[0028] 1.2d. Negative electrode composite layer The negative electrode mixture layer is a layer containing at least a negative electrode active material. The negative electrode mixture layer may contain a binder, a conductive material, and a solid electrolyte material as necessary. The binder, the conductive material, and the solid electrolyte material can be considered to be the same as those of the positive electrode mixture layer.

[0029] The negative electrode active material is not particularly limited. In the case of forming a lithium ion battery, examples of the negative electrode active material include carbon materials such as graphite and hard carbon, various oxides such as lithium titanate, Si and Si alloys, and metallic lithium and lithium alloys.

[0030] The negative electrode mixture layer is in the form of a quadrangular sheet in plan view, with the separator layer laminated on one surface and the negative electrode current collecting layer laminated on the other surface. The content of each component in the negative electrode mixture layer may be the same as in the past. The thickness of the negative electrode mixture layer is, for example, preferably 0.1 μm to 1 mm, more preferably 1 μm to 150 μm.

[0031] 1.2e.Negative electrode current collecting layer The negative electrode current collecting layer is laminated on the negative electrode mixture layer to collect current from the negative electrode mixture layer. The negative electrode current collecting layer has a rectangular foil shape in a plan view, and can be made of, for example, stainless steel, copper, nickel, carbon, or the like.

[0032] 1.2f.Positive terminal, negative terminal The positive electrode terminal 14a and the negative electrode terminal 14b are made of conductive materials and serve as terminals for electrically connecting each electrode to the outside. One end of the positive electrode terminal 14a is electrically connected to the positive electrode current collecting layer, and the other end passes through the joint 11a between the first exterior body 12 and the second exterior body 13 and is exposed to the outside. One end of negative electrode terminal 14b is electrically connected to the negative electrode current collecting layer, and the other end passes through joint 11a between first exterior body 12 and second exterior body 13 and is exposed to the outside.

[0033] 1.3.Spacer The spacer 15 is a member disposed between the laminate 14c of the electrode body 14 and the inner surface of the recess 12a of the first exterior body 12 at the corner 10a of the all-solid-state battery 10. FIGS. 7 to 13 are diagrams illustrating the spacer 15. FIG. 7 is an external perspective view, FIG. 8 is a plan view (viewed from the direction indicated by the arrow VIII in FIG. 7), FIG. 9 is a bottom view (viewed from the direction indicated by the arrow IX in FIG. 7), FIG. 10 is a front view (viewed from the direction indicated by the arrow X in FIG. 8), FIG. 11 is a rear view (viewed from the direction indicated by the arrow XI in FIG. 8), FIG. 12 is a side view (viewed from the direction indicated by the arrow XII in FIG. 8), and FIG. 13 is a cross-sectional view taken along the line indicated by XIII-XIII in FIG. 8.

[0034] 5 and 8, spacer 15 is substantially triangular in plan view, and is configured to fit along the inner corner of recess 12a of exterior body 11. Therefore, an angle formed by side surface 15a and side surface 15b of spacer 15 that fit along the inner corner of recess 12a of exterior body 11 in plan view is substantially 90°. Therefore, in this embodiment, spacer 15 is a triangular prism-shaped member.

[0035] As shown in Figures 6, 9, 11, and 13, the spacer 15 is provided with grooves 16 into which the corners of the laminate 14c of the electrode body 14 are inserted. The groove 16 is shaped and configured to receive the corners of the laminate 14c of the electrode body 14. Therefore, the groove 16 is a groove having openings on the side surface 15c (the side surface between the side surface 15a and the side surface 15b) and the bottom surface 15d. The groove 16 is not particularly limited, but can be, for example, a right-angled triangle in plan view (bottom view) as in this embodiment.

[0036] In spacer 15, it is preferable that each edge that touches the surface of exterior body 11 has an edge-removed shape, that is, an edge having a straight edge-removed shape (so-called C-chamfered shape) or a curved edge-removed shape (so-called R-chamfered shape). This can reduce the risk that the edge of spacer 15 will break through exterior body 11 (laminate film). In particular, it is preferable that the edge formed by side surface 15a and side surface 15b be curved, as shown in Figures 8 and 13. This part faces the corner of recess 12a of exterior body 11, and thus stress concentration is likely to occur, so by making it a curved shape, the stress concentration can be alleviated and it is possible to prevent the occurrence of tearing of exterior body 11.

[0037] The spacer 15 has a protrusion 17 on the bottom surface 15d side at an edge formed by the side surface 15a and the side surface 15b. As a result, the protrusion 17 is positioned at a corner of the recess 12a of the exterior body 11 in a position in which the spacer 15 is disposed on the all-solid-state battery 10.

[0038] As shown in Fig. 6, the protrusion 17 is configured to reduce the size of the space S caused by the non-jointed portion of the exterior body between the joint and the spacer described with reference to Fig. 17. The specific shape of the protrusion 17 is not particularly limited as long as it can reduce the space S in this way, but as a more effective shape, it is preferable to have an inclined surface 17a that is inclined toward the joint 11a in the thickness direction (the stacking direction of each layer in the electrode body 14), as shown well in Fig. 6 and Fig. 13. This gives the protrusion 17 a shape that is inclined so as to become narrower (thinner) toward the joint 11a, and the space between the joint 11a and the spacer 15 at the corner can be efficiently reduced. The shape of inclined surface 17a is not particularly limited, and may be a flat surface, or may be a concave surface as shown in Figures 6 and 13. By making inclined surface 17a a concave surface, it is possible to suppress abrupt changes to exterior body 11 arranged along the inclined surface, thereby mitigating stress concentration.

[0039] It is preferable that the width of the projection 17 (the size in the direction indicated by B in FIG. 8) is also configured to taper toward the tip of the projection 17. This allows the width to follow the shape of the corner, and makes it possible to more efficiently reduce the space between the joint 11a and the spacer 15 at the corner.

[0040] Moreover, it is preferable that protrusion 17 and other portions of spacer 15 are connected by a curved surface, which can ease the stress concentration on exterior body 11 that is in close contact with spacer 15 and suppress the occurrence of breakage. As a result, the boundary between protrusion 17 and other parts may become unclear, but essentially, it is a part that protrudes so as to extend toward joint 11a between first exterior body 12 and second exterior body 13 at a corner of exterior body 11. Although not particularly limited, for example, protrusion 17 may be a part on the tip side of inflection point A in the cross section shown in Fig. 13 (a cross section along a line (line XIII-XIII in Fig. 8) that includes the top of protrusion 17 in a plan view and bisects the area of ​​spacer 15).

[0041] Although the size of the protrusion 17 is not particularly limited, the thickness of the protrusion 17 shown by D in Fig. 13 is preferably 0.05 times or more the thickness E of the spacer 15. Moreover, the width of the protrusion 17 shown by B in Fig. 8 is preferably two times or more the thickness D, and the protrusion amount of the protrusion 17 shown by C is preferably 0.5 times or more the width B.

[0042] Such a spacer 15 is arranged as shown in Fig. 5 and Fig. 6. That is, it is arranged inside the exterior body 11 at the corner portion 10a of the all-solid-state battery 10, between the inside of the recess 12a of the first exterior body 12 and the laminate 14c of the electrode body 14. At this time, the corner portion (vertex portion) of the laminate 14c, which is a rectangle in a plan view, is accommodated inside the groove 16 of the spacer 15.

[0043] On the other hand, the surface of spacer 15 (the surface provided with protrusions 17) facing the inner surface of exterior body 11 is placed in contact with the inner surface of exterior body 11, and exterior body 11 covers the surface of spacer 15. In this case, if each edge of spacer 15 has an edge-removed shape, stress concentration on exterior body 11 can be alleviated and the occurrence of tearing of exterior body 11 can be suppressed.

[0044] As shown in FIG. 6, the protrusion 17 extends toward the joint 11a between the first outer casing 12 and the second outer casing 13 at the corner 10a of the all-solid-state battery 10 and is positioned so as to reduce the space between the joint 11a and the spacer 15. This makes it possible to suppress the occurrence of wrinkles in the exterior body 11 at the corners 10a of the all-solid-state battery 10.

[0045] The material constituting the spacer 15 is preferably an electrically insulating material that is easily elastically deformed to a certain degree. Although there are no particular limitations, various resins such as thermosetting resin, ultraviolet curing resin, and thermoplastic resin can be used.

[0046] 2. Manufacturing The all-solid-state battery 10 can be manufactured by known methods except for the spacer 15. The spacer 15 can be produced by pouring a molten material into a mold and hardening it by an appropriate method, although there is no particular limitation to this. If the material is a thermoplastic resin, it can be hardened by cooling, and if the material is an ultraviolet-curable resin, it can be hardened by irradiating it with ultraviolet light. As described above, spacers 15 are disposed on each of the apexes (corners) of laminate 14c, and electrode body 14 with spacers 15 attached is placed inside recess 12a of first exterior body 12. First exterior body 12 and second exterior body 13 are then stacked, and protruding portion 12b of first exterior body 12 is joined to the surface end portion of second exterior body 13. At this time, a vacuum may be drawn to degas the inside of recess 12a.

[0047] 3. Effects etc. According to the all-solid-state battery 10 of the present disclosure, the spacer 15 provided therein reduces the space formed between the spacer 15 and the joint 11a of the exterior body 11 at the corner 10a, thereby making it possible to suppress the occurrence of wrinkles in the exterior body 11. The exterior body (especially the laminate film) is vulnerable to heat cycles (repeated increases and decreases in temperature), and if wrinkles occur at the corners, stress is likely to concentrate there and cause cracks. The occurrence of cracks can cause damage to the exterior body and lead to battery deterioration. In contrast, the all-solid-state battery 10 equipped with the spacer 15 can suppress such defects. In conventional examples, wrinkles may occur during the production of an all-solid-state battery, or may occur during use or during a heat cycle test. However, according to the present disclosure, the occurrence of wrinkles can be suppressed in either case.

[0048] 4. Other Examples In addition to the above, an all-solid-state battery can be configured as shown in Fig. 14. Fig. 14 is a view corresponding to Fig. 6. In the example shown in Fig. 14, a second exterior body 13 is not used, and two first exterior bodies 12 are overlapped to form an exterior body. Therefore, the opening sides of the recesses 12a of the two first exterior bodies 12 and the protruding portions 12b are overlapped with each other, and the two protruding portions 12b become the joint portion 11a. In this embodiment, spacers 15 are arranged at both corners of the electrode body 14 in the thickness direction of the electrode body 14 (the vertical direction of the paper, the stacking direction of each layer in the laminate 14c of the electrode body 14). Therefore, in this embodiment, the spacers 15 are arranged so that their bottom surfaces 15d overlap each other, as shown in FIG. A battery of this type also provides the same effects as those described above.

[0049] In addition, in the above embodiment, the first outer casing 12 and the second outer casing 13 are joined together to form the two outer casing members. However, this is not limited to this, and the embodiment may also be such that one outer casing member is folded in half and the electrode body and spacer are sandwiched between the folded member and the outer peripheral ends of three sides are joined together.

[0050] In addition, in the above embodiment, the spacers arranged at each corner are individual independent members, but this is not limited thereto. For example, the spacers can be configured so that two of the above-mentioned spacers are connected by a connecting portion, and the connecting portion is arranged along one side of the laminate 14c.

[0051] 5. Working Example 5.1. Electrode structure An electrode assembly was formed by a known method. The specifications of each layer of the electrode assembly were as follows: Positive electrode current collecting layer: Made of 1000 series aluminum, 10μm thick Positive electrode composite layer: NCM material, 50μm thick Separator layer: Material is sulfide solid electrolyte, thickness is 30μm Negative electrode composite layer: Material is lithium titanate, thickness is 50μm Negative electrode current collecting layer: Made of 1000 series aluminum, 10μm thick Electrode dimensions: 100mm x 200mm, total thickness 5mm

[0052] 5.2. Shape of the exterior body The exterior body is made of a processed laminate sheet, which is made up of three layers: an insulating resin layer made of polyethylene terephthalate (PET), a metal layer made of aluminum, and a sealing resin layer made of polypropylene (PP), and is 0.15 mm thick. Its external dimensions are 120 mm x 220 mm in plan view, the external dimensions of the recess are 100 mm x 200 mm in plan view, the depth of the recess is 5 mm, and the edges are curved edge-removed, with a so-called R of 1 mm.

[0053] 5.3.Spacer Shape A spacer having a protrusion was produced as a spacer for the embodiment. The material of the spacer is PP (polypropylene), the length of the side (side 15a, 15b of the spacer 15) (the length of side 15a, 15b from the viewpoint of FIG. 8) is 5 mm, the thickness of the spacer (E in FIG. 13) is 6 mm, the thickness of the protrusion (D in FIG. 8) is 1.2 mm, the width of the protrusion (B in FIG. 8) is 2.4 mm, and the protrusion amount (C in FIG. 8) is 1.2 mm. On the other hand, a spacer having no protrusions was prepared as a comparative example, which was the same as the spacer for the embodiment except for the protrusions.

[0054] 5.4. Fabrication of all-solid-state batteries In the example, the spacers for the example were attached to the four corners of the electrode body, and the spacers and the electrode body were sealed in an exterior body. In the comparative example, the spacers for the comparative example were attached to the four corners of the electrode body, and the spacers and the electrode body were sealed in an exterior body.

[0055] 5.5. Test Method A heat cycle test was conducted on the fabricated all-solid-state battery. Specifically, the designated temperature on the high-temperature side was 100°C and the designated temperature on the low-temperature side was -20°C, with each cycle lasting 30 minutes, and this was repeated 2000 times. The fabricated all-solid-state battery was placed in a thermostatic chamber with high and low temperature air layers interchanged, and the layers were allowed to reach the designated temperature in about 10 minutes. The test was conducted so that the temperature of the all-solid-state battery remained at the designated temperature for at least 5 minutes.

[0056] 5.6.Results As a result of the test, in the comparative example, wrinkles occurred at the corners of the exterior body during production as shown in Figure 15, and cracks occurred in the exterior body after 300 cycles in the heat cycle test. In contrast, in the example, no wrinkles occurred as shown in Figure 16, and no cracks occurred even after 2000 cycles in the heat cycle test. [Explanation of symbols]

[0057] 10 All-solid-state battery 11 Exterior body 14 Electrode body 15 Spacer 17 Protrusion

Claims

1. A battery in which an electrode assembly that is rectangular in plan view is housed in an exterior body, The exterior body has a recess that accommodates the electrode body and the spacer, and a joint portion formed on at least three sides of an outer circumferential end portion, The spacer is disposed between a corner portion of the electrode assembly and an inner surface of the exterior body, The spacer has at least two side surfaces, an edge portion formed by the two side surfaces, and a protrusion protruding from the edge portion, The protrusion has a maximum protruding amount toward the joint portion where the protrusion intersects with a corner ridge line of the recess of the exterior body. battery.

2. The battery according to claim 1 , wherein the projections are configured to taper toward their tips.

3. The battery according to claim 1 or 2, wherein the projection has a surface that is inclined in the thickness direction of the electrode assembly toward the joint.

4. The battery according to any one of claims 1 to 3, wherein the protrusion has a concave surface.

Images