Battery

Abstract

To provide a battery capable of maintaining excellent insulation.SOLUTION: The battery 20 includes an electrode body 24 in which a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector are laminated, a case 22 housing the electrode body 24, and an insulating resin layer 26 provided in a gap between the electrode body 24 and the case 22, wherein the insulating resin layer 26 is provided in a gap between an end surface extending in a longitudinal direction in the electrode body 24 and the case 22, and at least one end portion of the insulating resin layer has a thin portion having a smaller thickness in contact with the electrode body than a central portion.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a battery. [Background technology]

[0002] Patent Document 1 discloses a secondary battery in which an electrode body is housed in an outer can. In the secondary battery disclosed in Patent Document 1, the electrode body is formed into an oval shape, and an insulating plate is attached to the bottom of the electrode body to provide insulation between the electrode body and the outer can. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-074424 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a structure such as that disclosed in Patent Document 1, in which insulating plates are arranged all the way to the corners of the outer can to ensure insulation, if the outer can is deformed due to the application of an external force, stress may be concentrated at the edge of the insulating plate, causing the insulating plate to peel off.

[0005] In consideration of the above, an object of the present invention is to provide a battery capable of maintaining good insulation properties. [Means for solving the problem]

[0006] The battery according to claim 1 comprises an electrode body in which a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector are stacked, a case that houses the electrode body, and an insulating resin layer provided in the gap between the electrode body and the case, wherein the insulating resin layer is provided in the gap between the case and an end face extending in the longitudinal direction of the electrode body, and at least one end of the insulating resin layer is formed with a thin portion that is thinner than the central portion and that comes into contact with the electrode body.

[0007] In the battery according to claim 1, an electrode assembly is housed in a case, and the electrode assembly is constructed by laminating a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector. An insulating resin layer is provided in the gap between the electrode assembly and the case. By providing the insulating resin layer between the electrode assembly and the case, the electrode assembly and the case are insulated from each other.

[0008] Here, the insulating resin layer is provided in the gap between the longitudinal end face of the electrode body and the case. Furthermore, at least one end of the insulating resin layer has a thin portion that is thinner than the central portion and that contacts the electrode body. By forming the thin portion at the end of the insulating resin layer in this way, peeling of the insulating resin layer from the case or the electrode body can be suppressed even when an external force is applied to the case.

[0009] A battery according to a second aspect of the present invention is the battery according to the first aspect, wherein the insulating resin layer contains a thermally conductive filler.

[0010] In the battery according to claim 2, the insulating resin layer contains a thermally conductive filler, so the insulating resin layer has thermal conductivity. This allows heat from the electrode assembly to be dissipated from the case to the outside via the insulating resin layer. In other words, the cooling performance of the electrode assembly can be improved.

[0011] The battery according to claim 3 is the battery according to claim 1, wherein a positive electrode tab is provided at one longitudinal end of the electrode body, where the positive electrode foil extending from the positive electrode current collector is collected, and the thin portion is formed at least at the end of the insulating resin layer on the positive electrode tab side.

[0012] In the battery according to claim 3, the thin portion of the insulating resin layer is formed at least at the end on the positive electrode tab side, thereby making it possible to maintain good insulation even in an environment where an external force is applied to the positive electrode tab side of the case.

[0013] The battery according to claim 4 is the battery according to claim 1, wherein a negative electrode tab is provided at the other longitudinal end of the electrode body, and the negative electrode foil extending from the negative electrode current collector is collected, and the thin portion is formed at least at the end of the insulating resin layer on the negative electrode tab side.

[0014] In the battery according to claim 4, the thin portion of the insulating resin layer is formed at least at the end on the negative electrode tab side, thereby making it possible to maintain good insulation even in an environment where an external force is applied to the negative electrode tab side of the case.

[0015] A battery according to claim 5 is the battery according to claim 1, wherein the thin portion has a shape in which the thickness gradually decreases from the center of the insulating resin layer toward the end portion.

[0016] In the battery according to claim 5, the thin portion has a shape in which the thickness of the insulating resin layer gradually decreases, so that it is possible to prevent stress from concentrating on a part of the insulating resin layer.

[0017] A battery according to a sixth aspect of the present invention is the battery according to the first aspect, wherein the thin portion has a recessed shape at the center in the thickness direction of the insulating resin layer.

[0018] In the battery according to claim 6, the insulating resin layer has a central portion in the thickness direction recessed to form a thin portion, whereby when an external force is applied, the recessed central portion can absorb part of the external force.

[0019] A battery according to a seventh aspect of the present invention is the battery according to the first aspect, wherein the thin portions are formed at both one end and the other end of the insulating resin layer.

[0020] In the battery according to claim 7, thin portions are formed at both ends of the insulating resin layer, so that peeling of the insulating resin layer can be prevented even when an external force is applied from any direction.

[0021] The battery of claim 8 is any one of claims 1 to 7, wherein the insulating resin layer is provided on both sides of the electrode body in the short direction, and the thin portion is formed only in one of the insulating resin layers.

[0022] In the battery according to claim 8, the insulating resin layer is provided on both sides of the electrode body in the short direction, thereby insulating the electrode body from the case on both sides of the short direction of the electrode body. Furthermore, the thin portion is formed only on one of the insulating resin layers. By disposing the insulating resin layer with the thin portion on the side of the case where external forces are more likely to act, peeling of the insulating resin layer can be effectively suppressed. On the other hand, by not forming a thin portion on the insulating resin layer on the side where external forces are less likely to act, insulation can be improved. [Effects of the Invention]

[0023] As described above, the battery according to the present invention can maintain good insulation properties. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic plan view showing a main part of a vehicle to which a battery according to an embodiment is applied; [Figure 2] FIG. 2 is a schematic perspective view of a battery module. [Figure 3] 1 is a schematic cross-sectional view of a battery cell according to an embodiment, viewed from the thickness direction. [Figure 4] FIG. 10 is a schematic cross-sectional view of a battery cell according to a first modified example, viewed from the thickness direction. [Figure 5] FIG. 10 is a schematic cross-sectional view of a battery cell according to a second modified example, viewed from the thickness direction. [Figure 6] 10 is a schematic enlarged cross-sectional view of a main part of a battery cell according to a third modified example, viewed from the thickness direction. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] (Overall configuration of vehicle 100) Fig. 1 is a schematic plan view showing the main parts of a vehicle 100 to which a battery pack 10 according to this embodiment is applied. As shown in Fig. 1, the vehicle 100 is a battery electric vehicle (BEV) with the battery pack 10 mounted under the floor. Note that the arrows UP, FR, and LH in each figure indicate the upper side in the vehicle vertical direction, the front side in the vehicle longitudinal direction, and the left side in the vehicle width direction, respectively. When describing using the front-rear, left-right, up-down directions, these directions refer to the front and rear in the vehicle longitudinal direction, the left and right in the vehicle width direction, and the up-down in the vehicle vertical direction, unless otherwise specified.

[0026] In the vehicle 100 of this embodiment, for example, a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 are arranged on the vehicle front side of the battery pack 10. In addition, a motor 108, a gearbox 110, an inverter 112, and a charger 114 are arranged on the vehicle rear side of the battery pack 10.

[0027] The DC current output from the battery pack 10 has its voltage adjusted by a DC / DC converter 102 and is then supplied to an electric compressor 104, a PTC heater 106, an inverter 112, etc. Furthermore, power is supplied to a motor 108 via the inverter 112, causing the rear wheels to rotate and causing the vehicle 100 to travel.

[0028] A charging port 116 is provided on the right side at the rear of the vehicle 100, and by connecting a charging plug of an external charging facility (not shown) to the charging port 116, power can be stored in the battery pack 10 via the charger 114.

[0029] The arrangement and structure of each component constituting vehicle 100 are not limited to the above-described configuration. For example, the present invention may be applied to a hybrid vehicle (HV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. In addition, in this embodiment, the vehicle is a rear-wheel drive vehicle in which motor 108 is mounted at the rear of the vehicle, but the present invention is not limited to this. The vehicle may be a front-wheel drive vehicle in which motor 108 is mounted at the front of the vehicle, or a pair of motors 108 may be mounted at the front and rear of the vehicle. Furthermore, the vehicle may be equipped with in-wheel motors on each wheel.

[0030] Here, the battery pack 10 is configured to include a plurality of battery modules 11. In this embodiment, as an example, ten battery modules 11 are provided. Specifically, five battery modules 11 are arranged on the right side of the vehicle 100 in the vehicle longitudinal direction, and five battery modules 11 are arranged on the left side of the vehicle 100 in the vehicle longitudinal direction. In addition, the respective battery modules 11 are electrically connected to each other.

[0031] Fig. 2 is a schematic perspective view of the battery module 11. As shown in Fig. 2, the battery module 11 is formed in a substantially rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. The case 13 of the battery module 11 is formed from an aluminum alloy. For example, the case 13 of the battery module 11 is formed by joining aluminum die-casting to both ends of an extruded aluminum alloy material by laser welding or the like.

[0032] A pair of voltage terminals 12 and a connector 14 is provided at each end of the battery module 11 in the vehicle width direction. In addition, bus bars (not shown) are welded to each end of the battery module 11 in the vehicle width direction.

[0033] Here, the battery module 11 contains a plurality of battery cells as batteries.

[0034] 3 is a schematic cross-sectional view of a battery cell 20 according to this embodiment, viewed from the thickness direction. As shown in FIG. 3, the battery cell 20 according to this embodiment includes an exterior can 22 as a case, an electrode assembly 24, and a first insulating resin layer 26 and a second insulating resin layer 28 provided in the gap between the exterior can 22 and the electrode assembly 24.

[0035] The exterior can 22 forms the outer shell of the battery cell 20 and is formed in a substantially rectangular parallelepiped shape. As an example, the exterior can 22 of this embodiment is configured to include a substantially cylindrical peripheral wall portion 22A, a positive electrode side lid portion 22B that closes an opening on one side of the peripheral wall portion 22A, and a negative electrode side lid portion 22C that closes an opening on the other side of the peripheral wall portion 22A.

[0036] The peripheral wall portion 22A is made of metal and has a generally rectangular cylindrical shape with both ends open, and is large enough to accommodate the electrode assembly 24 inside. The positive electrode side lid portion 22B is fixed to one opening of the peripheral wall portion 22A by fitting, welding, or other means, and closes the opening on one side of the peripheral wall portion 22A. An opening 22D is formed in the center of the positive electrode side lid portion 22B, and a generally frame-shaped positive electrode side insulator 30 is provided in this opening 22D. A positive electrode tab 34, which will be described later, is arranged inside the positive electrode side insulator 30.

[0037] The negative electrode side lid portion 22C is fixed to the opening on the other side of the peripheral wall portion 22A by fitting, welding, or other means, and closes the opening on the other side of the peripheral wall portion 22A. An opening 22E is formed in the center of the negative electrode side lid portion 22C, and a substantially frame-shaped negative electrode side insulator 32 is provided in this opening 22E. A negative electrode tab 36, which will be described later, is arranged inside the negative electrode side insulator 32.

[0038] The electrode body 24 housed in the outer can 22 is composed by laminating a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector. Further, the electrode body 24 has an outer shape corresponding to the outer can 22, and is formed in a substantially rectangular shape having a longitudinal direction and a short-side direction when viewed from the lamination direction. In addition, in the electrode body 24 of the present embodiment, the depth direction of the paper surface in FIG. 3 is the lamination direction. Further, in the electrode body 24, the left-right direction of the paper surface is the longitudinal direction, and the up-down direction of the paper surface is the short-side direction.

[0039] The positive electrode current collector and the negative electrode current collector are formed of a metal foil. Examples of the metal foil include aluminum foil, copper foil, nickel foil, titanium foil, stainless steel foil, and the like. Further, a coating layer may be formed on the surface of the current collector, and the coating layer may be formed by a known method such as plating treatment or spray coating. As the positive electrode current collector, aluminum foil is preferable, and as the negative electrode current collector, copper foil is preferable.

[0040] The positive electrode active material is not particularly limited, and conventionally known materials can be appropriately used. For example, examples of the positive electrode active material include LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li(NiCoMn)O2, Li(NiCoAl)O2, and LiFePO4. The positive electrode active material particles may be Hi-Nickel (a positive electrode active material with a high Ni ratio), a Li-Ni-Co-Mn-based composite oxide, or a ternary positive electrode active material.

[0041] Examples of the negative electrode active material include at least one selected from the group consisting of natural graphite, artificial graphite, hard carbon (carbon with low graphitization property), soft carbon (carbon with high graphitization property), Si, SiOx (0 < x < 2), Si-based alloy, Sn, SnOx (0 < x < 2), Li, Li-based alloy, and Li4Ti5O12. Examples of artificial graphite include highly oriented graphite, mesocarbon microbeads, and the like. As the negative electrode active material, artificial graphite is preferable.

[0042] Here, a positive electrode foil extends from one end of the positive electrode current collector to one side, and the positive electrode foils of the stacked positive electrode current collectors are collected to form a positive electrode tab 34. The positive electrode tab 34 passes inside the positive electrode-side insulator 30 and extends to the outside of the exterior can 22.

[0043] Meanwhile, a negative electrode foil extends from one end of the negative electrode current collector to the other side, and the negative electrode foils of the stacked negative electrode current collectors are collected to form a negative electrode tab 36. The negative electrode tab 36 passes inside the negative electrode-side insulator 32 and extends to the outside of the exterior can 22. In this way, in the battery cell 20 of this embodiment, the positive electrode tab 34 is provided at one longitudinal end of the electrode body 24, and the negative electrode tab 36 is provided at the other longitudinal end.

[0044] In the gap between the electrode body 24 and the exterior can 22, a first insulating resin layer 26 and a second insulating resin layer 28 are provided.

[0045] The first insulating resin layer 26 is provided in the gap between the outer can 22 and an end face on one end side in the short direction of the electrode body 24, and is bonded to at least one of the electrode body 24 and the outer can 22. In other words, the first insulating resin layer 26 is provided in the gap between the outer can 22 and an end face extending in the longitudinal direction of the electrode body 24.

[0046] In the present embodiment, as an example, the first insulating resin layer 26 is bonded to both the electrode body 24 and the outer casing 22. The first insulating resin layer 26 is also bonded to the entire end face of one end in the lateral direction of the electrode body 24, covering the entire end face.

[0047] Furthermore, the first insulating resin layer 26 of this embodiment is configured to contain a thermally conductive filler. Therefore, the first insulating resin layer 26 has thermal conductivity. In addition to the thermally conductive filler, the first insulating resin layer 26 also contains a known insulating resin that has insulating properties. Examples of the thermally conductive filler include metal, artificial diamond, and silicon carbide.

[0048] Here, a thin portion is formed at at least one end of the first insulating resin layer 26. In this embodiment, the thin portion 26A is formed at both one end and the other end of the first insulating resin layer 26 in the longitudinal direction.

[0049] The thin portion 26A is formed so that the thickness at which it comes into contact with the electrode body 24 is thinner than the central portion of the first insulating resin layer 26. Specifically, the thin portion 26A has a shape in which the thickness gradually decreases from the central portion toward the end portion of the first insulating resin layer 26. Therefore, in the thin portion 26A, when viewed in the stacking direction of the electrode body 24, the thickness of the first insulating resin layer 26 gradually decreases from the central side toward the end portion in the longitudinal direction of the electrode body 24.

[0050] In this embodiment, by forming thin portions 26A at both ends of the first insulating resin layer 26 as described above, spaces that are not filled with the first insulating resin layer 26 are provided at two corners of the outer can 22.

[0051] On the other hand, the second insulating resin layer 28 is provided in the gap between the outer can 22 and the end face on the other short end side of the electrode body 24, and is bonded to at least one of the electrode body 24 and the outer can 22. In other words, the second insulating resin layer 28 is provided in the gap between the outer can 22 and the end face extending in the longitudinal direction of the electrode body 24.

[0052] In the present embodiment, as an example, the second insulating resin layer 28 is bonded to both the electrode body 24 and the outer casing 22. The second insulating resin layer 28 is also bonded to the entire end face of one end in the lateral direction of the electrode body 24, covering the entire end face.

[0053] Furthermore, the second insulating resin layer 28 of this embodiment is configured to contain a thermally conductive filler, similar to the first insulating resin layer 26. The first insulating resin layer 26 and the second insulating resin layer 28 may be formed to be longer than the electrode body 24.

[0054] Here, the second insulating resin layer 28 of this embodiment does not have a thin portion formed therein, unlike the first insulating resin layer 26. Therefore, the thin portion is formed in only one of the insulating resin layers.

[0055] (action) Next, the operation of the battery cell 20 and the power storage device mounting structure according to this embodiment will be described.

[0056] In the battery cell 20 according to this embodiment, an electrode assembly 24 is housed in an exterior can 22, which serves as a case. The electrode assembly 24 is constructed by laminating a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector. A first insulating resin layer 26 and a second insulating resin layer 28 are provided in the gap between the electrode assembly 24 and the exterior can 22. In this way, by interposing the insulating resin layers between the electrode assembly 24 and the exterior can 22, the electrode assembly 24 and the exterior can 22 are insulated from each other.

[0057] Here, the first insulating resin layer 26 is provided in the gap between the exterior can 22 and an end face extending in the longitudinal direction of the electrode body 24, and a thin portion 26A that is thinner than the central portion and that comes into contact with the electrode body 24 is formed at at least one end of the first insulating resin layer 26. In this way, by forming the thin portion 26A at the end of the first insulating resin layer 26, it is possible to prevent the first insulating resin layer 26 from peeling off from the exterior can 22 or the electrode body 24, even when an external force is applied to the exterior can 22. As a result, good insulation properties can be maintained.

[0058] Furthermore, in this embodiment, the first insulating resin layer 26 and the second insulating resin layer 28 contain a thermally conductive filler, and therefore the first insulating resin layer 26 and the second insulating resin layer 28 have thermal conductivity. This allows heat from the electrode assembly 24 to be released to the outside from the exterior can 22 via the first insulating resin layer 26 and the second insulating resin layer 28. In other words, the cooling performance of the electrode assembly 24 can be improved.

[0059] Furthermore, in this embodiment, the thin portion 26A of the first insulating resin layer 26 is formed at the end on the positive electrode tab 34 side, so that good insulation can be maintained even in an environment where an external force is applied to the positive electrode tab 34 side of the outer can 22. Similarly, the thin portion 26A is also formed at the end on the negative electrode tab 36 side. This allows good insulation to be maintained even in an environment where an external force is applied to the negative electrode tab 36 side of the outer can 22.

[0060] Furthermore, the thin portions 26A have a shape in which the thickness of the first insulating resin layer 26 gradually decreases, which can prevent stress from concentrating on a part of the first insulating resin layer 26. In particular, in this embodiment, the thin portions 26A are formed at both end portions of the first insulating resin layer 26, which can prevent stress concentration and prevent the first insulating resin layer 26 from peeling off when an external force is applied from any direction.

[0061] Furthermore, in this embodiment, insulating resin layers (the first insulating resin layer 26 and the second insulating resin layer 28) are provided on both sides of the electrode body 24 in the short direction, and therefore the electrode body 24 and the outer can 22 are insulated from each other on both sides of the electrode body 24 in the short direction. Furthermore, the thin portion 26A is formed only in the first insulating resin layer 26, and therefore by arranging the first insulating resin layer 26 having the thin portion 26A on the side of the outer can 22 where external forces are more likely to act, peeling of the first insulating resin layer 26 can be effectively suppressed. On the other hand, by not forming a thin portion in the second insulating resin layer 28 on the side where external forces are less likely to act, insulation can be improved.

[0062] In this embodiment, thin portions 26A whose thickness gradually decreases are provided at both ends of first insulating resin layer 26, but the present invention is not limited to this. For example, structures described in a first modified example shown in Fig. 4, a second modified example shown in Fig. 5, and a third modified example shown in Fig. 6 may be employed. In the first to third modified examples described below, the same reference numerals are used to designate the same components as those in the embodiment, and descriptions thereof will be omitted where appropriate.

[0063] (First Modification) 4 is a schematic cross-sectional view of a battery cell 40 according to a first modified example, viewed from the thickness direction. As shown in this Fig. 4, in this modified example, an electrode body 24 is housed in an exterior can 22, and insulating resin layers are provided on both sides of the electrode body 24 in the short direction.

[0064] Specifically, a first insulating resin layer 42 is provided on one end side in the short side direction of the electrode body 24 (upper side on the paper), and a second insulating resin layer 28 is provided on the other end side in the short side direction of the electrode body 24 (lower side on the paper). The second insulating resin layer 28 has the same configuration as in the embodiment.

[0065] The first insulating resin layer 42 is provided in the gap between the outer can 22 and an end face on one end side in the short direction of the electrode body 24, and is bonded to at least one of the electrode body 24 and the outer can 22. In other words, the first insulating resin layer 42 is provided in the gap between the outer can 22 and an end face extending in the longitudinal direction of the electrode body 24.

[0066] The first insulating resin layer 42 is bonded to both the electrode body 24 and the outer can 22, and is bonded to the entire end face of one end in the lateral direction of the electrode body 24, covering the entire end face.

[0067] Furthermore, the first insulating resin layer 42 contains a thermally conductive filler, which gives the first insulating resin layer 42 thermal conductivity. In addition to the thermally conductive filler, the first insulating resin layer 42 also contains a known insulating resin that has insulating properties.

[0068] In this modification, a thin portion 42A is formed at one end of the first insulating resin layer 42. Specifically, the thin portion 42A is formed at the end of the first insulating resin layer 42 on the positive electrode tab 34 side. Also, the configuration differs from the embodiment in that no thin portion is formed at the other end of the first insulating resin layer 42.

[0069] In the battery cell 40 according to this modification, a thin portion 42A is formed at the end of the first insulating resin layer 42 on the positive electrode tab 34 side. This allows the battery cell 40 to maintain good insulation even in an environment where an external force is applied to the positive electrode tab 34 side of the outer can 22.

[0070] Furthermore, when the amount of heat generated differs between the positive electrode side and the negative electrode side of the electrode body 24, particularly when the amount of heat generated on the positive electrode side is greater, forming the thin portion 42A on the positive electrode side reduces the amount of heat exhausted on the positive electrode side compared to when the thin portion 42A is not formed. As a result, the amount of heat exhausted from the exterior can 22 on the positive electrode side and the negative electrode side can be balanced.

[0071] (Second Modification) Fig. 5 is a schematic cross-sectional view of a battery cell 50 according to the second modified example, viewed from the thickness direction. As shown in Fig. 5, in this modified example, an electrode body 24 is housed in an exterior can 22, and insulating resin layers are provided on both sides of the electrode body 24 in the short direction.

[0072] Specifically, a first insulating resin layer 52 is provided on one end side in the short side direction of the electrode body 24 (upper side on the paper), and a second insulating resin layer 28 is provided on the other end side in the short side direction of the electrode body 24 (lower side on the paper). The second insulating resin layer 28 has the same configuration as in the embodiment.

[0073] The first insulating resin layer 52 is provided in the gap between the outer can 22 and an end face on one end side in the shorter direction of the electrode body 24, and is bonded to at least one of the electrode body 24 and the outer can 22. In other words, the first insulating resin layer 52 is provided in the gap between the outer can 22 and an end face extending in the longitudinal direction of the electrode body 24.

[0074] The first insulating resin layer 52 is bonded to both the electrode body 24 and the outer can 22, and is bonded to the entire end face of one end in the lateral direction of the electrode body 24, covering the entire end face.

[0075] Furthermore, the first insulating resin layer 52 contains a thermally conductive filler, which provides the first insulating resin layer 52 with thermal conductivity. In addition to the thermally conductive filler, the first insulating resin layer 52 also contains a known insulating resin that has insulating properties.

[0076] In this modification, a thin portion 52A is formed at the other end of the first insulating resin layer 52. Specifically, the thin portion 52A is formed at the end of the first insulating resin layer 52 on the negative electrode tab 36 side. Also, the configuration differs from the embodiment in that no thin portion is formed at one end of the first insulating resin layer 52.

[0077] In the battery cell 50 according to this modification, a thin portion 52A is formed at the end of the first insulating resin layer 52 on the negative electrode tab 36 side. This allows the battery cell 50 to maintain good insulation even in an environment where an external force is applied to the negative electrode tab 36 side of the outer can 22.

[0078] Furthermore, when the amount of heat generated differs between the positive electrode side and the negative electrode side of the electrode body 24, particularly when the amount of heat generated on the positive electrode side is greater, by forming a thin portion 52A on the negative electrode side and not forming a thin portion 52A on the positive electrode side, heat can be actively dissipated from the positive electrode side, which is more likely to generate heat, and the temperature rise of the electrode body 24 can be suppressed.

[0079] (Third Modification) Fig. 6 is a schematic enlarged cross-sectional view of a main part of a battery cell 60 according to a third modified example, viewed from the thickness direction. As shown in Fig. 6, in this modified example, an electrode body 24 is housed in an outer can 22. Also, similar to the battery cell 20 of the embodiment, insulating resin layers are provided on both sides of the electrode body 24 in the short direction.

[0080] Specifically, a first insulating resin layer 62 is provided on one end side in the widthwise direction of the electrode body 24 (upper side on the paper surface). The first insulating resin layer 62 is provided in the gap between the outer can 22 and an end face on one end side in the widthwise direction of the electrode body 24, and is bonded to at least one of the electrode body 24 and the outer can 22. In other words, the first insulating resin layer 62 is provided in the gap between the outer can 22 and an end face extending in the lengthwise direction of the electrode body 24. The first insulating resin layer 62 is also configured to contain a thermally conductive filler.

[0081] Here, thin portions 62A are formed at both one end and the other end of the first insulating resin layer 62. The thin portions 62A differ from the embodiment in that the central portion in the thickness direction of the first insulating resin layer 62 has a recessed shape.

[0082] In the first insulating resin layer 62, the thin portion 62A formed on the positive electrode tab 34 side has a shape in which the central portion in the thickness direction of the first insulating resin layer 62 is recessed toward the negative electrode tab 36. In addition, one end portion in the thickness direction of the thin portion 62A is bonded to an end portion of the electrode body 24, and the other end portion in the thickness direction is bonded to the outer casing 22.

[0083] In the first insulating resin layer 62, the thin portion 62A formed on the negative electrode tab 36 side has a shape in which the central portion in the thickness direction of the first insulating resin layer 62 is recessed toward the positive electrode tab 34. In addition, one end portion in the thickness direction of the thin portion 62A is bonded to an end portion of the electrode body 24, and the other end portion in the thickness direction is bonded to the outer casing 22.

[0084] In the battery cell 60 according to this modification, a thin portion 62A is formed by recessing the center portion in the thickness direction of the first insulating resin layer 62. As a result, when an external force is applied, the recessed center portion can absorb part of the external force.

[0085] While the battery cells 20, 40, 50, and 60 according to the embodiment and modifications have been described above, the present invention is not limited to this and can of course be embodied in various forms without departing from the spirit of the present invention. For example, while the above embodiment has been described as having a structure in which a plurality of battery cells 20 are housed in the battery module 11 shown in Fig. 2, the present invention is not limited to this and may also have a structure in which the battery cells 20 are mounted directly on the vehicle body.

[0086] 3, the thin portion 26A is formed only in the first insulating resin layer 26 disposed on one side in the short direction of the electrode body 24, but this is not limiting. For example, a thin portion may also be formed in the second insulating resin layer 28 disposed on the other side in the short direction of the electrode body 24.

[0087] Furthermore, the second insulating resin layer 28 may not be provided. In this case, an insulating member may be disposed between the electrode body 24 and the exterior can 22 instead of the second insulating resin layer 28.

[0088] Furthermore, in the above embodiment, the first insulating resin layer 26 and the second insulating resin layer 28 are configured to contain a thermally conductive filler, but this is not limitative and they may be configured not to contain a thermally conductive filler. However, in terms of improving the cooling performance of the electrode body 24, it is preferable to use an insulating resin layer that contains a thermally conductive filler.

[0089] The following notes are provided regarding the above embodiment.

[0090] (Appendix 1) an electrode assembly in which a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector are stacked; a case for accommodating the electrode assembly; an insulating resin layer provided in a gap between the electrode body and the case; and A battery in which the insulating resin layer is provided in the gap between the end face extending in the longitudinal direction of the electrode body and the case, and at least one end of the insulating resin layer has a thin portion that is thinner than the central portion and that contacts the electrode body. (Appendix 2) 2. The battery according to claim 1, wherein the insulating resin layer contains a thermally conductive filler. (Appendix 3) a positive electrode tab on which a positive electrode foil extending from the positive electrode current collector is collected is provided at one longitudinal end of the electrode body; 3. The battery according to claim 1, wherein the thin portion is formed at least at an end of the insulating resin layer on the positive electrode tab side. (Appendix 4) a negative electrode tab on which a negative electrode foil extending from the negative electrode current collector is collected is provided at the other longitudinal end of the electrode body, 3. The battery according to claim 1, wherein the thin portion is formed at least at an end of the insulating resin layer on the negative electrode tab side. (Appendix 5) 5. The battery according to any one of claims 1 to 4, wherein the thin portion has a shape in which the thickness gradually decreases from the center of the insulating resin layer toward the end portion. (Appendix 6) 5. The battery according to any one of claims 1 to 4, wherein the thin portion has a recessed shape at the center in the thickness direction of the insulating resin layer. (Appendix 7) 7. The battery according to any one of claims 1 to 6, wherein the thin portion is formed at both one end and the other end of the insulating resin layer. (Appendix 8) the insulating resin layer is provided on both sides of the electrode body in a short direction, 8. The battery according to claim 1, wherein the thin portion is formed only on one of the insulating resin layers. [Explanation of symbols]

[0091] 20, 40, 50, 60 battery cells (batteries) 22 Outer can (case) 24 Electrode body 26, 42, 52, 62 First insulating resin layer (insulating resin layer) 26A, 42A, 52A, 62A thin section 28 Second insulating resin layer (insulating resin layer) 34 Positive electrode tab 36 Negative electrode tab

Claims

1. an electrode assembly in which a positive electrode current collector, a positive electrode active material, a solid electrolyte, a negative electrode active material, and a negative electrode current collector are stacked; a case for accommodating the electrode assembly; an insulating resin layer provided in a gap between the electrode body and the case; and A battery in which the insulating resin layer is provided in the gap between the end face extending in the longitudinal direction of the electrode body and the case, and a thin portion that is thinner than the central portion and that contacts the electrode body is formed at at least one end of the insulating resin layer.

2. The battery according to claim 1 , wherein the insulating resin layer contains a thermally conductive filler.

3. a positive electrode tab on which a positive electrode foil extending from the positive electrode current collector is collected is provided at one longitudinal end of the electrode body; The battery according to claim 1 , wherein the thin portion is formed at least at an end of the insulating resin layer on the positive electrode tab side.

4. a negative electrode tab on which a negative electrode foil extending from the negative electrode current collector is collected is provided at the other longitudinal end of the electrode body, The battery according to claim 1 , wherein the thin portion is formed at least at an end of the insulating resin layer on the negative electrode tab side.

5. The battery according to claim 1 , wherein the thin portion has a shape in which the thickness gradually decreases from a center portion of the insulating resin layer toward an end portion thereof.

6. The battery according to claim 1 , wherein the thin portion has a recessed shape at a center portion in a thickness direction of the insulating resin layer.

7. The battery according to claim 1 , wherein the thin portion is formed at both one end and the other end of the insulating resin layer.

8. the insulating resin layer is provided on both sides of the electrode body in a short direction, 8. The battery according to claim 1, wherein the thin portion is formed only in one of the insulating resin layers.

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