Battery

Abstract

A battery is provided in which heat conduction is efficiently performed between the outer casing and the electrode stack, and which also has excellent structural efficiency. [Solution] The battery of this disclosure comprises a hexahedral electrode stack, an outer casing that encloses the electrode stack, and a heat diffuser that contacts at least four sides of the outer casing and the electrode stack. The heat diffuser is made of a heat diffusing sheet.

Description

Technical Field

[0001] The present disclosure relates to a battery.

Background Art

[0002] As a lithium-ion secondary battery with excellent safety, a solid battery is known.

[0003] Patent Document 1 discloses an all-solid-state battery cell (hereinafter also referred to as a "battery"). The battery is formed by enclosing an electrode laminate in an exterior material. The electrode laminate includes a current collector tab extending from an end portion. The current collector tab is connected to a terminal led out from an end portion of the battery. Inside the exterior material, a first heat transfer material is disposed so as to contact the electrode laminate and the exterior material. The heat dissipation member is disposed so as to cover an end face of the electrode laminate in a stacking direction of the electrode laminate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An electrode laminate usually generates heat by charging or discharging. If heat dissipation of the electrode laminate is difficult, there is a risk of problems (for example, shortening of the battery life, etc.). Therefore, there is a demand for a battery in which heat conduction is efficiently performed between an exterior can and the electrode laminate and which has excellent structural efficiency. "Structural efficiency" indicates the ratio of the volume of a power generation element included in the battery to the volume of the battery.

[0006] The present disclosure has been made in view of the above circumstances. The problem to be solved by one embodiment of the present disclosure is to provide a battery in which heat conduction is efficiently performed between an exterior can and the electrode laminate and which has excellent structural efficiency. [Means for solving the problem]

[0007] The following embodiments are included as means for solving the above problems.

[0008] <1> The battery of the first embodiment is A hexahedral electrode stack, An outer can containing the electrode stack, A heat diffuser that contacts at least four sides of the outer can and the electrode stack, Equipped with, The aforementioned heat diffuser is made up of a heat diffusing sheet, and this is a battery.

[0009] A "thermal diffusion sheet" refers to a sheet with a thermal conductivity of 100 W / mK or more in the planar direction. The thermal conductivity of a thermal diffusion sheet in the planar direction may be 2000 W / mK or less. A thermal diffusion sheet may be a self-supporting sheet. A thermal diffusion sheet does not include sheets containing resin (hereinafter also referred to as "thermal conductive sheets") (for example, sheets made of resin, and sheets containing resin and thermal conductive fillers, etc.).

[0010] In the first embodiment, the battery includes a heat diffuser that contacts at least four sides of the outer casing and the electrode stack. The heat diffuser is made of a heat diffusing sheet. The heat diffusing sheet has high thermal conductivity even if it is thinner than the thickness of the heat conductive sheet. As a result, the battery of the first embodiment is a battery in which heat conduction is performed efficiently between the outer casing and the electrode stack, and which has excellent structural efficiency.

[0011] <2> The battery of the second embodiment is The heat diffuser surrounds all four sides of the electrode stack, <1> The battery listed.

[0012] In the battery of the second embodiment, heat conduction between the outer casing and the electrode stack is more efficient than in the case where the heat diffuser does not surround all four sides of the electrode stack.

[0013] <3> The battery of the third embodiment is The thickness of the portion of the heat diffuser facing the laminated end face of the electrode laminate is greater than the thickness of the portion of the heat diffuser facing the laminated surface of the electrode laminate. The electrode stack comprises a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector in this order along the stacking direction. The laminated end face includes the end face of the first current collector, the end face of the first active material layer, the end face of the solid electrolyte layer, the end face of the second active material layer, and the end face of the second current collector. The laminated surface includes the surface of the electrode laminate in the lamination direction, <1> or <2> This is the battery described in [the document].

[0014] During charging or discharging, the stacked end faces of the electrode stack tend to generate more heat than the stacked surfaces. In the third embodiment of the battery, the heat generated in the electrode stack by charging or discharging is efficiently transferred by the outer casing. As a result, in the third embodiment of the battery, heat conduction between the outer casing and the electrode stack is more efficient.

[0015] <4> The battery of the fourth embodiment is The thermal diffusion sheet includes a thermal diffusion layer and an electrical insulating layer formed on at least one main surface of the thermal diffusion layer. The heat diffusion layer comprises at least one of a graphite sheet, aluminum foil, and copper foil. The heat diffusion sheet is arranged such that the electrical insulating layer faces the electrode laminate. <1> ~ <3> The battery is one of the batteries listed in one of the following.

[0016] In the fourth embodiment of the battery, the occurrence of a short circuit in the electrode stack is more reliably prevented.

[0017] <5> The battery of the fifth embodiment is The aforementioned heat diffusion sheet consists only of a heat diffusion layer. The heat diffusion layer comprises at least one of a graphite sheet, aluminum foil, and copper foil. An electrically insulating resin body is interposed between the laminated end face of the electrode laminate and the heat diffuser. The electrode laminate has a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector in this order along the stacking direction. The laminated end face includes the end face of the first current collector, the end face of the first active material layer, the end face of the solid electrolyte layer, the end face of the second active material layer, and the end face of the second current collector, and the battery is the battery according to any one of <1> to <3>.

[0018] In the fifth aspect, the thickness of the heat diffusion sheet is thinner than the thickness of the heat diffusion sheet including the electrical insulation layer. That is, the thickness of the battery in the stacking direction of the fifth aspect can be thinner. As a result, in the battery of the fifth aspect, the occurrence of a short circuit in the electrode laminate is more reliably prevented, and the volume efficiency of the battery is more excellent.

Advantages of the Invention

[0019] According to the present disclosure, a battery is provided in which heat conduction is efficiently performed between the exterior can and the electrode laminate and the structural efficiency is excellent.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a perspective view of a battery according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view of a battery according to a second embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view of a battery according to a third embodiment of the present disclosure. [Figure 5] FIG. 5 is a cross-sectional view of a battery according to a fourth embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view of a battery according to a fifth embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0021] In this disclosure, a numerical range indicated using "~" means a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced by the upper or lower limit of another numerical range described in stages.

[0022] Embodiments of the battery of this disclosure will be described below with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals and will not be repeated in the description.

[0023] (1) First Embodiment The battery 1A of the first embodiment is a solid-state battery. As shown in Figure 1, the battery 1A comprises an electrode stack 10A, an outer casing 20, a heat diffuser 30A (see Figure 2), two positive electrode terminals 41, and two negative electrode terminals 42. The electrode stack 10A is a rectangular parallelepiped (an example of a hexahedral shape).

[0024] In the first embodiment, the longitudinal direction of the stacking surface S10A, which is the main surface of the electrode stack 10A, is defined as the X-axis direction. The short direction of the stacking surface S10A of the electrode stack 10A is defined as the Y-axis direction. The thickness direction of the electrode stack 10A is defined as the Z-axis direction (an example of a stacking direction). The X-axis, Y-axis, and Z-axis are all orthogonal to each other. The X-axis direction is an example of an axial direction. Note that these directions do not limit the orientation of the battery when it is used.

[0025] The two positive terminals 41, the electrode stack 10A, and the two negative terminals 42 are arranged in this order along the positive X-axis. The two positive terminals 41 and the two negative terminals 42 are electrically connected to the electrode stack 10A. The heat diffuser 30A is in contact with the four sides of the outer casing 20 and the electrode stack 10A (i.e., the stack surfaces S10A, S10B and the stack end faces S10C, S10D), surrounding the four sides of the electrode stack 10A. The outer casing 20 encloses the electrode stack 10A.

[0026] (1.1) Electrode stack The electrode stack 10A functions as a power generation element for the battery 1A. The electrode stack 10A includes a plurality of unit electrode bodies 10U. The plurality of unit electrode bodies 10U are stacked along the Z-axis direction. The plurality of unit electrode bodies 10U are connected in parallel.

[0027] The stacked structure of the unit electrode body 10U is a monopolar type structure. The unit electrode body 10U is stacked along the Z-axis in the following order: positive electrode current collector 101, positive electrode active material layer 102, solid electrolyte layer 103, negative electrode active material layer 104, negative electrode current collector 105, negative electrode active material layer 104, solid electrolyte layer 103, positive electrode active material layer 102, and positive electrode current collector 101.

[0028] The positive electrode current collector 101 collects current from the positive electrode active material layer 102. Examples of materials for the positive electrode current collector include stainless steel, aluminum, copper, nickel, iron, titanium, carbon, and aluminum alloys. The shape of the positive electrode current collector 101 may be, for example, foil-like or mesh-like.

[0029] The positive electrode active material layer 102 comprises a positive electrode active material and may further comprise at least one of a solid electrolyte, a conductive material, and a binder, if necessary. The positive electrode active material preferably contains a lithium composite oxide. Examples of lithium composite oxides include rock salt layered active materials, spinel-type active materials, and olivine-type active materials. The positive electrode active material may be any known positive electrode active material. Examples of solid electrolytes include sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, and halide solid electrolytes. The solid electrolyte may be any known solid electrolyte. Examples of conductive materials include carbon materials, metal particles, and conductive polymers. Examples of carbon materials include acetylene black and carbon fibers. Examples of binders include halogenated vinyl resins (e.g., polyvinylidene fluoride) and rubbers (e.g., acrylate butadiene rubber).

[0030] The solid electrolyte layer 103 contains a solid electrolyte and may further contain a binder as needed. The solid electrolyte and binder are the same as those exemplified as the solid electrolyte and binder that may be contained in the positive electrode active material layer 102.

[0031] The negative electrode active material layer 104 comprises a negative electrode active material and may further include, if necessary, at least one of a solid electrolyte, a conductive material, and a binder. Examples of negative electrode active materials include Li-based active materials (e.g., metallic lithium), carbon-based active materials (e.g., graphite), oxide-based active materials (e.g., lithium titanate), and Si-based active materials (e.g., elemental Si). The solid electrolyte, conductive material, and binder are the same as those exemplified as solid electrolyte, conductive material, and binder that may be included in the positive electrode active material layer 102.

[0032] The negative electrode current collector 105 collects current from the negative electrode active material layer 104. Examples of materials for the negative electrode current collector include stainless steel, aluminum, copper, nickel, iron, titanium, carbon, and aluminum alloys. The shape of the negative electrode current collector 105 is, for example, foil-like or mesh-like.

[0033] The electrode stack 10A is a rectangular parallelepiped. As shown in Figure 2, the electrode stack 10A has stacking surfaces S10A and S10B, stacking end surfaces S10C and S10D, and a pair of stacking end surfaces (not shown). The stacking surfaces S10A and S10B face each other in the Z-axis direction. The stacking end surfaces S10C and S10D face each other in the Y-axis direction. The pair of stacking end surfaces (not shown) face each other in the X-axis direction.

[0034] In the first embodiment, the laminated surfaces S10A and S10B are composed of the positive electrode current collector 101. The laminated end surfaces S10C and S10D are composed of the end surfaces of each layer constituting the unit electrode body 10U. That is, the laminated end surfaces S10C and S10D include the end surface of the positive electrode current collector 101, the end surface of the positive electrode active material layer 102, the end surface of the solid electrolyte layer 103, the end surface of the negative electrode active material layer 104, and the end surface of the negative electrode current collector 105. In the laminated end surfaces S10C and S10D, by a single cut, the end surfaces of each layer constituting the unit electrode body 10U are on the same plane.

[0035] (1.2) Outer can The outer container 20 is a metal container. The outer container 20 may have an electrical insulating film on its inner wall facing the electrode laminate 10A. The outer container 20 may be a known outer container.

[0036] (1.3) Thermal diffuser The heat diffuser 30A efficiently conducts heat between the outer casing 20 and the electrode stack 10A. In addition, in the first embodiment, the heat diffuser 30A electrically insulates the electrode stack 10A from the outer casing 20. The heat diffuser 30A is in physical contact with both the outer casing 20 and the electrode stack 10A.

[0037] The heat diffuser 30A is composed of a heat diffusion sheet 300A. In the first embodiment, the heat diffuser 30A is formed by wrapping the heat diffusion sheet 300A once around all four sides of the electrode laminate 10A.

[0038] As shown in Figure 2, the thermal diffusion sheet 300A has a thermal diffusion layer 301 and an electrical insulating layer 302 formed on one main surface S301 of the thermal diffusion layer 301. The thermal diffusion sheet 300A is arranged such that the electrical insulating layer 302 faces the electrode laminate 10A side.

[0039] The thermal diffusion layer 301 includes at least one of a graphite sheet, aluminum foil, and copper foil. The thermal diffusion layer 301 may be a single layer or a multilayer. Examples of materials for the electrical insulation layer 302 include resin and ceramics. The electrical insulation layer 302 may be tacky or adhesive. The thickness L300 of the thermal diffusion sheet 300A (see Figure 2) is appropriately selected according to the material of the thermal diffusion sheet 300A and may be 10 μm to 1000 μm or 10 μm to 400 μm. The thickness L301 of the thermal diffusion layer 301 (see Figure 2) may be thicker or thinner than the thickness L302 of the electrical insulation layer 302 (see Figure 2). The thickness L301 of the thermal diffusion layer 301 may be 10 μm to 700 μm, 10 μm to 300 μm or 10 μm to 50 μm. The thermal diffusion sheet 300A may be a known thermal diffusion sheet. From the viewpoint of further improving volumetric efficiency, the thermal diffusion layer 301 preferably includes a graphite sheet having a relatively thin thickness (e.g., 10 μm to 50 μm).

[0040] (1.4) Negative terminal and positive terminal The positive terminal 41 and the negative terminal 42 are used to discharge the electricity generated in the electrode stack 10A to the outside of the battery 1A. The positive terminal 41 and the negative terminal 42 may be known terminals.

[0041] (1.5) Effects As explained with reference to Figures 1 and 2, the battery 1A comprises an electrode stack 10A, an outer casing 20, and a heat diffuser 30A. The heat diffuser 30A is composed of a heat diffusion sheet 300A. The thermal diffusion sheet 300A has high thermal conductivity even though it is thinner than the thermal conductivity sheet. As a result, battery 1A is a battery in which heat conduction is efficiently performed between the outer casing 20 and the electrode stack 10A, and which has excellent structural efficiency.

[0042] As explained with reference to Figures 1 and 2, in battery 1A, the heat diffuser 30A surrounds all four sides of the electrode stack 10A. In the 1A battery, heat conduction between the outer casing 20 and the electrode stack 10A is more efficient than when the heat diffuser 30A does not surround all four sides of the electrode stack 10A.

[0043] As described with reference to Figures 1 and 2, in battery 1A, the thermal diffusion sheet 300A includes a thermal diffusion layer 301 and an electrical insulating layer 302. The thermal diffusion layer 301 includes at least one of a graphite sheet, aluminum foil, and copper foil. The thermal diffusion sheet 300A is positioned such that the electrical insulating layer 302 faces the electrode laminate 10A side. With a 1A battery, the occurrence of a short circuit in the electrode stack 10A is more reliably prevented.

[0044] (2) Second Embodiment Battery 1B according to the second embodiment is the same as battery 1A, except that the thickness of the heat diffuser is different.

[0045] Battery 1B comprises an electrode stack 10A, an outer casing 20, a heat diffuser 30B (see Figure 3), two positive terminals 41, and two negative terminals 42.

[0046] As shown in Figure 3, the heat diffuser 30B is composed of a heat diffuser sheet 300A. In the second embodiment, the heat diffuser 30B is formed by partially winding the heat diffuser sheet 300A twice around all four sides of the electrode stack 10A. The thickness L300B (see Figure 3) of the portion of the heat diffuser 30B facing the stacked end faces S10C, S10D of the electrode stack 10A is greater than the thickness L300A (see Figure 3) of the portion of the heat diffuser 30B facing the stacked surfaces S10A, S10B of the electrode stack 10A. For example, the thickness L300B is twice the thickness L300A.

[0047] (2.1) Effects Battery 1B is identical to battery 1A, except that the heat diffuser 30A has been replaced with heat diffuser 30B. Therefore, battery 1B produces the same effects as battery 1A.

[0048] As explained with reference to Figure 3, the thickness L300B of the portion of the heat diffuser 30B facing the laminated end faces S10C and S10D of the electrode laminate 10A is greater than the thickness L300B of the portion of the heat diffuser 30B facing the laminated surfaces S10A and S10B of the electrode laminate 10A. During charging or discharging, the stacked end faces S10C and S10D of the electrode stack 10A tend to generate more heat than the stacked surfaces S10A and S10B. In battery 1B, the heat generated in the electrode stack 10A during charging or discharging is efficiently transferred by the outer casing 20. As a result, heat conduction between the outer casing 20 and the electrode stack 10A is more efficient in battery 1B.

[0049] (3) Third Embodiment Battery 1C according to the third embodiment is the same as battery 1A, except that it has a different heat diffusion sheet and an electrically insulating resin body.

[0050] The battery 1C comprises an electrode stack 10A, an outer casing 20, a heat diffuser 30C, an electrical insulating resin body 31 (see Figure 4), two positive terminals 41, and two negative terminals 42. The electrical insulating resin body 31 is interposed between the stacked end faces S10C, S10D of the electrode stack 10A and the heat diffuser 30C.

[0051] (3.1) Thermal diffuser The heat diffuser 30C is composed of a heat diffusion sheet 300B. In the third embodiment, the heat diffuser 30C is formed by wrapping the heat diffusion sheet 300B around all four sides of the electrode laminate 10A. As shown in Figure 4, the heat diffusion sheet 300B consists only of a heat diffusion layer 301.

[0052] (3.2) Electrical insulating resin body The electrical insulating resin body 31 prevents short circuits in the electrode laminate 10A (for example, short circuits between the positive electrode active material layer 102 and the negative electrode active material layer 104). The electrical insulating resin body 31 includes known resins (thermoplastic resins, thermosetting resins, etc.). The thermoplastic resin may be an elastomer. The electrical insulating resin body 31 may include a thermal conductive filler to enable more efficient heat conduction between the outer can 20 and the electrode laminate 10A. Examples of materials for the thermal conductive filler include metal oxides (e.g., alumina, silica, and magnesia), metal nitrides (e.g., aluminum nitride, silicon nitride, and boron nitride), artificial diamond, and silicon carbide. The electrical insulating resin body 31 may be a film-like processed product (i.e., a self-supporting film) or a molded paste-like product.

[0053] (3.3) Effects Battery 1C is the same as battery 1A, except that the heat diffuser 30A has been replaced with a heat diffuser 30C and an electrical insulating resin body 31 has been formed. Therefore, battery 1C has the same effects as battery 1A.

[0054] As explained with reference to Figure 4, in battery 1C, the thermal diffusion sheet 300B consists only of a thermal diffusion layer 301. The thermal diffusion layer 301 includes at least one of a graphite sheet, aluminum foil, and copper foil. An electrically insulating resin body 31 is interposed between the laminated end faces S10C, S10D of the electrode laminate 10A and the thermal diffuser 30C. The thickness L301 of the thermal diffusion sheet 300B is thinner than the thickness L300A of the thermal diffusion sheet 300A, which includes the electrical insulation layer 302. In other words, the thickness of battery 1C in the Z-axis direction (i.e., the stacking direction) can be thinner. As a result, in battery 1C, the occurrence of short circuits in the electrode stack 10A is more reliably prevented, and the volumetric efficiency of battery 1C is improved.

[0055] (4) Fourth Embodiment The battery 1D according to the fourth embodiment is the same as battery 1A, except that it has a different heat diffusion sheet and an electrically insulating resin body.

[0056] The battery 1D comprises an electrode stack 10B, an outer casing 20, a heat diffuser 30C, an electrical insulating resin body 32 (see Figure 5), two positive electrode terminals 41, and two negative electrode terminals 42. The electrical insulating resin body 32 is interposed between the stacked end faces S10C, S10D of the electrode stack 10B and the heat diffuser 30C.

[0057] (4.1) Electrode stack As shown in Figure 5, the electrode stack 10B is the same as the electrode stack 10A, except that the end faces of each layer constituting the unit electrode 10U are not on the same plane at the stack end faces S10C and S10D.

[0058] (4.2) Electrical insulating resin The electrical insulating resin body 32 prevents short circuits in the electrode laminate 10B (for example, short circuits between the positive electrode active material layer 102 and the negative electrode active material layer 104). The electrical insulating resin body 32 may be the same as the one exemplified as the electrical insulating resin body 31. The electrical insulating resin body 32 may be a molded paste.

[0059] (4.3) Effects Battery 1D is the same as battery 1C, except that the electrode stack 10A is changed to electrode stack 10B and the electrical insulating resin body 31 is formed in place of the electrical insulating resin body 31. Therefore, battery 1D has the same effects as battery 1C.

[0060] As explained with reference to Figure 5, in battery 1D, the electrical insulating resin body 32 is interposed between the laminated end faces S10C, S10D of the electrode laminate 10B and the heat diffuser 30C. This makes it difficult for a gap to form between the electrode laminate 10B and the heat diffuser 30C. As a result, heat conduction between the outer casing 20 and the electrode laminate 10B is more efficient in battery 1D than when a gap is formed between the electrode laminate 10B and the heat diffuser 30C.

[0061] (5) Fifth embodiment The battery 1E according to the fifth embodiment is the same as the battery 1A, except that it has an electrically insulating resin body formed on it.

[0062] Battery 1E comprises an electrode stack 10A, an outer casing 20, a heat diffuser 30A, an electrical insulating resin body 33 (see Figure 6), two positive electrode terminals 41, and two negative electrode terminals 42. The electrical insulating resin body 33 is interposed between the portion of the heat diffuser 30A facing the stacked end faces S10C and S10D and the outer casing 20.

[0063] (5.1) Electrical insulating resin The electrical insulating resin body 33 reliably prevents electrical connection between the electrode laminate 10A and the outer casing 20. The electrical insulating resin body 33 may be the same as the example provided for the electrical insulating resin body 31. The electrical insulating resin body 31 may be a film-like processed product (i.e., a self-supporting film) or a molded paste-like material.

[0064] (5.2) Effects Battery 1E is the same as battery 1A, except that an electrical insulating resin body 33 is formed instead of the electrical insulating resin body 31. Therefore, battery 1E has the same effects as battery 1A.

[0065] As explained with reference to Figure 6, in battery 1E, the electrical insulating resin body 33 is interposed between the portion of the heat diffuser 30A facing the laminated end faces S10C, S10D and the outer casing 20. This makes it difficult for a gap to form between the heat diffuser 30A and the outer casing 20. As a result, heat conduction between the outer casing 20 and the electrode laminate 10A is more efficient in battery 1E than when a gap is formed between the heat diffuser 30A and the outer casing 20.

[0066] (6) Variant In batteries 1A to 1E, the heat diffusers 30A, 30B, and 30C surround all four sides of the electrode stacks 10A and 10B, but the disclosure is not limited to this. In the disclosure, the heat diffuser 3 does not need to surround all four sides of the electrode stack.

[0067] In batteries 1A to 1E, the thermal diffusion layer 301 includes at least one of a graphite sheet, aluminum foil, and copper foil, but the disclosure is not limited thereto. In this disclosure, the thermal diffusion layer does not need to include at least one of a graphite sheet, aluminum foil, and copper foil, as long as the thermal conductivity of the thermal diffusion sheet in the planar direction is 100 W / mK or more.

[0068] In batteries 1A to 1E, the electrode stacks 10A and 10B are rectangular parallelepipeds, but the disclosure is not limited thereto. In this disclosure, the electrode stacks may be cubic.

[0069] In batteries 1A to 1E, the carrier ions of the electrode stacks 10A and 10B are lithium ions, but this disclosure is not limited thereto. In this disclosure, the carrier ions of the electrode stacks may be sodium ions. [Explanation of symbols]

[0070] 1A, 1B, 1C, 1D, 1E: Battery, 10A, 10B: Electrode stack, 10U: Unit electrode, 101: Positive electrode current collector, 102: Positive electrode active material layer, 103: Solid electrolyte layer, 104: Negative electrode active material layer, 105: Negative electrode current collector, 20: Outer casing, 30A, 30B, 30C: Thermal diffuser, 300A, 300B: Thermal diffusion sheet, 31, 32, 33: Electrical insulating resin body, 41: Negative electrode terminal, 42: Positive electrode terminal, S10B: Stack end face

Claims

1. A hexahedral electrode stack, An outer can containing the electrode stack, A heat diffuser that contacts at least four sides of the outer can and the electrode stack, Equipped with, A battery in which the heat diffuser is composed of a heat diffusing sheet.

2. The battery according to claim 1, wherein the heat diffuser surrounds all four sides of the electrode stack.

3. The thickness of the portion of the heat diffuser facing the laminated end face of the electrode laminate is greater than the thickness of the portion of the heat diffuser facing the laminated surface of the electrode laminate. The electrode stack comprises a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector in this order along the stacking direction. The laminated end face includes the end face of the first current collector, the end face of the first active material layer, the end face of the solid electrolyte layer, the end face of the second active material layer, and the end face of the second current collector. The battery according to claim 1, wherein the laminated surface includes the surface of the electrode laminate in the lamination direction.

4. The thermal diffusion sheet includes a thermal diffusion layer and an electrical insulating layer formed on at least one main surface of the thermal diffusion layer. The heat diffusion layer comprises at least one of a graphite sheet, aluminum foil, and copper foil. The battery according to claim 1, wherein the heat diffusion sheet is arranged such that the electrical insulating layer faces the electrode laminate.

5. The aforementioned heat diffusion sheet consists only of a heat diffusion layer. The heat diffusion layer comprises at least one of a graphite sheet, aluminum foil, and copper foil. An electrically insulating resin body is interposed between the laminated end face of the electrode laminate and the heat diffuser. The electrode stack comprises a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector in this order along the stacking direction. The battery according to claim 1, wherein the laminated end face includes the end face of the first current collector, the end face of the first active material layer, the end face of the solid electrolyte layer, the end face of the second active material layer, and the end face of the second current collector.

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