All-solid-state batteries

Abstract

To provide an all-solid battery which allows improvement in heat dissipation.SOLUTION: An all-solid battery 1 comprises: a plurality of power generation elements 10 each of which has a positive electrode layer 11, a solid electrolyte layer 12, and a negative electrode layer 13 sequentially laminated on each other; a positive electrode collector 20 which is in contact with the positive electrode layer 11; and a negative electrode collector 30 which is in contact with the negative electrode layer 13. In the all-solid battery, at least three or more power generation elements 10 are laminated. The positive electrode collector 20 has: first to fourth contact parts 21a to 21d which are in contact with the positive electrode layer 11 in each of the power generation elements 10; and second to fourth extension parts 22b to 22d which extend from the first to fourth contact parts 21a to 21d, and which electrically connect the first to fourth contact parts 21a to 21d to one another so that the positive electrode layers 11 in the plurality of power generation elements 10 may be electrically connected to one another. The positive electrode collector 20 is wound around the plurality of power generation elements 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an all-solid-state battery. [Background technology]

[0002] In an all-solid-state battery, multiple electrode stacks are arranged, each containing a positive electrode layer, a negative electrode layer, and a solid electrolyte layer positioned between the positive and negative electrode layers (see, for example, Patent Document 1). In this all-solid-state battery, the positive electrode current collector is folded and positioned to electrically connect the positive electrode layers of the electrode stacks, and the negative electrode current collector is folded and positioned to electrically connect the negative electrode layers of the electrode stacks. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-113434 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, all-solid-state batteries have a problem in that they do not have an electrolyte that functions as a heat transfer medium, so the heat generated during charging and discharging is not easily released to the outside of the all-solid-state battery.

[0005] The problem that this invention aims to solve is to provide an all-solid-state battery capable of improving heat dissipation. [Means for solving the problem]

[0006] The present invention solves the above problem by winding the first current collector around the power generation element. [Effects of the Invention]

[0007] According to the present invention, by winding the first current collector around the power generation element, the surface area of ​​the portion of the first current collector exposed from the power generation element can be increased. As a result, heat can be dissipated by radiation from the exposed portion of the first current collector, thereby improving heat dissipation. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing an example of an all-solid-state battery in an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view along the line II-II in Figure 1. [Figure 3] Figure 3 is a cross-sectional view illustrating an example of a winding method for the positive electrode current collector of the all-solid-state battery shown in Figure 1. [Figure 4] Figure 4 is a cross-sectional view illustrating an example of a winding method for the positive electrode current collector of an all-solid-state battery in another embodiment of the present invention. [Figure 5] Figure 5 is a cross-sectional view showing an example of a modified all-solid-state battery according to an embodiment of the present invention. [Figure 6] Figure 6 is a cross-sectional view showing examples of first and second modified examples of the positive electrode current collector of an all-solid-state battery in an embodiment of the present invention. [Figure 7] Figure 7 is an exploded view showing an example of the third to sixth modified forms of the positive electrode current collector in an embodiment of the present invention. [Figure 8] Figure 8 is a cross-sectional view showing an example of a modified negative electrode current collector in an embodiment of the present invention. [Modes for carrying out the invention]

[0009] The all-solid-state battery 1 according to this embodiment will be described with reference to the drawings. Figure 1 is a cross-sectional view showing an example of the all-solid-state battery in this embodiment, and Figure 2 is a cross-sectional view along the line II-II in Figure 1. Figures 1 and 2 show the all-solid-state battery in a charged state. In addition to the power generation element and current collector, the all-solid-state battery 1 also has electrode tabs and an outer casing member that houses the electrode tabs and the power generation element.

[0010] As shown in Figure 1, the fully discharged all-solid-state battery 1 comprises multiple power generation elements 10 (six power generation elements 10a to 10f in this example), a positive electrode current collector 20, and multiple (three in this example) negative electrode current collectors 30.

[0011] Multiple power generation elements 10 are stacked along the Z direction in the figure, with a positive electrode current collector 20 and multiple negative electrode current collectors 30 interposed between the power generation elements 10. Each power generation element 10 has a positive electrode layer 11, a solid electrolyte layer 12, and a negative electrode layer 13. In this embodiment, the positive electrode layer 11 corresponds to an example of the "first electrode layer" or "second electrode layer" in the present invention, and the negative electrode layer 13 corresponds to an example of the "second electrode layer" or "first electrode layer" in the present invention.

[0012] Since the power generation elements 10a to 10f have basically the same structure, the structure of power generation element 10a will be described as representative. The positive electrode layer 11 of power generation element 10a is formed on the main surface of the positive electrode current collector 20. This positive electrode layer 11 contains at least a positive electrode active material capable of releasing and absorbing alkali metals such as lithium (Li), sodium (Na), or potassium (K), and is not particularly limited, but preferably contains a positive electrode active material containing sulfur. The sulfur-containing positive electrode active material can be any material that can release alkali metal ions such as lithium ions during charging and absorb those alkali metal ions during discharge by utilizing the oxidation-reduction reaction of sulfur. The type of sulfur-containing positive electrode active material is not particularly limited, but elemental sulfur (S), organic sulfur compounds, or particles or thin films of inorganic sulfur compounds can be used.

[0013] The organic sulfur compounds are not particularly limited, and disulfide compounds, sulfur-modified polyacrylonitrile, sulfur-modified polyisoprene, rubane acid (dithiooxamide), polysulfide carbon, etc. can be used. The inorganic sulfur compounds are not particularly limited, and examples include S-carbon composite, TiS2, TiS3, TiS4, NiS, NiS2, CuS, FeS2, Li2S, MoS2, MoS3, etc. Note that a sulfur-free material may be used as the positive electrode active material.

[0014] A solid electrolyte layer 12 is provided so as to be in contact with the positive electrode layer 11. As the solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte can be used, but it is preferable to use a sulfide solid electrolyte.

[0015] Examples of the sulfide solid electrolyte include LiI-Li2S-SiS2, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li2S-P2S5, LiI-Li3PS4, LiI-LiBr-Li3PS4, Li3PS4, 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 any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-LixMOy (where x and y are positive numbers and M is any one of P, Si, Ge, B, Al, Ga, or In), etc. The description "Li2S-P2S5" means a sulfide solid electrolyte formed using a raw material composition containing Li2S and P2S5, and the same applies to the other descriptions above. Alternatively, a sulfide glass or the like may be used as the sulfide solid electrolyte.

[0016] As the oxide solid electrolyte, for example, a compound having a NASICON-type structure or the like can be used. As the compound having a NASICON-type structure, for example, a compound represented by the general formula Li 1+x Al x Ge 2-x (PO4)3 (0 ≦ x ≦ 2) (LAGP), a compound represented by the general formula Li 1+x Al x Ti 2-x (PO4)3 (0 ≦ x ≦ 2) (LATP), etc. can be used. Further, as other oxide solid electrolytes, LiLaTiO (for example, Li 0.34 La 0.51 TiO3), LiPON (for example, Li 2.9 PO 3.3 N 0.46 ), LiLaZrO (for example, Li7La3Zr2O 12 ), etc. can be used.

[0017] A negative electrode layer 13 is provided so as to contact the solid electrolyte layer 12 from the side opposite to the positive electrode layer 11. This negative electrode layer 13 includes an alkali metal layer 13a and a negative electrode intermediate layer 13b.

[0018] The alkali metal layer 13a is deposited on the main surface of the negative electrode current collector 30 or the negative electrode intermediate layer 13b after being released from the positive electrode layer 11 and reaching through the solid electrolyte layer 12 as the all-solid-state battery 1 is charged. The volume of this alkali metal layer 13a increases as alkali metal is deposited with the charging of the all-solid-state battery 1, while it decreases as the alkali metal disappears (moves to the positive electrode layer 11 side) with the discharging. Examples of the main component of the alkali metal layer 13a include lithium metal, sodium metal, potassium metal, and the like.

[0019] The negative electrode intermediate layer 13b is provided between the solid electrolyte layer 12 and the alkali metal layer 13a. This negative electrode intermediate layer 13b is a layer that assists in the smooth deposition of alkali metals and / or prevents the alkali metal layer 13a from directly contacting the solid electrolyte layer. The negative electrode intermediate layer 13b contains a material capable of intercepting and releasing alkali metal ions or a material having electronic insulating and lithium ion conductive properties. The material capable of intercepting and releasing alkali metal ions contains one or more materials selected from the group consisting of carbon materials such as graphite and metallic materials such as silver. Furthermore, the material having electronic insulating and lithium ion conductive properties is more stable against reductive decomposition by contact with lithium metal than the solid electrolyte contained in the solid electrolyte layer. For example, it contains one or more materials selected from the group consisting of lithium halides (lithium fluoride (LiF), lithium chloride (LiCl), lithium bromide (LiBr), lithium iodide (LiI)), lithium ion conductive polymers, composite metal oxides represented by Li-MO (where M is one or more metal elements selected from the group consisting of Mg, Au, Al, Sn, and Zn), and Li-Ba-TiO3 composite oxides. All of these materials are particularly stable against reductive decomposition by contact with lithium metal. The negative electrode intermediate layer may also contain, for example, a resin binder. In this embodiment, the intermediate layer 13b is provided between the solid electrolyte layer 12 and the alkali metal layer 13a, but is not limited to this, and may be provided between the alkali metal layer 13a and the negative electrode current collector 30. Furthermore, the negative electrode layer 13 does not necessarily have to include the negative electrode intermediate layer 13b.

[0020] The positive electrode current collector 20 is a conductive plate-shaped (or foil-shaped) member, and is not particularly limited, but is composed of, for example, a metal or a conductive resin. As the metal, aluminum, nickel, iron, stainless steel, titanium, or copper can be used. Alternatively, a clad material of nickel and aluminum, or a clad material of copper and aluminum, etc., may be used. As the conductive resin, examples include a resin in which a conductive filler is added to a non-conductive polymer material.

[0021] The positive electrode current collector 20 is wound around the power generation elements 10a to 10f so as to be bent into contact with the positive electrode layer 11 of each power generation element 10a to 10f. Therefore, each positive electrode layer 11 is electrically connected to one another by this positive electrode current collector 20. In order to wind the positive electrode current collector 20 around the power generation element 10, the all-solid-state battery 1 is equipped with at least three or more power generation elements.

[0022] The positive electrode current collector 20 in this embodiment has a spiral shape wound around the power generation elements 10a to 10f, having the structure described below. Specifically, the positive electrode current collector 20 has first to fourth contact portions 21a to 21d that contact the positive electrode layer 11 of each power generation element 10, and first to fifth extension portions 22a to 22e that do not contact the positive electrode layer 11.

[0023] The first to fourth contact portions 21a to 21d are in contact with the positive electrode layers 11 of the power generation elements 10a to 10f, respectively. More specifically, the first contact portion 21a is interposed between the positive electrode layers 11 of power generation elements 10a and 10c, and the second contact portion 21b is interposed between the positive electrode layers 11 of power generation elements 10b and 10e. On the other hand, the third contact portion 21c is in contact with the positive electrode layer 11 of power generation element 10d, and the fourth contact portion 21d is in contact with the positive electrode layer 11 of power generation element 10f.

[0024] A first extension portion 22a extends from one end of the first contact portion 21a on one side (the side in the -X direction in the figure). This first extension portion 22a extends substantially parallel to the first contact portion 21a and extends from one end of the first contact portion 21a toward the -X direction in the figure. Note that this first extension portion 22a may be omitted from the positive electrode current collector 20.

[0025] A second extension portion 22b extends from the other end (the +X direction in the figure) of the first contact portion 21a and from the other end (the +X direction in the figure) of the second contact portion 21b. This second extension portion 22b has a U-shape that opens to the power generation elements 10a and 10b. This second extension portion 22b includes a pair of first and second opposing portions 23a and 23b and a first connecting portion 24a.

[0026] The first opposing portion 23a extends from the other end of the first contact portion 21a in the direction of +X in the figure, and the second opposing portion 23b extends from the other end of the second contact portion 21b in the direction of +X in the figure. These first and second opposing portions 23a and 23b face each other in the direction of Z in the figure.

[0027] The first connecting portion 24a extends along the stacking direction (Z direction in the figure). In this embodiment, the first connecting portion 24a is interposed between a pair of first and second opposing portions 23a and 23b, thereby connecting the first and second opposing portions 23a and 23b. This first connecting portion 24a faces the two power generation elements 10a and 10b.

[0028] A third extension portion 22c extends from one end of the second contact portion 21b and one end of the third contact portion 21c. This third extension portion 22c is located on the opposite side of the power generation elements 10a to 10d from the second extension portion 22b. The third extension portion 22c has a U-shape that is opposite to that of the second extension portion 22b and opens to the power generation elements 10a to 10d. The third extension portion 22c includes a pair of third and fourth opposing portions 23c, 23d and a second connecting portion 24b.

[0029] The third opposing portion 23c extends from one end of the second contact portion 21b in the direction of -X in the figure, and the fourth opposing portion 23d extends from one end of the third contact portion 21c in the direction of -X in the figure. These third and fourth opposing portions 23c and 23d face each other in the stacking direction.

[0030] The second connecting portion 24b extends along the stacking direction. This second connecting portion 24b is interposed between a pair of third and fourth opposing portions 23c and 23d, thereby connecting the third and fourth opposing portions 23c and 23d. Furthermore, the second connecting portion 24b faces the four power generation elements 10a to 10d, and the length of the second connecting portion 24b is longer than the length of the first connecting portion 24a.

[0031] A fourth extension portion 22d extends from the other end of the third contact portion 21c and the other end of the fourth contact portion 21d. This fourth extension portion 22d is located on the opposite side of the power generation elements 10a to 10f from the third extension portion 22c. This fourth extension portion 22d has a U-shape that opens to the power generation elements 10a to 10f. This fourth extension portion 22d is positioned outside the second extension portion 22b so as to contact the second extension portion 22b. The fourth extension portion 22d includes a pair of fifth and sixth opposing portions 23e, 23f and a third connecting portion 24c.

[0032] The fifth opposing portion 23e extends from the other end of the third contact portion 21c in the direction of +X in the figure, and the sixth opposing portion 23f extends from the other end of the fourth contact portion 21d in the direction of +X in the figure. These fifth and sixth opposing portions 23e and 23f face each other in the direction of Z in the figure.

[0033] The third connecting portion 24c extends along the stacking direction (Z direction in the figure). The third connecting portion 24c is interposed between the pair of fifth and sixth opposing portions 23e and 23f, thereby connecting the fifth and sixth opposing portions 23e and 23f. Furthermore, the third connecting portion 24c faces the six power generation elements 10a to 10f, and the length of the third connecting portion 24c is longer than the length of the second connecting portion 24b.

[0034] Furthermore, the third connecting portion 24c is in contact with the first connecting portion 24a. In this way, the contact between the second extension portion 22b and the fourth extension portion 22d allows current to flow between the third connecting portion 24c and the first connecting portion 24a. Therefore, the current flowing through the positive electrode current collector 20 can be dispersed starting from the contact surface between the third connecting portion 24c and the first connecting portion 24a, thereby reducing the current density in the positive electrode current collector 20. Thus, the amount of heat generated by the all-solid-state battery 1 can be reduced.

[0035] A fifth extension portion 22e extends from one end of the fourth contact portion 21d. This fifth extension portion 22e extends substantially parallel to the fourth contact portion 21d and extends from one end of the fourth contact portion 21d in the direction of -X in the figure. Note that this fifth extension portion 22e may also be omitted from the positive electrode current collector 20.

[0036] The negative electrode current collector 30 is a conductive plate-shaped (or foil-shaped) member and is not particularly limited, but is made of, for example, metal or a conductive resin. As the metal and conductive resin, the same materials as those used to make up the positive electrode current collector 20 can be used. As shown in Figures 1 and 2, the negative electrode current collector 30 in this embodiment has a rectangular planar shape and is not bent like the positive electrode current collector 20.

[0037] The winding method for the positive electrode current collector 20 of the all-solid-state battery 1 described above will be explained with reference to Figure 3. Figure 3 is a cross-sectional view illustrating an example of the winding method for the positive electrode current collector 20 of the all-solid-state battery 1 shown in Figure 1.

[0038] As shown in Figure 3, first, three negative electrode current collectors 30, each with a power generation element 10 formed on both sides, are prepared. Next, a positive electrode current collector 20 is wound around the positive electrode layers 11 of the power generation elements 10a and 10b formed on the negative electrode current collectors 30 so that the first and second contact portions 21a and 21b make contact (dotted line A in the figure).

[0039] Next, a negative electrode current collector 30 with power generation elements 10c and 10d formed on the first contact portion 21a of the positive electrode current collector 20 is placed, and a negative electrode current collector 30 with power generation elements 10e and 10f formed on the second contact portion 21b is placed (dotted line B in the figure).

[0040] Then, the positive electrode current collector 20 is wound around the positive electrode layers 11 of the power generation elements 10d and 10f such that the third and fourth contact portions 21c and 21d make contact with each other (dotted line C in the figure). In this way, the positive electrode current collector 20 of the all-solid-state battery 1 described above can be wound around the power generation element 10.

[0041] In the all-solid-state battery 1 of this embodiment, since the positive electrode current collector 20 is wound around the power generation element 10, the surface area of ​​the positive electrode current collector 20 that is not covered by the power generation element 10 can be increased. Therefore, even in an all-solid-state battery that does not contain an electrolyte, the amount of heat dissipated by radiation from the positive electrode current collector 20 can be increased. Furthermore, even in an all-solid-state battery with a high degree of internal vacuum and low heat transfer by air, heat can be dissipated by radiation from the positive electrode current collector 20, thereby improving heat dissipation performance and, consequently, improving high-temperature resistance.

[0042] Furthermore, in this embodiment, the positive electrode current collector 20 is wound, while the negative electrode current collector 30 is not. By limiting the area of ​​the negative electrode current collector 30 in this way, it is possible to suppress the deposition of alkali metals in areas other than the reaction surface of the negative electrode current collector 30. This makes it possible to suppress a decrease in the capacity of the all-solid-state battery 1.

[0043] Furthermore, as shown in Figure 3, in the case of the all-solid-state battery 1 of this embodiment, the power generation element 10 only needs to be formed on the negative electrode current collector 30, eliminating the need to form the power generation element 10 on both the negative electrode current collector 30 and the positive electrode current collector 20, thus improving manufacturability. In this embodiment, since the power generation element 10 is formed on the negative electrode current collector 30 in advance, the negative electrode current collector 30 and the power generation element 10 are joined, while the positive electrode current collector 20 and the power generation element 10 are merely in contact and not joined.

[0044] In the above embodiment, a winding method was described in which a power generation element 10 is formed on each of the multiple negative electrode current collectors 30 as shown in Figure 3, and then the positive electrode current collector 20 is wound around them. However, the invention is not limited to this. For example, the positive electrode current collector 20 in the all-solid-state battery 1B may be wound using the following winding method.

[0045] Figure 4 is a cross-sectional view illustrating an example of a winding method for the positive electrode current collector 20 of an all-solid-state battery 1B in another embodiment. In this embodiment, power generation elements 10a to 10f are formed on one main surface of a single negative electrode current collector 30B. This negative electrode current collector 30B is folded in a mountain fold portion 30a and in a valley fold portion 30b. Therefore, in this embodiment, two layers of negative electrode current collectors 30B are interposed between the power generation elements 10.

[0046] In this case as well, the positive electrode current collector 20 is wound around the positive electrode layers 11 of the power generation elements 10a and 10b formed on the negative electrode current collector 30B so that the first and second contact portions 21a and 21b make contact (dotted line A in the figure). Then, the positive electrode current collector 20 is wound around the positive electrode layers 11 of the power generation elements 10d and 10f so that the third and fourth contact portions 21c and 21d make contact, respectively (dotted line B in the figure). In this way, the positive electrode current collector 20 of the all-solid-state battery 1B described above can be wound around the power generation element 10.

[0047] Figure 5 is a cross-sectional view showing an example of a modified all-solid-state battery in this embodiment. This modified example differs from the above embodiment in that the all-solid-state battery 1C further comprises a heat dissipation material layer 40 on the positive electrode current collector 20.

[0048] In this modified example, the heat dissipation layer 40 covers the surface of the second to fourth extensions 22b of the positive electrode current collector 20. As this heat dissipation layer 40, an insulating material with heat dissipation properties can be used. Specifically, such materials include ceramics and rubber. Since ceramics and rubber have a higher radiation coefficient than metal foil, they can improve the heat dissipation effect through radiation.

[0049] Figure 6(a) is a cross-sectional view showing an example of a first modified example of the positive electrode current collector 20 of the all-solid-state battery in this embodiment. As shown in this modified example, the second to fourth extensions 22b to 22d of the positive electrode current collector 20D of the all-solid-state battery 1D may have bellows-shaped portions. In this modified example, the case in which the first to third connecting portions 24a to 24c have a bellows shape is shown, but the figure is not limited to this, and the opposing portions may also have a bellows shape. In this way, by including bellows-shaped portions in the second to fourth extensions 22b to 22d, the surface area of ​​the second to fourth extensions 22b to 22d can be increased, thereby improving the heat dissipation effect by radiation. Furthermore, such bellows shapes and arc shapes can follow the expansion and contraction of the power generation element 10 in the stacking direction accompanying charging and discharging.

[0050] Figure 6(b) is a cross-sectional view showing an example of a second modified example of the positive electrode current collector 20 of the all-solid-state battery in this embodiment. As shown in this modified example, the second to fourth extensions 22b to 22d of the positive electrode current collector 20E of the all-solid-state battery 1E may have arc-shaped portions. In this modified example, the case in which the first to third connecting portions 24a to 24c have an arc shape is shown, but the figure is not limited to this, and the opposing portions may also have a bellows shape. In this case as well, the surface area of ​​the second to fourth extensions 22b to 22d can be increased, thereby improving the heat dissipation effect by radiation. Furthermore, such bellows shapes and arc shapes can follow the expansion and contraction of the power generation element 10 in the stacking direction accompanying charging and discharging.

[0051] Figures 7(a) to 7(d) are unfolded diagrams showing examples of the third to sixth modified forms of the positive electrode current collector in this embodiment. As shown in Figure 7(a), the width of the positive electrode current collector 20F may increase from the first end 20a to the second end 20b. In this modified form, the width is changed by inclining the two long sides of the positive electrode current collector 20G. The first end 20a is the end located towards the center of the winding shape of the positive electrode current collector 20F, and the second end 20b is the end located towards the outermost circumference of the winding shape. Alternatively, as shown in Figure 7(b), the width of the positive electrode current collector 20G may be changed by inclining only one of its long sides.

[0052] Alternatively, contrary to Figure 7(a), the width of the positive electrode current collector 20H may increase from the second end 20b toward the first end 20a. Furthermore, as shown in Figure 7(d), the width of the positive electrode current collector 20G may be changed by tilting only one of the long sides of the positive electrode current collector 20I.

[0053] If the positive electrode current collectors 20F to 20I are as shown in Figures 7(a) to 7(d), then when the positive electrode current collectors 20F to 20I are wound, the widths of the opposing portions of the first to fifth extensions 22a to 22e (see Figure 1) are different, so the area of ​​the opposing portions can be reduced. Therefore, radiant heat from the first to fifth extensions 22a to 22e is more easily transmitted to the exterior member, thus increasing the amount of heat dissipated.

[0054] Figure 8 is a cross-sectional view showing an example of a modified negative electrode current collector in this embodiment. This modified example differs from the above embodiment in that not only the positive electrode current collector 20 but also the negative electrode current collector 30G is wound around the power generation element 10.

[0055] In this modified example, the negative electrode current collector 30G in the all-solid-state battery 1G is basically wound around the power generation element 10, similar to the positive electrode current collector 20 in the above embodiment. However, in this modified example, the first to third contact portions 31a to 31c of the negative electrode current collector 30G are interposed between the negative electrode layers 13 of the power generation element 10. A U-shaped first extension portion 32a extends from the first contact portion 31a and the second contact portion 31b, and a U-shaped second extension portion 32b extends from the second contact portion 31b and the third contact portion 31c.

[0056] In this way, the inclusion of the negative electrode current collector 30G in the winding increases the radiant heat from the negative electrode current collector 30G, thereby improving the heat dissipation performance of the all-solid-state battery 1G.

[0057] While embodiments of the present invention have been described above, these embodiments are provided to facilitate understanding of the present invention and are not intended to limit it. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0058] For example, the negative electrode current collector may be wound around the power generation element without winding the positive electrode current collector.

[0059] Furthermore, the number of power generation elements is not particularly limited, as long as there are at least three or more. [Explanation of symbols]

[0060] 1,1B~1G…All-solid-state battery 10a~10f...Power generation element 11…Positive electrode layer 12...Solid electrolyte layer 13…Negative electrode layer 13a…Alkali metal layer 13b…middle class 20,20D…Positive electrode current collector 21a~21d...1st to 4th contact points 22a~22e...1st to 5th extensions 23a~23f...1st to 6th opposing sections 24a~24c...1st to 3rd connecting section 30,30B,30G…Negative electrode current collector 30a... Mountain fold section 30b... Valley fold section 31a~31c...1st to 3rd contact points 32a, 32b... First and second extensions 40...Heat dissipation material layer

Claims

1. A plurality of power generation elements in which a first electrode layer, a solid electrolyte layer, and a second electrode layer are stacked in order, The first current collector in contact with the first electrode layer, The present invention comprises a second current collector in contact with the second electrode layer, The aforementioned power generation element is an all-solid-state battery in which at least three or more elements are stacked, The first current collector is A plurality of contact portions in contact with the first electrode layer of each of the aforementioned power generation elements, It has an extension portion that extends from the contact portion and electrically connects the first electrode layers of the plurality of power generation elements by electrically connecting the contact portions to each other. The first current collector is wound around the plurality of power generation elements, The plurality of extensions include a pair of first extensions that extend to one side relative to the contact portion, A solid-state battery in which the pair of extensions are in contact with each other.

2. A plurality of power generation elements in which a first electrode layer, a solid electrolyte layer, and a second electrode layer are stacked in order, The first current collector in contact with the first electrode layer, The present invention comprises a second current collector in contact with the second electrode layer, The aforementioned power generation element is an all-solid-state battery in which at least three or more elements are stacked, The first current collector is A plurality of contact portions in contact with the first electrode layer of each of the aforementioned power generation elements, It has an extension portion that extends from the contact portion and electrically connects the first electrode layers of the plurality of power generation elements by electrically connecting the contact portions to each other. The first current collector is wound around the plurality of power generation elements, The all-solid-state battery further comprises a heat dissipation layer covering the surface of the extension portion.

3. The all-solid-state battery according to claim 1, The aforementioned first electrode layer is a positive electrode layer, The first current collector is a positive electrode current collector, The above-mentioned second electrode layer is a negative electrode layer, The second current collector is a solid-state battery, which is a negative electrode current collector.

4. The all-solid-state battery according to claim 1, A solid-state battery in which the plurality of power generation elements are formed on either the first current collector or the second current collector.

5. The all-solid-state battery according to claim 1, The first extension portion is an all-solid-state battery including a bellows-shaped portion or an arc-shaped portion.

6. The all-solid-state battery according to claim 1, The first current collector is The first end, which is the end located on the central side of the winding shape of the first current collector, The first current collector includes a second end which is the outermost end of the winding shape of the first current collector, A solid-state battery in which the width of the first current collector increases from the first end to the second end.

7. The all-solid-state battery according to claim 1, The first current collector is The first end, which is the end located on the central side of the winding shape of the first current collector, The first current collector includes a second end which is the outermost end of the winding shape of the first current collector, A solid-state battery in which the width of the first current collector increases from the second end toward the first end.

8. A solid-state battery according to any one of claims 1 to 7, The second current collector is an all-solid-state battery wound around the plurality of power generation elements.

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