Battery

Abstract

A battery is provided in which the reaction between the solid electrolyte and water is suppressed. [Solution] The battery of this disclosure comprises an electrode body containing a solid electrolyte, a case housing the electrode body, and a resin body provided in the gap between the end face of the electrode body and the case. The resin body has a first layer laminated on the end face of the electrode body and a second layer laminated on the first layer. The resin component of the first layer is a resin having less than 100 ppm of hydroxyl groups. The second layer is a layer that electrically insulates the electrode body from the case.

Description

Technical Field

[0001] The present disclosure relates to a battery.

Background Art

[0002] Patent Document 1 discloses a rectangular storage device (hereinafter also referred to as a "battery"). The battery includes an electrode body, an insulating holder (hereinafter also referred to as a "resin body"), a rectangular exterior case, and a sealing body. The electrode body has a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate. The resin body has an insulating sheet formed in a box shape and houses the electrode body. The exterior case has an opening and houses the electrode body and the resin body. The sealing body seals the opening of the exterior case. The insulating sheet has a porous body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Water (e.g., moisture in the air, etc.) is likely to be adsorbed on a resin component having a hydroxy group. When the electrode body contains a solid electrolyte and the resin component of the resin body has a hydroxy group, water and the solid electrolyte in the electrode body are likely to come into contact. When water and the solid electrolyte come into contact, they may react with each other, and there is a risk that battery performance (e.g., ionic conductivity of the solid electrolyte, etc.) may deteriorate.

[0005] 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 the reaction between a solid electrolyte and water is suppressed.

Means for Solving the Problems

[0006] The following embodiments are included as means for solving the above problems.

[0007] <1> A battery according to a first aspect of this disclosure is An electrode body containing a solid electrolyte, A case for housing the electrode body, A resin body is provided in the gap between the end face of the electrode body and the case, Equipped with, The resin body comprises a first layer laminated on the end face of the electrode body and a second layer laminated on the first layer. The resin component of the first layer is a resin having less than 100 ppm of hydroxyl groups. The battery is characterized in that the second layer is a layer that electrically insulates the electrode body from the case.

[0008] In this disclosure, "resin having less than 100 ppm of hydroxyl groups" refers to a resin in which the ratio of the mass of hydroxyl groups to the mass of the resin component of a layer (e.g., the first layer) (hereinafter also referred to as "hydroxyl group content") is less than 100 ppm. The hydroxyl group content may be determined by Fourier transform infrared spectroscopy (FTIR). "Layer electrically insulating the electrode body and the case" refers to a layer containing resin and having electrical insulating properties. The electrical resistance of the second layer is 10 10 It may be greater than or equal to Ω·m.

[0009] In the first embodiment, the resin component of the first layer is a resin having less than 100 ppm of hydroxyl groups. In other words, water (e.g., moisture in the air) is less likely to adsorb to the first layer. As a result, the electrode body is less likely to come into contact with water. Consequently, the battery in the first embodiment is a battery in which the reaction between the solid electrolyte and water is suppressed.

[0010] <2> A battery according to a second aspect of this disclosure is The resin body further comprises a third layer laminated on the second layer, The resin component of the third layer is different from the resin component of the first layer. <1> This is the battery described in [the document].

[0011] In the second embodiment, the resin component of the third layer is different from that of the first layer. Therefore, the third layer may have a different function from that of the first layer (i.e., a function that makes it difficult to adsorb water) (for example, flexibility, thermal conductivity, or adhesion). As a result, the battery of the second embodiment is a battery with excellent design flexibility.

[0012] <3> A battery according to a third aspect of this disclosure is The resin body further comprises a third layer laminated on the second layer, The hardness of the third layer is lower than that of the first layer. <1> or <2> This is the battery described in [the document].

[0013] "Hardness" refers to JIS-A hardness, measured at room temperature of 23°C using a Type A durometer (Type A) in accordance with JIS K6253.

[0014] In the third embodiment, the hardness of the third layer is lower than that of the first layer. In other words, the third layer is softer than the first layer. As a result, the battery in the third embodiment has better shock resistance than a configuration in which the hardness of the third layer is equal to or greater than that of the first layer.

[0015] <4> A battery according to a fourth aspect of this disclosure is The resin component of the first layer includes an adhesive resin, <1> ~ <3> The battery is one of the batteries listed in one of the following.

[0016] "Adhesive resin" refers to a resin that is adhesive at room temperature (23°C). More specifically, "adhesive resin" refers to a resin that can reversibly adhere to an object at room temperature (23°C).

[0017] In the fourth aspect, the resin component of the first layer includes an adhesive resin. Therefore, the resin body is likely to be held in a state of being adhered to the electrode body. The exposed area of the resin body in a state of being adhered to the electrode body is smaller than that of a configuration in which the resin body is not adhered to the electrode body. As a result, it is more difficult for water to be adsorbed on the first layer. As a result, the battery of the fourth aspect is a battery in which the reaction between the solid electrolyte and water is more suppressed.

[0018] <5>The battery according to the fifth aspect of the present disclosure is where the second layer is a film, and the shape of the first layer follows the shape of the second layer, and the battery according to any one of <1> to <4> above.

[0019] In the fifth aspect, the second layer is a film. As a result, the battery of the fifth aspect is a battery having higher productivity than a configuration in which the second layer is not a film.

[0020] <6>The battery according to the sixth aspect of the present disclosure is where the resin body further has a third layer laminated on the second layer, and the third layer includes a heat-conductive filler, and the battery according to any one of <1> to <5> above.

[0021] In the sixth aspect, the third layer includes a heat-conductive filler. As a result, the heat conductivity of the third layer is superior to a configuration in which the third layer does not include a heat-conductive filler. As a result, the battery of the sixth aspect is a battery having superior cooling performance than a configuration in which the third layer does not include a heat-conductive filler.

Advantages of the Invention

[0022] According to the present disclosure, a battery in which the reaction between the solid electrolyte and water is suppressed is provided.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is an external perspective view of the battery of the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of the battery of the first embodiment in FIG. 1. [Figure 3] Figure 3 is a cross-sectional view of the battery of the first embodiment shown in Figure 1, taken along line III-III. [Figure 4] Figure 4 is a cross-sectional view taken along line II-II of the electrode body of the first embodiment shown in Figure 1. [Figure 5] Figure 5 is a cross-sectional view taken along line III-III of the electrode body of the first embodiment shown in Figure 1. [Figure 6] Figure 6 is a cross-sectional view of the battery according to the second embodiment. [Figure 7] Figure 7 is a cross-sectional view of the battery according to the third embodiment. [Figure 8] Figure 8 is a cross-sectional view of the battery according to the fourth embodiment. [Modes for carrying out the invention]

[0024] 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. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, the term "process" is included not only in the sense of an independent process, but also in the sense of a process that is not clearly distinguishable from other processes, as long as its intended purpose is achieved.

[0025] 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.

[0026] The batteries in this disclosure include so-called all-solid-state batteries that use a solid electrolyte, and the solid electrolyte may contain less than 10% by mass of electrolyte relative to the total amount of electrolyte. The solid electrolyte may also be a composite solid electrolyte containing an inorganic solid electrolyte and a polymer electrolyte.

[0027] (1) First Embodiment (1.1)Battery The battery 1A of the first embodiment is a solid-state battery. As shown in Figure 1, the battery 1A comprises an electrode body 10, a case 20, a resin body 30A (see Figure 2), a positive electrode terminal 41 (see Figure 2), and a negative electrode terminal 42 (see Figure 2). The electrode body 10 is a rectangular parallelepiped.

[0028] In the first embodiment, the longitudinal direction of the first main surface S11A of the electrode body 10 is defined as the X-axis direction. The short direction of the first main surface S11A of the electrode body 10 is defined as the Y-axis direction. The thickness direction of the electrode body 10 is defined as the Z-axis 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. The first main surface S11A is an example of an end face.

[0029] The positive terminal 41, the electrode body 10, and the negative terminal 42 are arranged in this order along the positive X-axis. Each of the positive terminal 41 and the negative terminal 42 is electrically connected to the electrode body 10. The resin body 30A is interposed between the electrode body 10 and the case 20. The electrode body 10 and the resin body 30A are sealed by the case 20, the positive terminal 41, and the negative terminal 42.

[0030] (1.1.1) Electrode body The electrode body 10 functions as a power generation element for the battery 1A.

[0031] As shown in Figure 2, the electrode body 10 includes an electrode body 11, a plurality of positive electrode current collector tabs 12, and a plurality of negative electrode current collector tabs 13. The plurality of positive electrode current collector tabs 12 and the plurality of negative electrode current collector tabs 13 are electrically connected to the electrode body 11.

[0032] The electrode body 11 is a rectangular parallelepiped. As shown in Figure 3, the electrode body 11 has a first main surface S11A, a second main surface S11B, a first side surface S11C, a second side surface S11D, a third side surface S11E (see Figure 2), and a fourth side surface S11F (see Figure 2). The first main surface S11A faces the second main surface S11B in the Z-axis direction. The first side surface S11C faces the second side surface S11D in the Y-axis direction. The third side surface S11E faces the fourth side surface S11F in the X-axis direction. The first main surface S11A is continuously connected to the first side surface S11C, the second side surface S11D, the third side surface S11E, and the fourth side surface S11F. The second main surface S11B is continuously connected to the first side surface S11C, the second side surface S11D, the third side surface S11E, and the fourth side surface S11F. Each of the second main surface S11B, the first side surface S11C, and the second side surface S11D is an example of an end surface.

[0033] Details of the electrode body 10 will be described later with reference to Figures 4 and 5.

[0034] (1.1.2) Case Case 20 houses the electrode body 10.

[0035] Case 20, as shown in Figure 2, comprises a metal cylinder 21, a pair of lids 22, and an electrical insulator 23. The metal cylinder 21 has a first opening R21A and a second opening R21B. One of the pair of lids 22 closes the first opening R21A of the metal cylinder 21. The other of the pair of lids 22 closes the second opening R21B of the metal cylinder 21. The pair of lids 22 are welded to the metal cylinder 21. The electrical insulator 23 is interposed between each of the positive terminal 41 and the negative terminal 42 and the lid 22.

[0036] (1.1.2.1) Metal cylinder In the first embodiment, the metal cylinder 21 is a rectangular tube, as shown in Figure 3. The metal cylinder 21 has a hollow section. The hollow section extends along the X-axis direction. The first opening R21A communicates with the second opening R21B through the hollow section. The first opening R21A faces the second opening R21B in the X-axis direction. The first opening R21A is located in the negative X-axis direction relative to the second opening R21B. The metal cylinder 21 has a first wall portion 211, a second wall portion 212, a third wall portion 213, and a fourth wall portion 214. The first wall portion 211 faces the first main surface S11A of the electrode body 11. The second wall portion 212 faces the second main surface S11B of the electrode body 11. The third wall portion 213 faces the first side surface S11C of the electrode body 11. The fourth wall portion 214 faces the second side surface S11D of the electrode body 11. The first wall portion 211 is continuously connected to the third wall portion 213 and the fourth wall portion 214. The second wall portion 212 is continuously connected to the third wall portion 213 and the fourth wall portion 214.

[0037] The material of the metal cylinder is metal (for example, aluminum, copper, stainless steel (SUS), or nickel).

[0038] (1.1.2.2) Lid The cover 22 is a plate-like object. As shown in Figure 2, the cover 22 has one through-hole R22 extending in the X-axis direction. The positive terminal 41 is exposed from the through-hole R22 of one of the pair of covers 22. The negative terminal 42 is exposed from the through-hole R22 of the other of the pair of covers 22. The material of the cover is metal (for example, aluminum, copper, stainless steel (SUS), or nickel, etc.).

[0039] (1.1.2.3) Electrical insulators The electrical insulator 23 prevents electrical contact between the positive terminal 41 and the negative terminal 42 and the cover 22. The shape of the electrical insulator 23 is not particularly limited as long as it is interposed between the positive terminal 41 and the negative terminal 42 and the cover 22. The material of the electrical insulator may be a known resin (thermoplastic resin, thermosetting resin, etc.). The thermoplastic resin may be an elastomer.

[0040] (1.1.3) Resin body The resin body 30A electrically insulates the electrode body 10 from the case 20. The resin body 30A is interposed between the electrode body 11 and the case 20. The resin body 30A is in physical contact with the electrode body 10 and the case 20.

[0041] In the first embodiment, the resin body 30A has a pair of three-layer portions 31A and a pair of single-layer portions 32A. One of the pair of three-layer portions 31A is provided in the gap between the first main surface S11A of the electrode body 11 and the first wall portion 211 of the metal cylinder 21 (hereinafter also referred to as the "first gap"), as shown in Figure 3. The other of the pair of three-layer portions 31A is provided in the gap between the second main surface S11A of the electrode body 11 and the second wall portion 212 of the metal cylinder 21 (hereinafter also referred to as the "second gap"). One of the pair of single-layer portions 32A is provided in the gap between the first side surface S11C of the electrode body 11 and the third wall portion 213 of the metal cylinder 21 (hereinafter also referred to as the "third gap"). The other of the pair of single-layer portions 32A is provided in the gap between the second side surface S11D of the electrode body 11 and the fourth wall portion 214 (hereinafter also referred to as the "fourth gap"). The three-layer section 31A and the single-layer section 32A may or may not be welded together.

[0042] (1.1.3.1) Three-layer part The three-layer portion 31A prevents electrical contact between the electrode body 10 and the case 20. The pair of three-layer portions 31A cover the entire first main surface S11A and the second main surface S11B of the electrode body 11.

[0043] The three-layer portion 31A has a first layer 311, a second layer 312, and a third layer 313A. One of the three three-layer portions 31A has a first layer 311 which is laminated on the first main surface S11A of the electrode body 11. The other of the three three-layer portions 31A has a first layer 311 which is laminated on the second main surface S11B of the electrode body 11. The second layer 312 is laminated on the first layer 311. The third layer 313A is laminated on the second layer 312.

[0044] In the first embodiment, each of the first layer 311, the second layer 312, and the third layer 313A may have different functions.

[0045] (1.1.3.1.1) First layer The first layer 311 is a layer that does not easily adsorb water (for example, moisture in the air). The first layer 311 is adhesive and flexible. The shape of the first layer 311 follows the shape of the second layer 312.

[0046] The resin component of the first layer contains a resin having less than 100 ppm of hydroxyl groups and being tacky (hereinafter also referred to as "tacky resin"). Examples of tacky resins include acrylic resin or silicone resin. The resin component of the first layer may further contain a resin having less than 100 ppm of hydroxyl groups and not being tacky (hereinafter referred to as "non-tacky resin"). Examples of non-tacky resins include epoxy resin or polyester resin. The resin component of the first layer may be used alone or in combination of two or more types.

[0047] The first layer may further contain compounding agents as needed. Examples of compounding agents include fillers (e.g., glass fibers, carbon fibers, or inorganic powders), heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, mold release agents, or antistatic agents.

[0048] The thickness L1 of the first layer 311 (see Figure 3) is not particularly limited. The thickness L1 of the first layer 311 may be thinner than the thickness L2 of the second layer 312 (see Figure 3) and the thickness L3 of the third layer 313A (see Figure 3).

[0049] (1.1.3.1.2) Second layer The second layer 312 is a layer that electrically insulates the electrode body 10 from the case 20. The second layer is a film.

[0050] The resin component of the second layer is not particularly limited as long as it is a resin that can electrically insulate the electrode body 10 and the case 20, and may be a known resin (thermoplastic resin, thermosetting resin, etc.). The thermoplastic resin may be an elastomer. The resin component of the second layer may contain a resin with less than 100 ppm of hydroxyl groups (i.e., the adhesive resin or non-adhesive resin described above), or it may contain a resin with hydroxyl groups (i.e., a resin with 100 ppm or more of hydroxyl groups). The resin component of the second layer may be the same as or different from the resin component of the first layer. The resin component of the second layer may be used alone, or two or more types may be used in combination.

[0051] The second layer may further contain compounding agents as needed. Examples of compounding agents are the same as those exemplified as compounding agents that may be included in the first layer.

[0052] The thickness L2 of the second layer 312 (see Figure 3) is not particularly limited. The thickness L2 of the second layer 312 may be thicker than the thickness L1 of the first layer 311 (see Figure 3) and the thickness L3 of the third layer 313A (see Figure 3).

[0053] (1.1.3.1.3)Third layer The third layer 313A is a layer with excellent thermal conductivity.

[0054] The third layer may contain a thermally conductive filler. The material of the thermally conductive filler is not particularly limited and includes metal oxides (e.g., alumina, silica, or magnesia), metal nitrides (e.g., aluminum nitride, silicon nitride, or boron nitride), artificial diamond, silicon carbide, or carbon nanotubes.

[0055] The resin component of the third layer 313A is different from the resin component of the first layer 311. The resin component of the third layer may include a resin having excellent thermal conductivity (hereinafter also referred to as "thermal conductive resin"). Examples of thermal conductive resins include polyactylene, polyaniline, polypyrrole, or polythiophene. If the resin component of the third layer includes a thermal conductive resin, the resin component of the third layer 313A may or may not include a thermal conductive filler.

[0056] If the third layer contains a thermally conductive filler, the resin component of the third layer may include a known resin different from the thermally conductive resin (such as a thermoplastic resin or a thermosetting resin). The thermoplastic resin may be an elastomer. The resin component of the third layer may include a resin with less than 100 ppm of hydroxyl groups (i.e., the adhesive or non-adhesive resins mentioned above) or a resin with hydroxyl groups (i.e., a resin with 100 ppm or more of hydroxyl groups), as long as it differs from the resin component of the first layer. The resin component of the third layer may be used alone or in combination of two or more types.

[0057] The third layer may further contain compounding agents as needed. Examples of compounding agents are the same as those exemplified as compounding agents that may be included in the first layer.

[0058] The thickness L3 of the third layer 313A (see Figure 3) is not particularly limited. The thickness L3 of the third layer 313A may be thicker than the thickness L1 of the first layer 311 (see Figure 3) and thinner than the thickness L2 of the second layer 312 (see Figure 3).

[0059] (1.1.3.2) Single-layer area The single-layer portion 32A prevents electrical contact between the electrode body 10 and the case 20.

[0060] The single-layer portion 32A is filled between the first side surface S11C of the electrode body 11 and the inner surface S213 of the third wall portion 213 of the case 20. The single-layer portion 32A is filled between the second side surface S11D of the electrode body 11 and the inner surface S214 of the fourth wall portion 214 of the case 20.

[0061] The resin component of the single-layer portion 32A may be a known resin (thermoplastic resin, thermosetting resin, etc.). The single-layer portion 32A may contain at least one of a thermally conductive filler and a compounding agent. The thermally conductive filler is the same as that exemplified as a thermally conductive filler that may be included in the third layer. The compounding agent is the same as that exemplified as a compounding agent that may be included in the first layer. The material of the single-layer portion 32A may be the same as the material of the third layer 313A of the three-layer portion 31A.

[0062] (1.1.4) Positive and negative terminals The positive terminal 41 and the negative terminal 42 are used to discharge the electricity generated in the electrode body 10 to the outside of the battery 1A. The materials for the positive and negative terminals include metals (for example, aluminum, stainless steel (SUS), or nickel).

[0063] (1.1.5) Details of the electrode As shown in Figure 2, the electrode body 10 includes an electrode body 11, a plurality of positive electrode current collecting tabs 12, and a plurality of negative electrode current collecting tabs 13. The electrode body 11 includes a plurality of unit electrode bodies 11U, as shown in Figures 4 and 5. The plurality of unit electrode bodies 11U are stacked along the Z-axis direction. The plurality of unit electrode bodies 11U are connected in parallel.

[0064] The first side surface S11C, the second side surface S11D, and the third side surface S11E of the electrode body 11 are flat surfaces (i.e., planar) as shown in Figures 4 and 5. The fourth side surface S11F of the electrode body 11 is a tapered surface (i.e., stepped surface) as shown in Figure 4.

[0065] The stacked structure of the unit electrode body 11U is a monopolar type structure. Specifically, the unit electrode body 11U has two solid electrolyte layers 111, two positive electrode active material layers 112, two negative electrode active material layers 113, two positive electrode current collectors 114, and one negative electrode current collector 115. The positive electrode current collector 114, positive electrode active material layer 112, solid electrolyte layer 111, negative electrode active material layer 113, negative electrode current collector 115, negative electrode active material layer 113, solid electrolyte layer 111, positive electrode active material layer 112, and positive electrode current collector 114 are stacked in this order along the Z-axis direction.

[0066] One positive electrode current collector tab 12 is connected to one positive electrode current collector 114. One negative electrode current collector tab 13 is connected to one negative electrode current collector 115. The number of positive electrode current collector tabs 12 on the electrode body 10 is greater than the number of negative electrode current collector tabs 13 on the electrode body 10.

[0067] (1.1.5.1) Solid electrolyte layer The solid electrolyte layer 111 contains a solid electrolyte. The solid electrolyte is not particularly limited and may be an aggregate of multiple particles. Preferably, the solid electrolyte contains one selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. The solid electrolyte may be a known solid electrolyte.

[0068] The solid electrolyte layer may further contain a binder. The binder may be used for bonding between solid electrolytes. The binder may be used for bonding the solid electrolyte to the positive electrode active material layer 112 or the negative electrode active material layer 113. Examples of binders include vinyl halogenated resins (e.g., polyvinylidene fluoride (PVdF), etc.), rubbers (e.g., acrylate butadiene rubber (ABR), or styrene-butadiene rubber (SBR), etc.), or polyolefin resins (e.g., polyethylene (PE), or polypropylene (PP), etc.).

[0069] (1.1.5.2) Positive electrode active material layer The positive electrode active material layer 112 contains a positive electrode active material. The positive electrode active material layer 112 may optionally contain at least one of a positive electrode solid electrolyte, a conductive additive, and a binder.

[0070] The positive electrode active material preferably contains a lithium composite oxide. The lithium composite oxide may contain at least one element selected from the group consisting of F, Cl, N, S, Br, and I. The lithium composite oxide may also have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc. Furthermore, the lithium composite oxide may have an O2-type structure in which the main arrangement of the transition metal, oxygen, and lithium is located. The positive electrode active material may be a known positive electrode active material.

[0071] The solid electrolyte for the positive electrode is similar to the solid electrolyte exemplified as being included in the solid electrolyte layer.

[0072] Examples of conductive additives include carbon materials (e.g., carbon black, carbon nanotubes, graphite, or carbon fluoride), metallic materials (e.g., aluminum powder, or conductive whiskers), or conductive polymer materials (e.g., polyaniline, polypyrrole, or polythiophene).

[0073] Examples of binders include those similar to those exemplified as binders contained in the solid electrolyte layer.

[0074] (1.1.5.3) Negative electrode active material layer The negative electrode active material layer 113 contains a negative electrode active material. The negative electrode active material layer 113 may optionally contain at least one of a negative electrode solid electrolyte, a conductive additive, and a binder.

[0075] 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), or Si-based active materials (e.g., elemental Si).

[0076] Examples of solid electrolytes for the negative electrode include those similar to those exemplified as solid electrolytes for the positive electrode that can be used in the positive electrode active material layer.

[0077] Examples of conductive additives that can be used in the negative electrode active material layer are the same as those exemplified for conductive additives that can be used in the positive electrode active material layer.

[0078] Binders that can be used in the negative electrode active material layer are similar to those exemplified as binders that can be used in the positive electrode active material layer.

[0079] (1.1.5.4) Positive electrode current collector The positive electrode current collector 114 collects current from the positive electrode active material layer 112. The material of the positive electrode current collector is not particularly limited and includes, for example, stainless steel, aluminum, copper, nickel, iron, titanium, or carbon. The positive electrode current collector may be an aluminum alloy foil or an aluminum foil. The aluminum alloy foil and aluminum foil may be manufactured using powder. The shape of the positive electrode current collector may be, for example, foil-like or mesh-like. The positive electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer on its surface.

[0080] (1.1.5.5) Negative electrode current collector The negative electrode current collector 115 collects current from the negative electrode active material layer 113. The material of the negative electrode current collector is not particularly limited and includes, for example, stainless steel, aluminum, copper, nickel, iron, titanium, or carbon. The negative electrode current collector may be copper foil. The shape of the negative electrode current collector may be, for example, foil-like or mesh-like. The negative electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer arranged on its surface.

[0081] (1.1.5.6) Positive electrode current collector tab The positive electrode current collector tab 12 electrically connects the positive electrode current collector body 114 and the positive electrode terminal 41. The positive electrode current collector tab 12 is connected to the positive electrode current collector body 114. As shown in Figure 2, the positive electrode current collector tab 12 protrudes in the negative X-axis direction relative to the fourth side surface S11F of the electrode body 11. Specifically, in the first embodiment, a bundle including a plurality of positive electrode current collector tabs 12 is electrically connected to the positive electrode terminal 41. It is preferable that the positive electrode current collector tab 12 is formed continuously from the positive electrode current collector body 114. The material of the positive electrode current collector tab is not particularly limited and may be metal (for example, aluminum, stainless steel (SUS), or nickel, etc.).

[0082] (1.1.5.7) Negative current collector tab The negative electrode current collector tab 13 electrically connects the negative electrode current collector body 115 and the negative electrode terminal 42. The negative electrode current collector tab 13 is connected to the negative electrode current collector body 115. As shown in Figure 2, the negative electrode current collector tab 13 protrudes in the positive X-axis direction relative to the third side surface S11E of the electrode body 11. Specifically, in the first embodiment, a bundle including a plurality of negative electrode current collector tabs 13 is electrically connected to the negative electrode terminal 42. It is preferable that the negative electrode current collector tab 13 is formed continuously from the negative electrode current collector body 115. The material of the negative electrode current collector tab is not particularly limited and may be metal (for example, aluminum, stainless steel (SUS), or nickel, etc.).

[0083] (1.1.6) Purpose Applications for the 1A battery include powering electrical equipment (e.g., vehicles, electronic devices, or electrical storage). Vehicles include electric four-wheeled vehicles, electric two-wheeled vehicles, gasoline cars, and diesel cars. Electric four-wheeled vehicles include electric vehicles (BEVs), plug-in hybrid vehicles (PHEVs), and hybrid vehicles (BEVs). Electric two-wheeled vehicles include electric motorcycles and electric-assist bicycles. Electronic devices include handheld devices (e.g., smartphones, tablet computers, or audio players), portable devices (e.g., notebook computers, or CD (Compact Disc) players), and mobile devices (e.g., power tools, or professional video cameras). In particular, the 1A battery is preferably used as a power source for hybrid vehicles, plug-in hybrid vehicles, or electric vehicles.

[0084] (1.2) Method of manufacturing a battery The battery manufacturing method of the first embodiment is a method for manufacturing battery 1A. This method includes a preparation step (A), an insertion step, a resin filling step (A), a terminal connection step, and a sealing step. The preparation step (A), the insertion step, the resin filling step (A), the terminal connection step, and the sealing step may be performed in this order.

[0085] (1.2.1) Preparation process (A) In preparation step (A), an electrode body with a resin sheet is prepared. The electrode body with a resin sheet comprises an electrode body 10 and a pair of resin sheets attached to the first main surface S11A and the second main surface S11B of the electrode body 10. The resin sheet is the same as the three-layer portion 31A, except that it does not have a third layer 313A.

[0086] The preparation method for an electrode body with a resin sheet includes an electrode body preparation step, a resin sheet preparation step, and an attachment step. The electrode body sheet preparation step and the attachment step are performed in this order. The resin sheet preparation step (A) is performed before the attachment step.

[0087] (1.2.1.1) Electrode body preparation process In the electrode preparation step, electrode body 10 is prepared.

[0088] Any known method can be used to prepare the electrode body 10.

[0089] (1.2.1.2) Preparation process for resin sheets In the resin sheet preparation process, the resin sheet is prepared.

[0090] Any known method is acceptable for preparing the resin sheet.

[0091] (1.2.1.3) Installation process In the mounting process, resin sheets are attached to the first main surface S11A and the second main surface S11B of the electrode body 10. This results in an electrode body with resin sheets.

[0092] Any known method is acceptable for attaching the resin sheet.

[0093] (1.2.2) Insertion process In the insertion process, the electrode body with the resin sheet is inserted into the first opening R21A of the metal cylinder 21 from the negative electrode current collector tab 13 side, and the electrode body with the resin sheet is positioned inside the metal cylinder 21. This gives rise to the first unfinished battery.

[0094] Any known method is acceptable for inserting the electrode body with the resin.

[0095] (1.2.3) Resin filling process (A) In the resin filling process (A), unsolidified resin composition is filled into the gap between the resin sheet electrode body of the first unfinished battery and the metal cylinder 21 to form the third layer 311 and the single-layer portion 32A. Specifically, unsolidified material of the third layer 313A of the three-layer portion 31A is filled into the gap between the first main surface S11A of the electrode body 11 and the inner surface S211 of the first wall portion 211 of the metal cylinder 21, and into the gap between the second main surface S11B of the electrode body 11 and the inner surface S212 of the second wall portion 212 of the case 20. Unsolidified material of the single-layer portion 32A is filled into the gap between the first side surface S11C of the electrode body 11 and the inner surface S213 of the third wall portion 213 of the metal cylinder 21, and into the gap between the second side surface S11D of the electrode body 11 and the inner surface S214 of the fourth wall portion 214 of the case 20. This gives rise to the second unfinished battery.

[0096] The method for filling the unsolidified material in the third layer 313A and the unsolidified material in the single-layer portion 32A can be any known method. The method for solidifying the unsolidified material in the third layer 313A and the unsolidified material in the single-layer portion 32A can be appropriately selected depending on the type of resin.

[0097] (1.2.4) Terminal connection process In the terminal connection step, multiple positive electrode current collector tabs 12 of the second incomplete battery are connected to the positive electrode terminal 41, and multiple negative electrode current collector tabs 13 are connected to the negative electrode terminal 42. Specifically, in the first embodiment, a first bundle including multiple positive electrode current collector tabs 12 is formed, and the first bundle is electrically connected to the positive electrode terminal 41. Similarly, a second bundle including multiple negative electrode current collector tabs 13 is formed, and the second bundle is electrically connected to the negative electrode terminal 42. This results in a third incomplete battery.

[0098] The connection method is not particularly limited; any publicly known method is acceptable.

[0099] (1.2.5) Sealing process In the sealing process, the electrode body 10 is sealed by attaching the lid 22 and the electrical insulator 23 to the first opening R21A and the second opening R21B of the metal cylinder 21 of the third unfinished battery. This results in a battery 1A.

[0100] Any known sealing method is acceptable.

[0101] (1.3) Effects As explained with reference to Figures 1 to 5, the battery 1A comprises an electrode body 10, a case 20, and a resin body 30A. The resin body 30A has a first layer 311 and a second layer 312. The resin component of the first layer 311 is a resin having less than 100 ppm of hydroxyl groups. The second layer 312 is a layer that electrically insulates the electrode body 10 and the case 20. The first layer 311 does not readily adsorb water (for example, moisture in the air). As a result, the electrode body 10 does not easily come into contact with water. Consequently, battery 1A is a battery in which the reaction between the solid electrolyte and water is suppressed.

[0102] As explained with reference to Figures 1 to 5, in battery 1A, the resin body 30A further has a third layer 313A. The resin component of the third layer 313A is different from the resin component of the first layer 311. Therefore, the third layer 313A may have a different function from the first layer 311 (i.e., a function that makes it difficult for water to be adsorbed) (for example, flexibility, thermal conductivity, or adhesion). As a result, battery 1A is a battery with excellent design flexibility.

[0103] As explained with reference to Figures 1 to 5, in battery 1A, the resin component of the first layer 311 includes an adhesive resin. The resin body 30A is easily held in a state of adhesion with the electrode body 10. The exposed area of ​​the resin body 30A when it is adhered to the electrode body 10 is smaller than in a configuration where the resin body 30A is not adhered to the electrode body 10. As a result, water is less likely to be adsorbed onto the first layer 311. Consequently, battery 1A is a battery in which the reaction between the solid electrolyte and water is more suppressed.

[0104] As explained with reference to Figures 1 to 5, in battery 1A, the second layer 312 is a film, and the shape of the first layer 311 follows the shape of the second layer 312. As a result, battery 1A is a battery with better productivity than a configuration in which the second layer 312 is not a film.

[0105] As explained with reference to Figures 1 to 5, in battery 1A, the resin body 30A further has a third layer 313A. Preferably, the third layer 313A contains a thermally conductive filler. As a result, the thermal conductivity of the third layer 313A is excellent. Consequently, battery 1A has superior cooling performance compared to a configuration in which the third layer 313A does not contain a thermally conductive filler.

[0106] (2) Second Embodiment (2.1)Battery Battery 1B according to the second embodiment is the same as battery 1A according to the first embodiment, except that the resin body has a different structure.

[0107] Battery 1B comprises an electrode body 10, a case 20, a resin body 30B, a positive terminal 41, and a negative terminal 42.

[0108] The resin body 30B electrically insulates the electrode body 10 from the case 20. The resin body 30B is interposed between the electrode body 11 and the case 20. The resin body 30B is in physical contact with the electrode body 10 and the case 20.

[0109] In the second embodiment, the resin body 30B has a pair of three-layer portions 31B and a pair of single-layer portions 32A. One of the pair of three-layer portions 31B is provided in the first gap, as shown in Figure 6. The other of the pair of three-layer portions 31B is provided in the second gap. One of the pair of single-layer portions 32A is provided in the third gap. The other of the pair of single-layer portions 32A is provided in the fourth gap. The three-layer portions 31B and the single-layer portions 32A may or may not be welded together.

[0110] The three-layered section 31B comprises a first layer 311, a second layer 312, and a third layer 313B. The three-layered section 31B is the same as the three-layered section 31A, except that the third layer 313A is replaced with the third layer 313B.

[0111] The third layer 313B is a layer whose hardness is lower than that of the first layer 311. The resin components of the third layer 313B are different from those of the first layer 311. The hardness of the third layer 313B tends to depend on the type of resin component. The resin component of the third layer can be any resin that can make the hardness of the third layer 313B lower than that of the first layer 311, and can be appropriately selected according to the resin component of the first layer.

[0112] The third layer may contain a thermally conductive filler. Examples of materials for the thermally conductive filler include those similar to those exemplified as thermally conductive fillers that may be included in the third layer of the first embodiment.

[0113] The third layer may further contain compounding agents as needed. Examples of compounding agents are the same as those exemplified as compounding agents that may be included in the first layer of the first embodiment.

[0114] (2.2) Method of manufacturing a battery The battery manufacturing method of the second embodiment is a method for manufacturing battery 1B. This method includes a preparation step (B), an insertion step, a resin filling step (B), a terminal connection step, and a sealing step. The preparation step (B), the insertion step, the resin filling step (B), the terminal connection step, and the sealing step may be performed in this order.

[0115] (2.2.1) Preparation process (B) In preparation step (B), an electrode body with a three-layer portion is prepared. The electrode body with a three-layer portion comprises an electrode body 10 and a pair of three-layer portions 31B attached to the first main surface S11A and the second main surface S11B of the electrode body 10.

[0116] The preparation method for the electrode body with a three-layer section includes an electrode body preparation step, a three-layer section preparation step, and an attachment step. The electrode body sheet preparation step and the attachment step are performed in this order. The three-layer section preparation step (A) is performed before the attachment step.

[0117] (2.2.1.1) Electrode body preparation process The electrode preparation step is the same as the electrode preparation step of the first embodiment.

[0118] (2.2.1.2) Three-layer part preparation process In the three-layer section preparation process, the three-layer section 31B is prepared.

[0119] The preparation method for the three-layer portion 31B can be any known method.

[0120] (2.2.1.3) Installation process In the mounting process, the three-layer portion 31B is attached to the first main surface S11A and the second main surface S11B of the electrode body 10. This results in an electrode body with the three-layer portion attached.

[0121] The mounting method for the three-layer section 31B can be any known method.

[0122] (2.2.2) Insertion process In the insertion process, the electrode body with the three-layer portion is inserted into the first opening R21A of the metal cylinder 21 from the negative electrode current collector tab 13 side, and the electrode body with the three-layer portion is positioned inside the metal cylinder 21. This gives rise to the first incomplete battery.

[0123] In the second embodiment, the third layer 313B is softer than the first layer 311. Therefore, the electrode body with the three layers can be inserted into the metal cylinder 21 more easily than in the case where the third layer is harder than the first layer.

[0124] Any known method is acceptable for inserting the electrode body with the resin.

[0125] (2.2.3) Resin filling process (B) In the resin filling process (B), unsolidified resin material is filled into the gap between the electrode body with the three-layer portion of the first incomplete battery and the metal cylinder 21 to form a single-layer portion 32A. Specifically, unsolidified single-layer portion 32A is filled into the gap between the first side surface S11C of the electrode body 11 and the inner surface S213 of the third wall portion 213 of the metal cylinder 21, and into the gap between the second side surface S11D of the electrode body 11 and the inner surface S214 of the fourth wall portion 214 of the case 20. This results in the second incomplete battery.

[0126] The method for filling the unsolidified material in the single-layer portion 32A can be any known method. The method for solidifying the unsolidified material in the single-layer portion 32A is appropriately selected depending on the type of resin.

[0127] (2.2.4) Terminal connection process and sealing process The terminal connection process and the sealing process are the same as those in the first embodiment.

[0128] (2.3) Effects Battery 1B is identical to battery 1A, except that the third layer 313A has been replaced with the third layer 313B. Therefore, battery 1B produces the same effects as battery 1A.

[0129] As explained with reference to Figure 6, in battery 1B, the resin body 30B further has a third layer 313B. The hardness of the third layer 313B is lower than that of the first layer 311. In other words, the third layer 313B is softer than the first layer 311. As a result, battery 1B has better shock resistance than a configuration in which the hardness of the third layer 313B is greater than or equal to the hardness of the first layer 311.

[0130] (3) Third Embodiment The battery 1C according to the third embodiment is the same as the battery 1A according to the first embodiment, except that the resin body has a different structure.

[0131] Battery 1C comprises an electrode body 10, a case 20, a resin body 30C, a positive electrode terminal 41, and a negative electrode terminal 42.

[0132] The resin body 30C electrically insulates the electrode body 10 from the case 20. The resin body 30C is interposed between the electrode body 11 and the case 20. The resin body 30C is in physical contact with the electrode body 10 and the case 20.

[0133] In the third embodiment, the resin body 30C has a pair of double-layered portions 31C and a pair of double-layered portions 32C. One of the pair of double-layered portions 31C is provided in the first gap, as shown in Figure 7. The other of the pair of double-layered portions 31C is provided in the second gap. One of the pair of double-layered portions 32C is provided in the third gap. The other of the pair of double-layered portions 32C is provided in the fourth gap.

[0134] The two-layer portion 31C and the two-layer portion 32C may be the same or they may be separate. If the two-layer portion 31C and the two-layer portion 32C are the same, the resin body 30C may be formed by covering the electrode body 11 with the first sheet. The first sheet has the same configuration as the two-layer portion 31C.

[0135] Each of the two-layer sections 31C and 32C has a first layer 311 and a second layer 312. Each of the two-layer sections 31C and 32C is the same as the three-layer section 31A, except that it does not have a third layer 313A.

[0136] Battery 1C is identical to Battery 1A, except that the resin body 30A has been replaced with resin body 30C. Therefore, Battery 1C performs the same function and effect as Battery 1A.

[0137] (4) Fourth Embodiment The battery 1D according to the fourth embodiment is the same as the battery 1A according to the first embodiment, except that the resin body has a different structure.

[0138] Battery 1D comprises an electrode body 10, a case 20, a resin body 30D, a positive electrode terminal 41, and a negative electrode terminal 42.

[0139] The resin body 30D electrically insulates the electrode body 10 from the case 20. The resin body 30D is interposed between the electrode body 11 and the case 20. The resin body 30D is in physical contact with the electrode body 10 and the case 20.

[0140] In the fourth embodiment, the resin body 30D has a pair of three-layer portions 31A and a pair of three-layer portions 32D. One of the pair of three-layer portions 31A is provided in the gap between the first main surface S11A of the electrode body 11 and the first wall portion 211 of the metal cylinder 21, as shown in Figure 8. The other of the pair of three-layer portions 31A is provided in the gap between the second main surface S11A of the electrode body 11 and the second wall portion 212 of the metal cylinder 21. One of the pair of three-layer portions 32D is provided in the gap between the first side surface S11C of the electrode body 11 and the third wall portion 213 of the metal cylinder 21. The other of the pair of three-layer portions 32D is provided in the gap between the second side surface S11D of the electrode body 11 and the fourth wall portion 214.

[0141] The three-layer portion 31A and the three-layer portion 32D may be the same entity or they may be separate entities. If the three-layer portion 31A and the three-layer portion 32D are the same entity, the resin body 30D may be formed by covering the electrode body 11 with a second sheet. The second sheet has the same configuration as the three-layer portion 31A.

[0142] The three-layered section 32D has the same configuration as the three-layered section 31A. The three-layered section 32D comprises a first layer 311, a second layer 312, and a third layer 313A.

[0143] Battery 1D is identical to battery 1A, except that the resin body 30A has been changed to resin body 30D. Therefore, battery 1D performs the same function and effect as battery 1A.

[0144] (5) Variant In the first, second, and fourth embodiments, the resin components of the third layers 313A and 313B are different from those of the first layer 313, but the disclosure is not limited thereto. The resin components of the third layer may be the same as those of the first layer.

[0145] In the second embodiment, the hardness of the third layer 313B is lower than that of the first layer 311, but the disclosure is not limited thereto. The hardness of the third layer may be the same as that of the first layer, or it may be higher than that of the first layer.

[0146] In the first to fourth embodiments, the resin component of the first layer 311 includes an adhesive resin, but the disclosure is not limited thereto. The resin component of the first layer does not need to include an adhesive resin.

[0147] In the first to fourth embodiments, the second layer 312 is a film, but the disclosure is not limited thereto. The second layer does not have to be a film. For example, the second layer may be a coating formed on the first layer. In the first to fourth embodiments, the shape of the first layer 311 follows the shape of the second layer 312, but the disclosure is not limited thereto. The shape of the first layer does not have to follow the shape of the second layer.

[0148] In the first, second, and fourth embodiments, the third layers 313A and 313B may contain a thermally conductive filler, but the disclosure is not limited thereto. The third layer may not contain a thermally conductive filler. At least one of the first and second layers may contain a thermally conductive filler.

[0149] In the first embodiment, the resin body 30A has a pair of three-layer portions 31A provided in the first and second gaps, and a pair of single-layer portions 32A provided in the third and fourth gaps, but the disclosure is not limited thereto. As long as the resin body has a first layer and a second layer, the layer configuration of the resin body portions provided in each of the first, second, third, and fourth gaps may be appropriately selected according to the application of the battery, etc. Specifically, the layer configuration of the resin body portion provided in the first gap, the layer configuration of the resin body portion provided in the second gap, the layer configuration of the resin body portion provided in the third gap, and the layer configuration of the resin body portion provided in the fourth gap may be the same, or at least one may be different. The function (i.e., material) of the resin body portion provided in the first gap, the function of the resin body portion provided in the second gap, the function of the resin body portion provided in the third gap, and the function of the resin body portion provided in the fourth gap may be the same, or at least one may be different.

[0150] In the first and second embodiments, the electrode body 10 includes a plurality of unit electrode bodies 11U, but the disclosure is not limited thereto. The electrode body 10 may consist of a single unit electrode body 11U.

[0151] In the first to fourth embodiments, the unit electrode body 11U is formed by stacking a positive electrode current collector 114, a positive electrode active material layer 112, a solid electrolyte layer 111, a negative electrode active material layer 113, a negative electrode current collector 115, a negative electrode active material layer 113, a solid electrolyte layer 111, a positive electrode active material layer 112, and a positive electrode current collector 114 in this order along the Z-axis direction, but the disclosure is not limited thereto. The unit electrode body 11U may also be formed by stacking a positive electrode current collector 114, a positive electrode active material layer 112, a solid electrolyte layer 111, a negative electrode active material layer 113, and a negative electrode current collector 115 in this order along the Z-axis direction. The unit electrode body 11U may consist of a negative electrode current collector 115, a negative electrode active material layer 113, a solid electrolyte layer 111, a positive electrode active material layer 112, a positive electrode current collector 114, a positive electrode active material layer 112, a solid electrolyte layer 111, a negative electrode active material layer 113, and a negative electrode current collector 115, all stacked in this order along the Z-axis direction.

[0152] In the first to fourth embodiments, the case 20 includes a metal cylindrical body 21, but the disclosure is not limited thereto. The case may be a battery can (e.g., cylindrical, rectangular, or coin-shaped, etc.) or a laminated casing.

[0153] In the first to fourth embodiments, the positive electrode current collector 114 and the positive electrode current collector tab 12 are separate components, and the negative electrode current collector 115 and the negative electrode current collector tab 13 are separate components, but the disclosure is not limited thereto. The positive electrode current collector 114 and the positive electrode current collector tab 12 may be the same component. The negative electrode current collector 115 and the negative electrode current collector tab 13 may be the same component.

[0154] In the first to fourth embodiments, the stacked configuration of the electrode body 11 is a configuration in which a plurality of unit electrode bodies 11U having a monopolar structure are connected in parallel, but the disclosure is not limited thereto. The stacked configuration of the electrode body may be a configuration in which a plurality of unit electrode bodies having a monopolar structure are connected in series (hereinafter also referred to as the "monopolar series configuration"). In the monopolar series configuration, the electrode body has a conductor that electrically connects the positive electrode current collector 114 and the negative electrode current collector 115, and does not have a bundle containing a plurality of positive electrode current collector tabs 12 or a plurality of negative electrode current collector tabs 13. The stacked configuration of the electrode body may be a configuration in which a plurality of unit electrode bodies having a bipolar structure are connected in series. [Explanation of symbols]

[0155] 1A, 1B, 1C, 1D: Battery, 10: Electrode body, 11: Electrode main body, 111: Solid electrolyte layer, 112: Positive electrode active material layer, 113: Negative electrode active material layer, 114: Positive electrode current collector, 115: Negative electrode current collector, 12: Positive electrode current collector tab, 13: Negative electrode current collector tab, 20: Case, 21: Metal cylinder, 22: Lid, 23: Electrical insulator, 30A, 30B: Resin body, 31A, 31B: Three-layer section, 31C: Two-layer section, 32A: Single-layer section, 32C: Two-layer section, 32D: Three-layer section, 41: Positive electrode terminal, 42: Negative electrode terminal

Claims

1. An electrode body containing a solid electrolyte, A case for housing the electrode body, A resin body is provided in the gap between the end face of the electrode body and the case, Equipped with, The resin body comprises a first layer laminated on the end face of the electrode body and a second layer laminated on the first layer. The resin component of the first layer is a resin having less than 100 ppm of hydroxyl groups. A battery in which the second layer electrically insulates the electrode body from the case.

2. The resin body further comprises a third layer laminated on the second layer, The battery according to claim 1, wherein the resin component of the third layer is different from the resin component of the first layer.

3. The resin body further comprises a third layer laminated on the second layer, The battery according to claim 1, wherein the hardness of the third layer is lower than the hardness of the first layer.

4. The battery according to claim 1, wherein the resin component of the first layer includes an adhesive resin.

5. The above second layer is a film, The battery according to claim 1, wherein the shape of the first layer follows the shape of the second layer.

6. The resin body further comprises a third layer laminated on the second layer, The battery according to claim 1, wherein the third layer includes a thermally conductive filler.

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