Solid state battery

Abstract

The invention relates to a solid state battery. A solid-state battery (100) has a first current collector (110), a first electrode layer (111), an electrolyte layer (120), a second electrode layer (131), and a second current collector (130) in this order, in which the first current collector (110) includes a resin layer (112) in contact with the first electrode layer (111), the first electrode layer (111) contains an electrode active material, and the electrode active material has an active material resin.

Description

Technical Field

[0001] This disclosure relates to a solid-state battery. Background Technology

[0002] Recently, the demand for rechargeable batteries has been increasing, and in addition to rechargeable batteries using electrolytes, progress has been made in the development of solid-state batteries using solid electrolytes. All-solid-state batteries are an example of solid-state batteries, featuring a solid electrolyte layer that replaces the electrolyte. Because all-solid-state batteries do not use flammable organic solvents, the design of safety devices is simplified, and these batteries offer excellent manufacturing costs and productivity.

[0003] As a negative electrode layer used in all-solid-state batteries, a negative electrode layer in which the negative electrode active material is a composite particle has a binder and a plurality of particles containing Si or Sn elements is known. Such a negative electrode layer can suppress the decrease in cycle characteristics caused by volume changes of the negative electrode active material during charge and discharge (Japanese Patent Application Laid-Open No. 2019-121557).

[0004] Furthermore, as a negative electrode active material powder capable of improving battery characteristics, a negative electrode active material powder having a fluoride layer on the surface of secondary particles formed from single particles such as Si and Sn is known (Japanese Patent Application Publication No. 2021-057216). Summary of the Invention

[0005] When materials that undergo volume changes are used as negative electrode active materials, it is difficult to completely suppress the amount of volume change of these materials during charging and discharging, and the internal resistance may increase significantly depending on the situation.

[0006] One embodiment of this disclosure addresses the problem of providing a solid-state battery in which the increase in internal resistance due to charging and discharging is suppressed.

[0007] This disclosure provides the following information:

[0008] A first aspect of this disclosure provides a solid-state battery comprising, in sequence, a first current collector, a first electrode layer, an electrolyte layer, a second electrode layer, and a second current collector, wherein the first current collector includes a resin layer in contact with the first electrode layer, the first electrode layer contains an electrode active material, and the electrode active material has a resin for use as an active material.

[0009] A second aspect of this disclosure provides a solid-state battery of the first aspect, wherein the electrode active material contains secondary particles, and the secondary particles contain a plurality of primary particles and a resin for the active material.

[0010] A third aspect of this disclosure provides a solid-state battery of the first or second aspect, wherein the resin layer contains resin, and the resin for the active material and the resin for the resin layer have a common structure.

[0011] A fourth aspect of this disclosure provides a solid-state battery according to any one of the first to third aspects, wherein the resin layer contains a resin, and the resin for the active material and the resin for the resin layer have common functional groups.

[0012] The fifth aspect of this disclosure provides a solid-state battery according to any one of the first to fourth aspects, wherein the resin layer contains a resin, and the resin for the active material and the resin for the resin layer have a common resin.

[0013] The sixth aspect of this disclosure provides a solid-state battery according to any one of the first to fifth aspects, wherein

[0014] The resin layer contains resin, and

[0015] The active material resin and the resin layer resin comprise structures represented by at least one of formulas (1) and (2).

[0016]

[0017]

[0018] In formula (1), R represents alkyl, allyl, hydroxy, carboxyl, methoxy or ethoxy, and n in formula (1) and formula (2) each independently represents an integer greater than 1.

[0019] The seventh aspect of this disclosure provides a solid-state battery of any one of the first to sixth aspects, wherein the resin for the active material and the resin for the resin layer comprise a structure represented by formula (1) or a structure represented by formula (2).

[0020] The eighth aspect of this disclosure provides a solid-state battery according to any one of the first to seventh aspects, wherein the active material is adsorbed onto the resin layer by a resin.

[0021] The ninth aspect of this disclosure provides a solid-state battery of any one of the first to eighth aspects, wherein the first current collector further has a metal layer.

[0022] The tenth aspect of this disclosure provides a solid-state battery according to any one of the first to eighth aspects, wherein the first current collector is a conductive resin current collector.

[0023] The eleventh aspect of this disclosure provides a solid-state battery according to any one of the first to tenth aspects, wherein the resin layer has a region that adheres to the electrode active material.

[0024] The twelfth aspect of this disclosure provides a solid-state battery according to any one of the first to eleventh aspects, wherein the electrode active material contains the element Si.

[0025] The thirteenth aspect of this disclosure provides a solid-state battery of the ninth aspect, wherein the metal layer is a nickel foil, and the first current collector sequentially comprises the nickel foil and the resin layer.

[0026] The fourteenth aspect of this disclosure provides a solid-state battery of any one of the first to thirteenth aspects, wherein the first electrode layer contains an adhesive, and the adhesive is at least one type selected from the group consisting of styrene-butadiene rubber, polyvinylidene fluoride, and vinyl resin.

[0027] The fifteenth aspect of this disclosure provides a solid-state battery according to any one of the first to fourteenth aspects, wherein the solid-state battery is an all-solid-state battery.

[0028] According to one embodiment of the present disclosure, a solid-state battery is provided in which the increase in internal resistance due to charging and discharging is suppressed. Attached Figure Description

[0029] Figure 1 This is a schematic cross-sectional view of a solid-state battery according to one embodiment of the present disclosure.

[0030] Figure 2 This is a schematic cross-sectional view of the negative electrode of a solid-state battery according to one embodiment of the present disclosure.

[0031] Figure 3 A graph showing the measurement results of the normalized resistance increase rate in the examples and comparative examples. Detailed Implementation

[0032] In this disclosure, the range of values ​​represented by "-" refers to the range in which the values ​​listed before and after "-" are respectively used as the minimum and maximum values.

[0033] Within the numerical ranges expressed in a segmented manner in this disclosure, the upper or lower limit values ​​listed within a given numerical range can be replaced by the upper or lower limit values ​​of another numerical range expressed in a segmented manner. Within the numerical ranges described in this disclosure, the upper or lower limit values ​​listed within a given numerical range can be replaced by the values ​​illustrated in the embodiments.

[0034] In this disclosure, a combination of two or more preferred aspects is a more preferred aspect.

[0035] In this disclosure, where there are multiple types of materials corresponding to the composition, unless otherwise stated, the amount of composition refers to the total amount of the multiple types of materials.

[0036] In this disclosure, when embodiments are described with reference to the accompanying drawings, the configuration of the embodiments is not limited to that shown in the drawings. Furthermore, the dimensions of the components in the various figures are schematic, and the relative relationships between the dimensions of the components are not limited thereto.

[0037] Solid-state batteries

[0038] like Figure 1 As shown, one embodiment of this disclosure relates to a solid-state battery (100) (hereinafter also referred to as a solid-state battery (100)) which sequentially comprises a first current collector (110), a first electrode layer (111), an electrolyte layer (120), a second electrode layer (131), and a second current collector (130). The first current collector (110) contains a resin layer (112) in contact with the first electrode layer (111), and the first electrode layer (111) contains an electrode active material. The electrode active material comprises a resin for use as an active material.

[0039] The first current collector and the first electrode layer, and the second current collector and the second electrode layer, respectively constitute the electrodes of the solid-state battery. When the first current collector and the first electrode layer constitute the negative electrode, the second current collector and the second electrode layer constitute the positive electrode. Conversely, when the first current collector and the first electrode layer constitute the positive electrode, the second current collector and the second electrode layer constitute the negative electrode. Therefore, the solid-state battery has a negative electrode, an electrolyte layer, and a positive electrode.

[0040] The following describes an embodiment in which the first current collector and the first electrode layer constitute the negative electrode and the second current collector and the second electrode layer constitute the positive electrode. In this embodiment, the first current collector is a negative current collector, the first electrode layer is a negative electrode layer, the second current collector is a positive current collector, and the second electrode layer is a positive electrode layer.

[0041] It is known that in solid-state batteries, the negative electrode active material contained in the negative electrode layer expands and contracts during charge and discharge. Due to this expansion and contraction, cracks may appear in the negative electrode layer, and the negative electrode current collector may separate from the negative electrode layer, leading to an increase in internal resistance. For example, Si-based active materials containing Si are high-capacity active materials, but their expansion tends to be large. Therefore, especially when using negative electrode active materials with large expansion, such as Si active materials, it is preferable to suppress the increase in internal resistance caused by expansion and contraction during charge and discharge, as such negative electrode active materials have the potential to significantly improve the cycle characteristics of the battery.

[0042] To suppress the increase in internal resistance of solid-state batteries during charging and discharging, the inventors investigated ways to suppress the separation of the current collector and the electrode layer. They discovered that by using a negative electrode active material containing a resin (resin for active materials) that has adhesive properties to the negative electrode current collector having a resin layer, the separation of the negative electrode current collector and the negative electrode layer is suppressed even in the presence of expansion and contraction of the negative electrode active material.

[0043] Although the mechanism for suppressing the separation of the current collector and the electrode layer is not clear, it is speculated that the structure in which the resin layer at the current collector has resin, the electrode active material at the electrode layer has resin for active material, and the current collector and the electrode layer are connected via resin interposed therebetween, provides an anchoring effect that effectively suppresses the separation between the current collector and the electrode layer.

[0044] (negative electrode)

[0045] In one embodiment of this disclosure, the negative electrode comprises a negative current collector and a negative electrode layer. The negative current collector contains a resin layer and may be in the form of a negative electrode substrate layer and a resin layer. Because the negative current collector contains a resin layer, and the negative electrode layer contains an electrode active material and the electrode active material has a resin for the active material, separation between the negative current collector and the negative electrode layer is suppressed, and the increase in internal resistance during charging and discharging is suppressed.

[0046] (Negative electrode current collector)

[0047] The negative electrode current collector contains a resin layer and can be manufactured in the form of a negative electrode substrate layer and a resin layer. The negative electrode sequentially contains a resin layer (or the negative electrode substrate layer and the resin layer) and the negative electrode layer.

[0048] like Figure 2As shown, the negative electrode (10) associated with one embodiment of the present disclosure sequentially comprises a negative electrode substrate layer (11), a resin layer (12) and a negative electrode layer (13).

[0049] (Resin layer)

[0050] One surface of the resin layer (12) is in contact with the negative electrode layer (13). In the case where the negative electrode current collector (14) has a negative electrode substrate layer (11), the other surface of the resin layer (12) is in contact with the negative electrode substrate layer (11). The resin layer (12) contains resin.

[0051] Preferably, the resin for the resin layer is capable of adhering to the negative electrode substrate layer and the active material resin of the electrode active material of the negative electrode layer. The ability of the resin for the resin layer and the active material resin to adhere means that they are chemically or physically bonded together and connected together. In an all-solid-state battery, it is preferable that the resin for the resin layer and the active material resin have regions that are chemically or physically bonded together and firmly connected, for example, in at least any of the following states: before charging, during charging, after charging, before use, during use, and after use.

[0052] Examples of resin layers capable of adhering to the negative electrode substrate layer and the resin for the active material include resins that have been melted or softened by heating.

[0053] Specific examples of resins that melt or soften upon heating include: polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, thermoplastic resins such as polyurethane and ethylene-vinyl acetate copolymer, rubber resins such as butadiene rubber (BR) and styrene-butadiene rubber (SBR), fluorinated resins such as polyvinylidene fluoride (PVdF), and vinyl resins such as polyvinyl chloride, polyvinylidene chloride, vinyl acetate, polyvinyl alcohol, and styrene resins.

[0054] From the viewpoint of adhesion to the resin for the active material, the resin layer preferably contains a common structure also present in the resin for the active material. This common structure will be described later in the description of the resin for the active material.

[0055] Furthermore, from the viewpoint of adhesion to the resin for the active material, the resin layer preferably contains common functional groups that are also present in the resin for the active material. These common functional groups will be described later in the description of the resin for the active material.

[0056] From the viewpoint of adhesion to the resin for the active material, the resin layer preferably contains a common resin that is also present in the resin for the active material. This common resin will be described later in the description of the resin for the active material.

[0057] In addition to the resin used in the resin layer, the resin layer may also contain a conductive material. By containing a conductive material, the resin layer can be made into a conductive resin layer. If the negative electrode current collector has a conductive resin layer, it can be made into a conductive resin current collector, and it does not necessarily have a negative electrode substrate layer as described later.

[0058] Examples of conductive materials include carbon materials, conductive polymers, and metal particles. One type of conductive material can be used alone, or two or more types can be used together.

[0059] Examples of carbon materials include particulate carbon materials and fibrous carbon materials. Examples of particulate carbon materials include acetylene black (AB) and Ketjen black (KB). Examples of fibrous carbon materials include carbon nanotubes (CNTs), carbon nanofibers (CNFs), and vapor-grown carbon fibers (VGCFs).

[0060] Examples of conductive polymers include polythiophene, polyacetylene, poly(p-phenylene), and polyisothioindene.

[0061] Examples of metallic particles are those made of nickel, copper, iron, and stainless steel.

[0062] From the viewpoint of improving the anchoring effect and further suppressing the separation of the active material layer from the resin current collector and the reduction of cycle characteristics, the conductive material preferably contains a carbon material, more preferably contains at least one of acetylene black (AB) and vapor-grown carbon fiber (VGCF), and even more preferably contains vapor-grown carbon fiber (VGCF).

[0063] The content of the conductive material relative to the total solids of the negative electrode current collector is preferably 10%–50% by mass, more preferably 15%–43% by mass.

[0064] From the viewpoint that even if the electrode active material expands and contracts, the resin layer adheres to the negative electrode substrate layer and the active material of the electrode active material adheres to the negative electrode layer, the thickness of the resin layer is preferably 1 μm or more, more preferably 3 μm or more. The thickness of the resin layer is preferably 50 μm or less, more preferably 30 μm or less.

[0065] The resin layer preferably has a region that adheres to the electrode active material of the negative electrode layer. Because the resin layer has a region that adheres to the electrode active material of the negative electrode layer, separation of the negative electrode current collector from the negative electrode layer is suppressed even during the expansion and contraction of the electrode active material during charging and discharging, and the increase in internal resistance of the solid-state battery due to charging and discharging is also suppressed.

[0066] (Negative electrode substrate layer)

[0067] The negative electrode substrate layer can be made of a known material used for current collectors of the negative electrode. The negative electrode substrate layer can be made of metal, resin, or the like.

[0068] Aluminum foil, nickel foil, titanium foil, or copper foil can be used as the negative electrode substrate layer made of metal.

[0069] Known materials for resin current collectors can be used as the negative electrode substrate layer made of resin. Conductive resin current collectors can be used, which are composite materials containing resins such as polyethylene or phenolic resins and conductive fillers such as graphite.

[0070] Preferably, a resin layer can be formed on the negative electrode substrate layer. The material of the negative electrode substrate layer can be selected according to the type of resin formed on the negative electrode substrate layer. From the viewpoint of adhesion to the resin layer and electronic conductivity, the negative electrode substrate layer is preferably a metal foil. Specifically, preferred examples of the metal foil are nickel, aluminum, copper, and stainless steel (SUS), and more preferably, a nickel foil is in contact with the resin layer. The negative electrode current collector may sequentially comprise a nickel foil and a resin layer.

[0071] It should be noted that the negative electrode substrate layer may be composed of two different types of layers, or it may be composed of only a single layer.

[0072] From the viewpoint of its ability to adhere tightly to the negative electrode layer and to follow the expansion and contraction of the electrode active material, the negative electrode substrate layer is preferably a conductive resin current collector. Known structures can be used as conductive resin current collectors.

[0073] (Preparation of negative electrode current collector)

[0074] The negative electrode current collector can be manufactured using known methods, as long as it can be prepared to include a negative electrode substrate layer and a resin layer. For example, the negative electrode current collector can be prepared by coating the negative electrode substrate layer with a resin composition containing the resin layer.

[0075] (Negative electrode layer)

[0076] The negative electrode layer contains a composite material. The composite material contains an active negative electrode material. The active negative electrode material can be in particle form. If the active negative electrode material is in particle form, the particles have a resin for the active material. Preferably, the resin for the active material can adhere to the resin layer.

[0077] (Negative electrode active material)

[0078] The negative electrode active material comprises the resin for the active material. Preferably, the resin for the active material is capable of adhering to the resin layer. The negative electrode active material can be a particulate active material. The particulate active material may contain at least one of primary particles and secondary particles. The negative electrode active material or the particulate active material preferably contains silicon (Si).

[0079] If the negative electrode active material contains the resin and particles used for the active material, the separation of the current collector and the electrode layer is effectively suppressed because the gaps formed between the particles mitigate the expansion and contraction.

[0080] Whether the particulate active material is a primary particle or a secondary particle can be distinguished by observation using SEM (scanning electron microscope).

[0081] (Primary particle)

[0082] The primary particles are preferably Si-active materials containing Si. Examples of Si-active materials include elemental Si, Si alloys, Si oxides, Si carbides, and Si oxycarbides (silicon oxycarbides). Si alloys are alloys whose main component is Si. Examples of metals other than Si in Si alloys are at least one type selected from, for example, W, Mo, Cr, V, Nb, Fe, Ti, Zr, Hf, and Os. An example of Si oxide is SiO. Furthermore, Si-active materials may have a diamond crystal phase as their main phase, or they may have a type I clathrate crystal phase as their main phase, or they may have a type II clathrate crystal phase as their main phase.

[0083] The primary particles can be solid particles or porous particles, but the latter is preferred. Porous particles have voids inside, thus absorbing volume changes and consequently reducing volume changes in the negative electrode layer due to charging and discharging.

[0084] The porosity of the porous particles is, for example, 4% or more, and may be 10% or more. On the other hand, the porosity of the porous particles is, for example, 40% or less, and may be 20% or less. The porosity is determined by, for example, the process described below. First, a cross-section is machined on an electrode layer containing active material by ion milling. Then, the cross-section is observed by SEM (scanning electron microscope) to obtain an image in which the porous particles are photographed. The silicon portion and the porosity portion are clearly distinguished from the obtained image using image analysis software, and binarization is performed. Then, the area of ​​the silicon portion and the porosity portion in the obtained image is determined, and the porosity (%) is calculated by the following formula.

[0085] Porosity (%) = (Area of ​​void portion) / (Area of ​​silicon portion) + (Area of ​​void portion)) × 100

[0086] Preferably, the porous particles have a large number of tiny pores with a pore diameter of 100 nm or less. Compared with pores with a pore diameter greater than 100 nm, pores with a pore diameter of 100 nm or less can suppress pore collapse caused by compression. The amount of pores X (integrated vacancy volume) with a pore diameter of 100 nm or less is, for example, 0.05 ml / g or more, and can be 0.10 ml / g or more, or can be 0.12 ml / g or more. On the other hand, the amount of pores X is, for example, 0.40 ml / g or less. The amount of pores in this disclosure can be determined by, for example, BET measurement.

[0087] The porous particles preferably have a large number of tiny pores with a pore diameter of 50 nm or less. Compared with pores with a pore diameter greater than 50 nm and less than 100 nm, pores with a pore diameter of 50 nm or less can further suppress pore collapse caused by compression. The amount of pores with a pore diameter of 50 nm or less, Y, is, for example, 0.05 cc / g or more, and can be 0.075 ml / g or more, or 0.10 ml / g or more. On the other hand, the amount of pores, Y, is, for example, 0.25 ml / g or less.

[0088] Preferably, the porous particles have a large number of tiny voids with a pore diameter of 10 nm or less. Compared to voids with a pore diameter greater than 10 nm, voids with a pore diameter of 10 nm or less can contain the deposited Li at a high filling rate, thus suppressing volume changes caused by charging and discharging. The void quantity Z of voids with a pore diameter of 10 nm or less is, for example, 0.015 ml / g or more, and can be 0.02 ml / g or more, or 0.03 ml / g or more. On the other hand, the void quantity Z is, for example, 0.09 ml / g or less.

[0089] An example of a method for forming the porous particles is a method in which a LiSi alloy is prepared by reacting metallic Li with primary particles (the Si active material) that are solid particles, and then Li is removed from the LiSi alloy. For example, the LiSi alloy is obtained by mixing the primary particles (the Si active material) with metallic Li. The molar ratio of Li to Si (Li / Si) is, for example, 1.0 or more, and can be 2.0 or more, or 3.0 or more, or 4.0 or more. On the other hand, the Li / Si ratio is, for example, 8.0 or less. An example of a method for removing Li from the LiSi alloy is a method of reacting the LiSi alloy with a Li extraction material. Examples of the Li extraction material are alcohols such as methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol, and acids such as acetic acid, formic acid, propionic acid, and oxalic acid.

[0090] Another example of a method for forming the porous particles is a method in which a MgSi alloy is prepared by reacting metallic Mg with primary particles (the Si active material) as solid particles, and then removing Mg from the MgSi alloy. For example, the MgSi alloy is obtained by heating a mixture of primary particles (the Si active material) and metallic Mg. The ratio of Mg to Si (Mg / Si) is, for example, 1.0 or more, and may be 1.5 or more, or 2.0 or more. On the other hand, the Mg / Si ratio is, for example, 6.0 or less. An example of a method for removing Mg from the MgSi alloy is a method in which the Mg in the MgSi alloy is converted to MgO by heating the MgSi alloy in an oxygen-containing inert gas atmosphere, and then the MgO is removed by an acid solution. An example of the acid solution is an aqueous solution containing hydrochloric acid (HCl) and hydrogen fluoride (HF).

[0091] There is no particular limitation on the particle size D50 of the primary particles; for example, it can be 0.3 μm or more, and may be 0.5 μm or more. On the other hand, the particle size D50 of the primary particles can be, for example, 3.0 μm or less, and may be 2.5 μm or less. In this disclosure, the particle size D50 is the cumulative 50% of the particle size in the volume-based particle size distribution obtained by a laser diffraction particle size distribution measuring device.

[0092] Furthermore, starting from the microparticle side, the cumulative 10% of the particle size in the volumetric reference particle size distribution obtained by the laser diffraction particle size distribution measurement device is the particle size D10, and the cumulative 90% of the particle size is the particle size D90. (D90-D10) / D50 refers to the width of the distribution; the smaller the value of (D90-D10) / D50, the narrower the distribution. There is no particular limitation on the (D90-D10) / D50 of the primary particles, and it can be, for example, 0.1 or more and 3.0 or less, or 0.3 or more and 2.0 or less.

[0093] There is no particular limitation on the BET specific surface area of ​​the primary particles, and it is, for example, 1 m². 2 / g or more, and can be 10 m 2 / g or more, or up to 20 m 2 / g or more, or up to 30 m 2 / g or more. On the other hand, the BET specific surface area of ​​the primary particles is, for example, 200 m². 2 / g or less and can be 150 m 2 / g or less.

[0094] The primary particles have the active material resin. Preferably, the active material resin is capable of adhering to the resin layer. The active material resin will be described later. Because the primary particles have the active material resin capable of adhering to the resin layer, the resin layer adheres to the active material resin, and even with the expansion and contraction of the particles during charging and discharging, separation of the negative electrode current collector from the negative electrode layer is suppressed, and the increase in internal resistance of the solid-state battery due to charging and discharging is also suppressed.

[0095] There is no particular limitation on the form in which the primary particles have the resin for the active material, and it can be any of the forms in which the primary particles have the resin for the active material on a portion of their surface, or in which the primary particles are coated with the resin for the active material.

[0096] There are no particular limitations on the method for forming the primary particles of the resin having the active material, and spray drying is one example. Spray drying is a method in which a slurry obtained by dispersing particles and resin in a solvent is spray-dried to coat the resin.

[0097] (Secondary particles)

[0098] The secondary particles are particles obtained by aggregating multiple primary particles. These secondary particles include aggregates formed by aggregating the primary particles, granules obtained by granulating the primary particles, etc. In cases where the particles of this disclosure contain the secondary particles, the primary particles of the secondary particles are fixed with resin using the active material.

[0099] The resin used for the active material will be described later.

[0100] The particle size D50 of the secondary particles is, for example, 2.5 μm or more and less than 20 μm. The particle size D50 of the secondary particles can be 3.0 μm or more, or 5.0 μm or more. On the other hand, the particle size D50 of the secondary particles can be 19 μm or less, or 17 μm or less, or 15 μm or less. Furthermore, there are no particular limitations on the (D90-D10) / D50 of the secondary particles, and it is, for example, 0.1 or more and 5.0 or less, and can be 0.3 or more and 1.0 or less.

[0101] There is no particular limitation on the ratio of the particle size D50 of the primary particle to the particle size D50 of the secondary particle, and it can be, for example, more than 3% and less than 60%, more than 5% and less than 40%, or more than 7% and less than 25%.

[0102] There are no particular limitations on the method for forming the secondary particles, and one example is a method of granulating particles by spray drying. Spray drying is a method in which a slurry containing a plurality of primary particles, the active material, a resin, and a dispersion medium is sprayed into hot air and thereby dried. In the case of forming secondary particles containing porous particles as the primary particles, firstly, primary particles as porous particles can be prepared, and then the secondary particles can be formed by using the primary particles. Alternatively, firstly, primary particles as solid particles can be prepared, and then the secondary particles can be formed by using these primary particles, after which the primary particles constituting the secondary particles can be made porous.

[0103] (Resin for active materials)

[0104] The active material resin is preferably a resin capable of adhering to the resin layer. One type of active material resin may be used, or two or more types may be used. Adherence to the resin layer means that the active material resin can chemically or physically bond with the resin layer resin, and that the active material resin and the resin layer are bonded together. In all-solid-state batteries, it is preferable that, for example, in at least one of the following states: before charging, during charging, after charging, before use, during use, and after use, the active material resin and the resin layer have regions that are chemically or physically bonded and firmly adhered to each other.

[0105] The active material resin and the resin layer resin preferably contain a structure represented by at least one of the following formulas (1) and (2). It is preferred that the active material resin and the resin layer resin have a structure represented by at least one of the following formulas (1) and (2) because they adhere appropriately together. It is even more preferred that the active material resin and the resin layer resin have a structure represented by at least one of the following formulas (1) and (2) in the main chain.

[0106]

[0107]

[0108] In formula (1), R represents alkyl, allyl, hydroxy, carboxyl, methoxy, or ethoxy, and n in formulas (1) and (2) each independently represents an integer greater than 1. These groups may be substituted or may be unsubstituted.

[0109] Examples of substituted or unsubstituted alkyl groups represented by R are alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, and isopropyl.

[0110] The alkyl group may be straight-chain, branched, or cyclic. Examples of substituents are halogen atoms, alkyl groups, allyl groups, phenyl groups, alkenyl groups, alkoxy groups, ester groups, carbonyl groups, sulfonyl groups, amino groups, amide groups, and combinations thereof.

[0111] The allyl, carboxyl, methoxy, and ethoxy groups represented by R can each be substituted or unsubstituted. Examples of substituents are halogen atoms, alkyl, allyl, phenyl, alkenyl, alkoxy, ester, carbonyl, sulfonyl, amino, amide, and combinations thereof.

[0112] The active material resin and the resin layer resin may each have a structure represented by at least one of formulas (1) and (2), and may be a combination thereof. For example, it may be any of the following cases: where the active material resin has a structure represented by formula (1) and the resin layer resin has a structure represented by formula (1); where the active material resin has a structure represented by formula (1) and the resin layer resin has a structure represented by formula (2); where the active material resin has a structure represented by formula (2) and the resin layer resin has a structure represented by formula (1); and where the active material resin has a structure represented by formula (2) and the resin layer resin has a structure represented by formula (2).

[0113] Preferably, the active material resin and the resin layer resin have a common structure. It is preferable that the active material resin and the resin layer resin have a common structure because they can adhere appropriately to each other. An example of a common structure is a vinyl polymer structure in which olefinic unsaturated double bonds are polymerized.

[0114] Preferably, the active material resin and the resin layer resin contain the structure represented by formula (1) above, or the active material resin and the resin layer resin contain the structure represented by formula (2) above. It is preferred that the active material resin and the resin layer resin have a common structure represented by either formula (1) or formula (2) because they can adhere properly together.

[0115] Preferably, the active material resin and the resin layer resin have common functional groups. This is preferred because the active material resin and the resin layer resin can adhere appropriately to each other.

[0116] An example of a common functional group is the phenyl group.

[0117] Specific examples of the resins used in the active material are rubber resins such as butadiene rubber (BR) and styrene-butadiene rubber (SBR), fluorinated resins such as polyvinylidene fluoride (PVdF), and vinyl resins such as polyvinyl chloride, polyvinylidene chloride, vinyl acetate, polyvinyl alcohol, and styrene resins.

[0118] Preferably, the active material resin and the resin layer resin share a common resin. It is preferable that the active material resin and the resin layer resin share a common resin, as they can adhere appropriately together.

[0119] Examples of the common resin are resins exemplified as resins used as the above-mentioned active materials, specifically rubber resins such as butadiene rubber (BR) and styrene-butadiene rubber (SBR), fluorinated resins such as polyvinylidene fluoride (PVdF), and vinyl resins such as polyvinyl chloride, polyvinylidene chloride, vinyl acetate, polyvinyl alcohol, and styrene resin.

[0120] In the secondary particles, the proportion of the active material resin relative to the total amount of the plurality of primary particles and the active material resin is, for example, 1% by mass or more and 30% by mass or less, and may be 5% by mass or more and 25% by mass or less. On the other hand, the secondary particles may be particles containing the active material resin in a sintered body obtained by aggregating a plurality of primary particles.

[0121] (Solid electrolyte)

[0122] The negative electrode composite material may contain a solid electrolyte. Examples of the solid electrolyte are inorganic solid electrolytes such as sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, and halide solid electrolytes.

[0123] The sulfide solid electrolyte is a solid electrolyte containing sulfur element (S element) as the main component of the anion element. An example of the sulfide solid electrolyte is a solid electrolyte containing Li element, X element (X is at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In), and S element. The sulfide solid electrolyte may contain one type of element or may contain two or more types of elements as the X element. The sulfide solid electrolyte preferably contains P element as the X element. The sulfide solid electrolyte may also contain at least one of O element and halogen elements. Examples of the halogen element are F element, Cl element, Br element, and I element.

[0124] The sulfide solid electrolyte may be glass (amorphous), or may be glass-ceramic, or may be crystalline. The sulfide solid electrolyte may have a crystal phase. Examples of the crystal phase are thio-LISICON crystal phase, argyrodite crystal phase, and LGPS crystal phase.

[0125] There is no particular limitation on the composition of the sulfide solid electrolyte, and examples thereof are xLi2S•(1-x)P2S5 (0.5≤x<1) and yLiI•zLiBr•(100-y-z)(xLi2S•(1-x)P2S5) (0.5≤x<1, 0≤y≤30, 0≤z≤30).

[0126] In these compositions, preferably, x satisfies 0.7≤x≤0.8. In addition, Li 7-x PS 6-x X x is another example of the composition of the sulfide solid electrolyte. X is at least one of F, Cl, Br, and I, and x satisfies 0≤x≤2. In addition, Li 4-x ​​​​​​​Oxide solid electrolytes are solid electrolytes containing oxygen as the main anion element. Nitride solid electrolytes are solid electrolytes containing nitrogen as the main anion element. Halide solid electrolytes are solid electrolytes containing halogen as the main anion element. Any known solid electrolyte can be used as these solid electrolytes. The solid content of the solid electrolyte in the negative electrode mixture is, for example, 10% by mass or more and 50% by mass or less, and can be 20% by mass or more and 40% by mass or less.

[0128] There is no particular limitation on the particle size D50 of the solid electrolyte, and it is, for example, 0.05 μm or more and less than 2.0 μm. The particle size D50 of the solid electrolyte can be 0.1 μm or more, or 0.2 μm or more, or 0.3 μm or more. On the other hand, the particle size D50 of the solid electrolyte can be 1.8 μm or less, or 1.5 μm or less, or 1.2 μm or less, or 1.0 μm or less.

[0129] The ratio (SE / Si2) of the particle size D50 of the solid electrolyte to the particle size D50 of the secondary particles is not particularly limited, and is, for example, 0.5% or more, and may be 1.0% or more, or 1.2% or more, or 1.5% or more. On the other hand, the ratio (SE / Si2) is, for example, 15% or less, and may be 12% or less, or 10% or less, or 5% or less.

[0130] (Other materials)

[0131] The negative electrode composite material may also contain a conductive material. Examples of the conductive material are carbon conductive materials and metallic conductive materials. Examples of carbon conductive materials are particulate carbon conductive materials such as acetylene black (AB) and Ketjen black (KB), and fibrous carbon conductive materials such as carbon fibers, carbon nanotubes (CNTs), and carbon nanofibers (CNFs). Preferably, the fibrous carbon conductive material is a carbon nanotube (CNT) such as a single-walled carbon nanotube (SWCNT) and a multi-walled carbon nanotube (MWCNT). Furthermore, if the conductive material is particulate, there is no particular limitation on the particle size D50 of the conductive material, and it may be, for example, 10 nm or more and 10 μm or less, and may be 20 nm or more and 1 μm or less, or may be 30 nm or more and 500 nm or less. The solid content of the conductive material in the negative electrode composite material is, for example, 0.05% by mass or more and 3% by mass or less.

[0132] In addition to the resin used as the active material constituting the secondary particles, the negative electrode mixture may also contain an adhesive that does not constitute the secondary particles.

[0133] The type of adhesive described is similar to that described for the resins used in the above-mentioned active materials. Specifically, examples include rubber resins such as butadiene rubber (BR) and styrene-butadiene rubber (SBR), fluorinated resins such as polyvinylidene fluoride (PVdF), and vinyl resins such as polyvinyl chloride, polyvinylidene chloride, vinyl acetate, polyvinyl alcohol, and styrene resin.

[0134] That is, the negative electrode layer contains an adhesive, and the adhesive is preferably styrene-butadiene rubber, polyvinylidene fluoride or vinyl resin.

[0135] The solid content of the binder in the negative electrode composite material is, for example, more than 0.1% by mass and less than 5% by mass.

[0136] The negative electrode composite material may also contain a dispersion medium, but is not required to do so. Examples of dispersion media include butyl acetate, butyl butyrate, mesitylene, tetrahydronaphthalene, heptane, and N-methyl-2-pyrrolidone (NMP). If the negative electrode composite material contains a dispersion medium, the solid content of the negative electrode composite material is, for example, 20% by mass or more and 80% by mass or less. Furthermore, the negative electrode composite material is typically used in batteries, preferably in solid-state batteries.

[0137] There are no particular limitations on the method for manufacturing the aforementioned negative electrode hybrid material. The negative electrode hybrid material can be obtained by preparing particles that serve as the negative electrode active material.

[0138] The particles of the negative electrode active material may comprise both primary particles and secondary particles. For example, when preparing the secondary particles by spray drying, by adjusting the preparation conditions (e.g., by making the amount of resin added for the active material relatively small), while the secondary particles are formed from the primary particles and the resin for the active material, a portion of the primary particles remain unformed and are not converted into secondary particles. Thus, the negative electrode active material can be prepared containing both primary and secondary particles. The primary particles that are not converted into secondary particles remain primary particles, resulting in a negative electrode mixture containing both primary and secondary particles.

[0139] (positive electrode)

[0140] One embodiment of this disclosure relates to a positive electrode comprising a positive current collector and a positive electrode layer. The positive current collector comprises a positive electrode substrate layer.

[0141] The positive electrode layer typically contains a positive electrode composite material. The positive electrode composite material contains at least a positive electrode active material, and may also contain at least one of a solid electrolyte, a conductive material, and a binder.

[0142] Examples of the positive electrode active material are oxide active materials. Examples of oxide active materials are layered rock salt type active materials such as LiCoO2, LiMnO2, LiNiO2, LiVO2, and LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 and LiNi 0.8 Co 0.15 Al 0.05 O2, spinel-type active materials such as LiMn2O4, Li4Ti5O 12 and Li(Ni 0.5 Mn 1.5 O4, as well as olivine-type active materials such as LiFePO4, LiMnPO4, LiNiPO4 and LiCoPO4.

[0143] A coating containing a Li-ion-conducting oxide can be formed on the surface of the oxide active material. This is because it suppresses the reaction between the oxide active material and the solid electrolyte (especially a sulfide solid electrolyte). An example of the Li-ion-conducting oxide is LiNbO3. The thickness of the coating is, for example, 1 nm or more and 30 nm or less.

[0144] The solid electrolyte, conductive material, and binder used in the positive electrode composite material are the same as those described for the negative electrode layer. Furthermore, the thickness of the positive electrode layer is, for example, 0.1 μm or more and 500 μm or less, or it can be 0.1 μm or more and 100 μm or less, or it can be 0.1 μm or more and 50 μm or less. Additionally, an example of a method for forming the positive electrode layer is, for example, a method in which a positive electrode composite material containing a dispersion medium is coated onto a positive electrode current collector and then dried.

[0145] (Electrolyte layer)

[0146] The electrolyte layer is formed between the positive electrode layer and the negative electrode layer and contains a solid electrolyte. The electrolyte layer may also contain a binder. The solid electrolyte and the binder are similar to those described above. The thickness of the electrolyte layer is, for example, 0.1 μm or more and 500 μm or less, or it may be 0.1 μm or more and 100 μm or less, or it may be 0.1 μm or more and 50 μm or less.

[0147] (Other structures)

[0148] One embodiment of this disclosure relates to a solid-state battery that preferably has a positive electrode current collector for collecting current in the positive electrode layer. Examples of materials for the positive electrode current collector are SUS, aluminum, nickel, iron, titanium, and carbon. On the other hand, examples of materials for the negative electrode current collector (specifically, the negative electrode substrate layer) are SUS, copper, nickel, and carbon.

[0149] The solid-state battery of this disclosure may also include a constraint fixture that applies constraint pressure to the positive electrode layer, the electrolyte layer, and the negative electrode layer along the thickness direction. The constraint pressure is, for example, 0.1 MPa or more, and may be 1 MPa or more, or 5 MPa or more. Alternatively, the constraint pressure is, for example, 100 MPa or less, and may be 50 MPa or less, or 20 MPa or less.

[0150] (Solid-state battery)

[0151] The solid-state battery has, in sequence, a negative electrode, an electrolyte layer, and a positive electrode. The negative electrode has a negative electrode current collector and a negative electrode layer. The positive electrode has a positive electrode layer and a positive electrode current collector.

[0152] There are no particular limitations on the type of solid-state battery, and it is typically a lithium-ion battery. The solid-state battery in this disclosure can be a primary battery or a secondary battery, but a secondary battery is preferred. This is because secondary batteries can be used as rechargeable batteries, for example, batteries installed in vehicles. The solid-state battery can be a semi-solid-state battery or a fully solid-state battery. The solid-state battery is preferably a fully solid-state battery.

[0153] Examples of applications for the solid-state battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, the solid-state battery is preferably used as a power source for driving hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or battery electric vehicles (BEVs). Furthermore, the solid-state battery can be used as a power source for mobile bodies other than vehicles (e.g., trains, ships, or aircraft), or as a power source for electrical products such as information processing equipment. There are no particular limitations on the method of manufacturing the solid-state battery, and known methods can be employed.

[0154] Example

[0155] The present disclosure is further described in detail below by way of examples.

[0156] [Example 1]

[0157] 1. Preparation of the negative electrode layer

[0158] (Preparation of primary particles)

[0159] LiSi precursor was obtained by mixing 0.65 g of Si particles (manufactured by High Purity Chemical Company) and 0.60 g of Li metal (manufactured by Honjo Metals Company) in an agate mortar under an Ar atmosphere. In a glass reaction vessel under an Ar atmosphere, 1.0 g of LiSi precursor and 125 ml of dispersion medium (1,3,5-trimethylbenzene, manufactured by Nacalai Tesque) were mixed using an ultrasonic homogenizer (UH-50, manufactured by SMT Company). The resulting LiSi precursor dispersion was cooled to 0°C. 125 ml of ethanol (manufactured by Nacalai Tesque Company) was added dropwise as a Li extraction solvent, and the reaction proceeded for 120 minutes. After the reaction, 50 ml of acetic acid (manufactured by Nacalai Tesque Company) was further added dropwise, and the reaction proceeded for 60 minutes. The liquid and solid reaction products were separated by filtration after the reaction. The obtained solid reaction product was vacuum dried at 120°C for 2 hours to recover the porous primary particles (nanoporous Si). The recovered primary particles were classified, and the particle size D50 of the primary particles was adjusted to 1.5 μm.

[0160] (Preparation of secondary particles)

[0161] The obtained primary particles (nanoporous Si) and PVDF-HFP binder (manufactured by Kureha) were dispersed and partially dissolved in dimethyl carbonate (manufactured by Nacalai Tesque) to obtain a primary particle:binder ratio (mass ratio) of 100:13.3, resulting in a slurry. This slurry was sprayed and dried in a nitrogen atmosphere at 140°C. This yielded secondary particles from which multiple primary particles aggregated. The obtained secondary particles were graded, and the particle size D50 was adjusted to 10 μm.

[0162] (Preparation of the negative electrode layer)

[0163] A resin slurry, prepared by mixing vinyl resin (used as the resin layer) with carbon in an organic solvent at a mass ratio of 50:50, was coated onto a negative electrode current collector (Ni foil) using a doctor blade method. The slurry was then dried on a hot plate at 80°C for 30 minutes, followed by further drying at 170°C for 30 minutes. This yielded a negative electrode current collector with a resin layer.

[0164] The primary and secondary particles obtained as described above were mixed together at a primary particle:secondary particle volume ratio of 5:95 to obtain a negative electrode active material. A negative electrode slurry (negative electrode mixed material) was prepared by mixing 1.0 g of the obtained negative electrode active material, 0.04 g of conductive material (VGCF, manufactured by Resonac), 0.776 g of sulfide solid electrolyte (LiI-LiBr-Li3PS4 sulfide solid electrolyte, D50=0.2 μm), 0.02 g of binder for the active material resin (PVDF, manufactured by Kureha), and 1.7 g of butyl butyrate (manufactured by Kishida Chemical) using an ultrasonic homogenizer (UH-50, manufactured by SMT). This negative electrode slurry was coated onto the resin layer on the negative electrode current collector obtained as described above using a doctor blade method and dried on a hot plate at 100°C for 30 minutes to obtain a negative electrode layer (thickness 30 μm).

[0165] The resins used in the resin layer and the resins used in the active material in Example 1 are listed in Table 1.

[0166] 2. Preparation of the positive electrode layer

[0167] 1.5 g of positive electrode active material (LiNi coated with LiNbO3) was homogenized using an ultrasonic homogenizer (UH-50, manufactured by SMT). 0.8 Co 0.15 Mn 0.05 A positive electrode slurry was prepared by mixing 0.023 g of conductive material (VGCF, manufactured by Resonac), 0.239 g of sulfide solid electrolyte (LiI-LiBr-Li3PS4 sulfide solid electrolyte, D50=0.2 μm), 0.011 g of binder (PVDF, manufactured by Kureha Corporation), and 0.8 g of butyl butyrate (manufactured by Kishida Chemical). This positive electrode slurry was then coated onto a positive electrode current collector (Al foil) using a doctor blade method and dried on a hot plate at 100°C for 30 minutes to obtain the positive electrode layer.

[0168] 3. Preparation of solid electrolyte layer

[0169] A binder and a solid electrolyte are added to an organic solvent. After addition, the mixture is kneaded using an ultrasonic homogenizer to obtain a slurry for the solid electrolyte. The obtained slurry for the solid electrolyte is then coated onto an Al foil to obtain a solid electrolyte layer.

[0170] 4. Battery manufacturing

[0171] The electrode layers prepared in steps 1 to 3 above are formed into strips. The surfaces of the mixed material of the positive electrode layer and the solid electrolyte layer are placed together and rolled at 165°C and 50 kN•cm, and the Al foil is peeled off. This transfers the solid electrolyte layer onto the positive electrode layer. Similarly, the surfaces of the mixed material of the negative electrode layer and the solid electrolyte layer are placed together and rolled at 25°C and 50 kN•cm, and the transfer foil (Al foil) is peeled off. This transfers the solid electrolyte layer onto the negative electrode layer. A sheet of the negative electrode with the solid electrolyte layer already transferred is stamped using a 13.00 mm diameter stamping press, and a sheet of the positive electrode layer is stamped using an 11.28 mm diameter stamping press. A solid electrolyte layer is further transferred onto the negative electrode with the solid electrolyte layer already transferred using a uniaxial press. The stamped negative electrode layer and positive electrode layer are placed face to face and formed into a battery. Finally, the current-carrying tabs are attached to both the positive and negative electrodes, and the structure is sealed in an aluminum sheet using a vacuum lamination sealing machine and constrained under a pressure of 5 MPa, thereby preparing the battery.

[0172] [Examples 2 to 9 and Comparative Examples 1 to 3]

[0173] The battery was prepared in the same manner as in Example 1, except that the resin for the resin layer and the resin for the active material listed in Table 1 were used respectively. When "No resin layer" was listed in the resin for the resin layer column of Table 1, a negative electrode current collector without resin for the resin layer was used, that is, the negative electrode current collector was a Ni foil, and the negative electrode slurry was coated on the Ni foil.

[0174] The resins used for the resin layer and the resins used for the active materials in Examples 2 to 9 are given in Table 1.

[0175] The resins used for the active materials in Comparative Examples 1 to 3 are given in Table 1.

[0176] (evaluate)

[0177] <Peel Strength Evaluation>

[0178] The negative electrode layers of the examples and comparative examples prepared in the above four cases were stamped to a diameter of 11.28 mm, and each sample was prepared using a LUMiFrac (manufactured by MS Scientific). The adhesion strength (peel strength) between the hybrid material layer and the current collector layer was measured. The normalized peel strength was calculated with Comparative Example 1 as 100. The results are shown in the "Normalized Peel Strength" column of Table 1.

[0179] Samples are prepared by attaching the object to the adapter, fixing it to the support plate, and installing a test base (weight) onto it.

[0180] The measurement conditions were such that the load applied to the sample increased at 10 rpm / second (approximately 0.2 N / second), the measurement atmosphere temperature was 25°C, and the adhesion surface area was 10 mm in diameter and approximately 78 mm². 2 .

[0181] <Battery Resistance Evaluation>

[0182] In each of the all-solid-state batteries prepared in the examples and comparative examples described above, the initial resistance value was calculated by adjusting the voltage to 3.7 V and then discharging at a 5 C rate for 5 seconds. Furthermore, after cycling 40 times at a 1 / 3 C rate from 3.0 V to 4.2 V and at 60 °C, the resistance was measured again, and the resistance value after durability was calculated.

[0183] The rate of increase was calculated from the initial resistance value and the resistance value after durability testing, and the normalized rate of increase was calculated separately with Comparative Example 1 as 100. The results are given in the "Normalized Rate of Increase in Resistance" column of Table 1, and are further detailed below. Figure 3 The figure shows the "normalized resistance increase rate".

[0184]

[0185] The compounds used in Table 1 are as follows.

[0186] PVDF: Polyvinylidene fluoride (weight average molecular weight: 800,000)

[0187] Vinyl resin: Polyacetal (weight average molecular weight: 500,000)

[0188] SBR: Styrene-butadiene rubber (weight average molecular weight: 200,000)

[0189] As shown in Table 1 and Figure 3 As shown, it has been demonstrated that in solid-state batteries using a negative electrode having the resin for the active material and the resin for the resin layer, peel strength is improved, the rate of increase in resistance is reduced, and the increase in internal resistance due to charging and discharging is suppressed.

Claims

1. A solid-state battery (100), comprising, in sequence, a first current collector (110), a first electrode layer (111), an electrolyte layer (120), a second electrode layer (131), and a second current collector (130), wherein: The first current collector (110) includes a resin layer (112) in contact with the first electrode layer (111). The first electrode layer (111) contains an electrode active material, and The electrode active material comprises an active material resin.

2. The solid-state battery (100) according to claim 1, wherein: The electrode active material contains secondary particles, and The secondary particles contain a plurality of primary particles and the resin used for the active material.

3. The solid-state battery (100) according to claim 1, wherein the resin for the active material and the resin for the resin layer (112) have a common structure.

4. The solid-state battery (100) according to claim 1, wherein the resin for the active material and the resin for the resin layer (112) have common functional groups.

5. The solid-state battery (100) according to claim 1, wherein the resin for the active material and the resin for the resin layer (112) have a common resin.

6. The solid-state battery (100) according to claim 1, wherein: The active material resin and the resin of the resin layer (112) comprise a structure represented by at least one of the following formulas (1) or (2): In formula (1), R represents alkyl, allyl, hydroxy, carboxyl, methoxy or ethoxy, and n in formulas (1) and (2) each independently represents an integer greater than 1.

7. The solid-state battery (100) according to claim 6, wherein: The active material resin and the resin layer (112) resin contain a structure represented by formula (1) or a structure represented by formula (2).

8. The solid-state battery (100) according to claim 1, wherein the active material is configured with a resin to adhere to the resin layer (112).

9. The solid-state battery (100) according to claim 1, wherein the first current collector (110) further comprises a metal layer.

10. The solid-state battery (100) according to claim 1, wherein the first current collector (110) is a conductive resin current collector.

11. The solid-state battery (100) according to claim 1, wherein the resin layer (112) has a region that adheres to the electrode active material.

12. The solid-state battery (100) according to claim 1, wherein the electrode active material contains Si.

13. The solid-state battery (100) according to claim 9, wherein: The metal layer is nickel foil, and The first current collector (110) comprises the nickel foil and the resin layer in sequence.

14. The solid-state battery (100) according to claim 1, wherein: The first electrode layer (111) contains an adhesive, and The adhesive is at least one type selected from the group consisting of styrene-butadiene rubber, polyvinylidene fluoride, and vinyl resin.

15. The solid-state battery (100) according to any one of claims 1 to 14, wherein the solid-state battery is an all-solid-state battery.

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