Batteries and methods for manufacturing batteries

Abstract

This invention provides a battery capable of increasing capacity and a method for manufacturing the battery. A battery that uses the dissolution and precipitation of lithium metal as a negative electrode reaction, wherein the battery comprises a negative electrode layer, an electrolyte layer, and a positive electrode layer, the negative electrode layer having a composite solid electrolyte, the composite solid electrolyte being a mixture of a first solid electrolyte and a second solid electrolyte, the first solid electrolyte being an oxide solid electrolyte, the second solid electrolyte being a solid electrolyte that plastically deforms under lower stress than the first solid electrolyte, and the composite solid electrolyte being secondary particles with voids, wherein during charging of the battery, lithium metal is precipitated in the voids within the secondary particles.

Description

Technical Field

[0001] This invention relates to a battery. Background Technology

[0002] Various technologies have been proposed for a type of battery disclosed in Patent Document 1.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-044064 Summary of the Invention

[0004] Patent Document 1 discloses an all-solid-state battery in which Li metal is deposited in the pores between oxide solid electrolytes. However, there is still room for improvement in terms of increasing battery capacity in Patent Document 1.

[0005] The present invention was made in view of the above-mentioned actual situation, and its main objective is to provide a battery that can improve capacity.

[0006] That is, the present invention includes the following solutions.

[0007] <1>

[0008] A battery that uses the dissolution and precipitation of lithium metal as the negative electrode reaction, wherein, The battery comprises a negative electrode layer, an electrolyte layer, and a positive electrode layer. The negative electrode layer has a composite solid electrolyte. The composite solid electrolyte is a mixture of a first solid electrolyte and a second solid electrolyte. The first solid electrolyte is an oxide solid electrolyte. The second solid electrolyte is a solid electrolyte that undergoes plastic deformation under lower stress than the first solid electrolyte. The composite solid electrolyte is composed of porous secondary particles. During the charging of the battery, lithium metal is deposited in the voids within the secondary particles.

[0009] <2>

[0010] According to the battery described in <1>, wherein, The composite solid electrolyte comprises a granulator, which comprises at least one of the first solid electrolyte, a first electronically conductive material, and a first binder.

[0011] <3>

[0012] According to the battery described in <2>, wherein, The mixture comprises at least one of the granules, the second solid electrolyte, the second electronically conductive material, and the second binder.

[0013] <4>

[0014] The battery according to any one of <1> to <3>, wherein, The second solid electrolyte is a sulfide solid electrolyte.

[0015] <5>

[0016] A method for manufacturing a battery, wherein the method for manufacturing a battery is any one of <1> to <4>, wherein, The mixture is prepared, and the negative electrode layer is shaped into a sheet by pressurizing the mixture.

[0017] Invention Effects

[0018] According to the present invention, a battery capable of increasing capacity can be provided. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram illustrating an example of the battery of the present invention.

[0020] Figure 2 This is a schematic diagram illustrating an example of a method for manufacturing the negative electrode layer used in the battery of the present invention. Detailed Implementation

[0021] The following describes embodiments based on the present invention. Furthermore, other than those specifically mentioned in this specification and necessary for the implementation of the present invention (e.g., the general structure and manufacturing process of the battery of the present invention are not specifically described) can be understood by those skilled in the art based on prior art. The present invention can be implemented based on the disclosures in this specification and common technical knowledge in the field.

[0022] Furthermore, the dimensional relationships (length, width, thickness, etc.) in the diagram do not reflect the actual dimensional relationships.

[0023] In this invention, an example of a method for calculating the average particle size is as follows. First, in a transmission electron microscope (TEM) image or a scanning electron microscope (SEM) image at an appropriate magnification (e.g., 50,000 to 1,000,000 times), the particle size of a single particle is calculated if it is considered to be spherical. The particle size is then calculated based on this TEM or SEM observation for 2 to 300 particles of the same type, and the average of these particle sizes is taken as the average particle size.

[0024] 1. Battery

[0025] This invention provides a battery in which the dissolution and precipitation of lithium metal is used as the negative electrode reaction, wherein, The battery comprises a negative electrode layer, an electrolyte layer, and a positive electrode layer. The negative electrode layer has a composite solid electrolyte. The composite solid electrolyte is a mixture of a first solid electrolyte and a second solid electrolyte. The first solid electrolyte is an oxide solid electrolyte. The second solid electrolyte is a solid electrolyte that undergoes plastic deformation under lower stress than the first solid electrolyte. The composite solid electrolyte is composed of porous secondary particles. During the charging of the battery, lithium metal is deposited in the voids within the secondary particles.

[0026] Oxide solid electrolytes typically have low ionic conductivity, making it difficult to achieve high output even when using the porous oxide solid electrolyte anode described in Patent Document 1. Sulfide solid electrolytes degrade at high temperatures, making sintering difficult compared to oxides. They are typically formed by pressure molding, but their soft nature leads to a decrease in porosity. Reducing the pressure results in insufficient contact and bonding between particles, compromising ionic conductivity. Therefore, it is difficult to fabricate porous structures with sulfide solid electrolytes, leading to reduced battery capacity in anodes using them.

[0027] A battery using Si-based materials as a high-capacity negative electrode was also proposed, but Si and other powders are highly reactive with oxygen in the air, making them difficult to handle in the manufacturing process.

[0028] According to the present invention, a negative electrode having electronic conductivity, ionic conductivity, and three-dimensional voids for lithium metal deposition can be safely fabricated. According to the present invention, the voids in the composite solid electrolyte can be utilized to ensure space for lithium metal deposition, and the battery capacity can be improved.

[0029] The battery of the present invention uses the dissolution and precipitation of lithium metal as the negative electrode reaction.

[0030] In the battery of the present invention, during charging, lithium metal is deposited in the voids within the secondary particles of the composite solid electrolyte. During discharging, the lithium metal deposited in the voids within the secondary particles of the composite solid electrolyte dissolves and moves towards the positive electrode.

[0031] A battery has a negative electrode layer, an electrolyte layer, and a positive electrode layer, and can have a negative electrode containing a negative electrode layer and a positive electrode containing a positive electrode layer.

[0032] Figure 1This is a cross-sectional schematic diagram illustrating an example of the battery of the present invention.

[0033] like Figure 1 As shown, the battery 100 of the present invention sequentially comprises a negative electrode layer 10, an electrolyte layer 20, and a positive electrode layer 30.

[0034] [negative electrode]

[0035] The negative electrode has a negative electrode layer and, as needed, a negative electrode current collector.

[0036] The negative electrode layer can be disposed on one surface of the negative electrode current collector or on both surfaces of the negative electrode current collector.

[0037] The negative electrode layer contains a composite solid electrolyte.

[0038] The negative electrode layer may contain lithium metal. Lithium metal is the negative electrode active material and exists in the voids within the secondary particles of the composite solid electrolyte during battery charging.

[0039] The composite solid electrolyte is a mixture of the first solid electrolyte and the second solid electrolyte.

[0040] Composite solid electrolytes are secondary particles with pores.

[0041] The average particle size of the composite solid electrolyte particles can be, for example, 0.5 μm to 100 μm.

[0042] The first solid electrolyte is an oxide solid electrolyte.

[0043] The first solid electrolyte can be porous. The first solid electrolyte can be a sintered body of a porous oxide solid electrolyte with pores.

[0044] The first solid electrolyte can be either primary or secondary particles.

[0045] The average particle size of the first solid electrolyte particles can be, for example, 1 nm to 100 μm.

[0046] Oxide solid electrolytes can be oxides that have Li ion conductivity and do not react with lithium metal.

[0047] Examples of oxide solid electrolytes include substances having a garnet-type crystal structure containing Li, La, A (where A is at least one of Zr, Nb, Ta, and Al), and O. Examples of oxide solid electrolytes include Li₂O-B₂O₃-P₂O₅, Li₂O-SiO₂, Li₂O-B₂O₃, and Li₂O-B₂O₃. 1.3 Al 0.3 Ti 0.7 (PO4)3, Li5La3Ta2O12 Li7La3Zr2O 12 Li6BaLa2Ta2O 12 Li 3.6 Si 0.6 P 0.4 O4, Li4SiO4, Li4TiO4, Li3PO4 and Li 3+x PO 4-x N x (1≤x≤3), etc.

[0048] At least part or all of the surface of the first solid electrolyte may be coated with a coating layer.

[0049] The coating layer may contain or be composed of a Li-ion conductive compound. Examples of Li-ion conductive compounds include B₂O₃, Li₂B₄O₇, LiBPO₄, Li₃PO₄, LiPO₃, and LiNbO₃. The thickness of the coating layer is, for example, 1 nm or more and 30 nm or less. The coating percentage of the Li-ion conductive compound coating the first solid electrolyte is, for example, 70% or more, 90% or more, or 100%. There are no particular limitations on the coating method of the Li-ion conductive compound, and conventionally known methods can be appropriately used.

[0050] The second solid electrolyte is a solid electrolyte that undergoes plastic deformation under lower stress than the first solid electrolyte.

[0051] The second solid electrolyte can be an oxide solid electrolyte of a different type than the oxide solid electrolyte used in the first solid electrolyte, provided it undergoes plastic deformation under lower stress than the first solid electrolyte. It can also be a sulfide solid electrolyte. Sulfide solid electrolytes are generally softer than oxide solid electrolytes and undergo plastic deformation under lower stress.

[0052] The second solid electrolyte can be either primary or secondary particles.

[0053] The average particle size of the second solid electrolyte particles can be, for example, 1 nm to 100 μm.

[0054] Sulfide solid electrolytes are electrolytes containing sulfur (S). They typically contain at least lithium (Li) and sulfur (S). They may also contain nitrogen (M) (M is at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In). Furthermore, sulfide solid electrolytes may contain halogens such as sulfur (F), chlorine (Cl), br, and iron (I).

[0055] Sulfide solid electrolytes can be glass-based (amorphous), glass-ceramic, or crystalline. Sulfide solid electrolytes can possess crystalline phases. Examples of such crystalline phases include the Thio-LISICON type, the Argyrodite type, and the LGPS type.

[0056] The composition of sulfide solid electrolytes is not particularly limited; examples include xLi₂S·(1-x)P₂S₅ (0.5 ≤ x < 1) and yLiI·zLiBr·(100-yz)(xLi₂S·(1-x)P₂S₅) (0.5 ≤ x < 1, 0 ≤ y ≤ 30, 0 ≤ z ≤ 30). In these compositions, x can satisfy 0.7 ≤ x ≤ 0.8. Furthermore, other examples of sulfide solid electrolyte compositions include Li 7-x PS 6-x X x X is at least one of F, Cl, Br, and I, and x satisfies 0 ≤ x < 2. Furthermore, as another example of the composition of a sulfide solid electrolyte, Li... 4-x Me 1-x P x S4 (0 < x < 1). Me is at least one of Al, Zn, In, Ge, Si, Sn, Sb, Ga, and Bi. Examples of sulfide solid electrolytes include LiI-LiBr-Li2S-P2S5, LiI-Li2S-P2S5, LiI-Li2S-P2O5, and LiI-Li3PO4-P2S5.

[0057] Composite solid electrolytes may include granules.

[0058] Granulations can have voids.

[0059] Granulations can be secondary particles.

[0060] The average particle size of the granules can be, for example, 0.5 μm to 100 μm.

[0061] The granules comprise at least one of a first solid electrolyte, a first electronically conductive material, and a first binder.

[0062] The proportion of first-electron conductive material in the granules can be, for example, more than 0.1% by mass and less than 5% by mass.

[0063] The proportion of the first binder in the granules can be, for example, more than 0.5% by mass and less than 15% by mass.

[0064] The mixture may include at least one of granules, a second solid electrolyte, a second electronically conductive material, and a second binder.

[0065] The proportion of the second electronically conductive material in the mixture can be, for example, more than 0.1% by mass and less than 5% by mass.

[0066] The proportion of the second binder in the mixture can be, for example, more than 0.5% by mass and less than 15% by mass.

[0067] Materials with first and second electronic conductivity are collectively referred to as electronically conductive materials.

[0068] Electronically conductive materials can be either electronically conductive particles or electronically conductive fibers.

[0069] Examples of electronically conductive materials include carbon-based materials, metal particles, and conductive polymers. Examples of carbon-based materials include particulate materials such as acetylene black (AB) and Ketjen black (KB), and fibrous materials such as vapor-phase carbon fiber (VGCF), carbon nanotubes (CNTs), and carbon nanofibers (CNFs).

[0070] The first and second adhesives are collectively referred to as adhesives.

[0071] Examples of adhesives include styrene-butadiene rubber (SBR), polyimide (PI), polyacrylic acid (PAA), acrylonitrile-butadiene rubber (NBR), butadiene rubber (BR), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), styrene-isoprene-styrene block copolymer (SIS), and ethylene-propylene-diene copolymer (EPDM).

[0072] Materials used as negative current collectors include, for example, SUS, aluminum, copper, nickel, iron, titanium, and carbon. Furthermore, the thickness of the negative current collector varies depending on its shape, ranging from 1 μm to 50 μm. The shape of the negative current collector can be foil-like or plate-like. The top-view shape of the negative current collector is not particularly limited; examples include circular, elliptical, rectangular, and arbitrary polygonal shapes. The negative current collector can be a structure with a buffer layer, elastic layer, or positive temperature coefficient (PTC) thermistor layer disposed on its surface.

[0073] [positive electrode]

[0074] The positive electrode has a positive electrode layer and, if necessary, a positive electrode current collector.

[0075] The positive electrode layer is a layer containing at least a positive electrode active material. Furthermore, the positive electrode layer may contain at least one of a solid electrolyte, an electronically conductive material, and a binder, as needed.

[0076] The positive electrode layer can be disposed on one or both surfaces of the positive electrode current collector. The positive electrode can have two or more positive electrode layers formed on at least one surface of the positive electrode current collector, forming a multilayer structure. Furthermore, when two or more positive electrode layers are formed, the types of positive electrode active materials contained in each positive electrode layer can be the same or different.

[0077] Examples of positive electrode active materials include oxide active materials. Examples of oxide active materials include LiCoO2, LiMnO2, LiNiO2, LiVO2, and LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 and LiNi 0.8 Mn 0.1 Co 0.1 O2 and other layered active substances in rock salt, LiMn2O4, Li4Ti5O 12 and Li (Ni 0.5 Mn 1.5 Spinel-type active substances such as O4, and olivine-type active substances such as LiFePO4, LiMnPO4, LiNiPO4 and LiCoPO4.

[0078] A coating containing a Li-ion conductive compound can be formed on the surface of the positive electrode active material. This is because it can suppress the reaction between the positive electrode active material and the solid electrolyte (especially a sulfide solid electrolyte). Examples of Li-ion conductive compounds include those used in the aforementioned coating layer. The coating thickness is, for example, 1 nm or more and 30 nm or less. The coverage percentage of the Li-ion conductive compound covering the positive electrode active material is, for example, 70% or more, 90% or more, or even 100%.

[0079] The positive electrode active material is usually in the form of particles. The positive electrode active material can be primary particles or secondary particles formed by the aggregation of primary particles.

[0080] There is no particular limitation on the average particle size of the positive electrode active material. For example, it can be greater than 0.01 μm and less than 50 μm, or it can be greater than 0.5 μm and less than 30 μm.

[0081] The proportion of positive electrode active material in the positive electrode layer can be, for example, 20% by mass or more, 30% by mass or more, or 40% by mass or more. If the proportion of positive electrode active material is too low, sufficient energy density may not be achieved. On the other hand, the proportion of positive electrode active material in the positive electrode layer can be, for example, 95% by mass or less, 70% by mass or less, or 60% by mass or less. If the proportion of positive electrode active material is too high, the ionic conductivity and electronic conductivity of the positive electrode layer may decrease.

[0082] Solid electrolytes can be inorganic solid electrolytes such as oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, and complex hydride solid electrolytes, or organic solid electrolytes such as gel electrolytes. Examples of oxide solid electrolytes and sulfide solid electrolytes used in the aforementioned negative electrode layer include those used in the latter.

[0083] As a halide solid electrolyte, it can be, for example, a solid electrolyte containing Li, D and X (D represents at least one of Ti, Al and Y, and X represents F, Cl or Br).

[0084] Gel electrolytes may comprise an electrolyte and a polymeric material. The polymeric material may form a polymeric matrix. The polymeric material may include, for example, at least one selected from the group consisting of polyvinylidene fluoride (PVdF), poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP), polyacrylonitrile (PAN), PVdF-PAN, polyethylene oxide (PEO), polyethylene glycol (PEG), and derivatives thereof.

[0085] From an operational point of view, solid electrolytes can be in the form of particles.

[0086] Furthermore, the average particle size of the solid electrolyte is not particularly limited and can range from 1 nm to 100 μm.

[0087] The proportion of solid electrolyte in the positive electrode layer can be, for example, 1% by mass or more. If the proportion of solid electrolyte is too low, the ion conduction pathways in the positive electrode layer may be insufficient. On the other hand, the proportion of solid electrolyte in the positive electrode layer can be, for example, 60% by mass or less. If the proportion of solid electrolyte is too high, the proportion of positive electrode active material will be relatively reduced, and the energy density may become lower.

[0088] The positive electrode layer can contain an electronically conductive material. By adding an electronically conductive material, the electronic conductivity of the positive electrode layer is improved. Examples of electronically conductive materials include those used in the aforementioned negative electrode layer.

[0089] The proportion of electronically conductive material in the positive electrode layer can be, for example, 0.1% by mass or more. If the proportion of electronically conductive material is too low, the electronic conduction pathways in the positive electrode layer may be insufficient. On the other hand, the proportion of electronically conductive material in the positive electrode layer can be, for example, 5% by mass or less. If the proportion of electronically conductive material is too high, the proportion of positive electrode active material will be relatively reduced, and the energy density may become lower.

[0090] The positive electrode layer may contain a binder. Examples of binders include those used in the negative electrode layer described above.

[0091] The proportion of binder in the positive electrode layer can be, for example, 0.5% by mass or more. If the proportion of binder is too small, it may not be able to sufficiently reduce the increase in resistance caused by charging and discharging. On the other hand, the proportion of binder in the positive electrode layer can be, for example, 15% by mass or less. If the proportion of binder is too large, the proportion of positive electrode active material will be relatively reduced, and the energy density may become lower.

[0092] The thickness of the positive electrode layer can be, for example, 0.1 μm or more and 1000 μm or less, or 1 μm or more and 500 μm or less, or 30 μm or more and 100 μm or less.

[0093] There are no particular limitations on the manufacturing method of the positive electrode layer. For example, the following method can be used: mixing a positive electrode active material, an electronically conductive material, and a solvent to obtain a positive electrode slurry; coating the positive electrode slurry onto a positive electrode current collector and drying it to form the positive electrode layer. During the formation of the positive electrode layer, a pressing process can be performed to press the positive electrode layer along its thickness direction. Examples of pressing processes include roller presses and flatbed presses.

[0094] Examples of solvents include N-methylpyrrolidone (NMP), tetrahydronaphthalene, diisobutyl ketone, butyl butyrate, mesitylene, heptane, dibutyl ether, decane, dodecane, isododecane, and toluene, and may contain two or more of these components.

[0095] Materials used as positive current collectors include, for example, SUS, Cr, Au, Pt, Zn, aluminum, copper, nickel, iron, titanium, and carbon. The thickness of the positive current collector is, for example, 0.1 μm or more and 100 μm or less. The shape of the positive current collector can be foil-like or plate-like. The top view shape of the positive current collector is not particularly limited; for example, it can be circular, elliptical, rectangular, or any polygonal shape. The positive current collector can have a structure with a buffer layer, an elastic layer, or a PTC thermistor layer disposed on its surface.

[0096] [Electrolyte layer]

[0097] The electrolyte layer is a layer formed between the positive electrode layer and the negative electrode layer, and contains at least an electrolyte.

[0098] The electrolyte layer can be a solid electrolyte layer composed of solids.

[0099] The solid electrolyte layer contains at least a solid electrolyte and, if necessary, a binder, etc. Examples of solid electrolytes include the same solid electrolyte described in the positive electrode layer above.

[0100] Solid electrolytes can be used alone or in combination with two or more types. Furthermore, when using two or more solid electrolytes, they can be mixed together or formed into two or more layers of solid electrolytes to create a multilayer structure.

[0101] The proportion of solid electrolyte in the solid electrolyte layer is not particularly limited. For example, it can be 50% by mass or more, or it can be in the range of 60% by mass or more and 100% by mass, or it can be in the range of 70% by mass or more and 100% by mass, or it can be 100% by mass. The solid electrolyte layer may contain less than 1% by mass of electrolyte relative to the total amount of solid electrolyte layer.

[0102] Examples of binders that can be contained in the above-mentioned positive electrode layer can be shown.

[0103] The content of binder in the solid electrolyte layer can be 0% to 10% by mass relative to the total amount of the solid electrolyte layer.

[0104] The thickness of the electrolyte layer can be, for example, 0.1 μm or more and 1000 μm or less, or 0.1 μm or more and 500 μm or less, or 0.1 μm or more and 100 μm or less.

[0105] The battery of the present invention may further include a constraint clamp that applies constraint pressure to the positive electrode layer, electrolyte layer, and negative electrode layer along the thickness direction. In particular, when the electrolyte layer is a solid electrolyte layer, constraint pressure can be applied to form good ion conduction paths and electron conduction paths. The constraint pressure may be, for example, 0.1 MPa or more, 1 MPa or more, or 5 MPa or more. On the other hand, the constraint pressure may be, for example, 100 MPa or less, 50 MPa or less, or 20 MPa or less.

[0106] [Battery]

[0107] The battery in this invention can be a solid-state battery with an electrolyte layer containing a solid electrolyte. The solid-state battery can be a semi-solid-state battery or a fully solid-state battery. In this invention, a semi-solid-state battery is a battery whose electrolyte layer contains both solid components such as an inorganic solid electrolyte and liquid components (e.g., solvent and electrolyte solution). In this invention, a fully solid-state battery is a battery whose electrolyte layer contains only solid components such as an inorganic solid electrolyte. Furthermore, the battery in this invention can be a primary battery or a secondary battery, wherein it can be a secondary battery. This is because it can be repeatedly charged and discharged, making it useful, for example, as a vehicle battery.

[0108] There are no particular limitations on the shape of the battery; for example, it can be button type, cylindrical type, square type, sheet type, button type, flat type, or stacked type.

[0109] In the case of a battery stack containing multiple batteries, the battery stack can be either unipolar or bipolar.

[0110] Batteries can be used in various applications, including as power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline vehicles, and diesel vehicles. In particular, they can be used as power sources for driving hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or battery electric vehicles (BEVs). Furthermore, batteries can be used as power sources for mobile bodies other than vehicles (e.g., railway vehicles, ships, aircraft) and for electrical products such as information processing devices.

[0111] 2. Battery manufacturing methods

[0112] In this invention, a method for manufacturing a battery is provided, wherein the hybrid body is made, and the negative electrode layer is formed into a sheet by pressurizing the hybrid body.

[0113] Figure 2 This is a schematic diagram illustrating an example of a method for manufacturing the negative electrode layer used in the battery of the present invention.

[0114] The mixture can be made by mixing porous particles, which are mainly composed of a first solid electrolyte, with a material containing a second solid electrolyte that plastically deforms under lower stress than the first solid electrolyte.

[0115] If necessary, a coating layer can be formed on the surface of the first solid electrolyte particle.

[0116] Granulations can be prepared by mixing at least one of the first solid electrolyte particles, the first electronically conductive material, and the first binder as needed.

[0117] The granules can be obtained, for example, by dispersing at least one of the first solid electrolyte particles, the first electronically conductive material, and the first binder in water, mixing and dispersing them with a mixer (planetary mixer, twin-shaft mixer, ultrasonic homogenizer, etc.), spray drying them with a spray dryer, and then heating and vacuum drying (120°C for about 6 hours) to completely remove moisture.

[0118] As another example, granules can be obtained by feeding various materials into a mixed dry / wet granulation device.

[0119] A mixture can be prepared by mixing granules, second solid electrolyte particles, and at least one of a second electronically conductive material and a second binder as needed.

[0120] The mixture can be obtained by adding at least one of the granules, the second solid electrolyte particles, the second electronically conductive material, and the second binder to an organic solvent and mixing and dispersing them using a mixer.

[0121] As an organic solvent, it can be an organic solvent that will not degrade the solid electrolyte, such as butyl butyrate.

[0122] As a method for forming the negative electrode layer into a sheet by pressing the mixture, an example is to coat the mixture onto a negative electrode current collector such as an SUS foil that serves as a support and dry it (using a die coating machine, etc.), form the mixture into a sheet, and then press it by rolling, isostatic pressing, etc.

[0123] Pressurization can increase the filling of the negative electrode layer, and the pressurization pressure, temperature and other conditions can be adjusted according to the degree of plastic deformation of the second solid electrolyte and the residual voids in the granulation body.

[0124] Examples of battery manufacturing methods include overlapping and pressurizing a negative electrode layer with a separately manufactured positive electrode layer and a solid electrolyte layer to bond them together, or pressing them separately and then overlapping them.

[0125] Furthermore, this invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and any technology having a structure that is substantially the same as the technical concept described in the claims of this invention and performing the same effect is included within the technical scope of this invention.

[0126] Symbol Explanation

[0127] 10 - Negative electrode layer, 20 - Electrolyte layer, 30 - Positive electrode layer, 100 - Battery.

Claims

1. A battery that uses the dissolution and precipitation of lithium metal as a negative electrode reaction, characterized in that, The battery comprises a negative electrode layer, an electrolyte layer, and a positive electrode layer. The negative electrode layer has a composite solid electrolyte. The composite solid electrolyte is a mixture of a first solid electrolyte and a second solid electrolyte. The first solid electrolyte is an oxide solid electrolyte. The second solid electrolyte is a solid electrolyte that undergoes plastic deformation under lower stress than the first solid electrolyte. The composite solid electrolyte is composed of porous secondary particles. During the charging of the battery, lithium metal is deposited in the voids within the secondary particles.

2. The battery according to claim 1, characterized in that, The composite solid electrolyte comprises a granulator, which comprises at least one of the first solid electrolyte, a first electronically conductive material, and a first binder.

3. The battery according to claim 2, characterized in that, The mixture comprises at least one of the granules, the second solid electrolyte, the second electronically conductive material, and the second binder.

4. The battery according to claim 1, characterized in that, The second solid electrolyte is a sulfide solid electrolyte.

5. A method for manufacturing a battery, which is the method for manufacturing the battery according to claim 1, characterized in that, The mixture is prepared, and the negative electrode layer is shaped into a sheet by pressurizing the mixture.

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