JP-7855389-B2 - Manufacturing method for positive electrode material

JP7855389B2JP 7855389 B2JP7855389 B2JP 7855389B2JP-7855389-B2

Inventors

木下結以
青木誠志
田中真実
小山莉央

Assignees

本田技研工業株式会社

Dates

Publication Date: 20260508
Application Date: 20220331

Claims (7)

A method for manufacturing a positive electrode material for a solid-state battery, A first compounding step involves mixing a positive electrode active material and a solid electrolyte to produce a first powder, The process includes a second compounding step in which the solid electrolyte is mixed with the first powder under different stirring conditions than those of the first compounding step to produce a second powder, The second compounding step is performed at a slower stirring speed than the first compounding step. A method for manufacturing a cathode material , wherein the second compounding step involves a shorter stirring time than the first compounding step .
A method for manufacturing a positive electrode material for a solid-state battery, A first compounding step involves mixing a positive electrode active material and a solid electrolyte to produce a first powder, The process includes a second compounding step in which the solid electrolyte is mixed with the first powder under different stirring conditions than those of the first compounding step to produce a second powder, The second composite step involves a smaller shear force than the first composite step. A method for manufacturing a cathode material , wherein the second compounding step involves a shorter stirring time than the first compounding step .
A method for manufacturing a positive electrode material according to claim 1 or 2 , A method for manufacturing a positive electrode material, wherein the positive electrode active material is coated with a solid electrolyte different from the solid electrolyte.
A method for manufacturing a positive electrode material according to claim 3 , The solid electrolyte is a sulfide-based solid electrolyte. The method for manufacturing a cathode material, wherein the other solid electrolyte is an oxide-based solid electrolyte.
A method for manufacturing a positive electrode material according to any one of claims 1 to 4 , A method for producing a positive electrode material, further comprising a slurry generation step of mixing the second powder with an auxiliary dispersion medium containing a conductive additive.
A method for manufacturing a positive electrode material according to any one of claims 1 to 5, The stirring speed in the first compounding step is a peripheral speed of 60 m/s to 100 m/s. A method for manufacturing positive electrode material.
A method for manufacturing a positive electrode material according to any one of claims 1 to 6, The stirring time in the first compounding step is 50 to 70 minutes. A method for manufacturing positive electrode material.

Description

This invention relates to a method for manufacturing a positive electrode material. In recent years, research and development has been conducted on rechargeable batteries that contribute to energy efficiency, aiming to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. Lithium-ion rechargeable batteries are widely used as secondary batteries. Lithium-ion rechargeable batteries, which use a liquid electrolyte, have a structure in which a separator is present between the positive and negative electrodes, and the battery is filled with a liquid electrolyte (electrolyte solution). The electrolyte in lithium-ion secondary batteries is typically a flammable organic solvent, which has sometimes raised safety concerns, particularly regarding heat. Therefore, solid-state batteries using flame-retardant solid electrolytes instead of organic liquid electrolytes have also been proposed. Solid-state rechargeable batteries have an electrolyte layer between the positive and negative electrodes, consisting of an inorganic solid electrolyte, an organic solid electrolyte, or a gel-like solid electrolyte. Compared to batteries using liquid electrolytes, solid-state batteries with solid electrolytes eliminate thermal problems, enable higher capacity and/or higher voltage, and can also meet the demand for compact designs. Various methods for manufacturing the positive electrode material of lithium-ion secondary batteries have been proposed (for example, Patent Documents 1 to 4). For instance, Patent Document 1 describes a method of creating secondary particles by mixing a sulfide-based solid electrolyte with positive electrode active material particles coated with an oxide-based solid electrolyte. Generally, the positive electrode of a secondary battery is made by mixing a positive electrode active material, a solid electrolyte, and a dispersion medium containing a binder to form a slurry, which is then applied to a current collector and dried. International Publication No. 2020/174868Japanese Patent Publication No. 2011-65887Japanese Patent Publication No. 2016-42417International Publication No. 2012/001808 This is a cross-sectional view of the solid-state battery 1.This is a schematic flowchart illustrating the manufacturing method of the positive electrode material.This table shows the experimental results for the example and comparative examples 1 and 2.This is a schematic diagram showing the state of particles dispersed in a slurry. First, we will describe a solid-state battery that uses a positive electrode material manufactured by the manufacturing method of the present invention. [Solid battery] As shown in Figure 1, the solid-state battery 1 comprises a battery body 10, a negative electrode current collector 50, and a positive electrode current collector 60. In this specification, a solid-state battery refers to a battery that is entirely solid. The negative electrode current collector 50 and the positive electrode current collector 60 are conductive plate-shaped members that sandwich the battery body 10 from both sides. The negative electrode current collector 50 has the function of collecting current from the negative electrode layer 30, and the positive electrode current collector 60 has the function of collecting current from the positive electrode layer 20. The battery body 10 comprises a positive electrode layer 20 that functions as a positive electrode, a negative electrode layer 30 that functions as a negative electrode, and a conductive solid electrolyte layer 40 located between the positive electrode layer 20 and the negative electrode layer 30. The positive electrode layer 20 is manufactured by applying a slurry containing a positive electrode active material, a conductive additive, and a solid electrolyte to the positive electrode current collector 60 and drying it. [Manufacturing method for positive electrode material] Hereinafter, one embodiment of the method for manufacturing the positive electrode material of the present invention will be described with reference to Figure 2. The method for manufacturing the positive electrode material includes the following steps. 1. A first compounding step in which a positive electrode active material PAM and a solid electrolyte SE are mixed to produce a first powder 21. 2. A second compounding step in which the solid electrolyte SE is mixed with the first powder 21 under different stirring conditions than those of the first compounding step to produce a second powder 22. 3. A slurry generation step in which the second powder 22 is mixed with a dispersion medium containing a conductive additive CA, a solvent, and a binder. 4. A slurry application step in which the slurry is applied onto a current collector. The manufacturing method of the cathode material in this embodiment differs from conventional manufacturing methods, which involved secondary particle formation (compounding) by mixing a sulfide-based solid electrolyte w