CN-121983544-A - Composite positive electrode material for all-solid-state battery, preparation method and all-solid-state battery

Abstract

The invention discloses a composite positive electrode material for an all-solid-state battery, a preparation method and the all-solid-state battery, which belong to the technical field of all-solid-state batteries and are composed of positive active material particles and solid electrolyte filled in the internal pore structures of the active material particles, wherein the solid electrolyte forms an ion conduction path in the active material particles. When in preparation, the precursor of the living substance is firstly mixed with the die plate material which can be sintered, decomposed and disappeared, and then the porous living substance is formed by heat treatment, and then the solid electrolyte is filled in the porous living substance. The all-solid-state battery adopting the anode material can remarkably improve the diffusion speed of ions in active material particles, has the characteristics of high output power, large capacity and long cycle life, and can meet the use requirements of electric vehicles, unmanned aerial vehicles and the like on the occasions with severe requirements on battery performance.

Inventors

• WANG HUAPING
• ZHANG MINGJU

Assignees

• 广东栖川能源科技有限公司

Dates

Publication Date

20260505

Application Date

20260129

Claims (8)

1. 1. A composite positive electrode material for an all-solid-state battery, comprising positive electrode active material particles and a solid electrolyte filled in a pore structure formed inside the active material particles, wherein the solid electrolyte forms an ion conduction path inside the active material particles.
2. 2. The composite positive electrode material for all-solid-state batteries according to claim 1, wherein said positive electrode active material particles are nickel-rich layered oxides.
3. 3. The composite positive electrode material for an all-solid battery according to claim 1, wherein the solid electrolyte is Argyrodite solid electrolyte.
4. 4. The composite positive electrode material for all-solid battery according to claim 1, wherein the porous structure formed by the pore structure inside the living material particles has a specific surface area higher than that of the positive electrode living material of the same composition without the porous structure.
5. 5. A method for producing the composite positive electrode material for all-solid battery according to any one of claims 1 to 3, characterized by comprising the steps of: 1) Mixing a precursor of positive active material particles with a template material which can be decomposed and disappeared by sintering; 2) Carrying out heat treatment at 700-900 ℃ on the mixture of the precursor and the template material to decompose and disappear the template material and form a porous structure in the positive active material; 3) The positive electrode active material having a porous structure is filled with a solid electrolyte.
6. 6. The method according to claim 5, wherein the template material in step 1) is any one of carbon nanotubes and mesoporous silica.
7. 7. The method for producing a composite positive electrode material for an all-solid battery according to claim 6, wherein the mixing ratio of the template material to the positive electrode active material precursor is 1 to 5% by weight.
8. 8. An all-solid battery characterized in that the composite positive electrode material according to any one of claims 1 to 3 is used as a positive electrode.

Description

Composite positive electrode material for all-solid-state battery, preparation method and all-solid-state battery Technical Field The invention relates to the technical field of all-solid-state batteries, in particular to a composite positive electrode material for an all-solid-state battery, a preparation method and the all-solid-state battery. Background The all-solid-state battery has wide application prospect in the field of new energy by virtue of the advantages of high safety, high energy density and the like, and the positive electrode material is a key part influencing the performance of the all-solid-state battery. The conventional positive electrode active material for all-solid-state batteries is composed of active material particles mixed with solid electrolyte particles. The diffusion rate of lithium ions inside the positive electrode active material is generally slower than the ion migration (interface resistance) between particles depending on the crystal structure of the active material itself. The slow diffusion problem becomes a main factor limiting the output characteristic and capacity performance of the all-solid-state battery, and is difficult to meet the use requirements of high power and large capacity of the battery in the scenes of electric automobiles, unmanned aerial vehicles and the like. Disclosure of Invention The invention aims to provide a preparation method of a positive electrode material and an all-solid-state battery, which radically improve the internal structure of a positive electrode active material, and obviously improve the ion diffusion speed in active material particles, so as to obtain the all-solid-state battery with high output power and high capacity characteristics, and expand the application field of the all-solid-state battery, wherein the content of the invention is as follows: a first object of the present invention is to provide a composite positive electrode material for an all-solid-state battery, which is characterized by comprising positive electrode active material particles and a solid electrolyte filled in a pore structure formed inside the active material particles, wherein the solid electrolyte forms an ion conduction path inside the active material particles. A second object of the present invention is to provide a method for producing a composite positive electrode material for an all-solid battery according to claim 1, comprising the steps of: 1) Mixing a precursor of the positive active material with a template material which can be decomposed and disappeared by sintering; 2) Carrying out heat treatment at 700-900 ℃ on the mixture of the precursor and the template material to decompose and disappear the template material and form a porous structure in the positive active material; The positive electrode active material having a porous structure is filled with a solid electrolyte. A third object of the present invention is to provide an all-solid-state battery, wherein the above composite positive electrode material is used as a positive electrode. Compared with the prior art, the invention can achieve the following beneficial effects: 1. The traditional positive electrode material only fully utilizes the surface area of the active material particles, and the porous structure is built in the active material particles and is filled with solid electrolyte to form an ion high-speed conduction path, so that ions can smoothly reach the inside of the active material, and the whole capacity of the active material is released to the maximum extent. 2. The composite structure can relieve the stress born by active material particles in the charge and discharge process, enhance the structural stability and effectively inhibit the performance attenuation in long-term charge and discharge cycle. Drawings Fig. 1 is a schematic diagram of Li 6P5S1Cl1 particles filling into micropores of porous NCM 811. Detailed Description 1. The composite positive electrode material is structurally designed, and the composite positive electrode material is composed of positive active material particles and solid electrolyte, wherein the solid electrolyte is filled in a pore structure formed in the active material particles, and an ion conduction path is formed in the active material particles. The structure can enable lithium ions to diffuse in living matter particles through two paths simultaneously, namely a diffusion path along the crystal structure of the traditional active matter and a high-speed conduction path penetrating through solid electrolyte inside the living matter, so that ion diffusion efficiency is greatly improved. 2. Preparation of composite positive electrode material The porous active material is prepared by selecting a precursor of a positive active material (such as a nickel-rich layered oxide precursor) and a template material (preferably carbon nano tubes), mixing the template material and the precursor according to the weight ratio of 1% -5%, and