Method for preparing lithium-rich composite cathode material, cathode and battery

Abstract

The invention discloses a method for preparing a lithium-rich composite cathode material, a cathode and a battery. Specifically, the invention provides a method for preparing a lithium-rich compositecathode material, comprising steps of: adding a coating layer material to water and stirring the water to form a first mixture; adding a lithium-rich material to the first mixture, stirring the obtained mixture for reaction so as to form a second mixture; filtering, drying, and first calcining the second mixture to obtain a lithium-rich material having a surface coated with the cladding layer material to obtain the lithium-rich composite cathode material, wherein the coating layer material is soluble in water and contains lithium ions and fluoride ions. Therefore, by using the method, the surface of the lithium-rich material can be easily coated with the coating layer material containing lithium ions and fluoride ions. The lithium-rich composite cathode material, when used as an electrode,can reduce the side reaction of the cathode and the electrolyte, is stable in electrode structure, and has a high discharge specific capacity, good rate performance and good cycle performance.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a method for preparing a lithium-rich composite positive electrode material, a positive electrode, and a battery. Background technique [0002] At present, lithium-ion batteries are widely used in cameras, mobile phones, notebook computers, electric vehicles and other equipment due to their advantages such as stable voltage, high capacity, high energy density, long cycle life, and environmental friendliness. The cathode material of lithium-ion batteries is the key factor determining its performance. Among them, lithium-rich materials are a new high-capacity cathode material in recent years. They have a solid solution structure and have a high charge-discharge specific capacity. There is a large irreversible capacity loss during the charge and discharge process, and there is voltage decay during the cycle, and the rate performance and cycle performance are poor. These problems h...

AI Technical Summary

Problems solved by technology

The cathode material of lithium-ion batteries is the key factor determining its performance. Among them, lithium-rich materials are a new high-capacity cathode material in recent years. They have a solid solution structure and have a high charge-discharge specific capacity. There is a large irreversible capacity loss during the charge and discharge process, and there is voltage decay during the cycle, and the rate performance and cycle performance are poor. These problems hinder the large-scale application of lithium-rich materials.

[0003] Therefore, the current method of preparing lithium-rich composite cathode materials, cathodes, and batteries still need to be improved.

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