Method for improving coulombic efficiency and cycling stability of lithium-rich positive electrode material

Abstract

The invention belongs to the technical field of preparation of positive electrode materials, and particularly relates to a method for improving the coulombic efficiency and cycling stability of a lithium-rich positive electrode material, and the surface of the lithium-rich positive electrode material is coated with a lithium-intercalated organic compound by adopting any one of a dry-method mixing mode and a wet-method mixing mode; and the mass of the lithium-intercalated organic group compound is 0.2-10% of the mass of the lithium-rich positive electrode material. The method is simple and convenient to operate, the raw materials are low in price, the manufacturing cost is low, industrial production is facilitated, the first coulombic efficiency, the capacity and the cycling stability of the lithium-rich positive electrode material can be effectively improved by utilizing the method, and meanwhile, other side effects cannot be introduced.

Description

technical field [0001] The invention belongs to the technical field of positive electrode material preparation, and in particular relates to a method for improving the coulombic efficiency and cycle stability of lithium-rich positive electrode materials. Background technique [0002] The rapid development of mobile electrical equipment such as consumer electronics, electric vehicles, and power tools has posed severe challenges to the energy density of lithium-ion batteries. In lithium-ion batteries, the positive electrode material, as the provider of Li+ in the charge and discharge process, has lower reversible capacity and poor cycle stability than negative electrodes such as graphite and silicon carbon, so it affects key indicators such as energy density and service life of the battery. play a decisive role. Compared with the specific capacity of 200mAh / g of high-nickel cathode material, the specific capacity of lithium-rich manganese-based cathode material reaches 300mAh...

AI Technical Summary

Problems solved by technology

However, the existing methods mainly work on the surface and structural stability of the material, and they have an effect on the problem of low initial coulombic efficiency caused by the inability of the lithium ions released during the charging process to fully insert back into the lattice during the discharge process of the lithium-rich manganese-based material very small

At the same time, the introduction of the existing conventional coating and doping methods will inevitably bring about some side effects while improving the cycle stability of the material, resulting in a decline in performance such as capacity and rate.

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