Preparation method of manganese-based compound positive pole material for secondary lithium ion battery

Abstract

The invention provides a preparation method of a manganese-based compound positive pole material for a secondary lithium ion battery. The general constitution formula of the positive pole material is Li (LixMn2-x-yMy) O4 / Az, wherein x is more than or equal to 0 and less than or equal to 0.5, y is more than or equal to 0 and less than or equal to 2, and z is more than or equal to 0 and less than or equal to 0.5; and M is a doped modified element, and A is an oxide of a coating element or a phthalocyanines large-ring transition metal complex. When the positive pole material is prepared, a lithium source and an M source are added into mixing equipment containing a medium and a dispersing agent to be mixed and dried; then the mixture and a manganese source are added into the mixing equipment containing the medium and the dispersing agent to be mixed and dried; then the new mixture is roasted and then is cooled to a room temperature; and the new mixture and an A source are added into the mixing equipment containing the medium and the dispersing agent to be mixed and dried, are roasted again, are cooled to the room temperature and are mixed and crushed to obtain the manganese-based compound positive pole material. The preparation method disclosed by the invention has the advantages of simple process, low raw material cost and processing cost, simple process route, short period and low energy consumption. The produced manganese-based compound positive pole material has the advantages of high energy density, mass specific capacity, power performance, high-temperature circulating performance and high-temperature storage performance; and the capacity efficiency of the material is high at -40 DEG C.

Description

technical field [0001] The invention relates to a method for preparing a positive electrode material for a secondary lithium ion battery, in particular to a method for preparing a manganese-based composite positive electrode material for a secondary lithium ion battery. Background technique [0002] Traditional secondary batteries mainly include lead-acid batteries, cadmium-nickel batteries, nickel-metal hydride batteries, etc., which cannot meet the market demand well due to problems such as low energy density and environmental pollution. According to the needs of social development, its application scope will become wider and wider. With the continuous expansion of the application field of lithium-ion batteries, countries all over the world, especially the governments of developed countries, and group companies are investing heavily in technology research and development and market applications. Lithium-ion battery applications range from mobile phones, notebook computers...

AI Technical Summary

Problems solved by technology

The open circuit voltage of the battery in the charging state is generally about 4V. Under this high voltage, the electrolyte itself will slowly decompose, and the positive electrode material in the charging state is a strong oxidant, which can catalyze and accelerate the oxidative decomposition of the electrolyte; In the charged state, due to the release of a large number of lithium ions, the structure of the material becomes unstable, and it is prone to oxygen decomposition, phase transition, and active material dissolution. The electrolyte not only corrodes the positive electrode material but also affects this change of the positive electrode material. Catalytic acceleration leads to increased self-discharge and irreversible capacity of the battery, which affects cycle performance and high temperature safety

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