Preparation method of double-layer composite low-cost lithium-rich manganese-based precursor

Abstract

The invention discloses a preparation method of a double-layer composite low-cost lithium-rich manganese-based precursor, and belongs to the technical field of lithium battery material preparation. The general formula of the lithium-rich manganese-based precursor is (NixMn (1-x)) OH2 (at) CO3, wherein x is more than or equal to 0.1 and less than or equal to 0.3. Preparing a nickel-manganese mixed solution and adding a complexing agent with a certain concentration; preparing a mixed alkali solution of sodium hydroxide and sodium carbonate; adding a buffer solution into the reaction kettle as a base solution; a first-stage reaction: adding the nickel-manganese mixed solution, ammonia water and a sodium hydroxide solution into a reaction kettle in a parallel flow manner, and carrying out a co-precipitation reaction; a second-stage reaction: after the particle size grows to 5 microns, replacing the sodium hydroxide solution with the mixed alkali solution prepared in the step (1), and closing the ammonia water; continuously reacting; controlling the temperature, stirring speed and feed liquid flow in the reaction process to be constant, and introducing nitrogen in the whole reaction process; according to the invention, the problems of uncontrollable pH and easy oxidation in the reaction process are solved, and the obtained lithium-rich manganese-based precursor has the advantages of high sphericity, high tap density and narrow particle size distribution.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery preparation, in particular to a preparation method of a double-layer composite low-cost lithium-rich manganese-based precursor. Background technique [0002] The development of high-performance, low-cost new electrode cathode materials has always been a hot research direction for lithium-ion batteries. Although as early as 1991 LiCoO 2 Cathode materials have been commercially used, but their reversible capacity is low and expensive; so researchers have focused on LiCoO 2 material substitutes. Among many layered cathode materials, lithium-rich manganese-based layered cathode materials have attracted widespread attention due to their high reversible specific capacity, high operating voltage, and excellent storage performance at room temperature. The key electrode material is regarded as the most promising cathode material. [0003] At present, the coprecipitation method is the most c...

AI Technical Summary

Problems solved by technology

The method provided by the invention solves the problem that the pH of the reaction process is uncontrollable and easy to oxidize. The obtained lithium-rich manganese-based precursor has high sphericity, high vibration, and narrow particle size distribution. The general formula is (Ni x mn （1-x） )OH 2 @CO 3 (0.1≤x≤0.3)

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