Sodium-ion battery positive electrode material precursor and preparation method thereof

Abstract

A sodium ion battery positive electrode material precursor has a chemical formula of NixMnyMz (OH) 2, 0.4 < = x < 0.6, 0.2 < = y < 0.5, and 0.1 < z < = 0.3. The preparation method comprises the following steps: 1, preparing a mixed solution of Ni, Mn and M salts; preparing a sodium hydroxide or potassium hydroxide solution as a precipitator; preparing an ammonia water solution as a complexing agent; 2, adding pure water, a precipitator and a complexing agent into the kettle to prepare a base solution; 3, introducing mixed gas of air and nitrogen according to the volume ratio of (3-5): 1, and adding the mixed solution, a precipitator and a complexing agent into a kettle for coprecipitation; overflowing to a concentration machine, and controlling the solid content in the kettle until the material reaches the target particle size requirement; and 4, carrying out filter pressing, washing and drying on the product to obtain the sodium ion battery positive electrode material precursor. The material structure phase change reversibility of the layered sodium ion transition metal oxide in the charging and discharging process can be improved, the sodium ion transmission efficiency is high, meanwhile, polarization is relieved, and the commercialized application requirement can be met.

Description

technical field [0001] The invention relates to the technical field of positive electrode materials for sodium ion batteries, in particular to a precursor of positive electrode materials for sodium ion batteries and a preparation method. Background technique [0002] The development of new energy vehicles has driven people's demand for lithium resources, and the price has also risen, which has greatly increased the cost of new energy vehicles. Compared with the shortage of lithium resources, the reserves of sodium on the earth are extremely abundant and cheap. Therefore, sodium-ion batteries have gradually entered the public's field of vision, and are expected to replace lithium-ion batteries in some fields. [0003] Among the many cathode materials for Na-ion batteries, layered Na-ion transition metal oxides have received extensive attention due to their high volumetric energy density, simple preparation, and relatively low price. However, the layered Na-ion transition me...

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Problems solved by technology

However, layered sodium ion transition metal oxides have poor reversibility of material structure phase transition during charge and discharge, insufficient electrode / electrolyte interface contact leads to slow diffusion of sodium ions, and large sodium ion radius reduces the speed of deintercalation, resulting in extreme Problems such as the phenomenon of globalization have hindered its commercial application

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