Preparation method of rubdium- and cesium-doped lithium-rich ternary cathode material for lithium-ion battery

Abstract

The invention discloses a preparation method of a rubdium- and cesium-doped lithium-rich ternary cathode material for a lithium-ion battery. The method comprises the following steps: (1) preparing a precursor solution A; (2) preparing a precipitant solution B; (3) preparing a pH value adjusting solution C; (4) simultaneously adding the precursor solution A, the precipitant solution B and the pH value adjusting solution C to water respectively, forming a nickel-manganese-cobalt ternary sediment, and washing, drying, crushing and sieving the sediment; and (5) mixing a lithium salt and a rubdium salt or a cesium salt or a rubdium-cesium mixed salt at the stoichiometric ratio, carrying out ball-milling, drying and sieving in an ethanol medium, carrying out calcination in air, and crushing and sieving the product to obtain a corresponding lithium-rich manganese-based material Li<1.13-x-y>Rb<x>Cs<y>Ni<0.2>Co<0.2>Mn<0.47>O<2>, in which x+y is smaller than or equal to 1.0 and greater than or equal to 0.01. The preparation method achieves equivalent cation doping in a lithium-rich ternary material structure; the lithium-rich ternary cathode material has relatively good ion and electron conductivity, rate capability and cycle lifetime, and is beneficial to improvement of the energy density of the battery; and the synthetic method disclosed by the invention is friendly to environment, simple, feasible, high in yield, good in controllability and suitable for mass production.

Description

technical field [0001] The invention relates to a method for preparing a rubidium-cesium-doped positive electrode material for a lithium-ion battery, in particular to a method for preparing a lithium-rich ternary positive-electrode material for a rubidium-cesium-doped lithium-ion battery. Background technique [0002] At present, the actual specific energy of lithium iron phosphate battery, which is widely used as the positive electrode material of power battery, is only about 130Wh / kg, which cannot meet the energy density requirements of future electric vehicles, while lithium-rich manganese-based positive electrode materials have higher energy density, and The discharge specific capacity is twice as high as the current positive electrode material, which has attracted widespread attention. Lithium-rich manganese-based materials are expected to replace lithium iron phosphate, which is currently gaining popularity in the market, and become the mainstream development direction ...

AI Technical Summary

Problems solved by technology

[0003] Although the lithium-rich cathode material xLi2MnO3 (1-x)LiMO2 has a high charge-discharge capacity, there are still some problems, such as high initial irreversible capacity, poor rate performance, poor cycle performance, etc.

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