LiNi0.6-xCo0.2Mn0.2AlxO2-yFy positive electrode material for lithium ion cell and preparation method thereof

Abstract

The invention belongs to the field of lithium ion cell and specifically relates to a LiNi0.6-xCo0.2Mn0.2AlxO2-yFy positive electrode material for the lithium ion cell and a preparation method thereof. X is more than 0 and y is less than or equal to 0.05. The positive electrode material is used for overcoming the defect of poor electrochemical performance of the Ni-Co lithium manganate ternary positive electrode material. According to the invention, a minute quantity of aluminum and fluorine are doped, so that the positive electrode material for the lithium ion cell has higher specific discharge capacity and excellent cycle performance; under a room temperature environment, when the voltage scope is 2.7-4.3V and the constant current charge-discharge multiplying power is 0.5C, the specific discharge capacity of the material at the first time can reach 187.9mAh g<-1>, and after circulation for 20 times, the specific discharge capacity still can reach 192.1mAh g1 and the capacity retention ratio reaches up to 102.2%; when the voltage scope is increased to 2.7-4.5V and the constant current charge-discharge multiplying power is 0.5C, the initial specific discharge capacity of the material can reach 225.8mAh g<-1>, and after circulation for 20 times, the specific discharge capacity still can reach 190.2mAh g<-1> and the capacity retention ratio reaches up to 84.2%. The preparation technique of the material is simple and controllable, the product purity is high, the chemical uniformity is high, the crystal quality is high, the product grain is small and the size distribution is uniform.

Description

technical field [0001] The invention belongs to the field of lithium-ion batteries, and relates to a lithium-ion battery positive electrode material and a preparation method thereof, specifically LiNi, a lithium-ion battery positive electrode material 0.6-x co 0.2 mn 0.2 Al x o 2-y f y and a preparation method thereof, wherein 0<x, y≤0.05. Background technique [0002] Lithium-ion batteries have the advantages of high potential, high energy density, no memory effect, etc., which have been widely used in portable electronic devices; the first positive electrode used in commercial lithium-ion batteries is LiCoO 2 , but Co is scarce in natural resources, expensive, and pollutes the environment, and LiCoO 2 The actual specific capacity is low, and overcharging will lead to irreversible capacity loss and increase in polarization voltage. Therefore, with the deepening of the research on cathode materials with low price and excellent performance, people have found that th...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to aim at lithium-ion battery cathode material layered nickel cobalt lithium manganese oxide (LiNi 0.6 mn 0.2 co 0.2 o 2 ) the shortcomings of poor electrochemical performance, providing a bulk composite co-doped modified lithium-ion battery cathode material LiNi 0.6-x co 0.2 mn 0.2 Al x o 2-y f y and its preparation method, wherein 0

Images