Double-layer coated cathode material LiNi0.6Co0.2Mn0.2O2 for lithium-ion battery and preparation method of double-layer coated cathode material

Abstract

The invention belongs to the technical field of preparation of cathode materials for lithium-ion batteries and specifically provides a double-layer coated cathode material LiNi0.6Co0.2Mn0.2O2 for a lithium-ion battery, wherein the coating amounts of Li3VO4 and PPy are 1 to 5 weight percent; Li3VO4 is a lithium fast ion conductor; by coating Li3VO 4, a protective layer can be provided and the lithium fast ion conductor also can be provided, so that ionic conductivity of the material is enhanced; in addition, lithium ions consumed during the formation of SEI and CEI films are made up and the cycle performance of the material is improved. The PPy is a fast electronic conductive material; by coating PPy, a second protective layer can be provided and the electronic conductivity of the materialcan be improved. Through double-layer coating of Li3VO4 and the PPy, the ionic conductivity is improved and the electrical conductivity is also improved; the cathode material is enabled to have super-high magnification discharge performance and higher discharge specific capacity; besides, double coating layers can more effectively inhibit the erosion effect of HF on the cathode material and enablethe cathode material to have excellent high voltage cycle stability.

Description

technical field [0001] The invention belongs to the technical field of preparation of positive electrode materials for lithium ion batteries, in particular to a positive electrode material for lithium ion batteries and a preparation method thereof. The positive electrode material has the following chemical formula LiNi 0.6 Co 0.2 Mn 0.2 O 2 @Li 3 VO 4 @PPy, which encapsulates Li 3 VO 4 The masses of @PPy are respectively the parent material LiNi 0.6 Co 0.2 Mn 0.2 O 2 1 to 5wt% (mass ratio). Background technique [0002] With the shortage of traditional fossil energy and the increasing problems of environmental pollution and climate warming, environmentally friendly new energy technologies have also become one of the hot spots for development and application. Among them, lithium-ion batteries have high energy density due to their high energy density. , small self-discharge, excellent cycle performance and no memory effect have become a crucial part of the power bat...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to aim at lithium-ion battery cathode material layered high nickel nickel cobalt lithium manganese oxide LiNi 0.6 co 0.2 mn 0.2 o 2 The shortcoming of poor cycle performance at high voltage provides a double-coated modified lithium-ion battery cathode material LiNi 0.6 co 0.2 mn 0.2 o 2 @Li 3 VO 4 @PPy, where, Li 3 VO 4 The coating amount with PPy is 3wt%; Li 3 VO 4 Is a lithium fast ion conductor, coated with Li 3 VO 4 It can not only provide a protective layer, but also provide lithium fast ion conductors, enhance the ionic conductivity of materials, and make up for the lithium ions consumed during the formation of SEI and CEI films; PPy is a fast electronic conductive material, and coating PPy can not only provide the first The second protective layer can improve the electronic conductivity of the material and improve the high rate discharge performance of the material

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