NCMA core-NCM shell cathode material, preparation method and purpose

Abstract

The invention provides a cathode material precursor which is of a core-shell structure. The material chemical formula of the core is Ni<1-x-y-z>Co<x>Al<y>Mn<z>(OH)2, and the material chemical formulaof the shell is Ni<1-r-s>Co<r>Mn<s>CO3, wherein 1-x-y-z is a value in the range of 0.80 to 0.96, x is greater than 0, y is a value in the range of 0.01 to 0.10, z is a value in the range of 0.01 to 0.10, 1-r-s is a value in the range of 0.34 to 0.70, r is greater than 0, and s is a value in the range of 0.20 to 0.40. The cathode material of the invention has a stable structure, high safety performance, long cycle life and good thermal stability.

Description

technical field [0001] The invention relates to the field of electrode materials, in particular to an NCMA core-NCM shell positive electrode material precursor, positive electrode material, preparation method and application. Background technique [0002] As a new type of green energy, lithium-ion batteries have the advantages of high specific energy, small self-discharge, high open circuit voltage, no memory effect, long cycle life, and no environmental pollution, so they are widely used in mobile phones, notebook computers, digital cameras, etc. At the same time, lithium-ion batteries are also power sources for electric vehicles and energy storage power sources for solar renewable energy. The positive electrode materials of ion batteries that we are familiar with mainly include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, ternary materials, and lithium iron phosphate, etc. However, due to the lack of cobalt resources and high toxicity, the productio...

AI Technical Summary

Problems solved by technology

The positive electrode materials of ion batteries that we are familiar with mainly include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, ternary materials, and lithium iron phosphate, etc. However, due to the lack of cobalt resources and high toxicity, the production cost of lithium cobalt oxide is high. However, its cycle performance is poor, which limits its industrial application; lithium manganese oxide has It has the advantages of rich resources, low cost, no pollution, good safety, and good rate performance, but its cycle performance and electrochemical stability are poor, which greatly limits its industrialization; the safety and cycle life of lithium iron phosphate materials are both It has obvious advantages, but the compaction density of the material itself is too low, resulting in low specific energy of the battery, which limits the room for improvement in the cruising range of the vehicle; the cost of ternary materials is low, equivalent to 1 / 4 of lithium cobalt oxide And it is more green and environmentally friendly. Compared with several other materials, the energy density of the battery has been improved, but its safety is not high enough at present.

Images