Nickel-rich concentration gradient type lithium nickel cobalt aluminum oxide positive pole material, preparation method thereof and lithium ion battery

Abstract

The invention provides a nickel-rich concentration gradient type lithium nickel cobalt aluminum oxide positive pole material, a preparation method thereof and a lithium ion battery. The nickel-rich concentration gradient type lithium nickel cobalt aluminum oxide positive pole material has a near-spherical appearance and a core-shell structure, wherein the content of Ni element in an inner layer is high, the content of Mn element in an outer layer is high, bulk molybdenum element doping is performed, and the surfaces of particles are coated with aluminum oxide. The reversible discharge capacity of the nickel-rich concentration gradient type lithium nickel cobalt aluminum oxide positive pole material provided by the invention under the current density of 350mA / g is more than 172mAh / g, and the capacity retention rate after 100 times of charge and discharge cycles at the rate of 2C is more than 85%. The lithium ion battery which takes nickel-rich concentration gradient type lithium nickel cobalt aluminum oxide as the positive pole material has the prominent advantages of high capacity, good thermal stability, good cycling stability, excellent rate property and the like, and has broad application prospects in the fields of electronic equipment, communication, transportation and the like.

Description

technical field [0001] The present invention relates to the technical field of lithium-ion batteries, in particular to lithium-ion battery positive electrode materials and lithium-ion battery preparation technology, in particular to a nickel-rich concentration gradient type nickel-cobalt lithium aluminate positive electrode material and the positive electrode material as a positive electrode active material. ion battery. Background technique [0002] Lithium-ion batteries have many advantages such as high voltage, high energy density, good cycle performance, and no memory effect. They are widely used in mobile power supplies, various portable electronic devices, high-end digital, electric vehicles and other fields. Correspondingly, people's requirements for lithium-ion battery cathode materials are getting higher and higher, but lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate and conventional nickel-cobalt-manganese ternary materials that have been matu...

AI Technical Summary

Problems solved by technology

The invention has gone through three high-temperature calcination processes, with the highest temperatures reaching 800°C, 950°C and 800°C respectively. Although the problem of cation mixing has been solved to a certain extent, the preparation process is relatively complicated, which increases the cost, especially for the final washing bag. The coating process cannot fundamentally solve the uniformity problem of coating