Cathode material of lithium-ion secondary battery and method for preparing same

Abstract

The invention provides a cathode material of a lithium-ion secondary battery and a method for preparing the same. The cathode material is a lithium nickel cobalt oxide material doped with a boron element. The preparation method comprises the following steps of: firstly, mixing compounds containing nickel, cobalt and lithium or a mixture consisting of various compounds and compounds containing boron or a mixture consisting of various compounds containing the boron according to a ratio; secondly, pretreating the mixture at a temperature of between 300 and 600 DEG C in an air atmosphere for 1 to 10 hours; thirdly, performing high-temperature synthesis on the mixture at a temperature of between 700 and 850 DEG C in an oxygen atmosphere for 3 to 15 hours; and finally, cooling the mixture to the room temperature, and then grinding and screening the mixture to obtain the lithium nickel cobalt oxide material doped with the boron element. The cathode material has the advantages of high specific capacity, good circulation property and good safety; the cathode material has the advantages of good crystallization property, uniform surface coating, narrow grain distribution and large packing density, so that the battery possesses good electrochemical property; and the preparation method has the advantages of simple production process, fewer steps, low energy consumption, no pollution, zero emission and the suitability for industrialized production.

Description

technical field [0001] The invention relates to the technical field of lithium ion secondary batteries, in particular to a positive electrode material for lithium ion secondary batteries with high cycle performance and a preparation method thereof. Background technique [0002] Since 1991, the lithium-ion battery made by SONY company with lithium cobalt oxide as the positive electrode was put on the market, because of its advantages such as high output voltage, high energy density, long cycle life and no memory effect, lithium-ion two Secondary batteries play an increasingly important role in people's daily life, and are widely used in mobile communications, notebook computers, electric vehicles, aerospace, biomedicine and other fields. With the advancement of science and technology, new positive electrode materials are constantly being introduced. The current commercialized lithium ion secondary battery positive electrode materials are mainly layered lithium cobaltate, laye...

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Problems solved by technology

[0004] Chinese Patent Application No. 03124282.0 has announced "Low-temperature Combustion Synthesis Method of Doped Lithium Nickel Oxide". Although the synthesis method has simple equipment, convenient operation and high specific capacity of the synthesized material, it utilizes nitrates and organic dyes. A large amount of NO will be produced in the process 2 and CO 2 Exhaust gas, pollutes the environment, and violates the sustainable development strategy

Although the material synthesized by this process has uniform particle size and high specific capacity, there is also NO in the synthesis process. 2 Exhaust gas emission, pollutes the environment, and at the same time, there are many heat treatment steps in the material synthesis process, which increases energy consumption

Patent application number 200510019552.8 published "doped and surface-coated lithium nickel cobalt oxide and its preparation method", using traditional solid-state reaction to synthesize doped and surface-coated lithium nickel cobalt oxide cathode material, although the process is simple, but traditional The defects of the solid-state reaction, such as the uniformity of material crystallization, particle shape and particle size distribution, are difficult to control accurately, and three times of heating and heat preservation are required, which increases the production cost

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