Method for preparing cathode material of lithium-ion battery, namely lithium vanadium fluorophosphates

Abstract

The invention belongs to the technical field of lithium-ion batteries and relates to a method for preparing the cathode material of the lithium-ion battery, namely lithium vanadium fluorophosphates through mechanical activated auxiliary solid phase sintering. The preparation method comprises the following steps: weighing a hypervalent vanadium source compound, a phosphorus source compound and a reducing agent according to a certain stoichiometric ratio, putting in a high-energy ball mill container for mechanical activation treatment, and then carrying out calcining treatment in a non-oxidizing atmosphere to obtain a precursor; after ball-milling and uniformly mixing the precursor with a lithium source compound and fluoride, and putting in the non-oxidizing atmosphere for heating to 600-800 DEG C; after keeping the temperature for 0.2-5hours, rapidly cooling to the room temperature to obtain lithium vanadium fluorophosphates. The method has the advantages of simple process, easiness in control and low cost. The synthetized lithium vanadium fluorophosphates material has high purity, particles are similar to spherical and are uniform, and the synthetized lithium vanadium fluorophosphates material has a good electrochemical performance. The lithium-ion battery is charged and discharged in the range of voltage of 3.0-4.6V, the discharge specific capacity for the first time can achieve 146.2mAh / g under 0.1 C rate, and the cycling performance is good.

Description

technical field [0001] The invention relates to a method for preparing lithium vanadium phosphate, a cathode material of a lithium ion battery, in particular to a method for preparing lithium vanadium phosphate with excellent performance by adopting a mechanical activation-assisted solid-phase method. Background technique [0002] In recent years, due to the relatively high energy density and long cycle life of lithium-ion secondary batteries, they are widely used in various portable electronic products and communication equipment, and they also have great application prospects in electric vehicles and energy storage equipment. . The performance of lithium-ion batteries depends largely on the cathode material. Among the positive electrode materials of commercial lithium-ion batteries, the positive electrode materials containing rare metal elements such as cobalt and nickel are the main ones. Not only the cost is high, but also the resources of cobalt and nickel in my countr...

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Problems solved by technology

[0004] The object of the present invention is to provide a kind of preparation lithium ion battery cathode material LiVPO by mechanical activation 4 The method of F overcomes the problem that the one-time solid-phase method is easy to produce impurities, and has the advantages of simple operation and easy industrialization, and the synthesized material has fine particles and uniform particle size distribution, which improves the lithium ion diffusion rate and electrical conductivity, thereby improving Electrochemical properties

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