Lithium ion battery positive electrode lithium iron pyrophosphate preparation method

Abstract

The present invention relates to a lithium ion battery positive electrode lithium iron pyrophosphate preparation method, which comprises: 1, mixing a lithium source-containing compound, an iron source-containing compound and a phosphorus source-containing compound, adding a solvent to form a transparent solution containing the lithium compound, the phosphorus compound and the iron compound, placing the transparent solution into an evaporator, and carrying out pressure reducing evaporation to obtain a small volume transparent gel; and 2, carrying out pre-decomposition and high temperature sintering on the small volume transparent gel, and naturally cooling so as to complete the lithium ion battery positive electrode lithium iron pyrophosphate preparation process. According to the present invention, the material synthesized through the wet sol-gel is sequentially subjected to pressure reducing evaporation, pre-decomposition and sintering so as to achieve the uniform molecular level of the raw material mixing, the material synthesis uniformity is good, the particle size is small, the rate performance is good, and the initial charge-discharge efficiency and the discharge capacity are high; and the inexpensive lithium source, the inexpensive iron source, the inexpensive phosphorus source and the doped elements are used so as to achieve the cheap material price, and the materials are easy to store.

Description

technical field [0001] The invention belongs to the technical field of cathode materials for lithium ion batteries, and in particular relates to a preparation method of lithium iron phosphate, an anode material for lithium ion batteries. Background technique [0002] Lithium-ion battery is a device that converts chemical energy into electrical energy through chemical reactions. It is one of the important ways of energy storage and conversion. It has been widely used in almost every field. It is the best way to alleviate the current energy crisis and reduce environmental pollution. important product. Among the secondary batteries, lithium-ion batteries have quickly become the rechargeable source of today's portable electronic products due to their advantages such as high working voltage, long cycle life, large capacity, small size, small self-discharge, no memory effect, and less environmental pollution. preferred. For lithium-ion batteries, the cathode material has a decis...

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Problems solved by technology

But its shortcoming is: this invention utilizes three raw materials to be mixed in solid state and then sintered. This method has the inherent disadvantages of solid-phase method, that is, raw material mixing is not uniform, and batch consistency is poor. In addition, due to solid-phase method The limitations of the grinding equipment make it impossible to further reduce the particle size of the material to a certain extent, which makes the performance of the positive electrode material with poor conductivity even less ideal.

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