Method for preparing carbon-coated lithium iron phosphate anode material of lithium ion battery

Abstract

The invention relates to a method for preparing carbon-coated lithium iron phosphate anode material of a lithium ion battery, which is characterized by comprising the following steps of: putting a plurality of compounds including three elements of lithium, ferrum and phosphor and citric acid complexing agent in water to form sol; adding ethylene glycol combustion-supporting agent and ammonium nitrate oxidizing agent for dissolution; heating and boiling down to obtain gel; igniting the gel in air; wet-milling and mixing an intermediate obtained by combustion and a carbon source, finally, calcining in an inert atmosphere or reducing atmosphere to obtain lithium iron phosphate which is carbon-coated lithium iron phosphate since the outer layer of the prepared lithium iron phosphate is coated with a layer of carbon. The method not only utilizes the advantages of a sol-gel method, which mixes materials with even molecular level, but also overcomes the problems of the sol-gel method, in which all parts of the gel have uneven water loss during drying and sever expansion in calcination and the content of product carbon is difficult to control. The carbon-coated lithium iron phosphate prepared by the method has excellent large and small multiplying power performance, especially has excellent super-large multiplying power performance, and excellent cycle performance.

Description

technical field

[0001] The invention belongs to the technical field of lithium ion battery materials, and in particular relates to a preparation method of carbon-coated lithium ferrous phosphate, a cathode material of lithium ion batteries. Background technique

[0002] Due to the wide source of lithium iron phosphate raw materials, low price, no environmental pollution, good thermal stability and structural stability of the material, the prepared battery has outstanding safety performance and long cycle life, making it suitable for various mobile power sources, especially The field of large-scale power supply required by new energy vehicles has great market prospects. This large-scale power supply has high requirements on the price, safety, service life and environmental performance of materials, so that lithium iron phosphate has become the most developed A new generation of cathode materials for lithium-ion batteries with potential applications.

[0003] The sol-gel meth...

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