Lithium iron phosphate composite and preparation method thereof

Abstract

The invention provides a lithium iron phosphate composite and a preparation method thereof. The preparation method of the lithium iron phosphate composite comprises the following steps of weighing a certain quantity of sodium benzene sulfonate, putting the sodium benzene sulfonate in a three-necked flask, thoroughly dissolving the sodium benzene sulfonate with 100ml deionized water, weighing a proper quantity of LiFe-PO4 and 1ml pyrrole, adding the LiFe-PO4 and the pyrrole in the three-necked flask, performing ultrasonic mixing for 1-3h, adding a proper quantity of Fecl3 solution under ice bath and nitrogen protection, performing electromagnetic stirring reaction for 6h, centrifugally washing an obtained product with the deionized water and ethanol for many times sequentially, and performing vacuum drying for 12h at the temperature of 60 DEG C to obtain the PPY / LiFePO4 composite. The lithium iron phosphate composite is high in tapping density, and thus the specific volumetric capacityof the LiFePO4 is increased.

Description

technical field [0001] The invention relates to material technology, in particular to a lithium iron phosphate composite material and a preparation method thereof. Background technique [0002] LiFePO 4 As a new generation of lithium-ion battery cathode materials with application potential, it has received extensive attention from all walks of life. It has the advantages of low price, abundant raw material sources, stable structure, high specific capacity, good cycle performance, high safety in use, and environmental friendliness. It is widely used in various mobile power sources, especially in the field of power sources. But on the other hand, since LiFePO 4 The material's low electronic conductivity, low lithium ion diffusion coefficient, and low packing density limit its wider application. At present, the main modification methods for the above shortcomings include metal ion doping, carbon coating, and increasing the specific surface area by reducing the particle size....

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Problems solved by technology

People usually use carbon coating to solve the problem of poor conductivity. In addition, carbon black needs to be added during the preparation of the positive electrode to further enhance the conductivity, but the carbon-based inactive material not only hinders Li + intercalation and extraction reactions, and reduces the LiFePO 4 The effective tap density of the positive electrode material reduces the volume specific capacity