A sol-assisted solvothermal method for preparing lithium vanadium phosphate/carbon composite cathode material with particle-rod mixed morphology and its preparation method

Abstract

The invention provides a particle-rod mixed morphology lithium vanadium phosphate / carbon composite cathode material prepared by a sol-assisted solvothermal method. Particularly, a lithium source, a vanadium source and a phosphorus source are rapidly transferred into a container after being ball-milled by using absolute ethyl alcohol as a medium, stirring is carried out, and a chelating agent is added to obtain yellow suspension; then the yellow suspension is placed into an oil bath and is heated to obtain blue suspension, the blue suspension is transferred into a reaction kettle, and ultrasonic heat preservation is carried out for 20 to 28 at a temperature of 175 to 190 DEG C to obtain concentrated precursor; the concentrated precursor is further ground into powder, a carbon source is added, ball-milling is carried out obtain mixed powder; and in a tube furnace, sintering is carried out for 8 to 12 hours in the atmosphere of nitrogen or argon, and grinding and sieving are carried out to obtain the carbon-coated lithium vanadium phosphate / carbon composite cathode material with a particle-rod mixed morphology. According to the invention, the sol method is sufficiently utilized to enable raw materials to reach uniformly mixing at a molecule level, the advantages of mild reaction condition and easiness for control of the solvothermal method are combined, and by carbon reduction, the lithium vanadium phosphate / carbon composite cathode material with the nano-rod and particle mixed morphology is obtained.

Description

technical field [0001] The invention relates to a sol-assisted solvothermal method for preparing a lithium vanadium phosphate / carbon composite positive electrode material with a particle-rod mixed shape and a preparation method thereof, belonging to the field of electrochemical power sources. Background technique [0002] Lithium-ion batteries are widely used in fields such as electric vehicles and hybrid electric vehicles due to their high energy density, good charge-discharge performance, and high safety. At the same time, the new power lithium-ion battery also shows a very broad application prospect in the fields of future power grid peak regulation, solar energy and wind energy storage. [0003] One of the main factors affecting the performance of lithium-ion batteries is the electrode material, and the cathode material plays a vital role in the future development of lithium-ion batteries. At present, the anode materials of commercial lithium-ion batteries mainly includ...

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Problems solved by technology

The solid-phase method has been widely used in industrial production because of its simple process, but the synthesis temperature is high, energy consumption is high, and the particle size of the obtained material is large

The sol-gel method can uniformly mix the raw materials in the liquid phase, form a stable sol in the solution through hydrolysis and condensation reactions, slowly polymerize between the aging colloidal particles, and form a three-dimensional network structure gel, which is dried and sintered Materials with molecular and even nano-substructures can be prepared by curing. However, due to the large number of micropores in the gel, many gases and organic substances will escape during the drying process and shrink, which is not conducive to actual production.

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