Lithium iron phosphate composite material, preparation method and use
AssigneeSvolt Energy Technology Co., Ltd.
InventorsNing Wan, Hongxin Yang, Jing Liu
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Abstract
The present application provides a lithium iron phosphate composite material, a preparation method and use. The lithium iron phosphate composite material includes a core and a shell coated on the core, in particular, the core is Li6MnO4, and the shell is carbon-coated lithium iron phosphate. The lithium iron phosphate composite material provided by the present application adopts Li6MnO4 as the positive electrode lithium supplement material, and solves problems of active lithium loss and capacity depletion under high-rate charge and discharge of lithium iron phosphate positive electrode, thereby improving the rate performance of the lithium iron phosphate materials and the cycle life of batteries at high rates.
Claims16
A preparation method for a lithium iron phosphate composite material, wherein the lithium iron phosphate composite material comprises a core and a shell coated on the core, the core is Li6MnO4, and the shell is carbon-coated lithium iron phosphate;
- the preparation method for the lithium iron phosphate composite material comprises:
- preparing a carbon-coated lithium iron phosphate precursor sol by adopting a sol-gel process, mixing a Li6MnO4 precursor and the carbon-coated lithium iron phosphate precursor sol under stirring until a solvent is completely evaporated to obtain a wet material, and calcining the wet material to obtain the lithium iron phosphate composite material,
- wherein a mass ratio of the core to the shell is (0.005-0.05):1,
- wherein a preparation process for the Li6MnO4 precursor comprises:
- weighing a manganese source and a first lithium source according to a stoichiometric ratio in Li6MnO4, respectively, mixing the manganese source and the first lithium source, ball milling, and pre-calcining at a temperature of 300-400° C. for a period of 1 to 3 hours in a nitrogen atmosphere or an argon atmosphere, in sequence, to obtain the Li6MnO4 precursor.
Dependencies are inferred from the claim text.