Abstract: The present application relates to lithium iron phosphate, a preparation method therefor, and a lithium-ion battery. The preparation method includes: sintering dry materials of an iron source, a lithium source, a phosphorus source, and a reductive carbon source to obtain lithium iron phosphate, wherein the sintering atmosphere includes a mild oxidizing gas, the mild oxidizing gas includes carbon dioxide, and the sintering temperature is 800-900° C.

Abstract: The present disclosure relates to the field of cathode materials, and provides a cathode material and a preparation method thereof as well as a lithium-ion secondary battery, wherein the cathode material comprises: a secondary particle comprising a plurality of primary particles, wherein the primary particles contain an active substance having a chemical general formula of LibNixCoyMzNwO2, where 0.95?b?1.05, 0.8?x<1, 0<y+z?0.2, x+y+z=1, and 0.0001?w?0.003; M is selected from at least one of Mn and Al; N is a metal and a coating layer, which comprises a first coating laver and a second coating laver, wherein the first coating laver is formed on the surface of the primary particles, the second coating laver is formed on the surface of the secondary particles, and both the first coating layer and the second coating laver contain a phosphate compound.

Abstract: A method for recycling waste lithium iron phosphate is by selective oxidation-reduction, to obtain recycled lithium iron phosphate, and a lithium ion battery. The method includes: primarily sintering waste lithium iron phosphate under a condition where a mild oxidizing gas is introduced; separating a lithium iron phosphate powder material; supplementing lithium and supplementing carbon to the lithium iron phosphate powder material and regulating the composition of the lithium iron phosphate powder material using a lithium source and a carbon source by secondary sintering to obtain recycled lithium iron phosphate, wherein the mild oxidizing gas is water vapor, CO2 gas, or a mixed gas thereof.