Composite lithium iron phosphate material, lithium ion battery using same, and preparation method of same

A lithium ion battery, comprising a positive electrode, wherein the positive electrode comprises a collector and a positive electrode active coating on at least one surface of the collector, the positive electrode active coating comprises a composite lithium iron phosphate material, the composite lithium iron phosphate material is made of a composition comprising an iron phosphate precursor, a lithium source, and a carbon source, the carbon source covers the iron phosphate and the lithium source, the carbon source comprises a synthetic polymer carbon source and a biomass carbon source, and the biomass carbon source comprises carbon fibers.

A method for preparing a composite lithium iron phosphate material, comprising the following steps:

• preparing a biomass carbon fiber using a plant powder;
• ball milling a mixed carbon source with iron phosphate, a lithium source, and anhydrous ethanol to obtain a composite lithium iron phosphate slurry, wherein the mixed carbon source comprises the biomass carbon fiber, a synthetic polymer carbon source, and a carbohydrate carbon source;
• drying and sintering the slurry to obtain the composite lithium iron phosphate material.