Lithium iron phosphate positive electrode active material, its preparation method, and lithium-ion battery

Abstract

A lithium iron phosphate cathode active material, a method for preparing the same, and a lithium-ion battery are provided. The cathode active material is formed by mixing first and second lithium iron phosphate materials. When the volume distribution percentages of the first and second lithium iron phosphate materials reach a maximum value, the corresponding particle sizes are D 1 mo μm and D 2 mo μm, 0.3≦D 1 mo ≦3.2 and 1≦D 2 mo ≦5, D 1 mo <D 2 mo The sphericity of the first and second lithium iron phosphate materials is A1 and A2, respectively. The first lithium iron phosphate material satisfies the following relationship: 0.49<0.643D 1 mo +0.439A1<2.3. The second lithium iron phosphate material satisfies the following relationship: 0.41<1.07D 2 mo +2.44A2-1.70D 2 mo ×A2<1.9.

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