Lithium iron phosphate having olivine structure and method for preparing the same

摘要

Provided is an olivine-type lithium iron phosphate composed of secondary particles having a mean particle diameter (D50) of 5 to 100 μm, formed by aggregation of primary particles having a mean particle diameter (D50) of 50 to 550 nm, wherein the primary and secondary particles have a composition represented by Formula I below and the secondary particles have a porosity of 15 to 40%: Li1+aFe1−xMx(PO4−b)Xb (I) wherein M is selected from Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn, Y and combinations thereof; X is selected from F, S, N and combinations thereof; −0.5≦a≦+0.5; 0≦x≦0.5; and 0≦b≦0.1.

主权项

1. An electrode comprising a cathode mix having an olivine-type lithium iron phosphate being applied to a current collector,
wherein the olivine-type lithium iron phosphate is composed of secondary particles having a mean particle diameter (D50) of 5 to 100 μm, and the secondary particles are formed by aggregation of primary particles having a mean particle diameter (D50) of 50 to 550 nm, wherein the primary particles are aggregated via physical bonds to form the secondary particles, wherein the olivine-type lithium iron phosphate is LiFePO4, wherein the secondary particles have a porosity of 18 to 22.9%, and a portion of the secondary particles are deformed and converted into primary particles, wherein the primary particles are prepared by a supercritical hydrothermal method, and wherein the olivine-type lithium iron phosphate has a bulk density of 0.5 to 1.5 g/mL.