Synthesis and Characterization of LiFe1-xGdxPO4/C (x = 0.01; 0.05; 0.07) for a Lithium Battery Cathode

Abstract

Synthesis of LiFe1-xGdxPO4/C with (x = 0.01; 0.05; 0.07) have been carried out using a solid-state method from LiH2PO4, Fe2O3, Gd2O3, and Carbon. Al reactant are mixed and mashed with a ball milling for 8 hours, then heated at 80°C for 2 hours to evaporate free water. To complete the reaction, the sample then was sintered at two different temperature; first at 350°C for 6 hours and continue at 830°C for 10 hours under Argon gas (Ar) atmosphere. The sintered powder was characterized by XRD to determine the structure and phase purity. Sample LiFe1-xGdxPO4/C (x = 0.01; 0.05; 0.07) was adopted orthorhombic crystal structure and pnma space group, and no impurities detected. In general, the lattice parameter decreases with increasing Fe concentration, because of the size of the Fe3+ ion is smaller than that Gd3+ ion. Conductivities of LiFe0.93xGd0.07PO4/C, LiFe0.95Gd0.05PO4/C and LiFe0.99Gd0.01PO4/C are 2.17 x 10-4 S/cm, 1.54 x 10-4 S/cm, and 2.02 x 10-4 S/cm, respectively.