High electrochemical performance of F-doped LiFePO4 as cathode for lithium-ion battery

Abstract

F-doped LiFePO4 was synthesized by solid-state reaction method through the formation of Fe2P2O7 from precursors of Li2CO3, F2O3, NH4H2PO4, and LiF. Variations at temperatures of 700 °C and 750 °C with 0.1F. XRD results show a peak shift towards a high degree at 28 around 35°-36°. The peak shift indicates an indication of substitution of F ions in the position of oxygen (O) in the LiFePO4, with the smaller lattice parameters and unit cells. The distribution of F in the LFP cathode material is homogeneously distributed by SEM-EDX results, and the number of atomic weight is 0.051%. The best electrochemical performance of F-doped LFP is demonstrated by LFP 700+0.1F with the CV test results in the presence of an oxidation reaction (3.69 V) and reduction (3.26 V). The best value of V at LFP 700+0.1F is 0.4305 V, an indicating faster diffusion movements from Li+. The LFP 700+0.1F sample has the highest specific discharge capacity of 131.50 mAh/g at current 0.001C.