ENHANCEMENT OF Li–ION BATTERY CAPACITY USING NICKEL DOPED LiFePO4 AS CATHODE MATERIAL

Abstract

Selective supervalent cations (M = Ni, Mn, La etc.) doped LiFePO4 (LFP) is an effective route to enhance its electrical conductivity, thereby improving electrochemical performances of lithium–ion batteries. For this purpose, nickel doped LiFePO4 based cathode material was investigated at different substitution amounts (xNi = 0.05, 0.10). LiFe1–xNixPO4 (LFNP) was synthesized from Ni(NO3)2.6H2O, LiOH.H2O, FeSO4.7H2O, H3PO4, and ascorbic acid precursors via solvothermal technique, followed by calcination in nitrogen atmosphere at 550 °C for 5 h. The structure and morphology of synthesized materials were examined by X–ray diffraction, Scanning electronic microscopy and Raman vibrational micro–spectroscopy. The electrochemical performances of doped materials were studied in Swagelok–type cell using LiPF6/EC–DMC (1:1) as electrolyte. LiFe1–xNixPO4 was shown to exhibit homogenous particles size of 50 ¸ 150 nm. The doped materials were titrated to quantify iron and nickel contents in samples. As anticipated, the electrochemical performances of LiFe1–xNixPO4were significantly enhanced compared to those of undoped LiFePO4.