Carbon supported, Al doped-Li3V2(PO4)3 as a high rate cathode material for lithium-ion batteries

Abstract

A high rate and high performance Li₃V₂(PO₄)₃ cathode was prepared by applying a carbon coating and Al substitution using the conventional solid-state approach. X-Ray diffraction was used to observe the structural properties of the synthesized powders. The presence of the carbon coating was confirmed by HR-TEM and reflected well with the Raman analysis. The Li/C-Li₃V_1.98Al_0.02(PO₄)₃ cell displayed a discharge capacity of 182 mA h g⁻¹ between 3 and 4.8 V vs. Li at a current density of 0.1 mA cm⁻¹, which is ∼20 mA h g⁻¹ higher than that of the native compound. The capacity retention was found to be 84 and 74% after 40 and 100 cycles, respectively. The C-Li₃V_1.98Al_0.02(PO₄)₃ powders demonstrated excellent rate performance at 20 C with a discharge capacity of ∼120 mA h g⁻¹ over 100 cycles. The elevated temperature performance was also evaluated and found to be similar to that under room temperature conditions.