A new low-temperature synthesis and electrochemical properties of LiV_3O_8 hydrate as cathode material for lithium-ion batteries

摘要

LiV_3O_8, synthesized from V_2O_5 and LiOH, by heating of a suspension of V_2O_5 in a LiOH solution at a low-temperature (100-200 ℃), exhibits a high discharge capacity and excellent cyclic stability at a high current density as a cathode material of lithium-ion battery. The charge-discharge curve shows a maximum discharge capacity of 228.6 mAh g' at a current density of 150 mA g~(-1) (0.5 Crate) and the 100 cycles discharge capacity remains 215 mAhg~(-1). X-ray diffraction indicates the low degree of crystallinity and expanding of inter-plane distance of the LiV_3O_8 phase, and scanning electronic microscopy reveals the formation of nano-domain structures in the products, which account for the enhanced electrochemical performance. In contrast, the LiV_3O_8 phase formed at a higher temperature (300 ℃) consists of well-developed crystal phases, and coherently, results in a distinct reduction of discharge capacity with cycle numbers. Thus, an enhanced electrochemical performance has been achieved for LiV_3O_8 by the soft chemical method via a low-temperature heating process.