Study on the silicon doped lithium trivanadate as cathode material for rechargeable lithium batteries

Abstract

Silicon doped lithium trivanadate LiSi x V 3O 8 ( x = 0.000, 0.025, 0.050, 0.075, 0.100) were prepared via a solid state reaction and then aqueous redox reactions. The compositions, structures and electrochemical properties of the materials were intensively characterized by inductive coupled plasma atomic emission spectroscopy (ICP-AES), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and galvanostatic charge–discharge cycle tests. The results show there are many advantages of the synthetic and modification method in this work such as simple elemental composition control. The structures of silicon doped samples behave readily for lithium transfer and intercalating/de-intercalating. The outstanding performances of the materials benefit from silicon doping significantly. LiSi 0.050V 3O 8 showed the best characteristics among the as-prepared materials. The specific discharge capacity of LiSi 0.050V 3O 8 remained 224.3 mAh·g − 1 at cycle 150 and 143.0 mAh·g − 1 at cycle 300 at a current density of 150 mA·g − 1 in the voltage range of 1.8–4.0 V.