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

Silicon doped lithium trivanadate LiSixV3O8 (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. LiSi0.050V3O8 showed the best characteristics among the as-prepared materials. The specific discharge capacity of LiSi0.050V3O8 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.