Li3V2(PO4)3/(SiO2 + C) composite with better stability and electrochemical properties for lithium-ion batteries

• Dihydroxydiphenylsilane (DPSD) was used as the sources of SiO2 and C to get a composite coating layer of SiO2+C by one step.
• The Li3V2(PO4)3 material with SiO2+C coating layer shows higher capacity and better cycle performance than pure Li3V2(PO4)3 material for the coating layer improving the conductivity and stability of Li3V2(PO4)3 material.
• The Li3V2(PO4)3 material with SiO2+C coating layer shows better electrochemical performances than the Li3V2(PO4)3 with core-shell structure coating layer of carbon first and then SiO2.

A kind of Li3V2(PO4)3/(SiO2 + C) composite was synthesized with dihydroxydiphenylsilane (DPSD) as the sources of SiO2 and C. This composite shows better stability and higher capacity than pure Li3V2(PO4)3 material. SEM with EDS, XPS, and HRTEM tests were used to prove the existence of the SiO2 + C coating layer. The Li3V2(PO4)3/(SiO2 + C) shows a discharge capacity of 191 mAh/g in the voltage range of 3.0–4.8 V at 0.1 C, and retains 90% of the capacity after 50 cycles.