Pyroxene LiVSi sub(2O) sub(6) as an electrode material for Li-ion batteries

Lithium vanadium metasilicate (LiVSi sub(2O) sub(6)) with pyroxene structure has been exploited as an electrode material for Li-ion batteries. Galvanostatic charge and discharge tests show that LiVSi sub(2O) sub(6) is able to deliver a capacity of 85 mAh g[super]-1 at 30 [deg]C, and a high capacity of 181 mAh g[super]-1 at 60 [deg]C. The high capacity is believed to be due to the reactions of V[super]3+/V[super]4+ and V[super]2+/V[super]3+redox couples, accompanied by the excess 0.42 Li[super]+ insertion into the lattice forming a Li-rich phase Li sub(1.42VSi) sub(2)O sub(6. High-energy synchrotron XRD combined with the Rietveld refinement analysis confirms that the electrochemical delithiation-lithiation reaction proceeds by a single phase redox mechanism with an overall volume variation of 1.9% between LiVSi) sub(2)O sub(6 and its delithiated state, indicating a very stable framework of LiVSi) sub(2)O sub(6 for Li[super]+ ions extraction-insertion.)