Synthesis and Electrochemical Studies on Li2CuSnO4 and Li2CuSnSiO6 as Negative Electrode in the Lithium Batteries

Li2CuSnO4 and Li2CuSnSiO6 were prepared from their precursors compounds using Brij surfactant and a hydrothermal autoclave method. X-ray diffraction characterization revealed that the crystal structures of these compounds were tetragonal. Scanning electron microscope investigation showed the particle size morphology of Li2CuSnSiO6 is larger than that of Li2CuSnO4. Electrochemical impedance spectroscopy (EIS) explained that Li2CuSnO4 cell had higher charge transfer resistance (Rct = 2936Ω) than that of Li2CuSnSiO6 (38Ω). Furthermore, the reversible specific discharge capacity of the Li2CuSnSiO6 cell was 870 mAh/g in comparison with 780 mAh/g for the Li2CuSnO4 cell after 100 cycles, which is even higher than the theoretical value of Sn, 783 mAh/g.