Flower-like Cu5Sn2S7/ZnS nanocomposite for high performance supercapacitor

Ternary nanocomposites of Cu_xZn_ySn_zS_(x+y+z) are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability. Recently, this nanocomposite used as anode material for Li-ion battery has been reported, but there is limited research on its application in supercapacitors which is considered a complementary energy storage device to battery. In this work, flower-like Cu₅Sn₂S₇/ZnS and pristine Cu₅Sn₂S₇ nanocomposite were prepared via a facile hydrothermal method. The electrochemical tests showed that the Cu₅Sn₂S₇/ZnS nanocomposite exhibited better performance than pristine Cu₅Zn₂S₇, suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu₅Sn₂S₇, with the good capacitance of 200 F/g at the current density of 1 A/g. Furthermore 170 F/g was obtained at the large current density of 10 A/g. Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.