Chemical route to the synthesis of novel ternary CuCr2S4 cathodes for asymmetric supercapacitors

Abstract

Transition metal dichalcogenides (TMDs) are valuable for various energy-storage applications due to their layered structures. To date, while several physical methods have been employed for the preparation of TMDs, very few chemical synthesis reports are available. Herein, novel CuCr2S4 (CCS) electrodes are chemically prepared using a simple and inexpensive hydrothermal method and investigated for supercapacitor applications for the first time. The CCS electrodes are highly porous with high specific surface areas (173–274 m2/g) and hence provide more electrochemically active sites, resulting in high capacities. The optimized CCS electrode exhibits a maximum specific capacity of 1807 C/g at a scan rate of 2 mV/s. Furthermore, when an asymmetric supercapacitor (ASC) is fabricated using the CCS and reduced graphene oxide electrodes, the ASC delivers a specific capacity of 210.6 C/g, a high specific energy of 65.83 Wh/kg, and a specific power of 750 W/kg at a current density of 1 A/g. Moreover, the ASC demonstrates an excellent cycling stability of 90 % over 10,000 charge/discharge cycles. Results suggest that the chemically prepared CCS is an excellent electrode material for high-performance ASCs. This study will significantly expand the possibilities for the development of TMD-based novel electrodes for high-performance energy-storage devices.