Nanoporous CuCo₂S₄ Microspheres: A Novel Positive Electrode for High-Performance Hybrid Energy Storage Devices

Abstract

Demands for safer, faster, and more efficient energy storage systems have motivated researchers to design and develop new electrode materials. Ternary transition metal oxides are the electrode materials commonly investigated for application in energy storage systems. Nevertheless, the low active surface area and poor conductivity limit their electrochemical performances. In the present study, nanoporous CuCo2S4 microspheres (CCS) electrode has been successfully prepared via a facile self-template method for high-performance hybrid energy storage devices. An ultrahigh specific capacitance of 1566 F g–1 at 2 A g–1 and a superb cycling performance of 95.7% retention after 5000 GCD cycles have been obtained for this electrode. In addition, when this CCS electrode is assembled with an activated carbon (AC) electrode, the as-fabricated asymmetric supercapacitor delivers outstanding performance with maximum power and energy densities of 16 and 43.65 W h kg–1, respectively, which is superior to conventional supercapacitors. The fabricated supercapacitor can light two green LEDs for more than 15 min. This work sheds a further light on the design of efficient electrodes which can be utilized in the next generation of high-performance hybrid energy storage devices.