Development of High-Performance Electrode Materials for Supercapacitor Application through Combinatorial Electrodeposition

Abstract

Electrochemical capacitors (ECs) are promising energy storage devices that have received great attention because of their excellent electrochemical performance with high output power, short discharging time, and long-term cycle stability. Metal chalcogenides (especially selenides and tellurides) are considered to be a new class of battery-like electrode materials and have contributed to ameliorate the electrochemical performance with better electronic conductivity and chemical stability. In the current investigation, a series of mixed transition metal-based chalcogenides have been grown directly on nickel foam by electrodeposition without the addition of a binder to the electrode composite. It was observed that the supercapacitor activity was dependent on the quantity of Cu and Co in the Cu-Co-Se ternary selenide electrocatalysts. Surprisingly, Cu–Co ternary selenides exhibit superior specific capacitance in comparison to their pure parent compounds, CoSe and Cu3Se2. Among the series of Cu–Co ternary selenides, the specific capacitance achieved for Cu0.6Co0.4Se2 showed the best specific capacitance value of 2063 F/g at a current density of 1 A/g and also maintained a cyclic stability of more than 90 % at a higher current density of 10 A/g after 1000 charge-discharge cycles. Moreover, doping effects at the transition metal site are also illustrated in this work and had a positive influence on the supercapacitor activity because, it led to lattice distortion, electronic structure modification, as well as helping to tune the surface redox behavior. The observed results clearly demonstrate that the binder free metal chalcogenide-based catalysts may be used as a potential electrode material for future energy storage devices. Figure 1