Three-Dimensional Nickel Cobalt Molybdenum Selenide Network Construction for High-Performance Supercapacitors

Abstract

Supercapacitors are valued for high power density and long cycle life, yet their low energy density remains a key challenge. Multi-metallic selenides, which are characterized by their extensive redox chemistry and high electrical conductivity, have been identified as a promising solution to address this challenge. This study employs a hydrothermal method to prepare Ni/Co/Mo-based metal nanocomposite selenide (NCMS) electrodes and revealed the kinetic origin of the enhanced selenide induced performance. The optimized electrode, delivers an outstanding areal capacitance of 16.24 F·cm–2 at 5 mA·cm–2 and retains 7.24 F·cm–2 even at 50 mA·cm–2, with 97.7% capacitance retention after 10,000 cycles. This superior rate capability is due to the significant reduction in charge transfer resistance and the enhancement of interface uniformity. When configured into an asymmetric supercapacitor, the device achieves maximum and retains areal capacitances of 0.89 F·cm–2 and 0.51 F·cm–2 at 5 and 50 mA·cm–2, respectively. The maximum surface energy density and maximum surface power density are 0.316 mWh·cm–2 and 3.969 mW·cm–2, respectively. These findings underscore the efficacy of the selenization strategy for developing high-performance electrode materials.