Synthesis of 3D cross-linked MoSSe/CNTs electrode materials for high-stability symmetrical supercapacitors

Abstract

In practical applications of supercapacitors, the cycling stability, specific capacity, and power density of electrode materials are crucial performance indicators. In this study, a low-cost and facile hydrothermal method was employed to interconnect MoSSe via carbon nanotubes (CNTs), constructing MoSSe/CNTs composites with a 3D cross-linked structure. This structure exhibits impressive electrochemical performance with a specific capacitance of 512.4 F g⁻¹ at 1 A g⁻¹. And the value exceeds the sum of the specific capacitances of pristine MoSSe (407.5 F g⁻¹) and pristine CNTs (69.4 F g⁻¹) and clearly confirms a synergistic effect between the two components. Furthermore, the composite maintains excellent long-term cycling stability: even after 3000 charge–discharge cycles, its specific capacity retention remains as high as 91.91%. A symmetric supercapacitor assembled based on MoSSe/CNTs exhibits a specific capacitance of 166.5 F g⁻¹ (at a current density of 1 A g⁻¹), accompanying an energy density of 7.4 Wh kg⁻¹ and a power density of 3333 W kg⁻¹. Notably, after 10 000 cycles, the rate of initial capacity retention and Coulombic efficiency remain at 96.04% and 98.69%, respectively. It is believed that this electrode material, with excellent cycling stability, high specific capacity, and high power density, holds great potential for practical applications in numerous fields, contributing to addressing the growing shortage of fossil energy and the continuous intensification of environmental problems.