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

Abstract

In practical applications of supercapacitors, the cyclic 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-cycle stability: even after 3000 charge-discharge cycles, its specific capacity retention remains as high as 91.91%. The 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 cyclic 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.