High-performance flexible solid-state supercapacitors based on binder-free V2CTx/Ni3S2 nanocomposites on carbon cloth

Abstract

Designing excellent binder-free composite materials with high performance flexible is an important research direction for energy storage devices. The high theoretical capacity of two-dimensional V₂CT_x MXene is ideal for electrode materials. However, the interlayer spacing and self-aggregation affect the practical application of the V₂CT_x. The reduced available surface area and hindered diffusion of electrolytes limit the application development. Designing and constructing self-supporting layered structural composite materials to increase ion transport paths and show excellent structural stability. Herein, the Ni₃S₂ nanoblock arrays were orderly arranged on the V₂CT_x supported by carbon cloth. The V₂CT_x nanosheets are coated on carbon cloth without binder. Thus, the synthesized hierarchical structure significantly increased the surface area with electrolyte penetration and ion transport. Additionally, the interlayer Ni₃S₂ nanoblock arrays prevent the collapse of the V₂CT_x interlayers. The designed flexible solid-state hybrid supercapacitor delivers an energy density of 55.69 Wh·kg⁻¹ at a power density of 413.82 W·kg⁻¹ and maintains 91.08 % cycling stability over 10,000 cycles. The strategy results indicate that the constructed composites provide a pathway for binder-free high performance energy storage devices.