Interfacially Ordered NiCoMoS Nanosheets Arrays on Hierarchical Ti3C2Tx MXene for High-Energy-Density Fiber-Shaped Supercapacitors with Accelerated Pseudocapacitive Kinetics

Abstract

Balancing electrochemical activity and structural reversibility of fibrous electrodes with accelerated Faradaic charge transfer kinetics and pseudocapacitive storage are highly crucial for fiber-shaped supercapacitors (FSCs). Herein, we report novel core–shell hierarchical fibers for high-performance FSCs, in which the ordered NiCoMoS nanosheets arrays are chemically anchored on Ti₃C₂T_x fibers. Beneficial from architecting stable polymetallic sulfide arrays and conductive networks, the NiCoMoS−Ti₃C₂T_x fiber maintains fast charge transfer, low diffusion and OH⁻ adsorption barrier, and stabilized multi-electronic reaction kinetics of polymetallic sulfide. Consequently, the NiCoMoS−Ti₃C₂T_x fiber exhibits a large volumetric capacitance (2472.3 F cm⁻³) and reversible cycling performance (20,000 cycles). In addition, the solid-state symmetric FSCs deliver a high energy density of 50.6 mWh cm⁻³ and bending stability, which can significantly power electronic devices and offer sensitive detection for dopamine.