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

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.