Heterostructured NiMo3S4/Ti3C2Tx MXene composite with enhanced electrochemical performance for supercapacitor electrodes

The increasing demand for fast, efficient, and durable energy storage systems highlights the need for electrode materials that can simultaneously deliver high energy and power densities. Here, we report a NiMo 3 S 4 /Ti 3 C 2 T x MXene composite synthesized through a two-step hydrothermal strategy, which couples the high pseudocapacitance of NiMo 3 S 4 with the excellent electrical conductivity and layered structure of Ti 3 C 2 T x MXene. The composite delivers a remarkable specific capacitance of 1443.6 F·g −1 , more than twice that of pristine NiMo 3 S 4 , benefiting from accelerated charge-transfer kinetics and the exposure of abundant electroactive sites. When assembled into an asymmetric supercapacitor, the device operates stably within a 1.5 V window and retains 82.84 % of its capacitance after 10,000 cycles. Furthermore, it achieves a notable high energy density of 46.85 Wh·kg −1 at a power density of 786.16 W·kg −1 . Density functional theory calculations reveal an increased density of electronic states near the Fermi level and a lowered K + diffusion energy barrier, corroborating the improved electrochemical kinetics. This work demonstrates a synergistic hybrid design that narrows the performance gap between batteries and supercapacitors, offering a promising pathway toward high-energy, high-power energy storage technologies.