Self‐Assembly of Nickel Cobalt Sulfide/MXene Microspheres for Supercapacitors With Excellent Electrochemical Performance

Abstract

Abstract MXene, a novel 2‐D material known for its exceptional conductivity and high hydrophilicity, holds significant promise in advancing supercapacitor technology. However, its layered structure tends to self‐stack, hindering ion transport and limiting its specific capacitance. In this paper, nickel cobalt sulfide (NCS)/MXene self‐assembled microspheres were prepared by a simple hydrothermal method. The introduction of NCS effectively mitigates MXene from self‐stacking, while providing abundant electrochemical active sites that enhance its performance. NCS/MXene demonstrates an exceptional specific capacitance of 2544.1 F g −1 at 1 A g −1 , surpassing the specific capacitance of both pure MXene and NCS. Moreover, it exhibits outstanding stability, maintaining 96% of its capacity after 5000 cycles. When assembled into asymmetric supercapacitors, the device achieves a high energy density of 43.2 Wh kg −1 at a power density of 768.1 W kg −1 . This work provides a simple and reliable method for the development of sulfide/MXene composite electrode materials for supercapacitors.