A hierarchical MXene@WS2/MnO2 hybrid as a ternary heterostructure electrode for high-performance asymmetric supercapacitors

With their distinctive merits of high power density and prolonged cycle life, supercapacitors have emerged as a compelling subject of research for advanced energy storage applications. To address the limitations of individual components in supercapacitor electrodes, such as MXene restacking and the poor conductivity of MnO 2 , a ternary MXene@WS 2 /MnO 2 heterostructure was rationally designed. This distinctive configuration suppresses layer restacking, thereby allowing a greater proportion of surface atoms to participate in electrochemical reactions and providing optimized pathways for the movement of ions and charge carriers. The fabricated MXene@WS 2 /MnO 2 electrode showed a high specific capacitance of 824.7 F g −1 at 5 mV s −1 , and it held 87.6% of its capacitance after 5000 charge–discharge cycles. Beyond this, an asymmetric supercapacitor built with activated carbon as the electrode substrate attained an energy density of 30.6 Wh kg −1 at an applied power density of 440.7 W kg −1 . Equipped with the as-prepared cathode material, this device maintained 90.1% capacitance retention over 5000 cycles and capably drove an LED array. The present work verifies the significant prospects of a ternary heterostructure design strategy in the construction of high-performance energy storage systems.