Hollow CuO and MXene dual-reinforced MoS2 heterostructures for high energy density supercapacitor negative electrode

MoS 2 is considered a highly promising anode material for supercapacitors owing to its distinctive two-dimensional structure. However, its relatively low electrical conductivity restricts its further development and practical application. For the purpose of addressing this issue, this study reports the first synthesis of a CuO@MoS 2 /MXene ternary heterostructure based on hollow CuO. The formation of the built-in electric field, along with the redistribution of local charge, facilitates the transformation of 2H-MoS 2 into highly conductive 1T-MoS 2 . In addition, the three-dimensional crosslinked network structure formed by the highly conductive MXene and MoS 2 layers offers additional storage capacity for electrolyte ions, thereby further enhancing the energy storage density of the material. This negative material exhibits a maximum specific capacitance of 1435.2 F g −1 , which is significantly higher than that of most reported MoS 2 -based negative materials. The synergistic support provided by the porous CuO substrate and the MXene layer effectively inhibits the lamellar aggregation of MoS 2 , thereby achieving a capacitor retention rate of 90.1 % after 5000 charge-discharge cycles. The asymmetric supercapacitor constructed from the material achieves a maximum energy density of 91.4 Wh·kg −1 , demonstrating excellent application potential in various fields. This study addresses the research gap concerning negative electrode materials for high specific capacitance MoS 2 -based supercapacitors and offers a novel approach to further enhancing the energy density of supercapacitors.