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

MoS2 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@MoS2/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-MoS2 into highly conductive 1T-MoS2. In addition, the three-dimensional crosslinked network structure formed by the highly conductive MXene and MoS2 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 MoS2-based negative materials. The synergistic support provided by the porous CuO substrate and the MXene layer effectively inhibits the lamellar aggregation of MoS2, 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 MoS2-based supercapacitors and offers a novel approach to further enhancing the energy density of supercapacitors.