In-situ synergistic W18O49/Ti3C2Tx heterostructure as negative electrode for high energy density supercapacitors

Ti3C2Tx has attracted great attention as negative electrode material of supercapacitors owing to its high metallic conductivity, abundant surface terminations, and suitable potential range. However, the inevitable restacking of two-dimensional nanosheets dramatically restrain the electrochemical performances of individual Ti3C2Tx electrodes. In this work, interface-induced in-situ growth strategy was developed to construct W18O49/Ti3C2Tx heterostructures through a simple solvothermal reaction. The optimized W18O49/Ti3C2Tx hybrid electrode delivered a high specific capacitance of 472.6 F g−1 at 1 mV s−1 and retained 73.3% of its initial capacitance under 100-fold scan rate. The asymmetric supercapacitor assembled with W18O49/Ti3C2Tx negative electrode and RuO2@CC positive electrode exhibited a high energy density of 29.6 Wh kg−1 and maximum power density of 7.0 kW kg−1. In sum, the designed negative electrode materials look promising for future use in high-energy-density supercapacitors.