Fabrication of MXene/reduced graphene oxide/MoO3 film electrode for flexible supercapacitors

Abstract

MXene nanosheets exhibit a tendency to agglomerate in electrochemical processes, significantly impairing the electrochemical performance and diminishes their practical applicability. However, this problem can be effectively suppressed by introducing functional intercalation materials. Herein, MXene/reduced graphene oxide (rGO)/MoO₃ films synthesized utilizing a vacuum-assisted filtration technique. MoO₃ nanofibers and rGO nanosheets serve as essential intercalation materials, establishing a highly stable interlayer configuration within MXene nanosheets. This arrangement significantly increases the spacing between the MXene layers, thereby facilitating the development of a multidimensional and efficient ion transport pathway and exposing more active sites. Under the synergistic effect of this composite structure, the film exhibited a specific capacitance of 854.2 F g⁻¹ at 1 A g⁻¹. In addition, an asymmetric supercapacitor (ASC) assembled with MXene/rGO/MoO₃ film as the positive electrode and activated carbon (AC) as the negative electrode shows a wide voltage window of 1.6 V and achieves a high energy density of 54 Wh kg⁻¹ at a power density of 800 W kg⁻¹. More importantly, at 3 A g⁻¹, this ASC maintained 85.4 % capacitance retention after 14,000 cycles, demonstrating excellent cycling stability. The optimization strategy for the MXene/rGO/MoO₃ electrode not only illustrates the technological progress of MXene within the domain of energy storage but also establishes a robust technological framework and theoretical underpinning for its utilization in flexible energy storage devices.