CoMn-LDH/Ti-MXene for asymmetric supercapacitor positive electrode

Abstract

The CoMn-LDH/MXene composite was fabricated via hydrothermal synthesis, with nanoscale CoMn-LDH encapsulated on MXene through surface functional groups. This effectively prevents CoMn-LDH aggregation and improves its electrochemical properties. The effects of cobalt-manganese ratio, reaction time, and temperature on the electrochemical properties of CoMn-LDH were explored, as well as the impact of MXene addition on CoMn-LDH composite properties. A comparative analysis of the structural features of pure CoMn-LDH and the composite CoMn-LDH/0.08MXene reveals that the latter exhibits a more pronounced hierarchical structure. Composite CoMn-LDH/0.08MXene has a specific capacity of 1517.8 C-g⁻¹ at a current density of 1 A g⁻¹, significantly surpassing the 1186.8 C·g⁻1 achieved by pure CoMn-LDH. The asymmetric supercapacitor constructed with this composite material reached an energy density of 48.5 Wh·kg-1 and a power density of 755.3 W·kg⁻¹, retaining 95% of its capacity after 5000 charge/discharge cycles.The synergistic effect of CoMn-LDH and MXene enhances the capacitance and stability of the CoMn-LDH/0.08MXene composite capacitor. The simplicity of the preparation process, coupled with the excellent performance of the CoMn-LDH/MXene composites, suggests that they have considerable potential for use in advanced energy storage applications.