High performance asymmetric supercapacitor assembled by Co‐Mn LDHs coating on hollow MOF structure as positive electrode and MXene‐based composite as negative electrode

Doping Mn element into host material is an efficient approach to enhance the specific capacitance and cycling stability of supercapacitor. In this aspect, we fabricate Co-Mn LDHs (CMLs) hollow polyhedron generated from ZIF-67 via a template sacrifice method. Controllable doping of Mn element with gradient contents on the effect of electrochemical performance are investigated in detail. Moreover, in order to assemble a hybrid supercapacitor with superior energy and power output, a negative electrode based on MXene/rGO/V10O24 is synthesized considering the integration of EDLC and pseudocapacitance. As expected, the asymmetric supercapacitor of CMLs-0.53//MXene/rGO/V10O24 delivers high energy density of 44.4 Wh kg−1, maximum power density of 12 750 W kg−1 and superior cycling life (91.6% capacitance retention after cycling 10 000 cycles). The special idea on the construction of CMLs with hollow structure can offer new insight to resolve the complicated steps during preparation procedure. The results also indicated that the device based on CMLs-0.53 and MXene/rGO/V10O24 is a good candidate in the utilization of energy storage and conversion system in the future.