ZIF-67-derived CoMoO 4 @Co 3 O 4 composite materials for high-performance asymmetric supercapacitors with efficient energy storage

Rational design of electrode materials is an important means to improve the performance of supercapacitors. In this paper, CoMoO 4 @Co 3 O 4 composite is prepared by hydrothermal treatment and sintering treatment using ZIF-67 as a self-supporting template. The CoMoO 4 @Co 3 O 4 electrode shows an excellent specific capacity of 2003 F g −1 at a current density of 1 A g −1 , and the capacity retention after 5000 cycles can reach 68% at a current density of 10 A g −1 . In addition, the asymmetric supercapacitor composed of CoMoO 4 @Co 3 O 4 composite and activated carbon (AC) shows an energy density of 56 Wh kg −1 at a power density of 750 W kg −1 and the capacity retention of 80% after 15,000 cycles at a current density of 10 A g −1 . The excellent electrochemical performance is attributed to the use of ZIF-67 as a self-supporting template to suppress the volume expansion and fragmentation of the CoMoO 4 @Co 3 O 4 electrode during charge and discharge.