Controllable fabricate hierarchical CoMoO3@Co9S8/Ni3S2 core-shell arrays for high-performance hybrid supercapacitor

Rational design and construction of multiphase composite with specifical structure is an effective strategy to fabricate high-performance supercapacitor electrode materials. Herein, the hierarchical CoMoO3@Co9S8/Ni3S2 core-shell arrays are constructed by preparing Co9S8/Ni3S2 core with ion-exchange reaction and fabricating CoMoO3 shell through in situ transformation behavior. Thanks to the special heterostructures core-shell structure, the synergistic effect between multiple components, and the driving action of S-vacancies, hierarchical CoMoO3@Co9S8/Ni3S2 core-shell arrays exhibit battery-type features and deliver a great area specific capacity of 8.14 C cm−2 at current density of 5 mA cm−2. In addition, when assembled into a hybrid supercapacitor with capacitive-type electrode, the device achieves high energy density of 0.33 mWh cm−2 at the power density of 5.66 mW cm−2 and displays long-term durability with capacity retention of 93.7% and high Coulombic efficiency of 95.01% after 6000 cycles.