In-situ MOFs-derived hollow Co9S8 polyhedron welding on the top of MnCo2S4 nanoneedles for high performance hybrid supercapacitors

Metal-organic frameworks (MOFs) have been considered as the outstanding templates and precursors in synthesizing advanced cathode materials for supercapacitor. Herein, a novel hierarchical structure with hollow Co9S8 polyhedrons welding on the top of MnCo2S4 nanoneedles are rationally designed via a facile in-situ vulcanization approach. The unique morphology can provide more abundant reaction sites and ensure the efficient electron transport. Due to the synergistic effect between MnCo2S4 and Co9S8, the hybrid electrode delivers a favorable specific capacity of 1100.5 F.g(-1) at a current density of 1 A.g(-1) in three-electrode system. Furthermore, an assembled asymmetric supercapacitor comprising MnCo2S4/Co9S8 and activated carbon delivers a high energy density up to 45.8 W.h.kg(-1) at a power density of 800 W.kg(-1). Moreover, the device holds more than 94.8% capacitance retention after 5000 cycles, demonstrating it could be a potential electroactive material for next-generation high performance energy storage device.