Nanohoneycomb-like manganese cobalt sulfide/three dimensional graphene-nickel foam hybid electrodes for high-rate capability supercapacitors

Abstract

Nanohoneycomb-like manganese cobalt sulfide/three dimensional graphene-nickel foam hybrid electrodes for supercapacitor are synthesized by chemical vapor deposition and electrodeposition. The ternary sulfide electrode exhibits high specific capacitance (1938Fg−1 at 5Ag−1) with excellent rate capability (76.8% capacitance retention at 100Ag−1) due to the intercrossed feature of the nanowalls and three-dimensional interpenetrating nanoarchitecture. Moreover, the specific capacitance of the electrode after 4000 cycles at a high current density of 50Ag−1 is 1320Fg−1. The asymmetric supercapacitor assembled with the manganese cobalt sulfide electrode and an activated carbon electrode displays an energy density of 14.33Whkg−1 at a power density of 74.87Wkg−1. The manganese cobalt sulfide is a promising electrode material for practical application.