Synthesis of NiMn-LDH Nanosheet@NiS Nanorod Hybrid Structures for Supercapacitor Electrode Materials with Ultrahigh Specific Capacitance.

One of the key challenges for pseudocapacitive electrode materials with highly effective capacitance output and future practical applications is how to rationally construct hierarchical and ordered hybrid nanoarchitecture through the simple process. Herein, we design and synthesize a novel NiMn-layered double hydroxide nanosheet@NiS nanorod hybrid array supported on porous nickel foam via a one-pot hydrothermal method. Benefited from the ultrathin and rough nature, the well-defined porous structure of the hybrid array, as well as the synergetic effect between NiMn-layered double hydroxide nanosheets and NiS nanorods, the as-fabricated hybrid array-based electrode exhibits an ultrahigh specific capacitance of 2703 F g at 3 A g. Moreover, the asymmetric supercapacitor with this hybrid array as a positive electrode and wood-derived activated carbon as a negative electrode demonstrates high energy density (57 Wh Kg at 738 W Kg) and very good electrochemical cycling stability.