All-solid state asymmetric supercapacitor based on NiCoAl layered double hydroxide nanopetals on robust 3D graphene and modified mesoporous carbon

The application of layered double hydroxides for supercapacitors is drastically impaired by their adverse agglomeration and poor conductivity. Herein, we have successfully deposited ultrathin nickel cobalt aluminum layered double hydroxide nanopetals onto a conductive three-dimensional graphene structure via dept dip-coating and hydrothermal reaction. Under this facile process, the as-fabricated electrode displays superior electrochemical performance. To bestow high power and energy densities simultaneously for the asymmetric supercapacitor, modified mesoporous carbon derived from a molecular sieve with high power density, is used as the negative electrode. The as-assembled all solid-state supercapacitor exhibits superior electrochemical properties, including high specific capacitance, high power density, as well as excellent cyclic performance. Furthermore, such isolated supercapacitors render an effective solution for the need of electric energy storage devices with the advantages of portability and stability. (C) 2017 Elsevier B.V. All rights reserved.