Biomass-Derived Graphene-Based Nanocomposite: A Facile Template for Decoration of Ultrathin Nickel–Aluminum Layered Double Hydroxide Nanosheets as High-Performance Supercapacitors.

One promising approach to design of high-performance supercapacitors is based on the coupling the conductive porous carbon matrixes and the electroactive components. However, the main challenge to this goal is the maintaining the long cycling life, high power and high energy densities of the related capacitors. Herein, we reported on an electroactive composite based on biomass derived 3D graphene coupled with nickel-aluminum layer double hydroxides for manufacturing a cathode material in a supercapacitor. The electrode exhibits a remarkable specific capacitance of 1390 F g−1 at 1 Ag-1, and ultrahigh rate capability of 60% from 1 to 30 Ag-1, as well as excellent cycling stability with a capacitance retention of 92% after 5000 cycles. Furthermore, the electrode was used as the positive electrode against a Vulcan XC-72R as the negative electrode to assemble an asymmetric supercapacitor. The asymmetric supercapacitor device exhibited a maximum energy density of 173 Wh kg−1 and power density of 28.8 kW kg−1 as well as excellent cycling stability of 92% after 5000 cycles. The asymmetric supercapacitor could lighted up LED lamps with different colors more than 24 min. The work showed promising performance of further application in electrochemical devices.