Facile method to prepare biochar–NiO nanocomposites as a promisor material for electrochemical energy storage devices

A new nanocomposite material based on biochar and nickel oxide (BC–NiO) was prepared by a simple co-precipitation method, using exhausted Acacia mearnsii de Wild as the biomass and nickel salts. The nanocomposite was obtained by pyrolysis at 700 °C and characterized by Raman spectroscopy, transmission electronic microscopy and DRX. Electrodes were assembled and the electrochemical properties were evaluated by cyclic voltammetry and galvanostatic charge/discharge curves. The specific capacitance of 10.66 F g−1 was found in an asymmetric configuration, presenting an interesting alternative for energy storage devices.