Investigation of band structure and electrochemical properties of h-BN/rGO composites for asymmetric supercapacitor applications

The effect of different content of graphene oxide (GO) on the electrical and electrochemical property of h-BN/reduced GO (rGO) hetero-structure is investigated elaborately. The increasing amount of rGO within the h-BN moiety plays fascinating role by reducing the electronic work function while increasing the density of state of the electrode. Furthermore, different h-BN/rGO architecture shows different potential window and the transition from pseudocapacitance to electrochemical double layer capacitance (EDLC) is observed with increasing pi-conjugation of C atoms. The rod like h-BN is aligned as sheet while forming super-lattice with rGO. Transmission electron microscopy images show crystalline morphology of the hetero-structure super-lattice. The valance band and Mott-Shotky relationship determined from Mott-Shotky X-ray photoelectron spectroscopy shows that the electronic band structure of super-lattice is improved as compared to the insulating h-BN. The h-BN/rGO super-lattice provides high specific capacitance of similar to 960 F g-(1). An asymmetric device configured with h-BN/rGO super-lattice and B, N doped rGO shows very high energy and power density of 73 W h kg(-1) and 14,000 W kg-1, respectively. Furthermore, very low relaxation time constant of similar to 1.6 ms and high stability (similar to 80%) after 10,000 charge discharge cycles ensure the h-BN/rGO super-lattice as potential materials for the next generation energy storage applications. (C) 2017 Elsevier B.V. All rights reserved.