Reduced graphene oxide/hexagonal boron nitride-based composite as a positive electrode in asymmetric supercapacitors

Supercapacitors appear to be attractive options for energy storage due to their high power density and lengthy cycling life. This work is focused on the design of reduced graphene oxide/hexagonal boron nitride (rGO/h-BN), via a hydrothermal method, as electrode materials for supercapacitor applications. Interestingly, the composite with rGO/h-BN 50:50 showed good capacity when compared to other ratios. Similarly, asymmetric supercapacitor devices were made up of rGO/h-BN and rGO as positive and negative electrodes, respectively, and nickel foam and stainless steel were used as a substrate. The nickel foam as substrate exhibits a high capacitance retention of 90% after 1000 cycles in a coin-cell configuration compared to stainless-steel substrate (71% after 500 cycles). Interestingly, a significant enhancement in the capacitance of Co3O4 was observed when incorporated with rGO/h-BN composite. The asymmetric supercapacitor made up of rGO/h-BN/Co3O4 delivered a good capacitance retention of 78% at 150 mA/g, after 5,000 cycles. As a result, h-BN/rGO-based composites with superlattice were synthesized using a hydrothermal approach as prospective materials for next-generation supercapacitor applications.