Asymmetric Aqueous Supercapacitor Based on Zinc Oxide‐Manganese Oxide Cathode Material and Fe─Ni Oxide/Reduced Graphene Oxide Anode Material

AbstractRecent advancements in negative electrode materials for supercapacitors have garnered significant attention due to their potential to enhance energy density. These materials are crucial in improving the performance of supercapacitors, particularly in terms of specific capacitance. Fe oxide‐based composites are attractive negative electrode materials for cutting‐edge supercapacitor technologies because of their high specific capacitance, broad potential window, outstanding cycle stability and adaptability in asymmetric design. The synthesized Fe─Ni oxide/reduced graphene oxide (FNG) composite delivered ≈500 F g−1 specific capacitance at ≈2 A g−1 current density. The work also describes the hydrothermal synthesis of a bimetallic oxide like zinc oxide‐manganese oxide (ZMO) as a positive material to fabricate asymmetric supercapacitor (ASC). The electrochemical results achieved from the three‐electrode configuration of ZMO indicate true pseudocapacitive behavior with the triangular charge–discharge curve. The fabricated ASC with ZMO as cathode and FNG as anode delivered energy, and power densities are ≈32 W h kg−1 and ≈2.3 kW kg−1, respectively.