Enhancement of electrochemical performance of lithium manganese oxide with graphene for aqueous supercapabattery

[Display omitted] •Graphene nanoplatelets (GNPs) served as a conductive enhancer for lithium manganese oxide (LMO).•The electrochemical performance increased by 63% after the introduction of GNPs to LMO.•LMO/GNPs retained 80% of the specific capacity after 1000 consecutive cycles, while LMO retained less than 60%. In this study, we synthesized lithium manganese oxide nanoparticles/graphene nanoplatelets (LMO/GNPs) as the cathode material for a supercapabattery using a hydrothermal method. The addition of GNPs resulted in a 63% and 68% increase in specific capacitance and capacity compared to LMO alone, attributed to the enhanced conductivity and efficient lithium-ion diffusion of GNPs. The LMO/GNPs exhibited excellent rate capability and stability, with 80% capacity retention after 1000 cycles, an energy density of 39.07 Wh kg−1 and a power density of 925.40 W kg−11, showcasing their potential for supercapabattery applications. These findings highlight the superior performance of LMO/GNPs in the supercapabattery, making it a promising energy storage solution.