Ni-Metal organic framework nanosheets and Ni3C/biomass porous carbon composite based long cycle life asymmetric supercapacitor

Asymmetric supercapacitors (ASCs), with their exceptional energy density and wider potential window while ensuring optimum power density, have gained substantial interest. Here, we introduce an ASC using Nickel-Metal Organic Framework (Ni-MOF) synthesized via On-pot solvothermal process as positive electrode and a hydrothermally grown composite encompassing Nickel-MXene with biowaste-derived brinjal carbon (MXAC) as negative electrode. The morphological analysis reveals the nanosheet-like morphology of Ni-MOF, whereas MXAC has a porous carbon skeleton bonded with MXene. In three-electrode configuration Ni-MOF shows specific capacitance of 536 F/g at 1 A/g at 0 to 0.4 V, while MXAC has 298 F/g at -1 to 0 V with 2M KOH. Further, the Ni-MOF//MXAC ASC device demonstrates specific capacitance of 146 F/g at 1 A/g with 1.5 V in 2M KOH, owing to the synergistic combination of Ni-MOF nanosheets with porous MXAC. Additionally, it provides 45.6 Wh/kg of energy density at power density of 750 W/kg and 85% capacitance retention after 10,000 cycles, signifying excellent stability.