Preparation of High Specific Capacitance Material Based on Activated Carbon-Manganese Dioxide Composite Using Lemon Peel (<i>Citrus limon</i>) Extract for Supercapacitor Electrode

In this study, the high specific capacitance material based on activated carbon-manganese dioxide (AC/MnO 2 ) composite was prepared by an impregnation method. The MnO 2 particle was synthesized via a redox reaction between KMnO 4 and lemon peel extract as a bioreductor. The steps taken in this research were the preparation of lemon peel extract, then synthesis of MnO 2 using lemon peel extract, synthesis of AC/MnO 2 composites, and electrodes characterization using powder XRD, SEM, and CV. According to the results, the AC/MnO 2 composite electrode had a higher specific capacitance compared to the synthesized MnO 2 . The powder XRD test results show that the synthesized MnO 2 consisted of α, γ, and δ polymorphs. SEM data show that the average MnO 2 particle size is 482.80 nm. The CV test results show that the highest AC/MnO 2 capacitance is 188.17 F g -1 which was obtained at an AC/MnO 2 ratio is 1:1. This suggests that the AC/MnO 2 composite material has the potential to be used as a supercapacitor electrode material.