Enhanced Supercapacitor Performance through Synergistic BaCO₃ Doping of Graphene Nanoplate Electrodes

Barium carbonate (BaCO₃) is a stable inorganic compound with a high ionic conductivity and thermal stability, making it valuable for electrochemical applications. This study develops BaCO₃-doped graphene nanoplate (GPL) electrodes and compares them to pure GPL electrodes. The BaCO₃/GPL composite exhibits a lower surface area and altered pore distribution but achieves a higher surface potential, enhancing the electrolyte penetration and ion transport. Its superior electrochemical performance makes it a strong candidate for energy storage. Using a 1.0 M Na₂SO₄ electrolyte, Cyclic voltammetry (CV) measurements revealed that at a scan rate of 0.03 V s^-1, the BaCO₃/GPL composite exhibited markedly enhanced capacitance compared to pristine GPL, attaining 164.524 F g^-1 versus 59.724 F g^-1 in the anodic sweep and 943.95 F g^-1 versus 510.124 F g^-1 in the cathodic sweep. The enhanced capacitance is attributed to the greater negative surface potential, improving charge storage. The BaCO₃/GPL electrode displays great cycling stability, still maintaining 91.17% and 90.08% of the initial capacitance in the negative and positive directions, respectively, after 1200 charge-discharge cycles. Structural and electrochemical properties were analyzed using XRD, FT-IR, Raman, AFM, XPS, and EIS at different cycling stages and SEM before and after cycling, confirming the material's stability and efficiency for supercapacitor applications.