Alkaline‐Based Electrolytes’ Impact on MXene‐Bismuth Titanate's Capacitive Behavior as an Electrode Material for Energy Storage Applications

MXenes exhibit exceptional capacitive performance due to their layered structure, high electrical conductivity, and large surface area. Their surface functional groups further facilitate rapid, reversible redox reactions, thereby enhancing pseudocapacitive behavior. In this study, a composite electrode material composed of MXene and Bismuth Titanate in a 95:5 ratio (MB5) was synthesized and evaluated under three aqueous electrolytic conditions: 1 M potassium hydroxide (KOH), 1 M Na 2 SO 4 , and a mixed 1 M KOH + 1 M Na 2 SO 4 solution. Electrochemical characterization using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) revealed a hybrid charge storage mechanism involving both electric double‐layer capacitance and pseudocapacitance. Among the tested electrolytes, 1 M KOH exhibited the most favorable performance, with quasi‐rectangular CV profiles, high specific capacitance values, and low charge‐transfer resistance, indicating rapid ion transport and excellent reversibility. The mixed electrolyte showed synergistic behavior, improving ion diffusion and interfacial stability, while Na 2 SO 4 offered moderate performance with stable but lower capacitance. These results underscore the role of electrolyte composition in tuning electrochemical response and highlight the MB5 composite as a promising candidate for high‐power‐density supercapacitor applications, particularly in alkaline environments.