MXene-Boosted Electrochemical Performance of Co-BiVO ₄ : Electrodes for High-Capacitance Symmetric Supercapacitor and Asymmetric Supercapacitor Applications

A green alternative to the fossil fuel-based economy can only be realized by integrating large-scale electrochemical renewable energy systems, particularly solar and wind, supported by efficient storage technologies. In this context, high-capacitive electrodes offer a promising solution by enabling high energy storage. The BiVO4, Co-BiVO4, and Co-BiVO4@Ti3C2 electrodes were synthesized using a simple hydrothermal method. Co-BiVO4@Ti3C2 demonstrated noteworthy electrochemical performance, executing a specific capacitance of 757 F/g at 1 A/g in a three-electrode setup. The device delivered 99.2 F/g in the SSC and 54.4 F/g in the ASC, as confirmed by extensive structural and morphological characterization. The Co-BiVO4@Ti3C2 electrode exhibited excellent cycling stability, retaining 87.1% in SSC and 90.1% in ASC after 15,000 cycles at a current density of 10 A/g. The hybrid Co-BiVO4@Ti3C2-based SSC delivered a high energy density of 55.1 W h/kg at a power density of 998.0 W/kg, whereas ASC device achieved 31 W h/kg at a power density of 1267 W/kg. The results reveal that the electrochemical activity is significantly enhanced as a result of the synergistic effects of Co-BiVO4 and Ti2C3, which emerges as a promising viable material for use as a negative electrode in supercapacitors.