Electrochemical Sensitization of Activated Carbon by Microporous MOF for Supercapacitor Applications

The remarkable performance of activated carbon as active electrode material in supercapacitors enabled its large-scale industrialization. Herein, the utilization of facile physical mixing process of microporous, chemically robust, Zr-based metal-organic framework for surface-modification of activated carbon to enhance its charge retention capacitance is reported. In this approach, the high surface area of the microporous MOF increases the active surface area of the activated carbon, providing an extra layer with facilitated electrolyte diffusion properties that effectively modulates the solid–electrolyte interface. A critical optimal coverage of 5wt % by the MOF crystallites is identified, resulting in increased specific capacitance of the activated carbon by ∼80 %, as compared to the pristine carbon. At higher MOF coverage, the poor electronic conductivity of the MOF hindered the inter-grain charge mobilization within the activated carbon, thus adversely affecting the overall capacitive performance.