Role of porosity and diffusion coefficient in porous electrode used in supercapacitors – Correlating theoretical and experimental studies

Porous electrodes are fast emerging as essential components for next-generation supercapacitors. Using porous structures of Co₃O₄, Mn₃O₄, α-Fe₂O₃, and carbon, their advantages over the solid counterpart is unequivocally established. The improved performance in porous architecture is linked to the enhanced active specific surface and direct channels leading to improved electrolyte interaction with the redox-active sites. A theoretical model utilizing Fick's law is proposed, that can consistently explain the experimental data. The porous structures exhibit ∼50%–80% increment in specific capacitance, along with high rate capabilities and excellent cycling stability due to the higher diffusion coefficients.