Analyzing the impact of porosity distribution in porous electrodes on cyclic voltammetry responses.

Electrochemical energy devices, such as batteries and fuel cells, rely on electrodes with porous structures to enhance their performance and overall efficiency. This is done by increasing their surface area for reactions. While researchers have made efforts to improve electrode performance, the complex nature of these structures makes it challenging to accurately quantify the factors contributing to the observed improvements. Traditional voltammetric measurements based on the Nicholson approach or the Randles-Sevcik equation have been commonly employed, but these approaches were originally derived for planar electrodes and do not account for intricate porous systems. This study presents a novel physiochemical macroscale model developed to simulate voltammetric responses of functionally graded electrodes, which have recently garnered significant attention. By investigating the effects of different functionally graded electrodes on voltammetric responses, our findings demonstrate that the choice of electrode structure significantly influences the quantification of fundamental parameters. It highlights potential misinterpretation of results when evaluating electrochemically active surface area, reaction rate constants, and mass transfer coefficients. By providing researchers with a comprehensive understanding of the effects of functionally graded electrodes on voltammetric responses, this work opens new avenues for accurately assessing the influence of structural parameters in electrochemical energy devices. The developed model represents a crucial step forward in elucidating the relationship between electrode design and electrochemical performance, enabling more informed research and development efforts in this field. [ABSTRACT FROM AUTHOR]