A multi-scale model of diffusion/reaction at play in a porous electrode is developed and solutions to thephysico-electro-chemical coupled problem are provided. This represents a key step to progress in theoptimization of new efficient and innovative micro-electro-devices that needs to be addressed from achemical engineering point of view. The pore-scale model based on Fickian diffusion in the porous mediumand Nernstian layer and the electrochemical reaction governed by the Buttler-Volmer equation isupscaled using volume averaging to obtain a macroscopic model that describes the process on an effectiveequivalent medium. The validity and accuracy of the macroscopic model is successfully checkedthrough the comparison with direct numerical simulations of the initial microscale model for amperometrytests. Predictions obtained from the upscaled model on the current intensity versus the scanningpotential during voltammetry reveal to be in very good agreement with experimental results reportedin the literature. These results show the capability of the macroscopic model to analyze the behaviorof the porous electrode. In particular, it provides an efficient tool to study the dependence of the currentintensity on the microstructure of the porous material and on the electrochemical parameters with theperspective of optimizing the electrode efficiency.Read less <