Digital simulations to solve electrochemical processes involving a diffusion coefficient varying linearly with the concentration

A simple mathematical procedure based on digital simulations is performed to solve electrochemical processes involving a concentration-dependent diffusion coefficient. Specifically, a semi-infinite diffusion process stimulated by a constant-flux is considered. The diffusion coefficient is assumed vary linearly with the concentration. This situation is not taken into account in most of the discussions presented in the scientific literature. A variable transformation is applied to obtain a dimensionless mathematical description of the problem. Concentration profiles are solved using explicit and implicit finite-difference algorithms. A more general and reliable description of the mass transport mechanism is obtained.