Finite element method for the numerical simulation of modified Poisson-Nernst-Planck/Navier-Stokes model

Abstract: The Nernst-Planck model has long served as a foundational framework for understanding the behavior of electrolyte systems. However, inherent deficiencies in this model have spurred the exploration of alternative approaches. In this context, this study presents simulation in multidimensional contexts for a new, fully-coupled, non-linear, thermodynamically consistent electrolyte model introduced by Dreyer et al. We present a robust mathematical formulation and employ a conforming finite element approximation to comprehensively explore both compressible and incompressible variants of the electrolyte mixture. Our investigation extends across diverse spatial dimensions, facilitating an in-depth analysis of parametric dependencies governing space-charge layer formation at boundaries under external voltage influence. Furthermore, meticulous consideration is given to finite ion size effects, which play a critical role in electrolyte flow dynamics. Insights from annular battery designs are also incorporated, which introduce unique dynamics to ion transport phenomena. Through rigorous simulations, we validate the accuracy and reliability of our numerical scheme, thereby laying the groundwork for an enhanced understanding and optimization of electrolyte system behaviors across various applications, notably in semiconductor devices and electrochemistry.