Digital Twin\nof a Standard Electrochemical Cell for\nCyclic Voltammetry Based on Nernst–Planck–Poisson Model

The three-electrode electrochemical cell is the cornerstone\nof\nthe cyclic voltammetry (CV) technique providing essential information\nabout redox processes. Accurate models of CV curves accounting for\nthe full physics of electrochemical systems, processes, and the electrochemical\ncell itself are prerequisites for calibration and quantitative analysis.\nRecent advancements in modeling, particularly using Nernst–Planck–Poisson\n(NPP) equations, have shown promise in accurately describing various\nelectrochemical systems. The specific details of the formulation and\nimplementation of the NPP approach vary across different studies (e.g.,\nthe chosen boundary conditions, treatment of the double layers, charge\nneutrality, etc.). Consequently, selecting the optimal model often\ninvolves balancing the accuracy of the system’s description\nwith the computational cost. Surprisingly, the validation of the models\ncan also be problematic, because experimental CV curves for the same\nsystems reported in the literature obtained under nominally identical\nconditions can differ from one another. This paper addresses these\nchallenges by presenting a state-of-the-art NPP model for three-electrode\ncells that balances computational efficiency and accuracy, while also\nanalyzing different levels of approximation utilized in the NPP approach.\nThe model is validated against experimental data, and possible sources\nof the discrepancy between different measured CV curves reported in\nthe literature are presented and discussed. A user-friendly simulator\n(a digital twin of the standard electrochemical cell) is introduced,\nmaking advanced electrochemical modeling accessible to the broader\nscientific community without requiring specialized knowledge in electrochemical\nmodeling and finite element method solvers.