Digital Twin of a Standard Electrochemical Cell for Cyclic Voltammetry Based on Nernst–Planck–Poisson Model

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