Towards Accurate Sodium-Ion Cell Modelling: Parametrization and Validation of a Commercial Sodium-Ion Cell Incorporating Temperature-Dependent Kinetic

In this study, a commercial cylindrical sodium-ion battery cell (Shenzhen Mushang NA18650-1250) was characterized, model parameters were identified, and the parameterized Doyle-Fuller-Newman (DFN) model was validated against experimental data. The cell features a layered oxide cathode and a hard carbon anode. For analysis, the cell was opened in an argon-filled glovebox to separate the electrode materials. Post-mortem analysis techniques were employed alongside half-cell setups with three-electrode configurations for electrochemical characterization. The electrochemical characterization included pseudo Open Circuit Potential (pOCP) experiments to determine cell balancing and specific capacities, as well as adapted Galvanostatic Intermittent Titration Technique (GITT) tests to evaluate electrode kinetics. In addition to conventional analytical methods, model-based optimization techniques were used to refine the determination of electrode parameters. To the best of the authors knowledge, this is the first study to investigate the influence of the temperature, to the state-of-charge-dependent solid-state diffusivity and exchange current density of a commercial sodium-ion battery cell. The obtained parameters were used to parametrize a DFN model incorporating a 0-dimensional thermal model, which was validated against experimental data. Therefore measurements of an experimental three-electrode cell as well as measurements of the commercial full-cell were compared with the model data of the parametrization results.