Towards Fast and Safe Recharging of Li-ion Batteries: Design, Parameterization and Experimental Validation of a Pseudo-2D Electrochemical Model Based on Homogenization
Abstract: Fast charging of lithium-ion batteries remains a major challenge due to degradation, safety risks and ageing. Preventing lithium metal deposition during fast charging requires dynamic current adjustment to keep the negative electrode potential above 0 V vs. Li+/Li. Since this potential is inaccessible to direct measurement in commercial batteries, we propose a new variant of the pseudo-bidimensional electrochemical model, enabling real-time estimation of the potential profile across the thickness of the electrodes. A non-linear state representation is obtained from the coupled partial differential equations of the system, via an electrode homogenization approach and non-uniform grid discretization. Experimental parameterization of the model is performed using a three-electrode setup. The model exhibits robust numerical stability, enabling reliable simulations down to 10C. Finally, its predictive capability is demonstrated by validation coupled with parameter estimation for constant load regimes between 2C and 6C.
Keywords: Lithium-ion battery, Fast charging, Pseudo-2D model, Parameterization, Homogenization technique, Lithium deposition
Towards Safe Fast Charging of Li-ion Batteries: Design, Parameterization, and Experimental Validation of a Homogenization-Based Pseudo-2D Electrochemical Model
Abstract: Despite the growing demand for shorter charging times, fast charging of lithium-ion batteries remains challenging due to performance degradation, safety risks, and aging constraints. Preventing lithium plating during fast charging necessitates dynamically adjusting the charging current to keep the negative electrode potential above 0 V vs. Li+/Li. As this potential is not directly measurable in commercial cells, this work develops a novel pseudo-two-dimensional electrochemical model variant. The model enables realtime estimation of the through-thickness potential profile in each electrode. Derived from coupled partial differential equations via electrode homogenization and a non-uniform grid, the model is formulated as a non-linear statespace system. The experimental parameterization of the model is achieved using a threeelectrode assembly. The model demonstrates robust numerical stability, enabling reliable simulations at rates as high as 10C. Finally, the model’s predictive capability is demonstrated through simultaneous validation and parameter estimation across charging rates of 2C to 6C.
Keywords: Lithium-ion battery, Fast charging, Pseudo-2D model, Parametrization, Homogenization Technique, Lithium plating
