Multi-zoned equivalent circuit modelling for health-aware battery fast charging optimization

Lithium-ion cells exhibit a great degree of dynamism. Using a single model, the conventional cell modelling technique presents challenges in accurately mapping and predicting the battery's performance. This paper proposes employing a novel multi-zoned equivalent circuit model to accurately represent the battery's charging characteristics. The charging zone has been divided according to the findings of electrochemical estimation. The galvanostatic intermittent titration method and electro-impedance spectroscopy measure the cell's diffusion coefficient and charge transfer resistance at an SoC interval of 1.18%. These indicate the primary degradation events that occur throughout the charging process of a lithium-ion battery. Electro-impedance spectroscopy is used to evaluate the multi-zoned equivalent circuit model. Three zonal modelling techniques have been discussed: dual, triple, and quad zoned. The accuracy of this model is proved by validating it using a cell cycling test bench, which predicts the voltage (98.14%), current (97.95%), and ageing (98.35%). Moreover, when compared to benchmark strategies, it clearly shows its efficacy. This presents the potential for using a similar approach to develop battery-fast charging systems that prioritize health and are built around digital twins.