An accelerated method for determining the solid-phase diffusion coefficient and reaction-rate constant for Li-ion batteries

This study presents a novel approach to accelerate galvanostatic intermittent titration technique (GITT) measurements for determining the solid-phase diffusion coefficient (Ds) and reaction-rate constant (k0) used in physics-based models such as the Doyle-Fuller-Newman (DFN) model. The approach addresses the challenge of lengthy measurement times associated with the conventional methods. By leveraging the benefits of the DFN model in predicting the local states in the cell during battery operation, the proposed accelerated method achieves high accuracy with a rest duration of 10 min, producing results comparable to the standard method with 6 h relaxation duration after each GITT pulse. Additionally, the introduction of a relaxation-rate of 10 mV h-1 reduces total measurement time by 95 %. The study also demonstrates that the extended single particle model (ESPM) provides an efficient alternative to the DFN model for the determination of Ds and k0, reducing computational requirements while maintaining accuracy. These findings significantly accelerate physics-based model parameterization, facilitating faster cell development and improves the accessibility of high-quality electrochemical parameters.