Evaluation of tortuosity: A radical tessellation-based method in porous spherical particle packing systems

Estimating the tortuosity of porous electrodes is important for understanding the performance of lithium-ion batteries and optimizing the design of electrode microstructures. In this work, a new method for estimating the tortuosity of porous electrodes is proposed based on radical tessellation, and the results agree well with those calculated by empirical formulas and finite element simulations. Compared with empirical formulas, the proposed method can estimate tortuosity for more complicated microstructures, regardless of particle distribution and size dispersity; compared with finite element simulations, the proposed method offers a significant advantage in computational efficiency. Based on the method, the influence of different microstructure characters on the tortuosity is discussed. It is found that in addition to the porosity, the particle size and particle aggregation morphology are all critical in influencing the tortuosity of the porous electrode. Finally, the tortuosity obtained by this method is integrated into the Pseudo-2-dimensional (P2D) model for the calculation of effective properties, and the results show that this method offers an efficient way in improving the prediction accuracy of P2D models.