Lithium dendrite deposition kinetics and its dynamic impact on capacity fading of lithium-ion batteries

Lithium dendrite growth limits lithium-ion battery applications, particularly in fast charging across temperatures. This study quantifies the dynamic effects of microscale lithium deposition on battery performance using a multi-scale model combining Phase Field Model (PFM) and pseudo 2D model. The image recognition program is introduced to achieve the identification of dead lithium and cross-scale transfer calculation of lithium deposition rate. The results show that the morphology of lithium dendrites is highly dependent on the magnitude of overpotential. Three distinct lithium dendrite morphologies are identified, each associated with varying degrees of overpotential. Additionally, the magnitude of lithium deposition rate is nearly proportional to the magnitude of overpotential. The formation of dead lithium, which is morphology-dependent, leads to the consumption of lithium ions in the electrolyte, thereby decreasing the capacity in subsequent cycles. The numerical predictions of battery capacity decay in good agreement with experimental results for high charging/discharging rate, demonstrating the reliability of the proposed multi-scale model in simulating the impact of lithium dendrites on battery performance during fast charging/discharging. This study shows important significance for the design and optimization of lithium batteries and also provides theoretical support for the further development of battery technology.