Development of a fast-charging strategy considering degradation in lithium-ion batteries

This study develops an advanced single-particle model to analyze the effects of C-rate and temperature on lithium-ion battery degradation during fast charging. By incorporating lithium plating overpotential, a predictive map of lithium plating generation is established, enabling the proposal of an optimal fast-charging strategy to extend battery cycle life. Degradation analysis reveals that activation overpotential dominates capacity loss in early charging cycles, whereas degradation overpotential becomes predominant over time. At a 2.1C charging rate, degradation overpotential contributes to a 45 % capacity reduction at the 120th cycle, with 82 % of the degradation attributed to lithium plating. Parametric studies show that lithium plating becomes severe at high C-rates and SOCs, increasing the plating rate by a factor of 20. Conversely, increasing the temperature from 25 °C to 55 °C improves lithium-ion diffusivity, reducing lithium plating by a factor of nine. An optimal fast-charging strategy is proposed by dynamically adjusting C-rate: starting at high C-rate to elevate temperature and progressively decreasing C-rate to regulate lithium plating overpotential. Experimental validation shows that this strategy extends battery life by 170 % compared to conventional CC-CV charging. These findings provide valuable insights for developing efficient and reliable battery management strategies.