An Online Fast Charging Strategy to Prevent Lithium Plating Based on Electrochemical-Thermal-Aging Coupled Model

Abstract

The fast charging of lithium-ion batteries (LiBs) plays a pivotal role in the widespread deployment of electric vehicles (EVs). However, conventional fast charging approaches usually cause battery life degradation in pursuit of the fastest charging speed, which is manifested in the acceleration of internal side reactions and the increase in byproducts. Additionally, offline control lacks real-time feedback of data, which increases the difficulty of control due to the data errors. Therefore, this work proposes a lithium-plating-constrained online fast-charging strategy based on an electrochemical–thermal–aging coupled model, in which the charging current is dynamically regulated to prevent lithium plating during fast charging. The model, after comprehensive validation for accurate battery characteristic simulation, is utilized for real-time charging optimization to determine the optimal current that prevents lithium plating. Experimental results demonstrate that the proposed method can charge the battery from 0% to 80% state of charge (SoC) within 705 seconds, representing a 31% reduction in charging time compared with conventional methods. Long-term cycling experiments indicate a 26.5% reduction in state of health (SoH) degradation compared with the same-charging-time constant current-constant voltage strategy, while post-mortem analysis shows weaker aging and less pronounced lithium-plating-related morphological features on the anode cycled with the proposed strategy.