MULTIPHYSICS-CONSTRAINED SAFE CHARGING BOUNDARY OF LITHIUM-ION BATTERY WITH MODEL PREDICTIVE CONTROL

The lithium-ion battery (LIB) is susceptible to overheating and rapid degradation during fast charging. Therefore, it is crucial to actively manage the key intermediate physical states of the LIB within acceptable parameters while maintaining fast charging speeds. Motivated by this concern, our paper proposes a multiple physics-constrained fast charging strategy for LIBs. We establish a comprehensive electro-thermal-aging model under typical charging scenarios. Building upon this foundation, we design a model-based observer to accurately estimate the state of charge and internal temperature of the LIB in real-time. To address the conflicting objectives of charging speed, temperature control, and degradation rate, we propose a model predictive control-based strategy to optimize the charging process. Experimental results demonstrate that our proposed strategy effectively keeps the internal battery temperature below the predetermined threshold while maintaining a comparable charging speed. Furthermore, our strategy leads to slower degradation compared to the widely-used constant-current-constant-voltage charging approach. After 200 charge-discharge cycles, the capacity decay rates are 2.12% and 4.88% for our proposed strategy and the traditional method, respectively. Through model predictive control, our fast-charging strategy effectively manages battery internal states, resulting in significant improvements in speed, safety, and battery lifespan extension.