Quantitatively Analyzing the Failure Processes of 4.45 V High-Voltage Licoo2/Graphite Battery by Constructing the Direct Current Internal Resistance Decomposition Model

Accurate failure analysis play a pivotal role in the optimization design and lifetime prediction of 4.45 V high-voltage LiCoO2/Graphite (LCO/Gr) batteries. Multiphysics coupling brings great opportunities to conduct battery failure analysis accurate and quantitatively, although it is quite challenging because a large number of model parameters need to be handled properly. Herein, we systematically elaborate the differences of ion and electron transport properties before and after cycling ageing of LCO/Gr batteries by constructing direct current internal resistance (DCR) decomposition model. The key parameters acquisition method is established, and the mechanism of DCR growth is elucidated. Furthermore, the aforementioned model parameters are refined by using a hybrid power pulse characteristics (HPPC) curve optimization algorithm based on DCR decomposition results obtained from the three-electrode battery system. Through analyzing the influence of single-factor parameter ageing on battery voltage output capacity and discharge temperature rise, the main factors affecting battery failure process are identified. This work provides a reliable protocol for the battery life predication and battery management of high voltage LiCoO2/graphite battery.