Improvements to Multi-Scale, Mechano-Electrochemical Modeling Methods

Automotive battery manufacturers are working to improve individual cell and overall pack design by increasing their performance, durability, and range, while reducing cost; and active material volume change is one of the more complex aspects that needs to be considered during this process. Designers try to control or mitigate the effects of volume change using a variety of methods: inserting foam layers into battery packs, programming specific charging algorithms, using multiple active materials, etc. However, designers must resort to extensive testing to fully develop these methods for each new battery design because of the complexity in measuring and understanding the links between active material volume change’s mechano-electrochemical effects on the electrode and cell level. A multi-scale modeling approach shows promise to comprehensively account for active material volume change. In the work shown here, a mechano-electrochemical model was employed [1-4] to explore mechano-electrochemical relationships: (1) understanding the effects of realistic mechanical behavior of each cell component including foam packaging, (2) understanding the effects of thermodynamically non-ideal volume change behavior, and (3) relative lithiation (thus, volume change) behavior for electrodes with multiple active materials (such as a silicon-graphite composite anode). The unique ties between active material voltage, active material volume, and N:P capacity ratio will be discussed as well. References T. R. Garrick, K. Higa, S.-L. Wu, Y. Dai, X. Huang, V. Srinivasan and J. W. Weidner, Journal of The Electrochemical Society, 164, E3592 (2017). T. R. Garrick, X. Huang, V. Srinivasan and J. W. Weidner, Journal of The Electrochemical Society, 164, E3552 (2017). T. R. Garrick, K. Kanneganti, X. Huang and J. W. Weidner, Journal of The Electrochemical Society, 161, E3297 (2014). D. J. Pereira, J. W. Weidner and T. R. Garrick, Journal of The Electrochemical Society, 166, A1251 (2019). D. J. Pereira, M. A. Fernandez, K. C. Streng, X. X. Hou, X. Gao, J. W. Weidner, and T. R. Garrick, Journal of The Electrochemical Society, 167, 080515 (2020).