Path Dependence of Battery Degradation

Electrification of transportation and grid-storage are crucial to combat climate change. Understanding and mitigating battery degradation is key to improving durability of electric transportation and the reliability of power grids. Complexity stems from the fact that battery degradation is path dependent. This imply that usage affects not only the degradation pace but also the type of degradation the batteries experience. Lithium-ion batteries are known to degrade slowly at first before a rapid acceleration of which starting time will depend on the mix of degradation mechanisms and thus on how the battery was used. To maximize the utility of large battery systems, it is essential to understand the impact of all the stress factors associated with an application and their combined effects.

Initially funded under DOT/EVTC, then ONR/APRISES, this research first delved into the effect of grid-vehicle interactions on the performance of Li-ion batteries facilitating the determination of the causes of cell deterioration and the accurate prediction of capacity loss during real-world use. Current work with DSTG (Australia) involves an experimental campaign of more than 700 cells tested under a HNEI defined design of experiments to predict the degradation of MW systems and maximize their durability and reliability in the field.