Correlation between Cell Thickness Profile and Lithium Plating: Applications in Lithium Plating Detection and Capacity Rollover Diagnostics

<div class="section abstract"><div class="htmlview paragraph">In the realm of low-altitude flight power systems, such as electric vertical take-off and landing (eVTOL), ensuring the safety and optimal performance of batteries is of utmost importance. Lithium (Li) plating, a phenomenon that affects battery performance and safety, has garnered significant attention in recent years.</div><div class="htmlview paragraph">This study investigates the intricate relationship between Li plating and the growth profile of cell thickness in Li-ion batteries. Previous research often overlooked this critical aspect, but our investigation reveals compelling insights. Notably, even during early stage of capacity fade (~ 5%), Li plating persists, leading to a remarkable final cell thickness growth exceeding 20% at an alarming 80% capacity fade.</div><div class="htmlview paragraph">These findings suggest the potential of utilizing cell thickness growth as a novel criterion for qualifying and selecting cells, in addition to the conventional measure of capacity degradation. Monitoring the growth profile of cell thickness can enhance the safety and operational efficiency of lithium-ion batteries in low-altitude flight systems. Furthermore, this study proposes an innovative approach for onboard Li plating detection by considering signals related to cell thickness data. This method reduces computational demands, enhancing detection efficiency—a vital advancement for real-time monitoring in low-altitude flight power systems. Moreover, our research establishes a strong correlation between the occurrence of Li plating and the loss of active material in the negative electrode, shedding light on the underlying mechanisms and emphasizing the need to mitigate this phenomenon.</div><div class="htmlview paragraph">Overall, this study significantly contributes to the existing research focused on improving the safety and efficiency of lithium-ion batteries in low-altitude flight applications. By emphasizing robust detection techniques for Li plating, we pave the way for safer and more efficient power sources in this rapidly evolving field.</div></div>