Stanford’s Simple Method to Supercharge Battery Lifespan

A groundbreaking study from the SLAC-Stanford Battery Center has uncovered a method to significantly enhance the lifespan of lithium-ion batteries, with implications for electric vehicles and energy storage systems. By charging these batteries at high currents during their first charge cycle—known as the formation charge—researchers achieved a 50% increase in average battery life, while reducing the initial charge time from 10 hours to just 20 minutes.

Traditionally, manufacturers opt for a slow, low-current charge to form the solid electrolyte interphase (SEI) layer, a critical component that protects the battery’s negative electrode from degradation. However, this process is time-consuming and costly, with no guarantee of optimal results. The Stanford study, published in Joule, suggests that a high-current formation charge not only accelerates the process but also results in a more efficient and longer-lasting SEI layer.

Machine Learning’s role

To reach these conclusions, the research team, led by Professor Will Chueh in collaboration with the Toyota Research Institute (TRI), utilized scientific machine learning to sift through numerous factors influencing SEI formation. Surprisingly, the analysis revealed that only two factors—charging temperature and current—played a decisive role in enhancing battery performance.

Experiments confirmed that charging batteries with high current during the first cycle deactivates a greater percentage of lithium ions—around 30%, compared to the typical 9%. While this initially seems counterproductive, it actually frees up space in the positive electrode, allowing for more efficient cycling in subsequent uses.

Charging new lithium-ion batteries at high currents depletes more lithium but forms a protective layer, boosting battery lifespan and performance, SLAC-Stanford research finds. STANFORD SLAC

“This approach not only provides a faster method for forming batteries but also offers deeper insights into the process, which are invaluable for battery manufacturers,” stated Xiao Cui, lead researcher for the battery informatics team at Stanford.

Implications for manufacturing

The findings have significant implications for the battery industry. The high-speed pre-charge technique could streamline production processes, reduce costs, and enhance the performance of batteries used in electric vehicles and other applications. The research, part of SLAC’s broader sustainability initiatives, exemplifies how industry partnerships, such as those with TRI, can lead to practical advancements in battery technology.

“This study showcases the potential of combining advanced machine learning with traditional battery research to solve real-world manufacturing challenges,” Chueh stated. “By understanding the ‘how and why,’ we can improve not just the batteries themselves but also the methods used to produce them.”