Cambridge experts have discovered an incredibly straightforward solution for extending the lifespan of EV batteries: simply apply some pressure to them.

      Researchers have discovered a method to extend the life of EV batteries without the need for new battery designs.

      Innovations in EV batteries usually involve advanced chemistry, unique materials, or enhancements in charging speed and capacity. However, a recent study indicates that a straightforward solution can yield impressive results. As per researchers from the University of Cambridge, applying the correct amount of pressure to the battery can help prolong its lifespan.

      The research focused on how physical pressure impacts the life of lithium-ion batteries and concluded that maintaining a constant pressure on the cells could potentially double their longevity. The findings, published in Nature Energy, suggest that these enhancements were achieved without altering the active materials, electrolyte, or fundamental battery chemistry.

      How does pressure contribute to battery performance?

      Lithium-ion batteries expand and contract during charging and discharging, a motion that Cambridge likens to the act of breathing. Over time, this repetitive mechanical strain can lead to deterioration within the cell. To conduct their study, the researchers created a custom device that applied consistent pressure to lithium-ion pouch cells through pneumatic bellows, functioning like adjustable air cushions. The system also monitored slight variations in battery thickness throughout the cycling process.

      The crucial discovery was the optimal pressure point, around 12.5 bar or approximately 181 psi, at which the cells exhibited nearly double the lifespan compared to those subjected to lower or higher pressure. While this translates to minimizing the battery's "breathing," it doesn't imply that every EV battery must be excessively compressed to achieve such outcomes. Instead, precise control of the pressure is essential.

      Why incorrect pressure levels can be detrimental

      The study identified various failure modes relative to the pressure applied. Low pressure accelerated cracking in the cathode, while excessive pressure led to lithium plating on the anode, which negatively impacts both battery longevity and safety. Consequently, there's a challenge in finding the right balance rather than implementing a simple solution. EV batteries can benefit from being maintained under optimal mechanical conditions, but the system must manage pressure consistently as the battery cycles, ages, and alters shape.

      The methodology is intriguing, as it takes a mechanical design approach rather than focusing solely on chemical and other factors. The research is still in the early stages and has only been tested in the lab, so it won't be seen in next year's EVs immediately. The University of Cambridge has filed a patent through Cambridge Enterprise, and the next step will be to devise a way to scale the pressure control concept for commercial battery packs.