EV battery breakthroughs typically involve new chemistry, exotic materials, or faster charging/higher capacity. But a new study reveals that you can skip all the fancy stuff and go with a very simple solution, Researchers from the University of Cambridge found that putting the battery under the right amount of pressure actually helps.
The study was about how physical pressure affects lithium-ion battery life, which found that keeping cells under constant pressure could double their lifespan. The work was published in Nature Energy, and the team says the improvement came without changing the active materials, electrolyte, or basic battery chemistry.
How does putting pressure help?
Lithium-ion batteries physically expand and contract as they charge and discharge. Cambridge compares this motion to breathing. Over time, that repeated mechanical stress can contribute to degradation inside the cell. To study it, the researchers built a custom device that applied steady pressure to lithium-ion pouch cells using pneumatic bellows, which act like self-adjusting air cushions. The setup also measured tiny changes in battery thickness during cycling.
The key finding was a pressure sweet spot. At around 12.5 bar, or roughly 181 psi, the cells lasted about twice as long as cells tested at lower or higher pressure levels. While in simpler terms it means not letting the battery “breathe”, this does not mean that we have to crush every EV battery to see amazing results. The pressure needs to be controlled carefully.
Why putting too much or too little pressure is bad
The study found different failure modes depending on pressure. When pressure was too low, cathode cracking accelerated. When pressure was too high, lithium plating appeared on the anode, which is also bad for battery life and safety. So there’s this Goldilocks problem than a straightforward fix. EV batteries can benefit from being held under the right mechanically conditions, however, the system needs to keep pressure steady as the battery expands, contracts, ages, and changes in shape.
But the approach is interesting. Rather than tackling the chemistry and other aspects, it is looking at the issue from a mechanical design perspective. The research is still early-stage and was tested at laboratory scale, so this is not something that will show up in next year’s EVs automatically. Cambridge has filed a patent through Cambridge Enterprise, and the next challenge is figuring out how to scale the pressure-control idea for commercial battery packs.