Early in December, researchers from Warwick Manufacturing Group (WMG) at the University of Warwick UK in collaboration with Jaguar Land Rover engineers froze batteries with liquid nitrogen. Research suggests this would allow lithium car batteries to be transported safely in a much cheaper and environmentally friendly way.
Transporting damaged and defective lithium car batteries is an expensive process; they need to be placed in an explosion proof box that costs thousands of dollars. An explosion proof box to transport a typical Tesla sized battery costs $13,000 plus governmental accreditation fees—another $13,000 with the UN. However, the ability to transport them in plastic containers, costing a few hundred dollars has been made more accessible, thanks to researchers from WMG.
In the paper, “Cycle life of lithium ion batteries after flash cryogenic freezing,” published in the Journal of Energy Storage, researchers highlight that cryogenic freezing allows for safe transportation without affecting a lithium ion battery’s energy capacity, cycle or service life.
As electric vehicle (EV) sales increase, there is more concern for the transportation of damaged and defective lithium ion battery packs, for which EV manufacturers are picking up the bill. Explosion-proof boxes are used to contain the battery in case it goes into thermal runaway, an overheating condition that can lead to violent explosions and the release of toxic gases. Being able to cryogenically flash freeze the battery completely removes the risk of an explosion, and could mean they can be transported safely in a standard box.
Researchers tested the batteries’ activity before and after freezing the cells with liquid nitrogen and showed that their performance was not affected by the freezing. The team tested the batteries in the most extreme abuse conditions, such as driving nails through the cells and inducing external short circuits, demonstrating that the freezing process is effective and safe.
When being transported, batteries will have to be kept in a container at -35 ºC. However, the amount of packaging is significantly less than explosion-proof boxes, making the process environmentally friendly.
“Transporting discarded batteries is an expensive and unsustainable process,” said Dr. Thomas Grandjean, researcher at WMG. “However, being able to freeze them with liquid nitrogen could save thousands of dollars and help electric vehicle manufacturers become more sustainable.”