When an electric car's lithium-ion battery is damaged or found to be defective, it has to be transported for recycling/disposal within an expensive explosion-proof container. According to a new study, though, such batteries could soon simply be frozen.
The danger in transporting compromised lithium-ion batteries lies in the fact that they could go into thermal runaway, a phenomenon in which a battery suddenly releases all of its stored energy, causing its temperature to rapidly rise. As a result, the battery may ignite, explode, and release toxic gases.
It is for this reason that the batteries have to be placed within an explosion-proof box for transit – those boxes aren't cheap, however. Scientists at Britain's University of Warwick state that a single such container, large enough to contain a "typical Tesla-sized battery," costs approximately €10,000 (about US$11,072). What's more, getting the required United Nations accreditation for that container reportedly costs another €10,000.
With that problem in mind, researchers at the university teamed up with engineers from Jaguar Land Rover, utilizing liquid nitrogen to flash-freeze and then store lithium-ion batteries for two weeks. Once those batteries thawed, it was found that the freezing process hadn't affected their energy capacity or service life. Additionally, even when nails were driven through the frozen batteries, no fires or explosions occurred.
The transit process would require some electricity, as the batteries would have to be constantly kept at a temperature of at least -35 ºC (-31 ºF). Their simple plastic transport container, however, should cost only about £200 ($259), overall making the whole setup considerably less costly than the use of traditional explosion-proof boxes.
"Transporting damaged and defective batteries is an expensive and unsustainable process, however being able to freeze them with liquid nitrogen could save thousands of pounds and help electric vehicle manufacturers be more sustainable," says U Warwick's Dr. Thomas Grandjean.
A paper on the research was recently published in the Journal of Energy Storage.
Source: University of Warwick