Tracking exploding Lithium-ion batteries in real-time

What happens when lithium-ion batteries overheat and explode has been tracked inside and out for the first time by a UCL-led team using sophisticated 3D imaging. Understanding how Li-ion batteries fail and potentially cause a dangerous chain reaction of events is important for improving their design to make them safer to use and transport, say the scientists behind the study. Hundreds of millions of these rechargeable batteries are manufactured and transported each year as they are integral to modern living, powering mobile phones, laptops, cars and planes. Although battery failure is rare, earlier this year, three airlines announced they will no longer carry bulk shipments of lithium-ion batteries in their cargo planes after the US Federal Aviation Administration tests found overheating batteries could cause major fires. The study by UCL and provides an indication of how this can spread to neighbouring batteries. First author, UCL PhD student Donal Finegan (UCL Chemical Engineering), said: "We combined high energy synchrotron X-rays and thermal imaging to map changes to the internal structure and external temperature of two types of Li-ion batteries as we exposed them to extreme levels of heat. We needed exceptionally high speed imaging to capture 'thermal runaway' - where the battery overheats and can ignite.