One of the many dirty secrets of smartphones involves their batteries. In general, lithium-ion batteries are relatively stable, but if the right conditions are met, we end up carrying a small bomb in our pockets. As lithium use increases, we need to develop safer batteries, but first… we need to know how they fail. That's where a recent study from University College London comes in.
The news spread with a speed that only the Web can achieve. For safety reasons, several airlines decided to limit or outright ban the commercial transport of lithium-technology batteries on their planes. The most recent tests, including one by the US FAA, indicate that a fire caused by an unstable cell aboard an aircraft would be extremely difficult to control at best, making that possibility an unacceptable risk for passengers, crew, and the aircraft. Another part of the problem is that battery demand is steadily rising, as their presence now extends to electric cars and even home solutions like the Tesla Powerwall. Everyone agrees that a method must be developed to make lithium-ion batteries safer, but the first step requires going in exactly the opposite direction, and blowing a few up.
University College London, in association with Imperial College London, the ESRF and NPL in London, has carried out a study that allowed observing in real time the failure of a lithium-ion battery exposed to high temperatures. The process combines thermographic images with X-rays, so that researchers were able to evaluate the situation of a cell both on the surface and inside it. The use of X-rays is not new in this case, but the difference is that previous studies were done post-mortem, that is, after the cell exploded, using static images, whereas here we can appreciate a video.
The batteries were "tortured" with temperatures above 250 degrees Celsius. One of them, manufactured with an internal support, managed to resist up to a thousand degrees before the copper inside melted, so we are talking about a more controlled thermal collapse. However, a battery without that support literally lost its top due to the explosion, scattering its contents. Experts highlighted that it is very unlikely that a lithium-ion battery would be subjected to such extreme conditions, but they are necessary to understand both the failures themselves and the theoretical damage and dispersal. Personally, I think this is excellent news. There will be more lithium-ion batteries among us in a few years, and if there is a way to make them safer, welcome it.
