Exploding-battery epidemic caused by 'lithium moss'
iPod trouser inferno horror a thing of the past?
Researchers at Cambridge University have proposed using nuclear magnetic resonance to work out why lithium batteries keep exploding.
Lithium batteries are great - lots of battery life and relatively fast charge time: so it seems churlish to avoid using them just 'cos they blow up every now and then. But now researchers are hopeful that a new way of looking at the problem will yield methods to prevent even that minor drawback.
The problem is in the dendrites - tiny fibres of lithium that form on the carbon anode when you charge a lithium battery. Charge it too fast, and too often, and the dendrites get long enough to short out the battery - cue explosion.
The details of how dendrites form are opaque; they're more usually associated with the freezing process and it's hard to look into a charging battery using optical or scanning electron microscopes, which is why NMR is now being proposed.
The paper describing the process, which appears in the Nature Materials, calls for a very small lithium-ion battery - about 1cm long - which can be watched in minute detail by an NMR scanner to monitor how the dendrites (or Li-moss as the researchers term it) grows.
The idea is that once the process is observed in real time scientists will be able to play around with the conditions to find out why it happens and, ideally, prevent it. That's going to be really important if we're going to be driving around in lithium-ion-powered cars, or riding lithium-powered motorcycles - though what happens when they hit each other is another question entirely. ®