Why do lithium-ion batteries start fires?

6/21/2022 (Permalink)

You’ve probably seen in the news plenty of reports of lithium ion batteries exploding or catching fire without warning.

To a degree, these reports are misleading. The vast majority of lithium ion batteries are safe and will never cause you any problems.

But that doesn’t mean that there’s absolutely no risk, either. Here’s why.

Inside every lithium ion battery, there are two electrodes. One is positively charged and one is negatively charged, and they are separated by a very thin piece of plastic. The reaction between these two electrodes, the other components and the electricity flowing through the battery is what gives lithium-ion batteries such incredible storage and recharging capacity.

But it’s that same technology that also gives them the capacity to explode. If the plastic separator fails, then all of the energy stored in the battery gets released in a single jolt when the electrodes touch. That leads to a huge discharge and potential disaster.

Again, these batteries are getting safer and more effective every day. But it’s interesting to note that what makes them so effective is also what causes fires.