The science behind exploding phone batteries

An exploding phone seems like a freak accident, but the same chemical properties that make batteries work also make them likely to catch fire. Samsung is learning this the hard way, as it becomes the latest company to recall a device — in this case, its new Galaxy Note 7 phone — because the batteries could be dangerous.

When batteries explode, it’s often the failure of manufacturers to make sure no explosion will happen. Exploding batteries can be the consequence of overeager companies pushing technology to the limit. As our screens gets bigger and phones more powerful, they need more energy, but most of us are unwilling to give up battery life or charging speed.

We’ve already achieved almost 90 percent of the maximum battery life...