Every few years, exploding phones find a way to dominate the news cycle. And while these accidents are incredibly rare, they’re a bit difficult to understand. Why do phones explode? And how do I know that my phone won’t explode?
Thermal Runaway Causes Phone Explosions
Whenever a Li-ion battery explodes or catches fire, it’s undergoing a process called thermal runaway. This process can be a bit difficult to understand, so we’ll keep things short, sweet, and free of dense scientific jargon.
Lithium-ion batteries contain a ton of Li-ion cells. Each of these cells has a critical temperature—think of it as a boiling point. When the critical temperature of a cell is reached (due to external heat, overcharging, damage, or poor manufacturing), it enters an exothermic breakdown. Basically, the cell itself starts to release a ton of heat.
This kicks off the process of thermal runaway, which is essentially a positive feedback loop (like when you put a microphone next to a speaker). Once a cell enters exothermic breakdown and releases heat, its neighboring cells are destined to hit their own critical temperatures. Depending on the speed of this process, a battery could quietly sizzle out, catch fire, or create a minor explosion.
Now that we understand the process of thermal runaway, it’s a lot easier to pinpoint how, when, and why phones (among other Li-ion devices) explode.
If your phone or another device has a swollen battery, however, you’ll want to do something about that right now.
RELATED: What to Do When Your Phone or Laptop Has a Swollen Battery
Don’t Leave Your Phone in the Car
If you live in a snowy area, you’re probably aware that car batteries work best when they’re a little warm—say, 80 degrees Fahrenheit. You’re probably also aware that too much heat can ruin a battery, along with other components in a car. Well, the same goes for phone batteries.
When a Li-ion battery discharges at a high temperature (sitting outside or in a car), its cells can become a bit unstable. They may not enter an exothermic breakdown, but they can permanently short, deteriorate, or (oddly enough) produce gases like oxygen and carbon dioxide. These gases can cause the battery to inflate like a balloon, which creates pressure (energy that can cause an explosion) or compromise the battery’s structure.
