Lithium-ion batteries are the heart of any smartphone, without which the devices would not even boot up. However, the batteries have been known to be quite risky. From smartphones manufactured by Samsung to NASA’s experimental robots, lithium-ion batteries have exploded and caught fire on several occasions.
Explosions and fires
In 2016, a NASA robot project ended up engulfed in a huge fireball, giving people a good idea of how dangerous lithium-ion batteries can be. The researchers had just completed installing a new battery into the bot and plugged it into the charging port. Shortly thereafter, the battery exploded. The team later concluded that the battery had a damaged cell that caused it to overcharge and overheat. Eventually, it caught fire and affected the rest of the 96 battery cells.
The most famous case of exploding batteries would be Samsung smartphones. Though many models have faced such issues, none was as notorious as the Galaxy Note 7. So many Note 7 phones exploded from faulty batteries that Samsung had to conduct two recalls that cost the company approximately US$5 billion. The cause of the explosions was found to be the irregular size of the batteries that resulted in overheating. Even in the second batch of replacement batteries, manufacturing defects resulted in fires.
So, how do lithium-ion batteries work? “Inside every lithium-ion battery, there are two electrodes — the positively charged cathode and the negatively charged anode — separated by a thin sheet of “microperferated” plastic that keeps the two electrodes from touching. When you charge a lithium-ion battery, lithium ions are pushed by electricity from the cathode, through the microperferations in the separator and an electrically conductive fluid, and to the anode,” according to How To Geek.
Lithium-ion batteries found in small devices like smartphones typically only have a single cell. For devices like laptops, 6 to 12 cells are used. And when it comes to bigger batteries like those of electric cars, hundreds of cells are involved.
There are many reasons why lithium-ion batteries tend to explode. A poorly made charger might result in batteries getting overcharged and bursting into flames. Batteries that are exposed to a very high heat source are also at risk of explosion. Dropping the phone very hard can cause the electrodes to touch each other and result in a spark. If the battery gets pierced, then a short circuit is almost guaranteed. And finally, there is the issue of manufacturing defects, as seen in the case of Samsung phones.
Dealing with battery explosions
Before a battery catches fire, it will usually swell up or get hot. You can sense this by feeling a slight bulge in the device. The battery will soon exhibit discoloration. Eventually, it will blister and start smoking. Remember to never touch a swelling battery with your bare hands.
When the battery catches fire, you can try to douse it with water. If a foam extinguisher is available, then definitely use it. Now, if you are unable to put out the fire, ensure that any flammable object near the burning battery is removed to a far distance. Cover your nose and try not to breathe in the fumes emanating from the battery.
In case the battery is lithium-metal instead of lithium-ion, you may need a class D fire extinguisher to put out the flames. Also known as dry powder extinguishers, they cut off the fire by separating the fuel from the oxygen element. Class D extinguishers are not suitable in the case of lithium-ion battery explosions.