Samsung made the news a few years back over their exploding batteries. 2.5 million Samsung phones shipped, and somewhere between 90 and 100 failed so badly they exploded. Exploding was the extreme case, and many more had issues of battery inefficiency and getting too hot inside the phone. Ultimately, the problem was a welding defect – the battery’s innards were squished up too close together, and so they overheated. This led to puff-ups and reactions inside the battery that produced more heat and more gas, and eventually, some phones got too hot to keep working, some overcharged and puffed, some exploded.
It wasn’t a consistent issue – as mentioned above, only about 90 phones went out with fireworks – but it was common enough to warrant a loose recall. This was followed by a more stringent recall when the replacement batteries also had the same problem. Airlines stopped letting people with Samsung phones travel, and the post office was unhappy with the number of fire-hazard boxes that were theoretically fine, but could also explode, traveling through their hands.
Here’s some information on the type of battery used in phones and other high-power battery electronics, as well as a few tips on what might come before an explosion like Samsung’s.
Lithium ion and Lithium polymer batteries
The premier choice for electronics batteries. They will behave badly if they come into contact with air, because the elements inside are very reactive! Lithium is in the first two columns of the periodic table. The periodic table is (more or less – this is extremely simplified) sorted by atomic weight, and then divided into rows by electron shell completeness. Being near the left side of it means that lithium has an incomplete electron shell, and will desperately try to snatch electrons from its surroundings. As a result, it’s very reactive. Meanwhile, on the right hand side where all the cool gasses hang out, you have things like Argon and Neon. These won’t react at all with other materials because their shell is complete – they don’t want any more electrons, and won’t react unless under extremes.
Overreacting
Lithium reacts poorly with air and even worse with water. In water, a piece of plain lithium peels the atoms apart to form lithium hydroxide, a more stable molecule than raw lithium alone. What it leaves behind is hydrogen gas, and splitting apart water creates some amount of heat because water is also stable – the lithium just wants the oxygen more than the hydrogen does. Hydrogen gas is flammable. End result: mild explosion! At least until the outside of the lithium chunk is coated in oxide. Air is much the same: the dramatic plumes of smoke that come from pierced batteries are a result of the reaction, but multiplied by internal pressure.It’s not as clean or quick as a plain old lithium chunk in air, as videos show!
Actual Safety
Lithium ion and lithium polymer batteries are good choices for cell phones. These batteries hold a lot of charge in a small space! Unfortunately, they’re extremely reactive with the air due to that lithium mentioned before. Even pinhole punctures lead to blowups, and if they were never made right in the first place, thermal runaway and overcharging can turn into fire hazards. If contaminants got in during the manufacturing process, it wouldn’t even take a pinhole puncture to puff up eventually – only heat and time. Dropping a poorly made battery could weaken the battery case enough to rupture it inside the phone, which is rare, but not unheard of.
However, assuming no damage or illegitimate parts, lithium batteries are generally safe. After all, how many times have you dropped your mobile device without it going off? Everything else tends to break before the battery does unless it’s something thrown together in a black-market ring.
Battery issues are pretty rare, and most people won’t run into one unless they’ve really screwed the phone up. That doesn’t mean they never happen though. Here’s some safety tips gathered from other folks who specialize in batteries, not just tech.
Fire!
If the phone’s smoking, DON’T FIDDLE WITH IT. It’s already beyond salvation. Don’t touch it, don’t try to turn it off – treat it like it’s a lit firework. Recommendations on what to do next are mixed, but a fire extinguisher is a controversy-free choice for putting out fires. Best thing you can do in that moment is to follow grease fire guidelines! Don’t move it with your bare hands, try to get it outside, and don’t use water! One man discovered that water didn’t do anything to stop the flames, and he was forced to let it run its course outside, under a pan lid (komando.com). Others say that cold water might cause the screen to splinter – which makes it sharp and on fire.
If the phone’s beginning to melt down while it’s still plugged into a charger, water can make the problem many, many times worse. Dumping water on the phone can trip a circuit in the house! Experts recommend letting it burn out outside away from flammables or using a fire extinguisher. Baking soda is also a common recommendation for grease fires, and if this article from TechnoBuffalo hasn’t gone out of date, it might help quell the flames of your phone, too.
Puff-Ups
If you notice your battery puffing up and pushing the screen away from the frame, get it to a shop – and don’t wait! If the battery is puffing up, that means something is happening inside it that’s creating gas. Most of the time with Li-Ion or LiPo batteries, that reaction’s due to contact with outside air, or contaminants getting inside the battery. Nothing that’s supposed to be there will produce gas by itself. If it’s noticeably hot to the touch and puffing up, stop messing with it.
It may be on the verge of catching fire, and Li-Ion batteries burn hot. Power it down if it’s safe to do so, take it outside and keep it away from flammables for observation. You might still have a chance to replace the battery if it cools down and doesn’t start heating up again, judging by Samsung’s recall statement. Turning the phone off might buy time, and at the very least it can’t hurt it. Don’t try to turn it off if it’s already on fire or too hot to touch (obviously). BatteryWorld recommends getting it repaired or replaced before it gets to that point, and we do too. Recovering data from a melted hard drive is nearly impossible. Don’t turn it back on, and don’t plug it in until that’s handled!
Side Note: How Batteries work, Kinda
Ions are what power batteries. In LiPo and Li-Ion batteries, an electrolyte solution (or solid) allows the ions to travel between the anode and the cathode inside the battery. An ion is just atom that’s not neutral: cations become positive by losing an electron, while anions become negative by gaining one.
Ions are attracted to their opposite charge, so they travel through the solution to get to the opposite node, which releases energy that the device can use. For a battery to be rechargeable, it needs to be able to re-store energy. Electrical energy reverses this process to create chemical energy, and the cycle repeats when it’s unplugged from the charger.
Certain decisions with materials lead to the battery reacting differently. The electrolyte medium changes a lot about the shape and size the battery can reach. Lead-acid batteries can be hazardous to throw away, but they hold charge pretty well, so they’re popular in cars! While nickel-metal batteries discharge evenly right up until they die, but not very powerfully, so they’re great for emergency equipment like radios. Consumer cell phone batteries are no exception. Lithium ion puts out a lot of power for a small amount of material, so it’s a favorite for high-power devices like phones.
Most batteries are pretty difficult to dispose of in an environmentally-friendly way. Batteries contain potent chemicals! But you know what’s even worse than having to drop off a car battery at an auto shop so they can dispose of it? Having it leak on your property, or even worse, having it leak and then having some kid or animal get into it. Dispose of your batteries responsibly! The same goes for cell phones – don’t just throw them straight in the trash. Wipe the drive first, and then take it somewhere that offers phone recycling. You don’t want people getting ahold of your data. You also don’t want that Li-Ion battery catching fire in the back of the dump truck!
Sources:
https://batteryuniversity.com/index.php/learn/article/the_li_polymer_battery_substance_or_hype
https://www.ifixit.com/Wiki/What_to_do_with_a_swollen_battery
https://www.howtogeek.com/425488/why-do-phones-explode-and-how-to-prevent-it/
https://www.theverge.com/2016/9/19/12900530/samsung-galaxy-note-7-imei-checker#content
https://www.komando.com/news/samsung-phone-caught-fire-and-exploded/740549/ (please note – ads take up a lot of the screen, you have been warned)
https://www.batteryworld.com.au/news/expert-advice/2020/i-have-a-swollen-battery-what-now
https://www.technobuffalo.com/fire-department-heres-what-to-do-if-your-galaxy-note-7-or-iphone-explodes
https://www.faa.gov/hazmat/resources/lithium_batteries/media/Battery_incident_chart.pdf
https://batteryuniversity.com/learn/article/nickel_based_batteries