Samsung recently recalled 2.5 million Galaxy Note 7 smartphones after reports of the phone exploding started doing the rounds worldwide. The U.S Consumer Product Safety Commission advised the consumers “to stop charging or using the device.” The Federal Aviation Authority also warned its passengers to not carry the device or even put them in checked in baggage over security threats.
But this isn’t the first time a lithium-powered device has exploded. In 2006, Dell recalled more than 4 million laptop battery packs over combustion problems. More than 500,000 hoverboards were also recalled this year due to battery explosions. A number of mobile phones too, over the years, have exploded, sometimes even injuring the user critically. So what happened to Galaxy Note 7? Why have we not evolved from lithium-ion batteries? And most importantly, how can we prevent our beloved smartphones from exploding on our face?
Why lithium-ion batteries?
Lithium-ion batteries have been an integral part of every mobile phone since its first commercial release twenty-five-years-ago in 1991. They were the choice of batteries for rechargeable electronic devices like laptops and cell phones. Not only because they last a lot longer than a regular AA, but more so because it was cheap to produce and buy and didn’t take ages to recharge. It works like most batteries too. It would store energy and release it as and when required via controlled chemical reactions. A Li-ion battery will have two electrodes on opposite ends. This is the place where the electricity enters and leaves the battery. Just like a normal battery that has a + and a – sign on either end, one electrode will be charged with positively-charged ions, called cathode and the other, will be filled with negatively charged ions called anode. So when we use a lithium powered device, let’s say our smartphone, the lithium moves from the cathode to the anode and when we put our phones to charge, the lithium moves back from the anode to the cathode. There is always a separator between the anode and the cathode to prevent the two from touching each other. Scientists around the world are working on alternative solutions that can be brought into the mainstream, but an affordable breakthrough is yet to be introduced.
How do these end up exploding then?
If the cathode and anode touch, it can trigger certain reactions like catching fire and explosions. Samsung, on its U.K website, released a statement confirming that at least 35 cases of phone explosion have been reported. They said that the batteries combusted due to a “very rare manufacturing process error” where the anode and cathode touched. But that isn’t the case every time.
Most of the times, phones or other devices explode because of errors in the charging process. The batteries rely on a software which basically instructs them how much the batteries should be charged and how fast. When there is an error in these set protocols, it can destabilise the chemicals inside the batteries. Lithium reacts with pretty much everything, by the way, so destabilised chemicals cause a chain reaction known as a “thermal runaway”. Thermal runaway can lead to fire or explosions.
Shoddy manufacturing of devices can also be blamed for the explosions. Sometimes scraps of metal or other objects find their way inside the battery when the phone is being made, which ends up setting off a thermal runaway.
Overheating can also be a reason. Many phones nowadays are completely made of metal (because, who likes plastic anymore, right?) which makes the phone even hotter. Many phones also send you a notification about needing to cool down when it gets too hot. Batteries can also heat up and fail when they’re charged too fast or kept in charge for way too long.
Dropping your device could also affect the way your phone behaves. Sometimes, the impact causes the separator between the anode and the cathode to break, and you know what happens when the anode and cathode react with each other, don’t you?
What can we do to prevent?
Smartphones don’t come cheap and are more valuable to some than human beings, so why not take the necessary precautions to treat it right?
– Always avoid 3rd-party/ non-certified/fake chargers. The Rs 1000 that you save on the charger might just come back to haunt you, making you shell out a lot later.
– Do not overcharge. A lot of people put their phones to charge next to them when they go to sleep. This is dangerous. Charge it through the day if you have to, never leave it for charge overnight.Â
– Do not use non-certified local power banks. They might be considerably cheaper than other branded ones, but they might also end up doing irreparable damage to your phone.Â
– Do not leave your phone out in the sun for too long, especially if you’re living in a hot country like India.
– Don’t put too much pressure on your phone.
– Use a good phone cover if you’re known to be clumsy. A good phone cover will always absorb the drop impact.Â
Stop freaking out, though.
Having said all this, you must know that there is still no reason to panic unnecessarily. Even in Samsung’s case, less than 100 cases have been reported in a batch of 2 million Samsung Galaxy Note 7s. That’s a probability of 0.005%. Most companies follow excessive quality control measures to make sure mishaps like this don’t happen. But a freak accident can never be ruled out.
By Rishabh Banerji