Bhubaneswar: The recent cellphone blast cases, which saw five students sustaining serious injuries and one among them losing an eye, raise the pertinent question as to why phone batteries explode.
As the demand for bigger and faster phones increases, so does the need for battery life. According to a report on ‘The Verge’ magazine who interviewed Lynden Archer, a materials scientist at Cornell University, manufacturers are pushing the limits more and more to eke out only a little bit more energy. “There’s been a bit of an arms race where every manufacturer of a smartphone wants to get the highest battery life. This trend in the field is producing more and more of a tendency for overcharging so all these models of failure are becoming more commonplace,” he said.
Samsung’s Note 7 battery catching fire in 2016 lead to a massive recall of around a million units. In Lithium batteries, there are two terminals, the cathode and the anode apart from the lithium gel-like electrolyte in them. The terminals are physically separated by a permeable polyethylene separator, often few microns thick. In the Note 7, the two terminals eventually came in contact with each other and that led to a short circuit with temperature reaching as high as 1000F.
“The separator has really gotten thin,” said Isidor Buchmann, founder and CEO of Cadex Electronics, a leader in battery testing and equipment manufacturer who runs the educational website Battery University while speaking to Consumer Reports. “And when that happens, the battery becomes more delicate,” he added.
Experts state that, apart from faulty manufacturing design (as in case of Samsung), the two other major reasons are heat and overcharging. Dan Steingart, a materials scientist at Princeton University, in a report published on The Verge, explains that the battery is like a rubber band during charging, it stretches and while using, you are releasing the rubber band. If it is stretched too hard, it can break. All modern phones have a way to stop overcharging by limiting the flow once the desired charge is reached. But a technical fault in the way of managing this can lead to overcharging. The demand for fast charging, and pushing the limits to achieve it is a concern. If a phone is not capable of handling the faster charging, it can make the lithium build on itself to form needle-like structures called dendrites that can lead to internal short-circuiting of the battery, said Steingart.
Are Lithium Batteries Safe?
K.M. Abraham, an expert on Li-ion battery and a professor at Northeastern University, USA on speaking with consumerreports.org said, “There are more than a billion cellphones and computers used in the world every day,” and “It’s a very, very low probability of your phone catching fire. Lithium-ion batteries have a failure rate that’s less than one in a million.” In comparison to that, the National Oceanic and Atmospheric Administration says there is one in 13,000 chance for everyone to get struck by lightning in their lifetime.
Things To Watch Out For:
- Heat is the biggest threat. Don’t keep charging your phone it if becomes too hot. Let it cool and also check if any app is causing it. Stick to verified apps. Phone covers usually prevent the heat from escaping. Remove it if it is getting too hot.
- Stick to manufacturer recommended or first-party chargers and also the cable of good quality.
- Don’t charge your phone in a place where heat cannot escape, such as the bed or under a pillow.
- Also don’t charge your phone for a long time in direct sunlight, inside a car or wherever it can get too hot. All phones come with a recommended operating temperature.
- Using your phone while charging can lead to overheating as in addition to charging and discharging, the processors and other components are working and producing heat, which can potentially damage the battery. The chances are even higher if there is a cover preventing the heat to escape. Same is applicable for power banks.
- If there is a hissing, popping sound or swelling, it is an indication that the battery is damaged and could explode. Remove the battery or turn off the device and keep it on a non-combustible surface in this situation.