Five questions that arise when and why smartphone batteries explode

Samsung’s Galaxy Note 7 has been in the headlines for the past couple of weeks after a series of reports of the device catching fire and exploding due to defective batteries surfaced. As a result, the South Korean giant was compelled to globally recall the Galaxy Note 7 and warn its customers to stop using the device.
The Galaxy Note 7 is the latest in a series of lithium-ion batteries catching fire on products ranging from laptops to hoverboards to airliners. This incident just serves as a reminder that pushing the technology cover can sometimes be difficult.
Here are some things to know about the recall and why batteries can be a fire hazard.

How do these batteries work and why do they catch fire?
A lithium-ion battery is a type of rechargeable battery in which lithium ions move from the negative electrode – the anode – to the positive electrode – the cathode – during discharge and back when charging.

Manufacturers insert separators to keep these two layers—or conductors— apart, as they are not supposed to touch each other. Regrettably, the chemical reaction that makes batteries work also generates heat. However, charging them too fast or overcharging the packs can lead to fires.
What is the issue with Samsung’s batteries?
While no one knows the reason, Samsung has however given some hints. It said due to a “very rare manufacturing process error,” parts of the battery came together that should never touch each other.
When manufacturing their next-generation technology, device makers consider all kinds of factors like performance, cost and safety. Further, the need to induce more battery life into their latest smartphone or tablet can lead to unexpected results.

“Smartphone makers are trying to squeeze these batteries into a small, thin package,” said Hideki
Yasuda, an analyst at Ace Research Institute in Tokyo.
“Since batteries generate energy through a chemical reaction, it’s really hard to reduce the risk (of fire) to zero.
“Sometimes convenience comes with a price.”
Has this happened before?
Yes. Products such as Sony Vaio laptops, last-year’s must-have toy – the hoverboard, electric bikes and even Boeing’s Dreamliner jet have reported instances of battery fires.
In Samsung’s case, defective batteries caused some devices to explode and catch fire while charging.
Following the recall announcement of Samsung’s Galaxy Note 7 devices, cases of exploding batteries continued to appear as users claimed a burning device had set a car on fire in the U.S. or damaged a hotel room in Australia.
How widespread is the problem?
Not much. In a year, millions of lithium-ion batteries are produced with a small fraction of those catching fire or exploding.
About 35 incidents that involved Samsung’s Galaxy Note 7 batteries were received at the start of this month.
“It’s not easy to know if Samsung’s problem is the same as others…at this point,” Yasuda said.
“If its battery suppliers sell these same ones to other producers, it could possibly affect them too.”
What does this mean for Samsung and other gadget makers that use these batteries?
It will harm Samsung’s reputation and likely upset profits at a time when it is facing tough competition from Apple’s iPhone and Chinese rivals in the lower-end category. A major share of Samsung’s profits comes from its mobile business accounts.
It will also put pressure on gadget manufactures to find out how to make battery packs safe for ever-smaller devices.
“We always want batteries to be safe but also to be more efficient,” said Guy Marlair, a France-based safety expert.
“The more that we boost the battery’s performance, the higher the energy density in a small space and the tougher it is to manage security.”