Courtesy of Samsung
Everyone loves their phone right? We use them every day and for many, their phone is never more than an arm’s length away. Lately however, it seems like some people’s phones are not loving them back.

When the Samsung Galaxy Note 7 was released in August, it was heralded by many as the most powerful smartphone on the market. It incorporated Samsung’s best technologies into a sleek, compact body. At first, all was well; critics were having a field day, pre-orders were proceeding at a record pace and it seemed the Note was set to be one of Samsung’s most successful products ever.

Within two weeks, reports of the phone exploding and catching on fire began to surface. In a press conference, Samsung representatives said the company was “conducting a thorough investigation [and] will share its findings as soon as possible.”

Shortly after the first reports of exploding phones, Samsung confirmed that it was recalling all 2.5 million phones that had already been sold, promising a speedy replacement program. The faulty phones gained even more attention when the FAA warned passengers not to turn on or charge their phones onboard aircraft. With other US transportation administrations following suit, passengers across the country were now being treated to a warning about exploding cell phones.

Finally replacement models begin to hit stores, surely the worst is over? Not quite, reports of the replacement phones exploding begin to emerge. At this point, major carriers began to stop sales of the Note 7. On October 11, 2016, Samsung officially kills the Note 7, halting all sales and production permanently.

Curious as to why the phones were exploding? The short answer is that there was a manufacturing defect regarding the lithium-ion battery. Nearly all smartphones on today’s market are powered by lithium-ion batteries; these batteries have a liquid inside them called an electrolyte, which is highly flammable. Normally this is not a problem, however, if the battery is poorly shielded, it can be punctured. When punctured, the path of least resistance for the electric charge is directly through the electrolyte; when this happens, the electrolyte, which is extremely sensitive to temperature, can explode.

This is the same problem that was associated with the flaming hoverboards of last year. It is also the primary safety concern for electric cars, which use massive batteries. However in the case of cars, the batteries are heavily shielded. Tesla, for example, uses a military grade titanium sheet and a ceramic firewall to protect the driver.

In the case of smartphones, where making the thinnest, most compact phone is the name of the game, battery shielding is not really a viable option. The Galaxy Note 7 is not the first exploding phone we have seen and as consumers demand longer and longer battery life, it certainly won’t be the last.