A defective design is allegedly what caused so many Samsung Galaxy Note 7 smartphones to catch fire and explode, not the lithium batteries as the Korean electronics giant once indicated, an independent team of engineers and developers who solve technical problems for a living has concluded.
Samsung started recalling its Note 7 devices in September as reports of fires and explosions mounted. The company remanufactured the phones using different batteries, but the problem persisted. In October, Samsung made the unprecedented move to stop production and kill the entire Note 7 product line. But the South Korean manufacturer hasn’t said much about the troubled smartphone since.
Instrumental’s team of technical problem solvers studied the Galaxy Note 7 and found that the lithium-ion batteries weren’t defective; instead, Samsung’s aggressive design, intended to compete with the iPhone 7 Plus, compromised the safety of the devices, they allege:
“The Note7’s lithium-polymer battery is a flattened ‘jelly-roll’ consisting of a positive layer made of lithium cobalt oxide, a negative layer made of graphite, and two electrolyte-soaked separator layers made of polymer. The separator layers allow ions (and energy) to flow between the positive and negative layers, without allowing those layers to touch. If the positive and negative layers ever do touch, the energy flowing goes directly into the electrolyte, heating it, which causes more energy to flow and more heat—it typically results in an explosion. Compressing the battery puts pressure on those critical polymer separator layers that keep the battery safe.”
The Instrumental researchers found that the Note 7’s battery could become compressed, thus subject to overheating and exploding, even during normal use.
It’s likely that Samsung’s drive to out-do Apple’s thin design prompted changes to the battery throughout the manufacturing process, and so the “newest versions of the batteries might not have been tested with the same rigor as the first samples,” Instrumental researchers surmised.
The researchers said even if Samsung hadn’t recalled the Galaxy Note 7 for exploding batteries, other problems would have become apparent as the devices aged.
“[We] believe that a few years down the road these phones would be slowly pushed apart by mechanical battery swell. A smaller battery using standard manufacturing parameters would have solved the explosion issue and the swell issue. But, a smaller battery would have reduced the system’s battery life below the level of its predecessor, the Note 5, as well as its biggest competitor, the iPhone 7 Plus. Either way, it’s now clear to us that there was no competitive salvageable design.”