In a postmortem report on the Galaxy Note 7, Samsung Electronics Co Ltd detailed faulty battery design and manufacturing issues that caused the devices to overheat and catch fire, forcing a massive recall.
Yet even as Samsung unveiled a series of new safety measures, including a new board that will consult on its battery designs, researchers advising the company acknowledged that there are risks to using lithium ion batteries, the longtime standard for mobile phones, in increasingly tight spaces.
"There's a demand from the electronics of wanting batteries that have higher energy density ... which means that the batteries last for longer," said Clare Grey, a professor of chemistry at the University of Cambridge, in a video Samsung released Jan. 23. "And then there's a tension of wanting to put them into increasingly smaller spaces ... so inevitably that comes with risks associated with the fact that you've got highly oxidized and highly reduced materials in very close proximity," she added.
Some experts have noted that while fires are relatively rare — Sony Corp. recalled lithium ion battery packs for its VAIO laptops last year and hoverboards have also been affected by faulty batteries — lithium ion batteries are vulnerable to manufacturing defects. A manufacturing defect was ultimately found to be the cause of the Sony VAIO battery pack recall, for example, said Donald Sadoway, a professor of materials chemistry at the Massachusetts Institute of Technology, in an email.
"The Samsung case is unusual for a major producer," Sadoway said.
A focus on safety
Yet despite the widespread publicity about the problems with the Galaxy Note 7, which Samsung scrapped permanently in October 2016, some observers said it was unlikely to spark a widespread shift to other battery technologies for mobile phones.
"Samsung's got a black eye from this, but from competitive pressure they can't do anything else but continue down this road," said Gene Armstrong, senior director of applications development at the Paper Battery Co., a Troy, N.Y.-based firm that makes an alternative to batteries that use supercapacitors.
Lithium ion's dominance is due to both the batteries' low cost and to their high energy density, which allows them to run for longer than other alternatives without being charged, a key requirement for consumers who use data-intensive mobile devices, Armstrong said in an interview. Other researchers have argued that alternatives would require a new chemistry or a new physical form, while also needing a larger infusion of funding to be commercialized.
"I don't see that there will be an emerging technology that will solve these problems," Armstrong said.
During its press conference Samsung stressed that safety was a top priority, describing a series of preventative measures designed to uncover faults. For example, the company disassembles and X-ray scans batteries from external suppliers at random before they are shipped to Samsung. It also detailed a test designed to measure how the phone batteries performed under accelerated usage conditions.
Samsung's initial battery design for the Galaxy Note 7, released when the device launched in August 2016, featured a damaged electrode in the battery's upper right hand corner. After recalling these phones, which had batteries made by its own supplier, Samsung SDI, according to Bloomberg News, the electronics maker switched suppliers to an outside company, Amperex Technology Ltd.
But in the rush to produce the replacement devices, the new batteries suffered manufacturing defects, including a high welding burr that caused an internal short circuit, the company said.
"That's always a worry. A good design can be undone if the supplier fails to meet specifications on the components," noted MIT's Sadoway.
As an alternative to a lithium ion battery, supercapacitors charge much more quickly and don't involve a chemical reaction, eliminating many safety concerns, said Shreefal Mehta, Paper Battery's CEO. But, as he noted in an interview, they lack the energy density of lithium ion batteries, making supercapacitors better suited for relatively low energy uses, such as game controllers or wearable technology, rather than high-powered mobile phones.
"We believe we are a good alternative for segments of the market that are able to see their charge point come up frequently enough that they are comfortable doing that quickly and then moving to their functional work, rather than someone who is out all the time and they have trouble finding a charge point," he said.
While Samsung and other mobile phone makers are unlikely to embrace another technology entirely, Mehta said, the public scrutiny around the Galaxy Note 7 investigation also offers Samsung a public platform to regain consumers' trust.
"I think the most important thing that people listening right now are looking for is 'Can they identify the specific reason to give confidence to people that they understand why this happened?,'" he said.
Still, as Samsung gears up for the launch of its Galaxy S8, reportedly in late March or April, the controversy around the Galaxy Note 7 may have little impact on consumers' appetites for a new phone, Mehta added.
"It is a very popular product line that they have succeeded in putting in the market so I'm sure ... that you will get people buying their phones without thinking twice about what the impact might be," he said.