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Oct. 3, 2016: EE Times

Liar, Liar, Phones on Fire!

The story behind the Galaxy Note 7.

The South Korean giant Samsung finds itself on the hot seat as the story behind the reported battery fires related to the Galaxy Note 7 unfolds even further. As of September, 92 incidents have been reported in the US alone.

As a recent article on Bloomberg reported, Samsung wanted to beat Apple at the game of innovation by releasing a better, more powerful smartphone before the iPhone 7 reached the shelves. By leveraging the lack of new features in Apple's latest device, executives at Samsung hoped that they could steal Cupertino's podium and finally assert their company as the leader in smartphone innovation. In order to achieve this, they decided to pack a 3500 mAh Li-ion battery into their Galaxy Note 7 (as compared to the 2900 mAh of the iPhone 7 plus) so as to deliver better performance and longer duration.

However, this addition came at the cost of quality, since -- in order to speed up the phone's commercialisation -- all of the testing and optimization were performed in a fraction of the time normally required. Samsung engineers were encouraged to sleep overnight in the office in order to save time from their daily commute, and suppliers were pushed to give Samsung priority with respect to other customers. By August 2016, the required technical deadlines had been met and shipping of the new Korean device began.

It did not take long before some customers started reporting spectacular failures of their new purchase with flames and smoke coming out of the battery compartment, but perhaps the biggest fiasco came from how the company managed the whole situation. At first, Samsung advised its customers to switch off their Note 7, but shortly thereafter, also announced the release of a software patch that would prevent said fires from happening, thus generating a good deal of confusion among the now-not-so-proud owners of Samsung's newest smartphone. By September, the issue had grown to such an extent that the company authorized a complete recall of all 2.5 million phones shipped thus far. The estimated cost for the firm runs into the billions of dollars, not to mention the loss of consumer confidence.

As a result, Samsung is now receiving major negative publicity on many international flights, where cabin crews invite all passengers to switch off their Galaxy Note 7 phones and prohibits them from charging these devuces while on the plane. Samsung SDI, the battery maker behind the incident, recently shrank its total staff from 7,408 in late 2015 to 6,937 as of June as a cost-saving measure. Samsung SDI is largely responsible for the battery fires, which seem to have been caused by the use of a thinner separator that could not cope well with the dense packing and caused short circuits within the device. The company no longer supplies batteries for the Note 7, and its role in future products might also be reduced. ATL China has now taken Samsung SDI's place in the supply chain.

Executives at KBIA, the Korean Battery Industry Association, fear that this accident might trigger a similar crisis to the one Sony experienced a few decades back, when Li-ion batteries were first introduced to the market. However, while at that time Li-ion was a relatively new technology and the numbers involved were relatively small, the current situation is very different, since the market has grown exponentially and Samsung is poised to remain one of the biggest players for the years to come. While some competitors like LGChem might benefit from Samsung's mistakes in the short term, the incident can well slow down the decrease in battery prices that has been witnessed in recent years, with negative repercussions for the whole budding industry behind the energy storage miracle. As consumers demand safer devices (would you leave your Samsung charging anywhere in your absence?), stricter regulations might also ensue, stifling what has otherwise been a technological success story second only to that of PV panels in recent years.

As the Note 7 incidents illustrate, Li-ion batteries are still prone to catching fire and endangering their owners. The reason behind this is the fact that flammable liquids are used as electrolytes. A number of additives are mixed with these electrolytes to act as flame retardants, but the truth remains that -- under the right conditions -- thermal runaway is still an issue, and even the best BMS (battery management systems) cannot fully prevent accidental fires from happening.

As a matter of fact, combustion in Li-ion batteries can be triggered hours, if not weeks, after a battery pack has been irreversibly damaged, but the reaction time of the BMS might be too slow to block thermal runaway once it is detected, since heat propagates at an exponential rate in these cases. The consumers' hunger for fast-charging smartphones also does not help, since in order to achieve this, batteries have to be charged at constant voltage. This might trigger the lithium plating phenomenon on graphite anodes, a preamble to the growth of so-called dendrites, which are lithium metal whiskers that can puncture the separator, create a short circuit, and offer a local source of overheating that is sufficiently strong to set the whole device on fire.

The solution lies in the quest for inherently safe batteries that do not contain flammable electrolytes. E-bus company Microvas showcased a non-flammable liquid electrolyte for their Li-ion batteries that can potentially revolutionize the sector, although it is yet to be seen if it can deliver the power capabilities needed by products other than buses (e.g., smartphones, laptops, and electric cars).

Ionic liquids have long been heralded as a viable solution due to their extremely high flashpoint; however, an industrial production that can bring their cost down has not yet been put into place. A more detailed analysis of their potential is available in our flagship report on Li-ion batteries. Inorganic and polymer electrolytes also have the potential to make batteries safer. This year, an article on the peer-reviewed journal Nature Energy reported a sulphur-chlorine-based solid conductor that conducts lithium ions faster than state-of-the-art liquid electrolytes; companies like Toyota, Samsung SDI, and LGChem are already looking into its potential.

Using non-flammable electrolytes also has the added benefit of increasing a battery's energy density at pack level, because they can make thermal management systems redundant and reduce the amount and weight of ancillary components. Solid Power, a Colorado-based start-up, will be presenting its take on safe, solid-state, sulphur-based batteries for electric vehicles by showcasing its 350 Wh/kg (750 Wh/L) energy storage technology for mobility applications at the IDTechEx Santa Clara conference.

More information on related topics will be covered at the forthcoming IDTechEx Show!, which will take place November 16-17, 2016, in Santa Clara, California.

At IDTechEx, Dr. Lorenzo Grande's activities revolve around energy storage for electric vehicles and consumer electronics. He focuses on lithium-ion, sodium-ion, lithium-sulphur, lithium-air, solid-state, and supercapacitors. Lorenzo holds a PhD magna cum laude in Physical Chemistry from the University of Münster in Germany, which he carried out at the MEET Battery Research Centre and at the Karlsruhe Institute of Technology. During his doctoral studies, he focused on advanced anodes and electrolytes for post-lithium-ion batteries, as well as thermal sensors for Li-ion batteries. Prior to that, he obtained his MPhil in Micro- and Nanotechnology Enterprise from the University of Cambridge and his BSc in Industrial Chemistry from the University of Rome.

Lorenzo has worked on graphene-based materials at the Nokia Research Centre in Cambridge (UK) and has been a visiting scholar at the University of Aveiro in Portugal and at the Italian National Agency for New Technologies and Energy in Rome. With an h-index of 5, his extensive experience on energy storage has resulted in seven peer-reviewed scientific articles, five of which as first author, and one book chapter. Lorenzo is also an alumnus of ELEEP, a US-EU network of ca. 100 experts in energy and environmental policy (an updated list of Lorenzo's publications can be found here).

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