Liar Liar phones on fire! The story behind the Galaxy Note 7

Dr Lorenzo Grande
Liar Liar phones on fire!  The story behind the Galaxy Note 7
The South Korean giant Samsung just got itself into dire straits as the story behind the reported battery fires related to the Galaxy Note 7 unfolds even further. As of September, 92 accidents have been reported in the US alone.
As a recent article on Bloomberg reports, 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 on the lack of new features on Apple's new device, executives at Samsung hoped that they could steal Cupertino's podium and finally assert their company as the one leading in smartphone innovation. 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) in order to deliver better performance and longer duration.
However, this addition came at the cost of quality, since all the testing and optimisation were performed in a fraction of the time normally required, in order to speed up the phone's commercialisation. 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 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 a few later also announced the release of a software patch that would prevent said fires from happening, thus ingenerating 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 officialised a complete recall of all 2.5M phones shipped so far, with an estimated cost for the firm that runs in the billions, not to mention the loss of consumer confidence.
As a result, Samsung is now getting major negative publicity on many international flights, where cabin crews invite all passengers to switch off their Galaxy Note 7 and prohibits them from charging it 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 avenue, and 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 now 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 as 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 might demand for 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 accidents show, Li-ion batteries are still prone to catching fire and endangering their owners. The reason behind it is the fact that flammable liquids are used as electrolytes. A number of additives is mixed with these electrolytes to act as flame retardants, but the truth is 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 that, batteries have to be charged at constant voltage and that might trigger the lithium plating phenomenon on graphite anodes, a preamble to the growth of the so-called dendrites. These 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 Microvast, who will be speaking at our Energy Storage Innovations conference in Santa Clara, CA, recently showcased a non-flammable liquid electrolyte for their Li-ion batteries that can potentially revolutionise the sector, although it is yet to be seen if it can deliver the power capabilities needed by products other than buses, like smartphones, laptops, and electric cars.
Ionic liquids have long been heralded as a viable solution as well, 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, and 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 at our Santa Clara conference too, by showcasing its 350 Wh/kg (750 Wh/L) energy storage technology for mobility applications.
IDTechEx follows the energy storage market very closely and we particularly like to focus on safety when evaluating all future technologies. At our Santa Clara conference, many players will be presenting on this issue, like California-based Polyplus and Boston-bred Solidenergy, both of which have developed innovative semi-solid electrolytes for safer batteries. IDTechEx will deliver a presentation on the state of the art of solid-state and polymer electrolytes, as well as promote our upcoming report on solid-state and polymer battery technology. The full speaker agenda may be found at the following link:
Top image: Samsung