While watching the news earlier today, my ears perked up on a segment about the Samsung Galaxy Note 7 smart phone. Why? Because I’m shopping for a new smart phone and this brand and model made my Top 5 list. The NBC News reporter informed viewers that the Consumer Product Safety Commission (CPSC) is urging anyone who owns a Galaxy Note 7 smart phone to stop using it immediately! WOW! That’s a lot of smart phones!!!
Coupled with the CPSC’s announcement, the Federal Aviation Administration (FAA) is also asking passengers to “switch-off” this brand and model of phone while on an air plane. When the batteries charge and overheat, they can catch fire.
The problem with the Galaxy Note 7 is not the phone itself. It is the risk of the lithium-ion batteries catching fire! This isn’t the first time I’ve written about the risk of fire from lithium-ion batteries. In an earlier post, How Do You Ban Hoverboards If None Have Been Sold?, I shared that these two-wheel self-balancing boards were all the rage in 2015 and on every other person’s holiday wish list.
Unfortunately, there was also a downside to these alternative transportation units. Some of the boards, primarily the lower priced models, caught fire while being charged or when being ridden. Others have had issues with smoke coming from the wheels or the battery unit. Regrettably, these units have been responsible for at least two home fires. During the last few weeks of 2015, news accounts of self-balancing boards smoking or exploding and catching fire while being ridden led to bans or restricted use by cities, airlines, high schools, colleges and universities, shopping malls and other places. Amazon and Overstock discontinued sales of some of the brands and/or models that were being sold.
Now, back to those smart phones. Wired Magazine reported that Samsung officially recalled millions of its popular new Galaxy Note 7 smartphones. The reason given is dozens of reports of devices overheating, burning, and even exploding.
So what is the problem with lithium-ion batteries? George Crabtree, director of the Joint Center for Energy Storage Research at Argonne National Lab explains it this way [Ref 1]: One is that you can overcharge, and that leads to heating, and can lead to unwanted chemical reactions in the anode. The problem can occur going the other direction, during discharge, as well. The cathode contains oxide, Crabtree says, which can combine with organic materials in the electrolyte and release heat. A “low-quality” battery, one where impurities sneak in, can also be responsible for unpredictable results.
In a conversation with the Wall Street Journal, Samsung Electronics’ handset division chief Koh Dong-jin said: The reported explosions in its Galaxy Note 7 devices were caused by a flaw in the battery cell and had nothing to do with the phone itself…In the Galaxy Note 7, a flaw in the battery cell resulted in negative and positive electrodes coming together which is abnormal.
“There was a minor flaw in the battery manufacturing process,” said Mr. Koh, adding that “the quality control standards in the production process may have been insufficient.”
And just so you know, Julianne Troiano does an excellent job of explaining how lithium-ion batteries work [Ref 2]:
a) Powering Mode:
Batteries store and releases energy by moving electrons from one “end” of the battery to the other. The energy from those moving electrons can be used to do work for us, like power a drill, a lighting unit, notebooks, or other electronic devices. These two battery “ends” are known as electrodes. One is called the anode and the other is called the cathode. Generally, the anode is made from carbon and the cathode from a chemical compound known as a metal oxide (cobalt oxide, for example). The final battery ingredient is known as the electrolyte, and it sits in between the two electrodes.
In the case of lithium-ion batteries, the electrolyte is a salt solution that contains lithium ions—hence the name.When you place the battery in a device, the positively charged lithium ions are attracted to and move towards the cathode. Once it is bombarded with these ions, the cathode becomes more positively charged than the anode, and this attracts negatively charged electrons.
As the electrons start moving toward the cathode, they are forced to go through the device and use the energy of the electrons “flowing” toward the cathode to generate power. As a comparison, think of a water wheel, except instead of water flowing, electrons are flowing.
b) Charging/Recharging mode:
One of the selling points of lithium-ion batteries is that they are rechargeable. When the battery is connected to a charger, the lithium-ions move in the opposite direction as before. As they move from the cathode to the anode, the battery is restored for another use. The fact that the lithium-ion battery is rechargeable makes it more desirable and sustainable.
Given the reoccurring problems of smoke, fire, and explosions of electronic devices, is there a fix for this problem? The good news is that there is and progress is already being made in that direction. Earlier this year, researchers at Stanford University published a report on a passive method of shutting down batteries when temperatures rise, a membrane that gradually expands when things get hot until it’s big enough to shut off current to the cathode. It’s always going to be a trade off between effectiveness and safety, but it’s an increasingly narrower one. [Ref 1]
CPSC advises all consumers to report product safety incidents involving lithium-ion batteries in smartphones to them at www.SaferProducts.gov.
- Why Smartphones Still Blow Up, by Brian Barrett for Wired Magazine – Gear Section, September 2, 2016, https://www.wired.com/2016/09/smartphones-still-blow/
- How do Lithium Ion Batteries Work? A Nanotechnology Explainer, by Julianne Troiano for The Center for Sustainable Nanotechnology, October 15, 2013, http://sustainable-nano.com/2013/10/15/how-do-lithium-ion-batteries-work/