As we all know the 7th generation of the Samsung Note did not live up to the of expectations Korean manufacturers.Tech enthusiasts all around the world suspect the cause of the explosion to the batteries.
According to battery expert Dr. Donald R. Sadoway, the John F. Elliott Professor of Materials Chemistry at the Massachusetts Institute of Technology (and onetime TIME Most Influential Person) to explain how batteries work, he decided to a little bit of battery chemistry.
He explained that :
[Lithium-ion batteries] are a classical battery in the sense that they have two electrodes separated by an electrolyte. In this case, the negative electrode is typically some kind of a carbon, like a graphite, and the positive electrode is a metal oxide, something like lithium cobalt oxide or lithium manganese oxide. The electrolyte, because it’s shuttling lithium, it has to be non-aqueous. They can’t use an acid or an alkaline solution, they have to use something that’s not water, and that’s part of the problem. It’s an organic liquid and so therefore it’s volatile and flammable. But it does dissolve lithium salt and it allows lithium to shuttle back and forth between the negative electrode and the positive electrode.
Let’s [talk about] the battery at full state of charge. At full state of charge, all of the lithium is up inside the negative electrode. It’s sitting inside the graphite. On discharge, the lithium wants to go from the graphite over to the cobalt oxide. So it takes a swim through the electrolyte and enters the cobalt oxide, and electrons go through the external circuit and power your devices. That’s what generates the current and so on.
In short Donald said,
What happened there was, somehow during the manufacturing process, very tiny particles of metal had ended up in the electrolyte . . . under the action of electric current, these metal fragments aligned, and they eventually formed an unbroken chain of metal from one electrode to another. So then you’ve got the current shorting through this filamentary wire, if you will, so you’ve turned the inner electrode gap into a toaster oven. That causes all of the current to short, and generates a lot of heat, and that causes the electrolyte to bloat, and then the next thing you know, it explodes.
If the temperature gets high enough . . . at some point, if you get up to about 400-500 degrees Centigrade, the metal oxide in the negative electrode actually starts liberating oxygen. And that’s really dangerous, because now, instead of having a fire . . . getting its oxygen from the air surrounding it, it’s getting its oxygen from inside the battery itself. The term of art is, this has now become a bomb. You’ve got fuel and oxygen in the same place at the same time.
Right now, it’s hard to tell exactly what’s causing Samsung’s problems. But Sadoway has some theories:
It’s either a statistical fluke in the manufacturing process where there are some local hotspots or there are perhaps some metal shavings, some kind of a shorting. But it seems as though, from what I’ve been able to read, the fires occurred when the owners are charging the phone. That means that while they’re forcing current through it, somehow there is a side reaction that is very different from just recharging the battery. And that starts charging the battery, and then the thing goes into thermal runaway.
So what are lithium batteries, this is a type of rechargeable battery in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging. lithium batteries are common in home electronics, smart phones, e.t.c.
lithium batteries are the best in the market, they are one of most popular types of rechargeable batteries in the market because of their high density, tiny memory effect, and low self charge.
Like I said earlier,leaving all the nerd stuff behind,samsung has decided to carry out an investigation to reveal cause of the Note 7 problem before the end of the year and it seem they are making headway with their investigation
According to gsmarena, Samsung conducted an internal investigation which as been completed and the results have been sent to the Korea Testing Laboratory and UL (an American safety organization), among others. The report is, however, yet to be released to the general public (us included).
Meanwhile, Instrumental suggested that extremely tight internal margins were the reason for the exploding batteries, but that remains to be confirmed by Samsung’s own analysis.