Volume 94 Issue 45 | p. 33
Issue Date: November 14, 2016

Periodic graphics: Why Li-ion batteries catch fire

Chemical educator and Compound Interest blogger Andy Brunning reveals reasons why the compact components sometimes burst into flame
By Andy Brunning
Department: Science & Technology
News Channels: Materials SCENE, Organic SCENE
Keywords: battery, lithium-ion, fire, Samsung, cathode, electrode, flammable, electrolyte

References used to create this graphic:

Burning batteries

What’s with all those flaming cell phones? A primer on battery safety

Assessing the safety of lithium-ion batteries

This heat-responsive coating could keep lithium-ion batteries from catching fire

To download a pdf of this article, visit http://cenm.ag/batteryfire.

To see more of Brunning’s work, go to http://compoundchem.com. To see all of C&EN’s Periodic Graphics, visit http://cenm.ag/periodicgraphics.

This article has been translated into Spanish by Divulgame.org and can be found here.

Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Kerry Swift (Wed Nov 16 16:09:49 EST 2016)
Very nice depiction, but why do most Li-ion batteries work just fine? They only seem to fail in certain cases or under certain conditions. What are those? Right now you are really only answering the question of "How?", not "Why?"
Andy Brunning (Sun Nov 20 10:51:30 EST 2016)
Well, physical damage can lead to short-circuiting, or design faults in the battery (which have been implicated, though not confirmed, in the recent Samsung cases). Short-circuiting occurs when the battery separator is damaged, say by an impact to the battery. Overcharging is self-explanatory, though many phones now have built-in measures to prevent this. Also, the electrolyte used in these batteries is very flammable. Hope that makes it a bit clearer!
Robert Hamers (Wed Nov 16 16:13:28 EST 2016)
Also note C&E News' article on "Top 10 Startup to Watch" Silatronix, Inc., which is improving battery safety through new electrolytes. http://cen.acs.org/articles/94/i43/Silatronix.html
James Francis (Wed Nov 16 16:19:19 EST 2016)
I am afraid that this is the tip of the battery iceberg. Lithium batteries can catch fire basically because they have so much stored energy - that's their appeal and usefulness. I suspect that ANY battery with the same high energy content will be capable of releasing it internally if mistreated, with similar results. Indeed I fail to see how this problem can be avoided. But will await future developments.
Ross Dueber (Wed Nov 16 19:39:58 EST 2016)
Lithium-ion catches fire due to its flammable electrolyte and not simply because it is a high energy battery. Silver-zinc batteries are equally energetic to lithium-ion, but use a water based electrolyte.
Andy Brunning (Sun Nov 20 10:53:59 EST 2016)
There was an interesting article which accompanied this graphic in the C&EN magazine which looked at some ways in which chemists are trying to tackle the problem. If you didn't catch it, you can read it here: http://cen.acs.org/articles/94/i45/Making-batteries-fire-resistant-solid.html
BMC (Wed Nov 16 18:19:16 EST 2016)
This is a simple chemical-electronics 101 problem. Basically, the design is turning the operation to work as a battery to a full on capacitor overload resulting in thermal eruption. There is a very easy way to amend the design to add an electron sink (also a thermal sink) that can be dynamic to match the power demands. The math is quite straight forward. I believe in the acronym of KISS. Keep it simple smarts'.
Karen (Thu Nov 17 13:58:24 EST 2016)
The Li batteries are key to having a small battery though. Of course there are safer designs, but the Li battery gives the user the power that they want without being bulky. I wander how bulky the amended design that you suggest would be.
Akash Mehta (Wed Nov 16 19:10:27 EST 2016)
This info graphic is a simplified version that will help a non-science person to follow and change few habits, such as, not overcharging, not mishandling, not leaving in sun/heat their smartphones. This should be put in all the shops where they sell lithium battery operated gadgets. It will very well serve the purpose of generating awareness among people as many people do not read C&EN !
Roald Hoffmann  (Thu Nov 17 20:13:11 EST 2016)
This is indeed a good idea!
Fride Vullum-Bruer (Thu Nov 17 05:04:42 EST 2016)
This is a nice but indeed simplified picture. LiCoO2 is not used as much anymore and other cathodes are replacing this cathode, particularly in electric vehicles. Many of these other materials are more stable and will f.ex not release oxygen upon overcharge. The battery can still catch fire. The main problem in Li-ion batteries as mentioned above here, is the electrolyte. The solid electrolyte interphase (SEI) on the anode is equally important. Also, the exact composition of the electrolyte and type of additives can play a major role. So although this graphic explains what can happen in a Li-ion battery based on LiCoO2, it is important to realize that it only shows a small fraction of the total picture.
Andy Brunning (Sun Nov 20 10:58:32 EST 2016)
Thanks, glad you like the graphic! It is indeed simplified to an extent, due to the focus on phone batteries. As far as I'm aware, LiCoO2 is still the primary cathode material used in lithium batteries for phones and tablets, which is why we focused on it here.
Michael Kenward (Thu Nov 17 10:56:48 EST 2016)
The title should, of course, read "Why some lithium-ion batteries catch fire". Likewise, the newsletyter touting it should read "Why do some lithium-ion batteries catch fire?"

Most don't.

It also needs proofreading. Pourous? Isn't that something to do with coffee?

Indeed, the words are semi-literate. Perhaps that is what makes an "infographic" different from a "diagram".
Andy Brunning (Sun Nov 20 11:02:41 EST 2016)
The subheader and graphic do clarify that we're talking about specific incidents. As for the typo, for that I can only apologise; it's clearly an typo left in during putting the graphic together, and subsequently missed in proof-reading (which I can assure you does happen!). One or two do slip through occasionally despite our best efforts!
laurenkwolf (Mon Nov 21 11:16:59 EST 2016)
Thanks for catching our typo, Michael. It's been corrected. As Andy has indicated, the subhead for the graphic makes it clear that this visual encapsulates some possibilities for why Li-ion batteries might catch fire.
Aanton Mann (Sun Dec 04 14:26:07 EST 2016)
Dear Mr Kenward
"Indeed, the words are semi-literate."
Robert Cuca (Thu Nov 17 20:08:25 EST 2016)
Just wondered if anyone has done a chemical analysis of a battery that has caught fire. It might eliminate some of the speculation as to why they do what they do.
Andy Brunning (Sun Nov 20 10:47:37 EST 2016)
I'd expect that Samsung have done many, but likely will also keep the results under wraps. As the graphic illustrates, there can be multiple causes, so without knowing the specifics of the individual cases it's hard to know. Some of the speculation regarding the Samsung batteries specifically was that a manufacturing error increased the risk of short-circuiting, but I've been unable to dig up anything definite on that.
Ahsan Habib (Sun Nov 20 01:53:47 EST 2016)
As we know the latest version of Samsung S7 has a big problem for catching fire if Li-battery. This model is water proofed. To make water proof, possibly the battery is air tight and/or Samsung used a thin film of perfluorinated polymer on the battery. Perfluorinated polymer exhibits super hydrophobicity that is logical to make a device water proofing. My speculation is, since there is a great chance for undesirable chemical reactions in Li-ion battery that provide gaseous compounds resulting in formation of high pressure or due to presence of fluorine in polymer, there could be a chance for formation of LiF.
Dalvaro Weaver (Sat Jan 14 12:06:09 EST 2017)
I concur that this battery design needs a new end cap charging mechanism to the circuit to shunt the charging once the battery is completely charged as well.
Mirjam Molenkamp (Mon Jan 23 17:14:03 EST 2017)
Does anybody know what the electrolyte is made of? I'd like to use this for a test question for my chemistry students.
Baraka mwatusekele (Tue Jan 24 05:02:35 EST 2017)
Does lio-ion battery also made up with sulphuric acid?and if so how other batteries made up mostly those used in vehicles and trucks?
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