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Topic: Safe Lithium purity test  (Read 2904 times)

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Offline Count of Monte Cristo

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Safe Lithium purity test
« on: July 22, 2014, 06:54:06 PM »
I recently did a little experiment where I opened a Lithium ion battery in order to extract the small amount of Lithium on the inside (approx 1g of Li per battery). I currently have them stored in a jar of mineral spirits to slow the oxidation process. The problem I face is the uncertainty of Sulfur contamination i.e. a layer of Li2S on the outside of the metal strip. The only test that comes to mind is dropping a piece of the metal into a solution of HCl, and then seeing if I can smell (very high tech, I know) the characteristic rotten egg smell of sulfur. Obviously I am incredibly wary of this method as Hydrogen Sulfide is highly poisonous and I do not have any of the facilities needed to control gas and vent it through a specified route. Any suggestions as to how I could test the metal safely would be greatly appreciated.

Offline Arkcon

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Re: Safe Lithium purity test
« Reply #1 on: July 22, 2014, 10:14:47 PM »
There are many things wrong with your plan -- and we be remiss if we didn't mention them.  Lithium is a very active metal, you can't even mix it with water -- water is too strong an acid.  So HCl is completely out of the question.  Elemental sulfur doesn't react with mineral acids to produce H2S.  If you can barely see the sulfur, how can you believe there will be enough H2S produced to require strong ventilation?
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Count of Monte Cristo

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Re: Safe Lithium purity test
« Reply #2 on: July 23, 2014, 11:20:41 AM »
You're right, even at my beginner level I should have remembered that even if there was a layer Li2S that the Lithium on the inside would have reacted with the water. And I suppose I really shouldn't worry about safety issues with Sulfur when I'm dealing with such small quantities. As for your third point I wasn't aware of that property of sulfur.

So should I not worry about contamination because of how little quantities of Lithium I have?

Offline Zyklonb

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Re: Safe Lithium purity test
« Reply #3 on: July 28, 2014, 11:34:55 AM »
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I recently did a little experiment where I opened a Lithium ion battery in order to extract the small amount of Lithium on the inside (approx 1g of Li per battery).
That wouldn't have been a lithium-ion battery, as they never contain elemental Li. Since (per your post) you did get Li, you must have had a regular Li battery (which are non-rechargeable, but last longer).
 
Quote
The problem I face is the uncertainty of Sulfur contamination i.e. a layer of Li2S on the outside of the metal strip.
This is actually not sulfur contamination, but the cathode of the battery. The black film of most Li batteries is mainly iron disulfide. I'm not certain of the actual process involved, but IIRC, depending on the state of the battery (how used it is) Li2S should be formed, which of course reacts with water in air and especially HCl (aq) to form toxic H2S.
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There are many things wrong with your plan -- and we be remiss if we didn't mention them.  Lithium is a very active metal, you can't even mix it with water -- water is too strong an acid.  So HCl is completely out of the question.
Don't be so quick to assume. Obviously he was aware that Li reacts with water and acids, he wanted to test the sulfide content.
Quote
Elemental sulfur doesn't react with mineral acids to produce H2S.  If you can barely see the sulfur, how can you believe there will be enough H2S produced to require strong ventilation?
So, it would appear that you are more clueless then he is.
He already knows there is no elemental sulfur present, why would you even suggest that?
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Any suggestions as to how I could test the metal safely would be greatly appreciated.
From the Li batteries I've disassembled, I don't remember very high sulfide content, so your idea of using HCl (aq) should work (that's how I did it). As long as you do it outside (or in a fumehood), and leave the area if you smell rotten eggs.

Offline nightguy

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Re: Safe Lithium purity test
« Reply #4 on: August 02, 2014, 06:46:23 AM »
@OP

If you will be mixing lithium and hydrochloric acid, do it in small quantities and use protective gloves and goggles as Li and HCl react very violently, releasing a lot of hydrogen and steam, reaction is boiling hot and even acumulated hydrogen can ignite and cause dangerous explosion that can throw all of the reactants in the air and you really don't want to have that stuff all over yourself. And if you're doing it in the glass containers, even glass particles can hit you if container explodes. So, be careful.

As far as I know, lithium sulfide should make hydrogen sulfide gas, when mixed with hydrochloric acid, but I don't think you will be able to smell anything, because of so low quantities. I already tried this experiment and I wasn't able to smell H2S. (and I used lithium metal from lithium battery)

Be safe!

Best regards, nightguy

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