itsallgoodjames
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1000%+ of expected yield of cobalt from lithium ion batteries. Why?
So I've been extracting cobalt from cell phone batteries. I found online a figure of 0.3 grams of lithium per 1000 milliamp hours. I started with
about approximately 8,000 milliamp hours of batteries, meaning that I'd expect 2.4 grams of lithium. This would mean I have 0.34 moles of lithium.
Lithium cobalt oxide, the material used in the batteries has equal numbers of cobalt and lithium atoms, meaning that I should get 0.34 moles of cobalt
out. This would mean I would expect 20 grams of cobalt. I did this:
Dissolve the black strip things inside the battery in HCl. Chlorine gas was liberated.
Decant off the liquid
Add sodium hydroxide, and gravity filter
Transfer the residue left in the filter paper into a beaker
Dissolve in HCl
Boil down to leave cobalt chloride
In step 3, I was expecting cobalt hydroxide to be produced. Instead, cobalt oxide was produced. I haven't been able to figure out why this happened,
but it doesn't really matter. The bigger issue is the fact that well over 200 grams of the oxide was produced. I haven't been able to weigh it yet,
as some of it is still filtering, as it needs two filter papers, but the half that was done filtering weighed at least 200 grams, probably even more.
I have no clue why that is. Any ideas? The half of the solution that finished filtering is pictured.
Any ideas why this is?
Thanks!
[Edited on 15-2-2021 by itsallgoodjames]
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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Fyndium
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FYI, you uploaded a 16k picture. A more proper size could be 800x600pix.
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itsallgoodjames
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Oh, I'll fix that. Sorry
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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Amos
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You say you expected 20 grams of cobalt to be in the batteries, and you say you were dissolving lithium cobalt oxide. But you didn't dissolve only 33
grams of pure lithium cobalt oxide in HCl, did you? Whatever you dumped into the acid, you've probably dissolved every single metal in the material,
and you're going to have to find a way to separate their hydroxides. Not to mention it's not exactly very accurate weighing when you put a sopping wet
mass of precipitate on the scale.
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itsallgoodjames
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Quote: Originally posted by Amos  | | You say you expected 20 grams of cobalt to be in the batteries, and you say you were dissolving lithium cobalt oxide. But you didn't dissolve only 33
grams of pure lithium cobalt oxide in HCl, did you? Whatever you dumped into the acid, you've probably dissolved every single metal in the material,
and you're going to have to find a way to separate their hydroxides. Not to mention it's not exactly very accurate weighing when you put a sopping wet
mass of precipitate on the scale. |
I put the copper sheets in the acid. The copper sheets were coated with the lithium cobalt oxide. I tested for copper after dissolving by putting a
bit of the solution in a test tube and adding ammonia. The solution did not become a blue color, as the production of the tetraamminecopper(ii) ion
would show. The copper appeared the exact same as it had before, just without the lithium cobalt oxide. The solution also was always the color I
expected it to be. So I don't think that the issue is contamination with other metals. I know it's not very accurate to measure while it's wet, but
I don't think that water is making up 180 extra grams of weight.
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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RustyShackleford
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You should read my post here about the extraction and purification of cobalt from Li batteries
http://www.sciencemadness.org/talk/viewthread.php?tid=156817
You must NOT include the copper foil, because in the HCl + Cl2 conditions it dissolve and is very difficult to separate.
[Edited on 16-2-2021 by RustyShackleford]
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itsallgoodjames
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the copper didn't really seem to be damaged. My test thing also didn't show any copper. So it doesn't seem to have dissolved. Also like I said, the
solution looked exactly how I expected it would look the entire time, blue/green at the beginning when dissolving, and purple when the sodium
hydroxide is added or it is diluted. Very typical cobalt ii colors, and exactly what I was expecting.
[Edited on 16-2-2021 by itsallgoodjames]
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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clearly_not_atara
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Some (but not very many) batteries are Li-Co. Some are Li-Co-Ni. Some are just Li-Mn. Modern ones are usually Li-Co-Ni-Al or Li-Co-Ni-Mn. In a few
cases you also see Fe or V make an appearance.
The primary metal in modern lithium battery cathodes is nickel, and other metals, usually one of Al/Co/Mn/Fe, are
added as dopants.
If you didn't have reliable information about the battery chemistry of the particular batteries you're working with, you could have any of about
six metals in the ppt. See the problem?
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itsallgoodjames
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I was unaware of that. I guess I'll have to go through some separation steps then. Kind of odd that the solution was all the right colors the whole
time.
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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Amos
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| Quote: Originally posted by Amos | | You say you expected 20 grams of cobalt to be in the batteries, and you say you were dissolving lithium cobalt oxide. But you didn't dissolve only 33
grams of pure lithium cobalt oxide in HCl, did you? Whatever you dumped into the acid, you've probably dissolved every single metal in the material,
and you're going to have to find a way to separate their hydroxides. Not to mention it's not exactly very accurate weighing when you put a sopping wet
mass of precipitate on the scale. |
If you're so sure that only the intended compound dissolved, you should try again measuring everything you put into the acid vs. everything that
survives.
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ChemTalk
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Actually, we've found that extra water weight can add a lot more weight to the precipitate than one would predict.
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ChemTalk
chemistrytalk.org
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