Sciencemadness Discussion Board

Exhaust Li-ion batteries, what to do with them?

math - 14-10-2025 at 01:05

Hi, I found some Li-ion batteries which seem to not to hold much charge anymore.
Just wondering if there could be any way to revive them or if any useful chemicals could be safely and worthwhile harvesting from them?

Yes, I am aware of the fire risk and don't want to start fires neither outdoors nor indoors. They're the large flashlight Li-ion battery type.

Thank you :)

Sulaiman - 14-10-2025 at 01:33

I have not seen or read much about lithium ion battery recycling so I guess that it is not worthwhile.

lithium PRIMARY cells have a nice recoverable lithium metal foil electrode,
zinc:carbon cells have a pure zinc pot, a carbon rod and lots of mess.
some of the lead from lead:acid batteries is easily recoverable.

anything else is probably best done at industrial scales.

j_sum1 - 14-10-2025 at 02:50

My experience is that they are a mess.

They often have a nice strip of copper foil. You can recover both lithium and cobalt (or salts).

But, they are painful to open. Recovery of compounds is tedious and not straightforward. There is a lot of waste material including polymers and electrolytes that smell bad. And there is a fine powdery carbon material that gets everywhere.

I have a stash of maybe 3kg of batteries collected for recycling. After the first small batch I have done a rethink.

charley1957 - 14-10-2025 at 03:17

Yes, I too have many kilos of these batteries. I have recovered a fair amount of cobalt from some of them. I would like to recover the lithium from them but haven’t yet researched how it is done. There are some very pure copper strips inside of them, along with some kind of polymer insulating strips which may come in handy for something. Yes, like most batteries they are hard to get into. I always discharge them completely with a lamp before I start tearing into them. I read somewhere that doing a little battery chemistry is almost a rite of passage among home chemists. I would tend to agree.

Sulaiman - 14-10-2025 at 04:22

Quote: Originally posted by charley1957  
....There are some very pure copper strips inside of them
... along with some kind of polymer insulating strips
... I always discharge them completely with a lamp before I start tearing into them.
... I read somewhere that doing a little battery chemistry is almost a rite of passage among home chemists. I would tend to agree.

- electrical copper wire is a simpler source
- I too have wondered if the polymers have a good re-use
- maybe charging before opening would give slightly more recoverable products ?
- imagine the history of chemistry without electrochemistry .. thank you Mr.Volta.

bnull - 14-10-2025 at 06:33

Quote:
- electrical copper wire is a simpler source

Unless you want copper strips.

The polymer is a semipermeable membrane, very useful if you like small scale electrochemistry.

Charging it would make things more flammable. Source: the guy who almost set his sofa on fire.

If you are going to open it, wear black clothes and put on a pair of gloves.

chempyre235 - 14-10-2025 at 08:50

I stumbled upon this article that shows lithum aldol condensation for making pure Li2CO3 from spent anodes. I don't know how well this works, short of experimentation.
https://www.sciencedirect.com/science/article/abs/pii/S25424...

Additionally, 12-crown-4 ether selectively complexes lithium ions in solution, but this is expensive and hard to get.

RU_KLO - 14-10-2025 at 11:16



I have dissasembled a lot. I want to post a video in youtube.

You can get:

* Aluminium hydroxide
* Nickel chloride
* Cobalt carbonate (a lot of)
* Lithium carbonate (or chloride if carbonate needs to be "cleaned")
* Copper foil (aprox 8-10 cm width - the height of the battery and 50/100 cm long. Depending on the battery it could be very thin.
* Plastic "membrane", very good for electrolisys, but getting it "clear white" depends on how old and exploited was the battery.
* Graphite (not very clean, you need hot HCl washing to clean it - not worth it.


(only dissasembly if you want the cobalt/ lithium, or if several elements for experimenting further. The good thing, is that you get carbonates that can easily be transformed to any other salt, by using the corresponding acid.)

Try to find the datasheet of the battery. This process is for LiCo batteries. if they contain nickel - old batteries, then you need to separate the nickel from the cobalt and is difficult.

Not asked but here is the procedure I use:

1) VERY IMPORTANT: discharge the batteries. Use a tester if possible. Voltage should be less that 0.5V or it could catch fire.
Have a bucket with water next to you. In case some fissing, the battery becames hot or smoke is starting to get generated, dump it in the bucket of water.
For discharging: at least 3 days submerged in salt water (a tea spoon of table salt in 200ml H2O) (NOTE: 1 day does not discharge it completely.)
or solder a 10 ohm resistor to the battery terminals and wait 3-4 days.

2) Once discharged, disassembly it mechanicaly (DO IT OUTSIDE OR FUMEHOOD - nasty solvent vapor). If you use a dremmel or a saw, you will get some iron impurities. Better is to slighly open at one side and, if the casing is metal, strip it by gripping at some lose part and rolling in the clamps tips. (cellphone batteries are simplier, laptop batteries are not.)

Nickel is removed in this step. In laptop batteries the link (strip) that joins the different cells togheter is mostly made of nickel.
Put this strip in HCl, heat it, add some H2O2 to speed up dissolution. And once dissolved heat it to dryness. (you will get nickel chloride)

3) Get a clean bucket with water. Under the water dissasemble by unrolling the battery. Get 3 containers, in one put the copper foil (wash the carbon layer in the bucket.), in another the membrane and in another the aluminium foil with its carbon layer. Carbon on aluminium its glued, very difficult to remove.
Here you get the copper foil and membrane.

For next steps: Filtering is a PITA (aka difficult), decantation should be used (a lot of time and water)

4) Decant the carbon/black goo from the bucket. Wash by adding water and decanting - at least 4 times to remove solvent.

5) Filter the carbon/black goo from the bucket with a strainer to remove bits of metal/plastics. I use also a toothbrush on the strainer to reduce carbon size.

6) Prepare a solution of at least 2M NaOH (WARNING: CAUSTIC). And add the aluminium carbon foil + the carbon/black goo from the bucket from last part.
It will heat.
We want to remove the aluminium chemically by transforming to sodium aluminate.

7) Swirl from time to time, we dont want do see aluminium bits. Add more NaOH if needed, but give some time to process. Do not add a lot of NaOH.

8) Decant, remove (pour in a new plastic/glass vessel) most of the sodium aluminate solution. Wash the left black goo, 4 times by decanting.

SIDEQUEST: if you are want the Al(OH)3 (not worth it), pass CO2 (from carbonate + acid) to the solution of the aluminate. After some time (depends on the NaOH used) a white precipitate, easily filterable, is obtained. Wash it and dry it.

9) Processing the black goo:

a) Add the goo to HCl (I use 6M), heat it and swirl it . I heat it for 1/2 hour but I thing is too much. Maybe 10 min is ok.
Here the cobalt and lithium will convert to chlorides (soluble)

b) First decant, and then filter (decanting first and filtering the liquid first speeds things up. The goo is difficult to filter (take 5 hrs or more by gravity filtration.
Discard the goo, keep the filtrate.

c) Reduce liquid volume by boiling water - I reduce to aprox 10% of original solution volume.

d) Prepare a saturated solution of sodium carbonate (sodium bicarbonate maybe could be used, but carbonate is better, because we need to get at least ph of 11..

e) In the cold filtrate (it needs to be cold), add the carbonate solution, BY SMALL ammounts (or feel the carbonate/acid volcano wrath), if you can meassure the ph, try to get as close as ph 11. Try not to get further because cobalt hydroxide is amphoterous. If you done this many times, you could eyeball with the changing color of the cobalt carbonate - from green-blue to violet.

(NOTE: Cobalt carbonate is in reality a mix of cobalt carbonate/hydroxide salt.)

f) Filter the carbonate and wash it, and, if lucky, you will get a clear filtrate. This will contain your lithium carbonate. If you are not, you will get some contamination of cobalt (light violet solution)

g) If clear solution, heat it to boiling. Lithium carbonate will precipitate starting 80C aprox. Filter and wash with boiling water.

f) If contaminated by cobalt, add a solution of oxalic acid till very acidic (red ph paper). This will precipitate cobalt oxalate (pink salt). Filter it.
If step h1 there is no need to boil to dryness, but to reduce volume.
If step h2 And boil the filtrate to dryness, to get a salt.

2 paths

h1) To the the lithium oxalate + oxalic acid, add a solution of calcium chloride, dropwise, until no more precipitate is formed. (it takes time, because it takes time for the calcium oxalate to decant.
Filter the calcium oxalate: you will get lithium chloride solution.

h2) (best solution) Heat the lithium oxalate/oxalic acid salt in a porcelain crucible (or any crucible) (at 400 -500 C for one hour) to decompose the oxalate into carbonate or hydroxide + some carbon.
Cool it and add some water. Filter the carbon or any salt that did not decompose, and boil to dryness the filtrate to get lithium carbonate.
(you could check with ph paper the salt before heating (red - acidic) and after heating (blue -basic)

And thats what I do.

Always when you work with carbon, its messy. And a lot of water is used, because decanting is better than filtering.


MrDoctor - 14-10-2025 at 12:13

they contain rather exotic, i think aprotic ether solvents that are rather hard to buy, only because of their niche use though, so you are limited to the biggest chem suppliers and its in a really high grade. Idk if its worth harvesting just for those though. Not worth collecting for the solvents, but its just an added merit. to get them though youd likely need to solvent extract from a wet blended mess, or opening the cells and subjecting to vacuum or something, this is even on industrial scale problematic and why lithium cell recycling is so hard. in the process of opening the cells properly, seperating the various foils and plastic, the valuable solvents evaporate away, in the case of monoglyme. propylene carbonate however is very non volatile but, that one can be bought somewhat easily even just as cyanoacrylate debonder or graffiti remover, it has mainstream uses so its commonly stocked.