Extracting lithium metal from batteries

Abstract:
Being an extremely reactive alkali metal, anybody would suggest lithium would be a hard find for the grubby mitts of the home chemist. Thankfully, a few brands of battery allow the best and easiest method of extracting large chunks of the metal, without any more hassle than a little time and some old-fashioned elbow grease. Depending on your tools and methods for attempting to crack open a steel casing though, the job can range from much harder to slightly easier.

Introduction:
Lithium, as well as alkali metals in general, are pretty cool. Metals are usually associated with strength and longevity, holding bridges and buildings tall and lasting years upon years. These peculiar metals are the rebels of the bunch; just touching water can cause them to explosively react, the high temperatures igniting the hydrogen given off to produce a flame.

They also sport very low melting points around the boiling point of water. Any bridges made of these alkali metals would not win any awards if they existed, any rain would signal the melting and exploding doom of the structure.

Out of the crew though, lithium beats the rest in a flame, producing a fantastically bright white light when burning in air, with the resulting product producing a red flame, characteristic of the lithium ion.

Being such a reactive metal and being relatively expensive, it is a nice surprise to find the pure metal so easily available to the amateur in the form of lithium batteries. Lithium-ion batteries will not work for this however, as the lithium inside is in ion form and producing lithium metal from lithium ions is very difficult – just buying batteries, such as Energizer Ultimate Lithium batteries, that have the metal in its elemental, metal state is much easier.

These types of batteries love shorting-out however so developing a strategy that consistently works to open them is key. You cannot though drain the batteries to prevent any shorting-out as this chemically uses all of the lithium inside – therefore brand new batteries are also the best.

Safety:

Substance	Hazard information
Lithium	Corrosive/Highly flammable It reacts violently with many substances. It reacts rapidly with water to produce hydrogen, an extremely flammable gas. Although difficult to ignite, once lit, it burns readily in air and is difficult to extinguish. It causes burns. Contact with moisture produces lithium hydroxide which is an irritant to the skin and eyes.

• Gloves and goggles should always be worn when handling chemicals to protect your sensitive eyes and skin.
• Chemical gloves are always useful, but I recommend thick, tough working gloves to protect your skin from the jagged metal created when hacking open the battery.
• I recommend wearing a lab coat to protect your clothing and skin from any internal fluids of the battery. Be aware that this type of battery is extremely prone to shorting out, easily heating up very hot and potentially exploding if any pressure build up can not be vented. If the battery becomes hot, place it on a hard surface such as a brick and back up a few metres, leaving it to cool down before attempting again to open the battery.
• Metal tools when opening the battery casing can easily short-out the battery if they connect the positive end to the negative end (anode to the cathode).
• Work should be carried out in a well ventilated area such as outside or in a fume hood to reduce the chance of inhaling any fumes given off if the battery is shorted-out. Also any open flames or containers of water should be removed from the area due to lithium reacting with air when heated and also reacting violently with even cold water.
• If the lithium is to be stored, an airtight and watertight container is recommended. Also the lithium must be stored in an appropriate liquid to prevent decomposition in air – kerosene or paraffin oil is suggested, I use cheap baby oil which is purified parraffin oil. You obviously can not use water as this will violently react with the lithium. I also recommend a marble to act as a small weight on top of the lithium to prevent the lithium from floating to the top of the storage liquid and reacting with the small volume of air in the container. I write more on storage nearer the end of this post.
• If you hate the smell of rotten eggs then you are in big trouble! (You can use a breathing mask to reduce it if you really do hate the smell!)

Experimental:
I tried two ways of opening the batteries, the second method was easier but required extra tools; I will show the original method I tried first. Just for reference, these are AA batteries.

Notice the small punctures in the positive end (anode) cap. Lithium batteries are some of the most infamous batteries for building up pressure and exploding under stress in certain conditions – these holes allow any pressure from the inside to vent in an attempt to prevent the building up of pressure inside. (Also the expiry date is quite impressive, over 20 years into the future from when I did this experiment.)

The plastic coating around the battery was immediately in the way, I felt, and so my first course of action was to remove it. This is not strictly necessary and actually keeping the plastic on, I found, made it easier to avoid shorting-out the battery when removing the positive end cap.

The metal ball represents a valve which plays a large part in increasing the safety of the battery. Having the insides of the battery exposed to the outside air at all times would quickly destroy the battery and the lithium inside. To avoid this inconvenience, as well as any pressure build up, this valve will keep the insides sealed off, but the force of any pressure building up inside will cause the valve to briefly open, therefore venting the gas, closing again, and saving the day, hurrah!

Talking about removing the positive end cap, this is the proper first step. I struggled for a while though to find any tool that might make my dreams of even completing the first step a reality. In the end, brute force coupled with a pair of pliers are the best for the job. If the nose of the cap is squeezed with the pliers and bent to the side, half the cap will bend and come undone, allowing the whole positive end cap to be removed with a pull away from the battery body.

Patience is key for most of these steps, slowly peeling away steel is no quick and effortless task.

This is where it gets quite tough. Using a tiny pair of metal pliers, the outer metal rim was gruellingly bent over and torn in a somewhat vain effort to pop the valve out. This is not necessarily a bad thing; the difficulty of removing the valve shows the manufacturers were not messing around with safety when they built the little fortress.

While attempting this step, it is almost unavoidable to not short-out the battery. The metal tools provide a great medium for the stored electricity to jump through when accidentally connecting the negative shell (cathode) with any part of the positive valve (anode). Several times a beautiful, unfortunately unwanted, orange spark would appear and, almost as quickly, disappear due to a slip with the metal pliers.

The metal foil roll inside that has been uncovered is the lithium we have been searching for.

Eventually I managed to tear all the way around the valve and pop it out. Unfortunately, this was not the end and more of the metal shell was required to be peeled back again. The threat from shorting-out was still as evident as before, due to the intriguing foil pattern also being part of the anode.

There was not much left of the poor metal casing after the quarrel my pliers had with it had finally come to an end.

Once enough of the metal was peeled away, the pliers could be used to grab the inner part of the metal foil and tug the inner lithium roll out and away from the metal casing.

Notice the small tab at the base of the roll, this is what connects the negative part of the roll, where a chemical reaction occurs and electrons are generated, to the metal casing which thus acts as the negative side of the battery.

What looks like a fancy cigar is actually just what we were looking for. I would not attempt lighting this cigar though! All that work was to remove it from the casing. From here on it is extremely simple. Find the overlap of the outer plastic sheet and begin to unravel the cylinder like a roll of tape. In the end you are left with three layers of tape loosely stuck together which can be easily separated from each other.

If memory serves, one is a black tape of crumbly iron disulfide, one is a plastic membrane, and the last is our final beautiful foil of lithium metal. Do you smell the sweet smell of victory and perseverance?! No, actually, you do not – that is the stench of rotten eggs coming from the iron disulfide you threw everywhere in your dance of happiness. Good luck cleaning that up! It is not worth keeping and can be thrown out as general rubbish along with the rest of the battery pieces.

The easier way I found to get into the batteries was by using a metal pipe cutter to slice through the steel of the battery. I tried this by cutting the steel casing in two, although this immediately shorted-out as it cut into the lithium roll as well. A second attempt showed no difference and both batteries got so hot they had to be left to cool for several minutes. I found cutting at the neck of the battery though yielded the best results.

This is one of the same photos as earlier, I am using it to show the neck which is the dip in the side of the metal casing near the top of the battery.

When cutting at the neck this does not hit the lithium roll but does remove all of the valves and fancy bits, saving a large chunk of time and labour. Also the indent allows for easy cutting. After cutting, all you have to do is pull back and tear some of the steel casing out the way a little bit and the lithium roll can be pulled out with only a minimal amount of effort. There is still the danger of shorting-out the battery here though.

Results:
Once the lithium has been extracted, the long piece of foil should be quickly folded up and plopped into a container of unreactive oil such as kerosene or paraffin, as mentioned in the safety section. Lithium will float on almost any liquid so I recommend a marble or two to hold down all of the lithium so it does not oxidise in the air in the container. If you take too long fiddling with the lithium foil it will quickly tarnish in the air and turn black before your eyes; be quick with getting it into storage!

I was not able to weigh the lithium before using most of it up, but when I need more lithium and extract more I will add the yield of lithium here. I will say though there is quite a hefty amount of lithium in each battery, enough for any needs you might have after opening a pack of four. I definitely recommend extracting some lithium this way and using it for a few fun experiments. I will leave you with a photo of some of the lithium I extracted that I have left.

I dislodged some of the lithium so it would float, showing you how low the density of this metal is and how marbles or another heavy weight is quite useful. Otherwise the lithium can react with the air to form oxides and carbonates, seen by the thick layer of black coating that not even my lithium could escape. If the lithium is cut though to obtain a smaller piece, the underneath metal silvery finish will be seen.

 

 

Further reading or watching:

YouTube channel NileRed – Getting Lithium from a Battery

YouTube channel NurdRage – Get Lithium Metal From an Energizer Battery