Experiment 45: Lithium Metal from Coin Cells

A very long time ago, in Experiment 2: Lithium Battery, I extracted lithium foil from some old lithium cordless phone batteries.  The batteries were constructed similarly to AA batteries, with a cathode and an anode wrapped up in a very tight roll.  While fun to play with, the lithium from the batteries oxidized quickly and was really hard to store well.  I wanted some shiny lithium and had some "2032" coin cell batteries, so I decided to extract the lithium from them.

For this experiment, fresh batteries are crucial.  If the battery voltage is much less than 3V, the lithium inside will be corroded unrecognizably.  I practiced my battery-opening skills on a dead coin cell and used side cutters to twist the cathode rim away from the anode cup.  I then pried the anode cup out and removed the paper separator to get to where the lithium would have been had the battery not been dead.  When dealing with lithium, speed is important because exposure to moist air will oxidize and darken the lithium, which makes it less appealing than shiny metal.

Once I practiced my technique, I rapidly disassembled three fresh lithium coin cells and scraped the lithium off of the anode cup into a beaker of mineral oil.  I was impressed by the amount of lithium inside such a tiny battery.  With the lithium temporarily protected from the atmosphere in the oil, I submerged a small sample vial in the oil and flicked all the bubbles off of its sides.  After the vial and its lid were free of air, I coerced all my lithium shavings into entering the container.  This was especially tricky because lithium is lighter than oil and wants to float.  In the end, however, I got all of the lithium into the vial.

To finish up, I let the lithium react with whatever was in the mineral oil and then carefully tipped the vial just a bit to let the small gas bubble escape.  I capped the vial tightly (while still under mineral oil) and then dried it off with a paper towel.  Even weeks after the extraction, the lithium metal is still shiny where fresh surfaces were exposed during the scraping.  The sample is a nicely dangerous and beautiful addition to my element collection.