I’m working on a beginner electronics kit with squishy circuits conductive clay.
Here’s a battery…
This is a coin battery with conductive clay as the electrolyte. It produces 2.25 V and 200 uA. It didn’t matter what coinage I used as long as I used aluminum on the cathode (or is that anode, I get them mixed up). This one is made up of 5 cells. 2 nickels, 2 pennies and a dime.