Robert Murray-Smith is an internet phenomenon and a true work of art. He is a hands-on experimenter, a brilliant scientist and a creative genius with a specialty in graphene and supercaps. Here is his latest.
https://www.youtube.com/watch?v=sGYVqRLQ_eQ He has made a "dry cell" battery in every sense of the phrase but not exactly a capacitor. The difference between the two is the charge carrier and a few other details. This new battery conducts ions but not electrons. Best of all, instead of graphene, RMS has found a way to substitute minimally processed seaweed for the graphene or carbon layer. The key is probably the iodine in the seaweed. He is very excited about this breakthrough, as you can see. No lithium, no precious metals, no graphene - so the cost should go down by several orders of magnitude. AA batteries from China use zinc and cost almost nothing these days, but are not rechargeable. There is a billion dollar market for a perfected version of this. In another video, RMS makes a paper battery - ink-jet printed to power an electric motorcycle for 100 km. Eat your heart out, Elon. Actually, one suspects that Tesla is already looking for a large source of seaweed, and he does not have to look far ;-)
