A battery filled with algae is somehow managing to power this computer for months: https://www.newscientist.com/article/2319584-computer-powered-by-colony-of-blue-green-algae-has-run-for-six-months/

No-one's quite sure what's going on. Possibly the algae is serving as the medium catalyzing the interaction between the anode and cathode in the battery.

Except research shows the anode isn't degrading, which suggests ...

... the *algae* is producing the electrons.

Some thoughts on this in my blog post here, item 6: https://clivethompson.medium.com/lavaforming-ai-writes-heavy-metal-and-drones-that-deliver-hamburger-helper-59b9bcfda9a8