What's wrong with C0G?

Sounds like a good match for sensor nodes where energy harvesting may be slow and consumption is intermittent. You don't need massive energy capacity, but you need good power density to support transmit bursts, and you need very high cycle durability.

Why Zinc if Carbon is sufficient?

From "Eco-friendly artificial muscle fibers can produce and store energy" https://news.ycombinator.com/item?id=42942421 :

> "Giant nanomechanical energy storage capacity in twisted single-walled carbon nanotube ropes" (2024) https://www.nature.com/articles/s41565-024-01645-x :

>> 583 Wh/kg

That's with mechanical twisting though; graphene supercapacitors in general have lower energy density than (micro-) capacitors?

> Zinc Microcapacitors Are the Best of Both Worlds

Lifetime ,?