I agree. I’m very skeptical about their claims and so far I can’t find any evidence of 3rd party verification of anything. All the “news” about their batteries is just glorified press releases.

In the context of lithium-ion batteries, “solid state” means that there’s no liquid electrolyte, rather than meaning there are no moving parts.

It should be noted that the OGL stuff for D&D is included in the free part, along with the ORC licensed rules from Paizo for Pathfinder 2e. I think there are one or two other systems included as well but I’ve never looked at them.