Well, in order: - The physics has been done but the engineering is proving tricky (www.openstar.tech) - Chemistry (although I fell out with inorganic chemistry in 1980) - Deeply, deeply, interesting but I'm not sure how the information would change my life

OpenStar Technologies

OpenStar’s mission is to deliver clean, abundant, and available fusion energy to the world.

I know Open Star, and there is a lot of complex plasma physics to what they need to do, not to mention the superconductors themselves. At that level of detail, batteries are chemistry not physics. And I am sorry if you are not excited by it.