Is There a New Battery?

I want to do a role-playing game that takes place in an ancient Roman steampunk universe. We were this close to steampunk and we just missed it. What if what if there were massive amounts of free hydrogen, gaseous hydrogen under the ground that we could mine for fuel? That's a big deal. It'd be a game changer. All right. My news item this week is extremely interesting. This is one of those ones where I'm like, you know, I'm teetering on the fence between being really hyped about it and really skeptical about it. You know what I mean? So what would you say? New batteries. Better than a new