edit I am an idiot, who uploaded the image link as the URL. The original source should now be accessible
RMIT engineers say they’ve tripled the energy density of cheap, rechargeable, recyclable proton flow batteries, which can now challenge commercially available lithium-ion batteries for capacity with a specific energy density of 245 Wh/kg.
And you basically have 2 options for hydrogen production: oil consuming and GG-emitting steam reformation, or energy intensive electrolysis of water, unless there’s another i don’t know