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.
You should definitely read the linked article. You’re right about it being for your car, not your phone, but seriously, read the article.