This sounds promising, but as Elon said, production is hell. And GT—more charging stations are no doubt needed, but maybe no where near that many. As this article proves, range will increase geometrically and more & more cars will be charged at home.
This is the kind of thing that may one day make EVs usable for the mainstream car buyer. They also need to have 2 to 3 charging stations for every gas pump in use today due to the longer fueling time required.
The Mercedes-Benz partner in solid-state battery development - ProLogium - will be demonstrating a new technology called Large-Footprint Lithium Ceramic Battery that can double the energy-density of solid-state cells. The LLCB battery will be sampling with OEMs later this year.