[k8wk1]

> hydrogen fuel cells are technically batteries and have absurdly high energy densities.

The devil is in the details - this is only partially right. Hydrogen has absurdly high energy densities when considering weight, however when considering volume it has absurdly low density. The low volumetric density is one of the primary barriers to hydrogen adoption.

[_hypx]

Even by volume, a tank of hydrogen has higher energy densities than li-ion batteries.

[mlindner]

Liquid or gaseous, and at what pressure?

[_hypx]

Gaseous, and at 700 bar (the standard pressure in use today).