Still better than current batteries. You could pump that up if you store it in a liquid state to a level above common fossil fuels. Not saying you don't open a can of worms for implementing it...
Hydrogen in liquid state leaks out of any container that you put it in. 70kg lead bottle stores only 1L of hydrogen and all of it evaporates naturally in 1-2 months through the metal. So no, storage of liquid hydrogen is a terrible idea.
It does diffuse through everything, but there are several research projects in that direction. It is the smallest element and it helps if that bottle is solid, but I still see potential.
Besides in-vehicle storage being completely infeasible for many reasons, how exactly do you propose to safely allow consumers to refill a tank with liquid hydrogen? They use it for rockets sometimes, but it's handled very carefully by highly trained technicians under very controlled conditions and the fueling procedure is nothing like a stop at your local gas station.
