Some things to keep in mind about liquid hydrogen. It's highly reactive (dangerous), has 3 times the volume of gasoline for the same energy content
Both very true, which is why people are studying ways to contain and pressurize it safely and efficiently.
Any energy storage medium, be it gasoline, propane, lithium batteries, supercapacitors or even flywheels pack a ton of energy into a small space, so there's always going to be some inherent risk. If all we worried about was risk, then we'd have ditched gasoline back when Pintos were blowing up after every wreck. I liken it to, "if the Hindenburg was full of gasoline, the whole city of Lakehurst, NJ would have been fucked."
There's a lot of fascinating work using carbon "meshes" to increase hydrogen's density. It seems really counter-intuitive to increase the amount of hydrogen in a fixed volume by adding
other crap to there, but it really works.
The simple example is that, given two jars at room temperature and 1 atmosphere of pressure, there is far, far more hydrogen in 1 liter of water than there is in 1 liter of pure hydrogen gas. You've increased its density by storing it at a lower energy-state (in oxygen bonds). Whereas you have to use a ridiculous amount of energy to liberate hydrogen from water, it can be liberated from carbon meshes just by heating it.
The research into using hydrogen as a portable fuel is mostly along the lines of how to manufacture these meshes cheaply, and redesigning other containers/fuel lines/etc such that they won't corrode or leak from hydrogen exposure. I'm not saying it's the silver-bullet solution to everything, but it's a field that's quickly evolving and thus very interesting.