Here's why I'll keep my Prius Prime

There are metal hydrides, and I've seen small batter bank sized fuel cells that use them for sale. The issue for cars is the weight, though if that can be reduced, you have the potential for swappable fuel containers. One avenue used discs about the size of CDs. Easy swapped fuel containers would lessen the pressure to get actual hydrogen stations on every corner before people would buy.

 

This is starting to sound more like regular batteries... But it might still be worthwhile if the energy density is better.

 

All the drawbacks of batteries and hydrogen.

Storing hydrogen on the car isn't the real issue. It's the infrastructure getting the hydrogen to the car.

 

They actually powered a Mirai using simple Ammonia (NH3) and a membrane to separate the hydrogen from ammonia. https://www.abc.net.au/radio/programs/worldtoday/automotive-hydrogen-membranes-huge-breakthrough-for-cars/10089510

They may commercialize it as a cheap way to ship and/or pipeline hydrogen.


Unsupervised!

 

Hydrogen fuel breakthrough in Queensland could fire up massive new export market - ABC News (Australian Broadcasting Corporation)
It will help with shipping. Ammonia is poison the PEM fuel cells in most FCEV, so care needs to be done in making sure trace amounts of it are removed. Still need to pressurize the resulting hydrogen to get it into the car.