Afaik it has a higher energy density than common batteries, so it could be useful in things like aviation where this is the main concern and you can build special infrastructure to support it.

The frustrating thing is that a car running on hydrogen works really well, has a pretty long range and can be refueled quickly, so it looks like a good alternative. It's only when you ask how that hydrogen was made and how it arrived at the refueling station that things start to fall appart.