Hyzon Motors Inc (HYZN)

[BioChica]

So far density to power ratio is held by Hyzon Motors. As far as engineering goes fuel cells are all highly engineered. Many complex issues crop up that need to be solve. Like battery technology, performance suffers over time. Battery performance is based on the number of charges, I believe fuel cell performance is reduced by oxidization. So over a period of run time.

Bosch seems to work with around three fuel types. But looks like cool technology, focus on primarily providing power for EV trucks. So the next couple of years will be fun watch how technology evolves. I bought my son a model hydrogen car, we had fun with that a few years ago.

Here is a nice shot of Hyzon Fuel Cell Stack.
Hyzon (Horizon)

Hyzon-Fuel-Cell-Stack-300KW