I may add to this post - depsite hydrogen and helium been...

I may add to this post - depsite hydrogen and helium been lighter than lithium at this stage there is very limited future with these in battery technologies. I posted on this in post Post #:56535539 Below is a duplication of what I indicated in that post.

In terms of hydrogen fuel cells, it is about cost in vehicles for the moveable market, and the size of the fuel cells themselves. That is not to say, in future there will be opportunities for advancement in hydrogen fuel cell technologies in the vehicle market .......................... I see a limited role of hydrogen fuel cells in the passenger vehicle market especially but time will tell. For others, these two links below are an ok read of for and against:

https://www.bmw.com/en/innovation/how-hydrogen-fuel-cell-cars-work.html

https://www.autoexpress.co.uk/car-news/electric-cars/93180/hydrogen-fuel-cell-do-hydrogen-cars-have-a-future

All IMO IMO IMO but at the end of the day depends on one's perspective of which renewable energy technology will dominate, especially in the vehicle market. I think lithium will dominate there, and most think hydrogen will have a limited role in the moveable market. So lithium is here to stay for a hell of a long time, and the links provided provide further data. The graph below comes from the link immediately below:

Hydrogen fuel cell vehicles will make up just 1 pct of cars by 2050 (thedriven.io)


Whist the article above is a few years old, in a nutshell hydrogen vehicles are estimated to account for a minor fraction of demand to 2050

All IMO IMO