[xzins]

Another question: the article mentions the need for electrodes of cobalt and platinum.

Aren’t those exhaustible in supply?

[neverdem]

Another question: the article mentions the need for electrodes of cobalt and platinum. Aren’t those exhaustible in supply?

Second question first: See comment# 30. New sources of cobalt may yet be found. Virtually all of the platinum now used as a catalyst will be recovered. It's too expensive to ignore. There will be more research for cheaper catalysts.