Chinese researchers say they've demonstrated a seawater electrolyzer that works as efficiently as a commercial freshwater electrolyzer for months on end without corroding itself to death. It also looks like these machines could harvest lithium, too.
One problem with renewably-produced hydrogen is that it uses fresh water – and with a quarter of the world's population already facing severe water scarcity at least one month of every year, freshwater is an ever more finite and precious resource. So technologies that can electrolyze hydrogen out of the abundant seawater that blankets most of the planet are a vital area of enquiry.