The previous discussion was of an article of <i>much</i> higher quality:<p><a href="https://news.ycombinator.com/item?id=26159068" rel="nofollow">https://news.ycombinator.com/item?id=26159068</a><p>This is some sort of development on using magnesium hydride as a storage mechanism for hydrogen. You combine magnesium with hydrogen, get MgH2, and then when MgH2 comes into contact with water, the H2 is released.<p>This is an old idea, and Wikipedia links to a 2006 effort along these lines:<p><a href="https://www.greencarcongress.com/2006/01/safe_hydrogen_r.html" rel="nofollow">https://www.greencarcongress.com/2006/01/safe_hydrogen_r.htm...</a><p>that achieved a specific energy of 2kWh/kg and 1.5kWh/L. This is about 10x better than lithium ion. However it's about 5x worse than gasoline. But since ICE are horribly inefficient relics of the past, a typical engine is only about 20% efficient, so it cancels out.<p>As for something like flight, jet engines are far more efficient than ICE, so this may or may not work there...