If you could run your celly on hydrogen you'd have power for days and days -- but, you'd also need to lug around a high-pressure tank to store the stuff. That's no fun, and that's why we're still using Li-ion batteries and the like. But, scientists at the Lawrence Berkeley National Laboratory look to have found a way to possibly ditch the tank, creating a gas-barrier polymer matrix out of polymethyl methacrylate, allowing the H2 gas in but keeping oxygen and everything else out. That matrix contains magnesium nanocrystals that react with the hydrogen to form MgH2, enabling safe, (relatively) low-pressure storage. The H2 can then
