Lithium Hydride contains more hydrogen per unit volume than liquid hydrogen does, so what is stopping us from developing a Lithium Hydride storage solution to supply hydrogen to a vehicle's engine? The reactivity of the substance would throw up some substantial challenges, but compared to distributing gaseous Hydrogen, it seems to me that a solution that allows a solid substance to be used, with a higher energy density than elemental Hydrogen would be something worth looking at. An easily swapped out combination Reaction Chamber/Storage Unit would need to be designed that would allow for the LiH to be mixed with water to release the hydrogen content for use as a fuel, and some way to input measured amounts of the LiH to the reaction chamber, but surely, this is do-able. Lithium hydrides are white crystalline solids (m.p. 620 deg C), of generally salt-like physical character. The term "lithium hydride" may refer specifically to a compound of light hydrogen or may be used generically to refer any lithium-hydrogen compound regardless of hydrogen isotope. They are usually prepared by direct reaction between hydrogen and metallic lithium at elevated temperature. Lithium hydrides have low density (0.82 for LiH). Lithium hydrides have no known solvent. LiH reacts violently with water, producing hydrogen gas and have been used in the past for special purpose hydrogen gas generators, such as those used to inflate lifeboats. (Thanks to Corey Sublette for this detail). Granted, there are some proliferation concerns with enriched Li-6 and even natural Li-7, but I can picture a car pulling into a station and having a (large) fuel cartridge replaced by a robot in a few minutes, from the same spot that a gas tank already sits in and something of the same size. And all it spits out is water, so the greenies will be happy. Thoughts? Am I crazy? Cheers.