N Cranenburgh, Better storage might give hydrogen the edge as renewable car fuel, Energy, 29 May 2019

In UK, a breakthrough has occurred with hydrogen storage by means of a low-cost molecular sieve. In view of the low density, and thus energy density, of hydrogen, vehicle fuel tanks must be designed for large volumes, and arranged to contain the fuel either as pressurised gas, or as cryogenic liquid. Consequently, the tanks tend to be bulky and heavy. Attempts are being made to carry the hydrogen in liquid ammonia or formic acid, but research at Lancaster University has shown that four times as much hydrogen can be carried in a given volume by means of a material known as Kubas Manganese Hydride-1 (KMH-1) that would permit storage at 120 bar rather than the current practice of 700 bar.