Figure 3.

Hydrogen storage techniques

High pressure tank whereby hydrogen gas is kept under high pressures to boost the storage density (A). Cryogenic tanks that are used to store hydrogen at cryogenic temperatures (B). Metal hydride technique that employs chemical reactions between certain metals and hydrogen to store hydrogen (C). Microporous carbon material with high surface area used to store hydrogen (D). Hydrogen hydrate formed based on physically trapping molecular hydrogen in water lattices (E).