Hydrogen storage material is a kind of material that can reversibly absorb and release hydrogen. Since the 1970s, due to the increasing importance of the research and development of hydrogen energy, the safe storage, and transportation of hydrogen should be solved first, and the range of hydrogen storage materials has been increasingly extended to transition metal alloys. For example, lanthanum-nickel intermetallics have the properties of reversible absorption and release of hydrogen. At present, there are three commonly used hydrogen storage methods: gaseous hydrogen storage, liquid hydrogen storage, and solid hydrogen storage.
- "Solid-state" storage and transportation of hydrogen: Using liquid hydrogen tanker tanks and high-pressure hydrogen cylinders to transport or store hydrogen is not only expensive and demanding safety measures, but also not suitable for long-term storage because of evaporation and leakage. Using hydrogen storage material like LaNi6 alloy as medium, hydrogen and hydrogen storage alloy are synthesized into solid metal hydride to store and transport hydrogen, which can solve the problems of long-term storage and safe transportation.
- Ultra-pure purification of hydrogen: Compared with the current hydrogen cylinder-membrane hydrogen purifier system, the hydrogen accumulator with both storage and purification functions has the advantages of low price, small volume, large capacity, easy to operate, not easy to damage and so on. It is suitable for all departments that need high purity hydrogen, such as electronics, chemical industry, metallurgy, meteorology and so on. This kind of hydrogen storage purifier uses TiMn2, TiFe and other hydrogen storage alloys, and has been applied in the department of electronic chemical analysis.
- Separation of hydrogen: Hydrogen can be separated from various hydrogen-containing mixed gases by making use of the selective absorption of hydrogen gas in hydrogen storage materials. For example, Mg(NIAI)5 hydrogen storage alloy is used to absorb, purify and store hydrogen in the tail gas of synthetic ammonia plant. It can replace the hydrogen production system of electrolytic water and has a good industrial application effect.
- Sensor: Some hydrogen storage materials can react with certain chemicals and can be used in chemical and medical sensors. For example, Polyaniline and the prepared Polyaniline/inorganic nanoparticle composites have completely reversible adsorption-desorption properties for HCl, so they are most suitable to be used as HCl gas sensor materials.
- Hydride-nickel battery: A new type of high capacity secondary battery (rechargeable battery) can be made by using hydrogen storage material as a negative electrode, nickel as a positive electrode and KOH as the electrolyte. For example, LiAlH4 contains 10.6% hydrogen by mass fraction, which makes lithium aluminum hydride a potential hydrogen storage medium for future fuel cell locomotives because of its hydrogen content and reversible hydrogen storage properties.
At present, hydrogen storage materials include metal hydride, carbon fiber carbon nanotubes, non-carbon nanotubes, glass hydrogen storage microspheres, complex hydrogen storage materials and organic liquid hydrides. Among them, the most important ones are alloys, organic liquids, and nano-hydrogen storage materials.
- Alloy hydrogen storage materials: Hydrogen storage alloys are metal compounds that can reversibly absorb, store and release hydrogen at a certain temperature and hydrogen pressure. The principle is that metals and hydrogen form conjugates such as ionic compounds, covalent metal hydrides, metal phase hydrides-intermetallic compounds, and hydrogen can be released under certain conditions.
Figure 1. Alloy hydrogen storage materials
- Liquid organic hydrogen storage materials: Organic liquid hydride hydrogen storage is achieved by the reversible reaction of unsaturated liquid organic matter with hydrogen, that is, hydrogenation and dehydrogenation. Hydrogen storage during hydrogenation reaction, hydrogen release during dehydrogenation reaction, and organic liquid as hydrogen carriers are used to achieve the purpose of storing and transporting hydrogen.
Figure 2. Carbon aerogel hydrogen storage materials
- Nano-hydrogen storage materials: Nano-hydrogen storage materials are divided into two ways. One is to nanocrystallize the original hydrogen storage materials, and the other is to develop new nanomaterials as hydrogen storage materials.
Figure 3. Nanotube hydrogen storage materials
- Zhou Suqin et al. (2010), "Research Progress of hydrogen Storage Materials." Materials Science and Engineering 28(5).
- Zhang Wencheng. (2008), "Research progress of mg-based hydrogen storage materials." Technology and Technology 30(1).