Alternative Energy Materials

Hydrogen Storage Alloys


Hydrogen storage alloys are metallic materials that have a unique ability to reversibly absorb and release significant amounts of hydrogen from the gas phase or electrochemically (see Figure below).

Gas Phase Hydrogenization

Gas Phase Hydrogenization


 

Electrochemical Hydrogenization/ Electrochemical Charging

Electrochemical Hydrogenization/ Electrochemical Charging

This unique property of hydrogen storage alloys is used in numerous applications1 such as:

  • rechargeable batteries
  • cooling devices
  • hydrogen storage systems for fuel cells

 

Among the broad variety of hydrogen storage alloys that have been studied to date,1,2 two groups of materials, AB5 and AB2 type alloys, have the most advantageous combination of high hydrogen storage capacities and operations parameters.

AB5 alloys combine a hydride forming metal A, usually a rare earth metal (La, Ce, Nd, Pr, Y or their mixture known as Mischmetal), with a non-hydride forming element – nickel. The latter can be doped with other metals, such as Co, Sn or Al, to improve material’s stability or to adjust equilibrium hydrogen pressure and temperature required for its charging discharging with hydrogen.2

AB2 alloys, also known as Laves phases, represent a large group of alloys containing titanium, zirconium or hafnium at the A-site and a transition metal(s) at a B-site (Mn, Ni, Cr, V and others). Reversible hydrogen storage capacities of this group of materials are comparable with those of AB5-type alloys. However, AB2 alloys are capable of storing additional amounts of hydrogen at high hydrogen pressures and have higher capacities at high discharge rates when used as negative electrodes in batteries2. Due to reasonably high hydrogen storage capacities (1.4-1.6 wt%) and consistent performance, AB5 and AB2 – type alloys can serve as excellent reference materials in hydrogen absorption and desorption experiments using gas-sorption systems3.

Reference Kit for Hydrogen Storage (686115)

Materials included in the kit are offered as references with the PCTPro-2000 System. They can also be used for demonstration purposes and as references during the development of novel hydrogen storage and battery materials.

Product Information


 

Product Number Product Name Chemical Composition Hydrogen Storage Capacity wt.% Equilibrium Pressure Plateau Add to Cart
685933 Lanthanum-Nickel Alloy, LaNi5 LaNi5 1.5 -1.6
(25oC)
~2 bar (25oC)
685968 Lanthanum-Nickel-Cobalt Alloy, LaNi4.5Co0.5 LaNi4.5Co0.5 1.4 -1.5
(25oC)
<0.5 bar (25oC)
685976 Mischmetal-Nickel Alloy, (Ce, La,Nd, Pr)Ni5 MmNi5Mm: La: 20-27%; Ce: 48-56%; Pr : 4-7%; Nd : 12-20% 1.5 -1.6
(25oC)
~10 bar (25oC)
685941 Titanium-Manganese Alloy,TiMn2, Alloy 5800 Ti0.98Zr0.02V0.43Fe0.09Cr0.05Mn1.5 1.6 - 1.7
(25oC)
~10 bar (25oC)

For more materials for hydrogen storage applications sigma-aldrich.com/hydrogen.

References:
1. Hydrogen Materials Science and Chemistry of Metal Hydrides, NATO Science Series, v.71. Eds.: M.D.Hampton, D.V.Shur, S.Y.Zaginaichenko, V.I.Trefilov, Kluwer Academic Publishers, Dodrecht, Boston, London, 2002.
2. Battery Technology Handbook, 2nd Ed., Ed.: H.A.Kiehne, Expert Verlag GmbH, Renningen-Malsheim, Germany, 2003.
3. Hydrogen Storage Materials, Material Matters, Vol. 2 No.2, 2007.