Investigation of Microscale Periodic Ni-Mg-Ni-Mg Film Structures as Metal-Hydride Hydrogen Accumulators

Abstract

Here, the authors report the results of their study on the key characteristics of microscale periodic Ni-Mg-Ni-Mg film structures as metal-hydride hydrogen accumulators, namely, the microstructure, phase state, operation temperatures and rate of the sorption/desorption processes, complete and reversible mass content of hydrogen, and enthalpy of metal hydrides’ phase-formation. The study has shown that hydride-formation films can be saturated with up to 7.0–7.5 wt.% of hydrogen at pressures up to 30 atm and temperatures of 200–250 °C, with a reversible amount of stored hydrogen up to 3.4 wt.% during its desorption at a pressure of 1 atm and temperatures of 250–300 °C with the phase-formation enthalpy in the range of 19.8–46.7 kJ/mol H2 depending on the nickel content (the thickness of the nickel layer). Structural and constructive schemes are proposed for film metal-hydride hydrogen accumulators for various applications of the hydrogen power industry.

Keywords

• metal hydride
• hydrogen accumulator
• Ni-Mg-Ni-Mg film structure
• X-ray diffraction analysis
• sorption/desorption process
• mass content of hydrogen