TITLE:
Hydrogen Storage in VNx-Hy Thin Films
AUTHORS:
Viktor Bryk, Aleksey Guglya, Aleksandr Kalchenko, Ivan Marchenko, Yuriy Marchenko, Elena Solopikhina (Melnikova), Victor Vlasov, Evgeniy Zubarev
KEYWORDS:
Nanocrystalline Structures, Hydrogen, Absorption, Storage, Thin Films, Ion-Beam Assisted Deposition
JOURNAL NAME:
Open Access Library Journal,
Vol.2 No.12,
December
14,
2015
ABSTRACT:
Vanadium or its alloy-based hydrides are intensively studied at the
moment with regard to their use as hydrogen absorbents. Most experiments were
carried out using “bulk” materials. This paper uses ion beam-assisted deposition technology (IBAD) to create
thin-film nanocrystalline VNx-Hy hydrogen storages. The
transmission electron microscopy and
scanning electron microscopy were
used to study the initial stages of the film formation. The main mechanisms of
the formation of intergranular pores in nanogranular structures have been
established. The interrelation of the parameters of the IBAD and those of film
structure has been shown. The obtained data allowed for the explanation of the
mechanisms of hydrogen absorption and desorption by thin films. It was shown
that the availability of branched network of intergranular pores allows VNx-Hy structures to accumulate hydrogen within a few minutes at a pressure of 0.5
MPa. Hydrogen in amount of up to 2.55 wt% is retained in the films of 3 μm thick at room temperature and atmospheric pressure.
The hydrogen desorption starts at 100℃.