Design of a hydrogen storage device for evaluating tensions induced by volumetric expansion during hydrogen absorption

MARÍN, J.; BIASETTI, A.; MEYER, G.; BORZONE, E.M.; AVERSENTE, N.; BARUJ, A.

Journal of Physics: Conference Series

Institute of Physics

Año: 2023 vol. 2605

1742-6588

Hydride-Forming Materials (HFM) allow the storage of hydrogen in solid state. The reaction can be reversed by delivering heat or lowering pressure, releasing gaseous hydrogen. When hydrogen is incorporated into its structure, the HFM experiences a volumetric expansion. In the case of LaNi5, a commonly studied AB5 type material, it can be as high as 25%. This mismatch produces stress within the material, which breaks apart. Successive cycles produce further decrepitation into a fine powder, which reduces heat transfer, and compaction, which affects diffusion of the gas phase and, in extreme cases, may deform or even break the container. For these reasons, in order to make a safe and efficient hydrogen storage system it is of crucial importance to characterize the volumetric expansion and the mechanical stress originated by the HFM. With these objectives, we have designed a device with an adequate geometry for being studied by neutron imaging. This technique allows to observe the interior of a metallic vessel and, at the same time, to distinguish the hydrogen distribution in a HFM through a convenient contrast difference. Furthermore, we have designed and manufactured a mechanical indicator of the volume changes caused by cycling and allows their direct observation.