200 NL H2 hydrogen storage tank using MgH2-TiH2-C nanocomposite as H storage material

MgH2-based hydrogen storage materials are promising candidates for solid-state hydrogen storage allowing efficient thermal management in energy systems integrating metal hydride hydrogen store with a solid oxide fuel cell (SOFC) providing dissipated heat at temperatures between 400 and 600 degrees C. Recently, we have shown that graphite-modified composite of TiH2 and MgH2 prepared by high-energy reactive ball milling in hydrogen (HRBM), demonstrates a high reversible gravimetric H storage capacity exceeding 5 wt % H, fast hydrogenation/dehydrogenation kinetics and excellent cycle stabidlity. In present study, 0.9 MgH2 + 0.1 TiH2 + 5 wt %C nanocomposite with a maximum hydrogen storage capacity of 6.3 wt% H was prepared by HRBM preceded by a short homogenizing premilling in inert gas. 300 g of the composite was loaded into a storage tank accommodating an air-heated stainless steel metal hydride (MH) container equipped with transversal internal (copper) and external (aluminium) fins. Tests of the tank were carried out in a temperature range from 150 degrees C (H-2 absorption) to 370 degrees C (H-2 desorption) and showed its ability to deliver up to 185 NL H-2 corresponding to a reversible H storage capacity of the MH material of appr. 5 wt% H. No significant deterioration of the reversible H storage capacity was observed during 20 heating/cooling H-2 discharge/charge cycles. It was found that H-2 desorption performance can be tailored by selecting appropriate thermal management conditions and an optimal operational regime has been proposed. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

MgH2-based hydrogen storage materials, such as the TiH2 and MgH2 graphite-modified composite prepared by HRBM, show high reversible gravimetric H storage capacity, fast hydrogenation/dehydrogenation kinetics, and excellent cycle stability. Through optimal thermal management conditions, a nanocomposite with a maximum hydrogen storage capacity of 6.3 wt% H was successfully prepared and demonstrated good H2 desorption performance.