Metal hydride systems for hydrogen storage and supply for stationary and automotive low temperature PEM fuel cell power modules

Metal Hydrides (MH) provide efficient hydrogen storage for various applications, including Low Temperature PEM Fuel Cells (LT PEMFCs), when system weight is not a major and critical issue. Endothermic dehydrogenation of MH leading to decreased rates of H-2 evolution eliminates the risk of accidents even in the case of rupture of the hydrogen storage containment. At the same time, it poses a number of challenges related to the constant, stable and sufficient H-2 supply for stable FC operation. This paper reviews recent efforts in MH hydrogen storage and supply systems for LT PEMFC applications, including the ones developed at HySA Systems/SAIAMC/University of the Western Cape. The systems are characterised by a series of hydrogen storage capacities ranging from 10 NL to similar to 10 Nm(3) H-2 in turns providing stable operation for stationary and mobile PC power modules (from a few W to several kW). The MH systems use unstable hydride materials (equilibrium H-2 pressure at ambient temperature around 10 bar) that, in combination with special engineering solutions of MH containers (both liquid- and air-heated-cooled), and optimised system layout, facilitates H-2 supply to LT PEMFC stacks. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.