Development of a Portable Polymer Electrolyte Membrane Fuel Cell System Using Metal Hydride as the Hydrogen Storage Medium

Abstract

This paper describes the development of a Portable Polymer Electrolyte Membrane Fuel Cell / PEMFC system that was developed at HySA Systems Competence Centre. The system has a rated peak output power of 130W at 240Vac and 5Vdc USB output power. Hydrogen is supplied from Metal Hydride (MH) hydrogen storage canister which uses multi-component AB2 – type hydrogen storage hydride alloy. The in-house developed MH canister was made up of stainless steel tube with external aluminium fins and had a maximum hydrogen storage capacity of 90 NLH2. The improvement of H2 discharge dynamic performance of the MH bed, which is cooled down in the course of H2 desorption, was achieved by the placement of the MH canister in front of exhaust of air cooling system of the PEMFC stack. By the utilisation of the PEMFC waste heat, in combination with the external fins (increase of heat exchange area) and compacting the MH material with Thermal Expanded Graphite / TEG (improvement of the effective thermal conductivity in the MH bed), the MH canister allowed for >40 minutes-long stable operation at the stack power of 130 W (225 W/kg(MH)) with the utilisation of >90% of the stored H2.