• Gkanas, Evangelos I.
• Shepherd, Simon
• Wang, Chongming
• Curnick, Oliver J.

Abstract

The successful and fast start-up of proton exchange membrane fuel cells (PEMFCs) at<br/>subfreezing temperatures (cold start) is very important for the use of PEMFCs as energy sources<br/>for automotive applications. The effective thermal management of PEMFCs is of major importance. When hydrogen is stored in hydride-forming intermetallics, significant amounts of heat are released due to the exothermic nature of the reaction. This excess of heat can potentially be used for PEMFC thermal management and to accelerate the cold start. In the current work, this possibility is extensively studied. Three hydride-forming intermetallics are introduced and their hydrogenation behavior is<br/>evaluated. In addition, five thermal management scenarios of the metal hydride beds are studied in order to enhance the kinetics of the hydrogenation. The optimum combination of the intermetallic,<br/>hydrogenation behavior, weight and complexity of the thermal management system was chosen forthe study of thermal coupling with the PEMFCs. A 1D GT-SUITE model was built to stimulate the<br/>thermal coupling of a 100 kW fuel cell stack with the metal hydride. The results show that the use of the heat from the metal hydride system was able to reduce the cold start by up to 8.2%.

Topics

• impedance spectroscopy
• Hydrogen
• forming
• intermetallic