20. Stack Concepts for High Temperature Polymer Electrolyte Membrane Fuel Cells

Stationary and mobile applications are attractive applications for high temperature polymer electrolyte membrane fuel cells (HT-PEMFC). Examples for stationary applications are electricity and heat generation for households or uninterruptible power supply (UPS) systems. In the case of mobile applications the on board power supply with auxiliary power units (APUs) and backup power for the recreation area are most promising. In comparison to the low temperature PEMFC (operated at 60–80 °C) the operating temperature of a HT-PEMFC, which is between 120 and 200 °C, allows a more effective co-generation of power and heat. The higher temperature also leads to an improved tolerance to fuel impurities and a simpler system design [1]. Therefore applications where hydrogen is generated with reformer systems are ideally suited for a HT-PEMFC due to the increased CO tolerance [1, 2]. The majority of these demands have electric power requirements between some hundred Watt and the low kW range.