Fuel Cells - Proton-Exchange Membrane Fuel Cells: Freeze Operational Conditions

Since proton-exchange membrane fuel cells (PEMFCs) are considered as alternative power devices for automotive applications, cold start-up ability is regarded as an important requirement. Low-temperature polymer fuel cells operating under humid conditions produce water-freezing effects and can cause severe problems. This article gives an overview starting with basic processes occurring during freezing/thawing in the layered structure of membrane, electrode, gas-diffusion layer (GDL) and flow field up to ice blockages in a fuel cell system. Resulting degradation effects of the fuel cell and their influence on transient operation behavior are as well introduced as mitigation strategies by means of optimized operating conditions and fuel cell system architecture. Today operation of PEMFCs and systems under freezing conditions is still a challenge but it is by far not anymore a knockout criterion for commercialization

Brennstoffzellenmodul und dessen Verwendung

DE 102006048860 A1 UPAB: 20080615 NOVELTY - The planar fuel cell module (20) has a module base unit (21), which has two laminarly arranged recesses for fuel cells (14) that are inserted into the recesses concerning to its shape in a form-fitted manner. The module base unit has a strip conductor (15), which is electrically connected with the fuel cells, for electrically interconnecting the fuel cells and a fluid distributing structure for distributing the fuel. The recesses have a depth of 2 millimeter to 4 millimeter. USE - Planar fuel cell module for supplying current for a telecommunication system, a mobile phone, a pocket personal computer, a global positioning system-device, an automatic advertising panel, a lighting, a toy, applications for the camping area and outdoor area, a teaching aid and a demonstration aid, a radio, a TV, a mobile computer, an emergency power supplier, an alarm system, a network-independent battery charger, a medical device and a military application (all claimed). ADVANTAGE - The planner fuel cell module enables high flexibility for interconnecting the fuel cells, so that the module can be universally applicable