Microscopic Monitoring of Local Temperature in the High Temperature Proton Exchange Membrane Fuel Cell Stack

摘要

The non-uniform distributions of internal temperature in a membrane electrode assembly (MEA) ofproton exchange membrane fuel cell (PEMFC) stack affect not only the reactions that occur in it, butalso its performance and lifetime. In this work, micro-electro-mechanical systems (MEMS) are utilizedto develop a new generation flexible micro temperature sensors for use in high-temperatureelectrochemical environments, and they were applied in high temperature fuel cell stack to measure thetemperature. Polyimide foil (50m) is selected as a substrate, and liquid polyimide is used as theprotecting layer because of its high temperature resistance. The micro sensors were embedded in thecathode flow plate of HT-PEMFC stack (7 cells). The results demonstrate that they do not influencestack performance, and the calibration curves was measured by micro sensors are linearity andreliability. The curves of local temperature that were measured by micro sensors in the cell stack at theoperating temperatures of 160C and at constant currents of 2, 10 and 20A are fairly consistent eachother. The results show that the non-uniform of heat distributions, and its internal chemical reaction ismore severe, resulting in a large temperature difference inner HT-PEMFC stack at a constant currentof 20A.