The characteristics and the performance of dual air supply polymer electrolyte membrane fuel cell

Abstract

After industrialization, environmental pollution and global warming become more crucial than before to living things and people on earth. So researchers focus on developing eco-friendly, renewable energy. Polymer electrolyte membrane fuel cell (PEMFC) is regarded as one of the promising power generator. PEMFC generates electricity by reaction of hydrogen and oxygen. So PEMFC produces water and heat after reaction, that doesnt make pollutant like sulfur oxide (SOx) and nitrogen oxide (NOx). PEMFC has also other charming advantages, High efficiency, high power density and operation at low temperature. But there are some problems to be solved for commercialization and popularization of PEMFC like Water management, flow distribution, high cost of Pt-catalyst, etc. If flow doesnt distribute uniformly inside fuel cell, it cannot show high performance. In addition, un-uniform gas distribution can cause unstable operation of fuel cell and durability problem. So many researchers make studies on flow distribution inside fuel cell. In this study, dual air supply concept was applied to fuel cell to enhance the performance of fuel cell by improving flow distribution. For dual air supply fuel cell, an additional air inlet port was added to normal fuel cell. Through this additional air inlet port and main air inlet, air can be divided and supplied to fuel cell. When experiments were conducted using dual air supply fuel cell, it is necessary to air flow ratio through main and an additional air inlet. So, experiments were carried out first on various air flow ratio conditions. After that, operating characteristics of dual air supply fuel cell was investigated. Stoichiometric ratio of air and relative humidity of air were selected in each experiment, operating characteristics of dual air supply fuel cell was figured out. Also, Stability characteristics and EIS measurement were investigated. As written before, Voltage fluctuation was analyzed on various air flow ratio conditions, then results were compared that of normal fuel cell. Lastly, EIS measurement was conducted on various air flow ratio. Reactance and resistance value could be gained. Using that, performance difference in each various air flow ratio conditions was analyzed.