Experimental And Modeling Study For Alkaline Membrane Fuel Cell

Fuel cell has attracted considerable attentions due to its favorite features such as the quick start-up, high efficiency, low noise and zero/low emission. Among the different kinds of fuel cells, alkaline membrane fuel cell(AMFC) has been widely studied in recent years because of its merits such as fast electrochemical kinetics, low dependence on non-precious catalyst and high tolerance on the carbon dioxide. Water management is one of the most important issues affecting the performance, cost and durability of AMFC, which requires comprehensive understanding of the heat and mass transfer process.First, different membrane electrolyte assemblies for AMFC are fabricated, single AMFCs are designed and assembled, testing system is developed, and in-situ experiments for performance test with different operating conditions are carried out.Then, a three-dimensional multiphase non-isothermal AMFC full cell model is developed. This model solves the processes of electrochemical reactions, heat and mass transfer, phase change in all the components of AMFC. The model is also validated with experimental results.After that, the effects of anode inlet relative humidity, cathode water supply, operating temperature, membrane thickness and electrode wettability on the performance and mass transfer of AMFC in steady-state are comprehensively investigated based on the developed model. The modeling results show that the performance is improved with more anode humidification, but the improvement becomes less significant at higher humidification levels. Cathode humidification is more critical than anode. Liquid water supply in cathode has a positive effect on performance, especially at high current densities.Finally, the effects of output voltage, anode inlet relative humidity, cathode water supply and operating temperature on the dynamic operating characteristics of AMFC are investigated. In the cases of load circulation, the frequency of load change and voltage increment/decrement all have considerable effect on the performance. With less humidification conditions, the transient response becomes slower.