Water Transport Experiment And Numerical Simulation Of Alkaline Anion Exchange Membrane Fuel Cell

With the growth of global energy demand,hydrogen and fuel cells have gradually become an important direction of the global energy technology revolution.Fuel cells are also considered to be one of the most promising technologies for the clean energy industry in the future.Alkaline anion exchange membrane fuel cells(AEMFC)have received widespread attention at home and abroad in recent years due to their ability to use non-precious metal catalysts and their high electrochemical kinetics in alkaline operating environments.The internal water transport mechanism of AEMFC is complex,and it is affected by the operating conditions such as the temperature of the reactant gas and humidification,which affects the performance and stability of AEMFC.In order to further understand the water transport mechanism of AEMFC,related experiments and numerical simulations were performed in this paper.First of all,this paper has carried out experimental investigations,including the preparation of the Membrane Electrode Assembly,the assembly of AEMFC single cells,and the composition of the test system.The water collection experimental device was set up,and different working conditions such as air intake flow and humidity were set to collect the quality of the outlet water was combined with the amount of humidified water calculated from the intake dew point temperature and the amount of water generated by the internal reaction of the battery to establish a water balance with the experimental data of water collection.In addition,based on the establishment of the water balance,the water movement in the AEMFC was investigated the direction of the water in the AEMFC is opposite to that of the PEMFC.It is concluded that the water moves from the anode to the cathode,and the phenomenon that the anode water flux increases with the increase of the current is observed.Then the AEMFC fluid mechanics model,the water transfer model in the alkaline membrane,and the electrochemical model are established,including the mass conservation equation,the momentum conservation equation,the component conservation equation,and the charge conservation equation,including heat and mass transfer,and electrochemical reactions.,Gas diffusion,water activity and other aspects,the multi-physics coupling simulation software COMSOL Multiphysics is used to simulate the AEMFC,and the battery performance polarization curves obtained by comparing the model simulation and the experiment are in good agreement,which illustrates the model Accuracy and reasonableness.Finally,the model was used to investigate the effects of current density,film thickness,battery operating temperature,anode relative humidity and cathode inlet relative humidity on the performance and water transport of the AEMFC.Electroosmosis has an enhanced effect.At the same time,the water content on the anode side increases and the water content on the cathode side decreases.Therefore,the cathode side needs more water supply at high current density,otherwise the performance will be affected by the cathode film being too dry.The relative humidity of the anode inlet air and the relative humidity of the cathode inlet air have a significant impact on performance,both of which have a greater impact on the stage of higher current density.The difference is that when the anode humidity changes from 50% to60%,the performance and water content The improvement is most obvious,and the cathode humidity shows a greater impact on performance and water content above 80%.The transient analysis shows that the performance during the load increase phase is generally better than that during the load decrease phase,and this difference is more obvious with the increase of relative humidity.