Experimental And Modeling Study On Electrochemical Characteristics Of Alkaline Membrane Fuel Cell

Since human society entered the 21 st century,depletion of fossil fuels and environmental pollution had become increasingly serious.Due to the rapid start-up,high efficiency,low environmental pollution,fuel cell has attracted widespread concern.AEMFC(alkaline anion exchange membrane fuel cell)operates in an alkaline environment,making it possible for using no-precious metal catalysts and low-cost metal hardware.In addition,AEMFC also has the advantages of low fuel permeation rate and rapid electrochemical reaction.In the experiment of this study,based on the A901 anion exchange membrane,the preparation of membrane electrode and fuel cell assembly are carried out.In-situ experiments for performance test,durability test and electrochemical impedance analysis with different operating conditions are carried out.The results show that increasing the operating temperature and the backpressure can improve the performance of the fuel cell,and the pressure gradient from anode to cathode is good for the equilibrium distribution of liquid water between the anode and the cathode,which can obviously improve the operating characteristics of the fuel cell.The proper electrolyte content is necessary to ensure the fuel cell performance.Anode MPL can decrease the ohmic loss and activation loss of the fuel cell,which improves the performance.The main reason for the poor durability of the AEMFC is the dramatic increase of the anode activation loss with time.In the simulation part,a single-channel AEMFC multiphase model is established.Based on the liquid pressure continuity method,the fuel cell operating characteristics and multi-phase transport inside the fuel cell are simulated.The simulation results have good consistency with the experimental data.The results show that increasing the working pressure of the anode and the cathode can improve the electrochemical kinetics of the fuel cell.It can also increase the thermodynamic reversible voltage and reduce the concentration loss of the reactant,thereby improving the performance of the fuel cell.Increasing the pressure gradient from anode to cathode can significantly promote the permeation of liquid water,which alleviates the flooding of anode.In addition,considering that water is the main reactant in the cathode reaction,the liquid water permeation can alleviate the water deficit of the cathode and greatly reduce the activation potential of the cathode.Although the pressure gradient significantly enhances the permeation of liquid water,the average water content in the membrane electrode remains relatively stable,leading to the relatively stable membrane resistance.