Characteristics Of Porous Electrode Polarization Of Novel Fuel Cells

Environmental pollution and energy crisis are two of the most important issues that we are facing today.The sustainable development of human society will be realized when the two issues are solved.Utilizing a heat engine burning fossil fuels to get energy is neither environmentally friendly nor efficient.Hence,fuel cell technology has received extensive attention and research in recent decades due to the high efficiency and sustainability.Among them,the direct alcohol fuel cells have received more attention because of its using small molecule alcohol as a fuel,whose source is abundant and storage and transport are convenient.As complete oxidation of alcohol into carbon dioxide in the fuel cell is difficult,so the electron transfer rate is low,but electron transfer rate of ethylene glycol in the fuel cell can be as high as 80%,resulting in ethylene glycol as a kind of extremely potential fuel.Direct ethylene glycol fuel cell output voltage is determined by the anode and cathode potential.When the fuel cell is operating,the actual potentials will deviate from the electrode theoretic potentials,leading to the performance loss.This article is to build up a one-dimension model of direct ethylene glycol fuel cell to investigate the influence of various operation conditions on the electrode polarization,which avoids complicated battery assembly and testing procedure.It is believed that this work is of great reference to the actual design of the fuel cells.The main outcomes are summarized as follows:(1)Build up the polarization model of direct ethylene glycol fuel cellIn direct ethylene glycol fuel cell system,its performance is influenced by temperature,electrocatalysts,and ion exchange membrane as well as the structure.In order to study the influence of design parameters on the performance directly,in view of the mass transport,charge transfer,and the electrochemical reaction,we use mass transport equation,electrochemical kinetics equation,and equation of boundary conditions to establish the relationship between the fuel cell output voltage and the current density.(2)Calculate and analyze the polarization model of direct anion exchange membrane ethylene glycol fuel cellWith the established polarization model,comprehensive analysis has been carried out on the fuel cell polarization to get the direct anion exchange membrane ethylene glycol fuel cell anode activation polarization,concentration polarization and ohm polarization curve.Then we analyze the effects of different mass concentration and cell structure parameters on the performance of the fuel cell.Based on the results,we study the best operating conditions and provide guidance for improving fuel cell performance.(3)Calculate and analyze the polarization model of direct proton exchange membrane ethylene glycol fuel cellAs the concept that proton exchange membrane can also be used as an ion exchange membrane to transfer hydroxide ions in alkaline conditions to maintain charge balance has been put forward,we analyze the influence of different operating conditions on the fuel cell performance and get the best operating conditions based on the previous model.(4)Experiment research on the electrode polarization of direct proton exchange membrane ethylene glycol fuel cellAiming at the polarization model of direct proton exchange membrane ethylene glycol fuel cell,we use experimental research to explore the influence of different conditions on the fuel cell performance.We choose anode alkali concentration and cathode oxygen concentration as two effects to investigate the influence on the fuel cell performance.It can provide the reference for the operation parameter selection for practical proton exchange membrane directly glycol fuel cells.