Study On Feed Structure And Performance Of Passive Micro Direct Methanol Fuel Cell

Compared with other energy sources,Passive Micro Direct Methanol Fuel Cell(PMDMFC)has many advantages such as wide fuel source,simple structure,low cost,low pollution,high safety and convenient fuel storage.Direct methanol fuel cells are gradually being paid attention.In this paper,a passive micro-direct methanol fuel cell was designed and fabricated,and the cell was tested in various feed structures and complex environments.The effects of membrane electrode hot pressing process,the anode and cathode feeding structure and complex environment on the performance of the cell were discussed.The main contents of this paper are as follows:1.The basic structure of passive miniature direct methanol fuel cell is introduced,including end plate,anode and cathode feed structure,MEA membrane electrode(proton exchange membrane,diffusion layer,catalytic layer)and sealing pad.The basic principle of the passive miniature direct methanol fuel cell and the electrochemical reaction occurring during the working process are introduced in detail,which provides a theoretical basis for the whole experiment and result analysis.2.The whole experimental procedure is introduced in detail,including pretreatment,hot pressing,assembly,wetting and activation,and testing.Several factors affecting the membrane performance of the hot pressing process were discussed.These factors were pressure,temperature and time respectively.Then,according to the experimental results,the optimal hot pressing process parameters were 1.0 Mpa,135? and 4 min.The effect of the concentration of methanol solution on the performance of the cell was discussed and the optimum methanol solution concentration was 4 mol/L.3.The effects of cathode and anode feed structures with different flow path shapes and different opening ratios on cell performance were discussed.Three different flow path shapes of horizontal,vertical and circular shapes and three different opening ratios of 50.0%,63.6%and 72.7%were fabricated,and the methanol fuel cells were fabricated with these feed structures,respectively.Conduct a performance test experiment.The optimum flow path shape of the anode feed structure is vertical,and the optimum opening ratio is 63.6%;the opening ratio is inversely proportional to the optimum methanol concentration,and the larger the opening ratio,the smaller the optimal methanol concentration.The optimum flow path shape of the cathode feed structure is a vertical shape with an optimum opening ratio of 50.0%.4.The effects of complex environments such as vibration,operating temperature and placement on cell performance were investigated.In the vibration frequency range of 0 HZ-30 HZ,the increase of vibration frequency helps to improve the performance of the cell,and then the frequency continues to rise without affecting the performance of the cell;in the temperature range of-10??50?,the cell performance with temperature increase and increase.In the temperature range of 10??30?,the temperature has a greater impact on the performance of the cell.Then the increase in temperature helps the performance,but the lifting effect is smaller and smaller;when the cell is placed vertically the battery has the best performance.