Study On Current-Collecting Diffusion Structure Of Foam Titanium-based Micro Methanol Fuel Cell

The micro direct methanol fuel cell(μDMFC)is a fuel cell that directly uses a methanol solution as a fuel and oxygen in the air as an oxidant.It is not only environmentally friendly but also has high energy efficiency.It is one of the ideal power sources for all kinds of portable electronic products in the future.At present,it has become a research focus throughout the world.However,the practical application of μDMFC still needs to solve a large number of basic science and engineering problems.Among them,the gas diffusion layer(GDL)and current collector(CC)have an important influence on the output performance of fuel cells,which is practical for μDMFC.This article has conducted exploratory research around this key issue.Firstly,the effects of different gas diffusion layers on the mass transfer resistance and contact resistance of μDMFC were investigated.GDL and CC are important components of direct methanol fuel cells,providing a support layer for catalysts,electron channels and gas delivery channels.In this paper,different materials are used directly as the gas diffusion layer of μDMFC.The results show that three-dimensional graphene(3DG)is used as the anode gas diffusion layer of μDMFC,and foam titanium(FTi)as the cathode gas diffusion layer of μDMFC can significantly improve the performance of the cell.With this structure,the peak power of the fuel cell reached 33 mW,which was 32%higher than that of carbon paper(CP).Then,the effects of different materials on the mass transfer resistance and ohmic internal resistance of μwere studied when carbon paper and three-dimensional graphene were used as gas diffusion layers.Different materials were used as flow fields to investigate the effects of different materials on cell performance.The results show that when carbon paper is used as the diffusion layer,foam nickel(FNi)is used as the anode flow field,and foam titanium is used as the cathode flow field.When three-dimensional graphene is used as the diffusion layer,stainless steel felt(SSF)is used as the anode flow field,foam nickel is used as the cathode flow field.The μDMFC achieves maximum performance.Finally,based on the above experimental analysis and research,I proposed an electrode structure of titanium-based current-diffusion integrated cathode foam,which integrates the current collecting plate and the diffusion layer.Foam titanium is used as the electrode material of the current collecting-diffusion integrated structure.Foam titanium has good chemical stability and corrosion resistance,it is especially suitable for complex electrochemical environment of fuel cell.At the same time,the mechanical properties and microporous penetration of foam titanium are better than others.Therefore,it can be reasse-mbled without affecting its porosity.The integrated structure of the current collecting plate and the diffusion layer eliminates the contact resistance in the conventional fuel cell,significantly reduces the internal resistance of the cell,and improves the output performance.Morever,this structure also simplifies the structure and manufacturing process of the μDMFC,and increases its volumetric specific energy,which can promote its further miniaturization.