Study On Fuel Cell Composite Bipolar Plate

Bipolar plate is one of the core components of proton exchange membrane fuel cell（PEMFC）.It is of great significance to find the materials and processing methods of bipolar plate with excellent performance and low cost for the large-scale application of fuel cell.In this paper,expanded graphite paper is selected as the original material of bipolar plate,T90sealant is used as the plugging material,and vacuum pressure impregnation technology is used to inject sealant into the middle hole and micropore of expanded graphite paper,fill the middle micropore,block the leakage of impurities in graphite,improve the mechanical strength of expanded graphite,and improve its sealing performance;graphite stainless steel composite plate is prepared,and its Physicalization is carried out Characterization and performance test.Firstly,the conditions of sealant injection and the subsequent heat treatment process were optimized.Among them,the best condition for sealant injection is to keep it for 0.5h under vacuum of-0.2MPa,to keep it for 12h under pressure of 0.7MPa,and to inject it twice;after treatment at 120℃for 4h,the sealant shape can be solidified first,and then to keep it for4H under temperature of 160℃to ensure that the sealant is fully hardened,so that the dense expanded graphite paper has good mechanical strength.The results show that the micropore content of the paper is close to 0cm³?g^-1,the ion exudation rate is reduced by 74.27%,and the hydrophobicity of the paper remains unchanged.After the passivation film of stainless steel sheet was removed by acid pickling,the graphite metal composite plate was prepared by bonding the conductive adhesive and the expanded graphite paper.The conductivity of the composite plate was tested.The contact resistance was 9.6mΩ·cm²at 1.4Mpa.The electrochemical test shows that the working voltage is 0.64V and the corrosion current is 1.605μA?cm^-2,which meets the requirements of fuel cell for bipolar plate materials.