Effect of compression on the water management of polymer electrolyte fuel cells: An in-operando neutron radiography study

JOURNAL OF POWER SOURCES

卷:412

Article

Wu, Y.¹  Cho, J. I. S.^1,2  Lu, X.¹  Rasha, L.¹  Neville, T. P.¹  Millichamp, J.¹  Ziesche, R.¹  Kardjilov, N.³  Markoetter, H.³  Shearing, P.¹  Brett, D. J. L.¹ 

[1] UCL, Dept Chem Engn, Electrochem Innovat Lab, London WC1E 7JE, England

[2] UCL, Dept Chem Engn, EPSRC Frontier Engn Ctr Nat Inspired Engn, London WC1E 7JE, England

[3] HZB, Hahn Meitner Pl 1, D-14109 Berlin, Germany

关键词: Compression;    Water management;    Neutron imaging;    Gas diffusion layer;    Droplet;    Porosity;   

DOI  :  10.1016/j.jpowsour.2018.11.048

来源: Elsevier

【 摘 要 】

In-depth understanding of the effect of compression on the water management in polymer electrolyte fuel cells (PEFCs) is indispensable for optimisation of performance and durability. Here, in-operando neutron radiography is utilised to evaluate the liquid water distribution and transport within a PEFC under different levels of compression. A quantitative analysis is presented with the influence of compression on the water droplet number and median droplet surface area across the entire electrode area. Water management and performance of PEFCs is strongly affected by the compression: the cell compressed at 1.0 MPa demonstrates similar to 3.2% and similar to 7.8% increase in the maximum power density over 1.8 MPa and 2.3 MPa, respectively. Correlation of performance to neutron radiography reveals that the performance deviation in the mass transport region is likely due to flooding issues. This could be ascribed to the loss of the porosity and increased tortuosity factor of the gas diffusion layer under the land at higher compression pressure. The size and number of droplets formed as a function of cell compression was examined: with higher compression pressure, water droplet number and median droplet surface area rapidly increase, showing the ineffective water removal, which leads to fuel starvation and the consequent performance decay.

【 授权许可】

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