Effect of compression on the water management of polymer electrolyte fuel cells: An in-operando neutron radiography study
Effect of compression on the water management of polymer electrolyte fuel cells: An in-operando neutron radiography study
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DOI：
10.1016/j.jpowsour.2018.11.048
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发表时间：
2019-02-01
影响因子：
9.2
通讯作者：
Brett, D. J. L.
中科院分区：
文献类型：
--
作者：
Wu, Y.;Cho, J. I. S.;Brett, D. J. L.
深入了解压缩对聚合物电解质燃料电池（PEFC）中水管理的影响对于优化性能和耐久性是必不可少的。在这里，在operando中子射线照相是用来评估液态水的分布和运输PEFC在不同的压缩水平。定量分析了压缩对整个电极面积上水滴数和中值液滴表面积的影响。PEFC的水管理和性能受到压缩的强烈影响：在1.0 MPa下压缩的电池在1.8 MPa和2.3 MPa下的最大功率密度分别增加了3.2%和7.8%。性能与中子射线照相的相关性表明，在质量传输区域的性能偏差可能是由于洪水问题。这可能是由于在较高的压缩压力下，孔隙率的损失和增加的气体扩散层的弯曲因子的土地。检查了作为单元压缩的函数形成的液滴的尺寸和数量：随着较高的压缩压力，水滴数量和中值液滴表面积迅速增加，显示出无效的水去除，这导致燃料饥饿和随之而来的性能衰减。
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.