缓解干湿循环的机械因素造成燃料电池电极质膜失效的五种方法（其三）：加压低湿度金属多孔流场燃料电池Effect of Porous Metal Flow Field in Polymer Electrolyte Membrane Fuel Cell under Pressurized Condition

C．－Y． Ahn

M． S． Lim

W． Hwang

S． Kim

J． E． Park

J． Lim

I． Choi

Y．－H． Cho

Y．－E． Sung

Abstract

A flow field represents an interesting research area related to polymer electrolyte membrane fuel cells （PEMFCs）， as it is a component crucial for the distribution of gas－phase reactants． In this study， a metal foam was characterized and applied as a flow field in a PEMFC unit cell． In addition， the electrochemical performance of the metal foam was compared with that of the commonly used serpentine flow field． At a relative humidity （RH） of 100％， no significant difference in performance was observed between the metal foam and serpentine flow field． However， the performance of a single cell with the metal foam was superior to that of the common flow field under an RH of 20％ under pressurized conditions． Furthermore， the factors affecting fuel cell performance by application of the flow field were discussed．

这篇文章结论和内容比较简单，比较适合我。

2014年丰田的规则多孔流场让人们意识到孔状流场的特异性，不断也有类似的研究公布出来。一种常见的想法是这样的：

作为流道压缩前后的多孔材料状态对比，压缩后是指在燃料电池中压缩到67．5％。

孔尺寸差异不大，孔隙率有所下降

Fig． 4 Voltage profiles of single cells with （a） the conventional serpentine （b） nickel foam， and （c）copper foam flow fields during activation． The inset shows pictures of each flow field． The temperatures of the single cells and all humidifiers were maintained 70 C （100％ RH） during this process without backpressure， and H2 and O2 were supplied to the anode and cathode at a constant flow of 150 and 200 sccm， respectively．

镍无法获得的稳定的极化性能。nickel can not only undergo facile corrosion but also dissolve under acidic， and relatively high－temperature conditions．

蛇形流道是SCF，铜多孔流场是SCCF。

SCCF略差

以铜为多孔流场材料，燃料电池运行10分钟后，铜表面生成氧化物。

这里提到的部分矫正是To understand the manner in which the porous structure affects the metal flow field， the performance curve of the metal foam was reconstructed by the correction of the differences in
the high－frequency resistance （HFR） values of SCS and SCCF
（HFR（SCCF） – HFR（SCS）） （Figure 7）．

加压操作

To investigate the structural effects of porous metals， partially corrected data，such as atmospheric conditions of 100％ RH （Figure 7）， are
shown in Figure 8． （Figure S3 shows the performance curve
before correction．）

加压、低湿度操作，SCCF占优

推测是多孔流场能够一定程度缓解低湿度条件对膜的影响，可以称为缓解干湿循环的机械因素造成燃料电池电极质膜失效的五种方法（其三）。

缓解干湿循环的机械因素造成燃料电池电极质膜失效的五种方法（其二）

Conclusions

In this study， the effects of the structure of metal foam as a
fuel cell flow field were investigated． From the results
obtained for the experiment under normal pressure and 100％
RH， better performance for the conventional serpentine flow
field （771 mW cm–2） was observed as compared with that
observed with the metal foam in the cell （702 mW cm–2），
caused by metal oxidation， as well as the decreased performance
of the fuel cell related to the increased contact resistance．
For compensating the effect of metal oxidation， the performance
was similar to that of the conventional one， but the
performance drastically decreased in the high－current－density
region． To investigate the effect of water， experiments were
conducted under low－humidity conditions， but no improvement
in performance was observed． To compensate the disadvantages
of the porous structure as flow field， and to uniformly
distribute the reactant gas， the experiment was
conducted under pressurized conditions． Performance similar
to that observed under atmospheric conditions was observed
at 100％ RH in the low－current－density region， with drastic
performance reduction in the high－current－density region．
However， high performance was observed under low RH conditions．
Hence， the porous flow field exhibits favorable effects
under pressurized and low－humidity conditions， considered
to be caused by the characteristics of porous materials， such as
the capillary phenomenon． Furthermore， better results are expected to be obtained with further research via surface treatment
and／or material changes because preventing material
corrosion is an important issue in selecting materials for fuel
cell components， and it is necessary to use materials which are
stable material under fuel cell operating conditions．