中文摘要：

考察了H3PO4／PBI高温PEMFC单体电池间放时的磷酸流失及对电池性能的影响。用磷钼蓝法测定了电极排水中的磷酸流失量；运用交流阻抗技术测试了电池内阻的变化；用SEM-EDX测量了运行不同时间后MEA中磷酸的含量。在正常操作时，电极排水中都含有少量的磷酸，且阴极侧比阳极侧的流失量大；500h磷酸的流失总量很小，约为H3PO4／PBI膜中吸附磷酸量的0．43％；单体电池500h间歇运行过程中内阻的变化不明显；运行不同时间后，阴极催化层中的磷酸减少，而阳极催化层中的磷酸含量比阴极高，但H3PO4／PBI膜中的磷酸含量未明显减少。在电池中有液态水存在时，磷酸的流失严重，返水5s的流失量约是正常操作时500h两极流失总量的3倍。正常操作时，电池中没有液态水存在，磷酸流失对电池性能的影响很小；当电池中存在液态水时，磷酸的流失严重，导致电池的性能降低。

英文摘要：

The H3PO4 leaching during intermittent working and its influences on the performance of the single cell of HaPO4/PBI high temperature PEMFC were studied. The H3PO4 leaching from the electrode drainage was analyzed by Phospho-Molybdenum-blue spectrophotometry method. The changes in the internal resistance of the cell were tested by AC impedance technology. The H3PO4 contents in MEA were also measured by SEM-EDX after different working time. There was a little H3PO4 in the electrode drainage,and the H3PO4 leaching from cathode was more than that from anode at right operation condition. The total H3PO4 leaching amount during the 500 h test was very small,about 0.43% of the total H3PO4 content in H3PO4/PBI membrane. The change in the internal resistance of the cell was not obviously. After different working time, the H3PO4 content in cathode reduced and was less than that in the anode, but the H3PO4 content in H3PO4/PBI membrane did not change. When there was liquid water in the cell, the H3PO4 leaching was too much badly,and during the only 5 s water back flow operation, the H3PO4 leaching was three times than the total amount of the 500 h test. During right operation, there was no liquid water in the cell, the H3PO4 leaching had little influence on the performance of the cell. A little liquid water in the cell would result in a severe H3PO4 leaching and a badly decrease in the performance of the cell.