The main reasons of performance degradation of PEFCs in the freezing condition were tried to find out. For the normally operated cells, 2 types of Freeze/thaw tests were conducted. The first set was the the F/T cycle (-30 °C ～ 70 °C) with gas purge during shut-down process. The second was exactly the same process to the second set except the cycle temperature of 30 ～ 70 °C. The result showed that it's difficult to correlate the changes in cyclic voltammogram, ECSA, H_2 crossover rate and so on the I-V performance degradation. The only clear evidence of performance degradation is the increase of cell resistance with the number of F/T cycles.
展开▼
