High-stability dead-end anode proton exchange membrane fuel cells by purge optimization

The crossover of nitrogen and oxygen from cathode to anode aggravates the non-uniformity inside dead-end anode proton exchange membrane fuel cell (DEA-PEMFC), inducing some other effects, such as carbon corrosion, to cause irreversible damage to catalyst. Therefore, developing a purge strategy according to the non-uniformity is necessary to improve its stability. In this study, the effects of operating parameters on the uneven electrical-thermal-water performance are investigated based on a three-dimensional transient model of DEA-PEMFC. Afterwards, a purge optimization is carried out based on the uneven distribution of field variables. The results show that the calculated standard deviation (STDEV) of overvoltage is reduced first and then increased quickly for all the cases. Therefore, the purge should be started when the STDEV approaches the minimum value, to avoid the irreversible damage to DEA-PEMFC, achieving high-stability output performance meanwhile. On this basis, the purge interval is optimized to 100 s, which is suitable for almost all the discussed cases. The purge duration is reduced to 0.2 s. In this situation, the minimum voltage is decreased by about 0.95% compared with the maximum value, indicating a good voltage stability. This study is beneficial to provide guidance for the efficient and long-term operation of DEA-PEMFC.