平整层对PEM燃料电池自增湿性能的影响

制备了不同聚四氟乙烯(PTFE)含量与不同碳载量的电极平整层,经过相同的膜电极成型工艺处理后,组装成单电池进行极化曲线与交流阻抗分析,发现平整层中的聚四氟乙烯含量从24%增到35%时,H₂/O₂型燃料电池自增湿发电最高功率密度增长了0.1W/cm²,但当聚四氟乙烯含量增大到42%时,电性能略有下降;然而H₂/Air型燃料电池自增湿发电性能却随着聚四氟乙烯含量增大而提高.平整层载量对自增湿发电影响较大,平整层载量为4.0mg/cm²的膜电极与无平整层的膜电极在H₂/O₂自增湿操作下相比,最高功率密度提高约0.27W/cm².通过压汞仪与扫描电镜(SEM)对平整层的物化性能进行了结构分析.

Influence of Sub-layer on Self-humidifying Performance of PEMFC

To research the effect of sub-layer on self-humidifying performance of PEMFC, the membrane electrode assemblies with different PTFE contents and different loading amount of PTFE/C mixture in sub-layer were prepared, and then single PEMFCs were assembled for experimental studies of polarization and AC impedance. The results indicated that the peak power density of H_2/O_2 PEMFC was improved about 0.1 W/cm2 when PTFE content in sub-layer increased from 24% to 35%, but its peak power density decreased with PTFE content up to 42%. However, the self-humidifying performance of H_2/air PEMFC increased all along. The loading amount of sub-layer had an important influence on self-humidifying performance of PEMFC, the peak power density of H_2/O_2 PEMFC was improved about 0.27 W/cm2 when sub-layer loading amount increased from 0 to 4.0 mg/cm2. Finally, the microstructures of the sub-layer were analyzed by the methods of intrusion Hg measurement and SEM.