The ionomer binder within catalyst layer (CL) plays a vital role in proton exchange membrane fuel cell (PEMFC). Short-side-chain (SSC) perfluorosulfonic acid (PFSA) ionomers have recently gained considerable attention due to their superior PEMFC performance. However, most studies have focused primarily on SSC ionomer cell performance and seldomly explore the internal mechanism. The intrinsic relationships between catalyst ink and cell performance are still vague. Herein, the structure-property correlations among catalyst ink, CL microstructure, and PEMFC performance with different equivalent weight (EW) ionomers were proposed, especially, the distribution of different EW ionomers in the CL was observed. Our results show that the high ion exchange capacity (IEC) and low ionomer adsorption on Pt/C increase the ease of SSC ionomer to form Pt/C-ionomer connection network in the catalyst ink. Subsequently, a more uniform and continuous ionomer proton conduction network was observed in the CL containing SSC ionomer, which increased the active area, but at the cost of macropore volume. Combined with the high IEC of SSC ionomer, superior proton conductivity and high mass transport resistance for SSC ionomer electrodes are manifested in the ultimate performance. This work also provides an effective way to construct high-performance fuel cells containing SSC PFSA ionomer.

催化剂层 (CL) 内的离聚物粘合剂在质子交换膜燃料电池 (PEMFC) 中起着至关重要的作用。短侧链 (SSC) 全氟磺酸 (PFSA) 离聚物最近由于其卓越的 PEMFC 性能而受到广泛关注。然而，大多数研究主要集中在 SSC 离聚物电池性能上，很少探索内部机制。催化剂墨水和电池性能之间的内在关系仍然模糊不清。在此，提出了具有不同当量（EW）离聚物的催化剂油墨、CL 微观结构和 PEMFC 性能之间的结构-性能相关性，特别是观察了不同 EW 离聚物在 CL 中的分布。我们的结果表明，Pt/C 上的高离子交换容量 (IEC) 和低离聚物吸附增加了 SSC 离聚物在催化剂油墨中形成 Pt/C-离聚物连接网络的容易性。随后，在含有 SSC 离聚物的 CL 中观察到更均匀和连续的离聚物质子传导网络，这增加了活性面积，但以大孔体积为代价。结合 SSC 离聚物的高 IEC，SSC 离聚物电极卓越的质子传导性和高传质阻力体现在最终性能上。这项工作还提供了一种构建含有 SSC PFSA 离聚物的高性能燃料电池的有效方法。这增加了活性面积，但以大孔体积为代价。结合 SSC 离聚物的高 IEC，SSC 离聚物电极卓越的质子传导性和高传质阻力体现在最终性能上。这项工作还提供了一种构建含有 SSC PFSA 离聚物的高性能燃料电池的有效方法。这增加了活性面积，但以大孔体积为代价。结合 SSC 离聚物的高 IEC，SSC 离聚物电极卓越的质子传导性和高传质阻力体现在最终性能上。这项工作还提供了一种构建含有 SSC PFSA 离聚物的高性能燃料电池的有效方法。