Li Wenkai, Zhao Yixin, Pan Xingchen, Liu Mingqi, Qiu Shi, Xie Zhiyong
Carbon-Carbon Composite Materials Research Institute, Powder Metallurgy Research Institute, Central South University, Changsha 410017, China.
Nanomaterials (Basel). 2023 Jul 12;13(14):2055. doi: 10.3390/nano13142055.
Composite bipolar plates (BPs) hinder their application in proton exchange membrane fuel cells (PEMFC) because of their poor conductivity and mechanical properties. Nanofillers can effectively solve this problem but often have a limited effect due to their easy agglomeration. In this work, a continuous mesh carboxylated multi-walled carbon nanotube (MWCNT) coating on the surface of graphite was synthesized by chemical vapor deposition (CVD) and carboxylation modification, and the composite BPs were prepared by molding using prepared reticulated carboxylated MWCNTs, expanded graphite, and resin. By optimizing the carboxylation treatment time and the content of the nano-filler, the composite BPs had the best performance at a 15 min carboxylation treatment time and 2.4% filler content. The planar conductivity reached up to 243.52 S/cm, while the flexural strength increased to 61.9 MPa. The thermal conductivity and hydrophobicity were improved compared with the conventional graphite/resin composite BPs, and good corrosion resistance has been demonstrated under the PEMFC operating environment. This work provides a novel nanofiller modification paradigm for PBs.
复合双极板（BPs）由于其导电性和机械性能较差，阻碍了它们在质子交换膜燃料电池（PEMFC）中的应用。纳米填料可以有效解决这个问题，但由于它们容易团聚，往往效果有限。在这项工作中，通过化学气相沉积（CVD）和羧基化改性，在石墨表面合成了连续网状羧基化多壁碳纳米管（MWCNT）涂层，并使用制备的网状羧基化MWCNT、膨胀石墨和树脂通过模塑制备了复合双极板。通过优化羧基化处理时间和纳米填料的含量，复合双极板在羧基化处理时间为15分钟和填料含量为2.4%时具有最佳性能。平面电导率高达243.52 S/cm，而弯曲强度提高到61.9 MPa。与传统的石墨/树脂复合双极板相比，热导率和疏水性得到了改善，并且在PEMFC运行环境下已证明具有良好的耐腐蚀性。这项工作为双极板提供了一种新颖的纳米填料改性范例。
