Cui Jincan, Xu Jingcheng, Xiu Huixin, Wang Heng, Li Jing, Yang Junhe
School of Materials Science and Engineering, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093, China.
School of Mechanical Engineering, Nantong University, No. 9 Seyuan Road, Jiangsu 226019, China.
ACS Appl Mater Interfaces. 2022 Aug 17;14(32):37059-37067. doi: 10.1021/acsami.2c09999. Epub 2022 Aug 8.
Highly conductive corrosion protection coatings are necessary for metallic bipolar plates (BPs) of the proton-exchange membrane fuel cell. Graphene coatings have the potential of protecting metal substrates from corrosion without obscuring their excellent electrical conductivity. The electron transfer in the coatings facilitates the formation of galvanic cells, so the challenge is to block the mass transfer of the corrosion process. Here, we constructed highly compacted hybrid coatings with aligned water-dispersible graphene layers. The water-dispersible graphene (SG) held an electrical conductivity of >270 S cm while providing an unprecedented dispersibility, which can be redispersed from filter cake with a concentration of 120 mg mL or even dry state. The cohesion of the hybrid coatings was attributed to the interaction between highly aligned SG layers and the heterointerface between SG and polydopamine (PDA), as proven by the molecular dynamics simulations. The hybrid coatings presented a corrosion current density of 0.023 μA cm and an interfacial contact resistance of 9.94 mΩ cm, which meets the requirements of corrosion protection and electron transfer for the coatings on metallic BPs. The water-based fabrication method of the graphene-dominated hybrid coatings was a promising alternative of the vacuum-based deposition method for industrial production.
高导电性防腐涂层对于质子交换膜燃料电池的金属双极板（BP）而言是必不可少的。石墨烯涂层有潜力在不影响金属基底优异导电性的情况下保护其免受腐蚀。涂层中的电子转移促进了原电池的形成，因此挑战在于阻止腐蚀过程中的传质。在此，我们构建了具有排列整齐的水分散性石墨烯层的高度致密混合涂层。水分散性石墨烯（SG）的电导率大于270 S/cm，同时具有前所未有的分散性，其可以从浓度为120 mg/mL的滤饼甚至干燥状态下重新分散。分子动力学模拟证明，混合涂层的内聚力归因于高度排列的SG层之间以及SG与聚多巴胺（PDA）之间的异质界面之间的相互作用。混合涂层的腐蚀电流密度为0.023 μA/cm²，界面接触电阻为9.94 mΩ·cm²，满足金属双极板上涂层的防腐和电子转移要求。以石墨烯为主的混合涂层的水基制备方法是工业生产中基于真空的沉积方法的一种有前景的替代方法。
