Investigation of the nanostructure of ionomer in fuel cell catalyst ink by SANS

Fuel cells are used in hydrogen-powered electric vehicles, where developments in performance and durability are crucial for further commercialization, which the final structure of the electrode (catalyst layer, CL) strongly influences. Composed of Pt nanoparticles supported on a carbon composite, embedded in a proton conductive polymer, the CL structure is known to be directly connected to that of the catalyst ink, where the components are dispersed in solvent, which is then dried to give highly heterogeneous structures. These are currently not well understood, leaving new developments reliant on a trial and error approach. The aim of this experiment is to develop our understanding of component interactions in catalyst inks, specifically related to the ionomer, via small angle neutron scattering to establish the impact on the final CL structure and hence fuel cell performance.

燃料电池应用于氢动力电动汽车，其性能与耐久性的提升对于进一步商业化落地至关重要，而电极的最终结构——催化层（catalyst layer，CL）——对此具有决定性影响。该催化层由负载于碳复合材料上的铂（Pt）纳米颗粒构成，并嵌入质子传导聚合物中，其结构与催化墨水的结构直接相关。催化墨水是将各组分分散于溶剂中形成的分散体系，经干燥后会形成高度非均一的微观结构。目前学界对这类非均一结构的形成机制与特性仍缺乏充分认知，使得相关技术的研发仍需依赖试错法。本实验旨在通过小角中子散射（small angle neutron scattering）技术，深化对催化墨水内各组分间相互作用（尤其是与离聚物（ionomer）相关的相互作用）的理解，以此明确其对催化层最终结构乃至燃料电池整体性能的影响。