Understanding Binary Interactions and Aging Effects in Catalyst Layer Inks for Controlled Manufacturing

Abstract

Controlled manufacturing and processing of multi-material electrodes and catalyst layers for energy storage and conversion applications is important for achieving low-cost and durable systems. Typically electrodes are coated using solution-based or wet- methods to achieve high aspect ratio thin films. The processing conditions as well as the ink formulation affect the ultimate material arrangment and electrode properties. Currently, ink formulation primarily focuses on macro-scale process-specific optimization (i.e. viscosity and surface/interfacial tension) rather than understanding local and nano-scale interactions between in constituents in an ink. Herein, we investigate local interactions between carbon and polymer components in a carbon based ink. We specifically investigate the role of active material surface chemistry plays on aggregation, stability, and sedimentation dynamics in multi-component inks 1,2 . The material arrangement and organization in a cast thin film is discerned from both shear and elongational flow processing methods. Finally, we introduce novel direct and indirect (rheological ) techniques to probe shear induced transformationd in inks or viscoelastic materials 3,4 . [1] Holdcroft, S. (2013). Chemistry of Materials , 26 (1), 381-393. [2] Takahashi, S., Shimanuki, J., Mashio, T., Ohma, A., Tohma, H., Ishihara, A.,& Miyazawa, A. (2017). Electrochimica Acta , 224 , 178-185. [3] Hatzell, K. B., Eller, J., Morelly, S., Tang, M., Alvarez, N. J., & Gogotsi, Y. (2017). Faraday Discussions [4] Hatzell, K. B., Boota, M., & Gogotsi, Y. (2015). Chemical Society Reviews , 44 (23), 8664-8687.