Authors: G. Dadheech, M. Abd Elhamid, R. Blunk
Affilation: General Motors Corporation, United States
Pages: 180 - 183
Keywords: hydrophilic, bipolar plate, fuel cells, water management
A stably superhydrophilic coating is required on composite and metal bipolar plates to manage byproduct liquid water and, in turn, to enable good PEM fuel cell performace under low power vehicle operating conditions. Silica-based coatings, particularly those derived from particulate sols and applied using a self-assembly layer-by-layer (LbL) process, can be rendered superhydrophilic by tailoring its nanostructure. These nanoparticle coatings can also meet other bipolar plate requirements such as low electrical contact resistance, high electrochemical stability, good wet adhesion and low cost. However, it’s questionable whether these desired coating properties can be maintained over a 10-year stack life as three modes of hydrophilicity loss--dissolution, adhesion, and contamination--are observed. New nanostructured coating materials and processing developments are needed to mitigate these loss mechanisms, particularly the latter.