Zhenye Kang[1], Jingke Mo¹, Gaoqiang Yang¹, Scott T. Retterer[2], David A. Cullen², and Feng-Yuan Zhang*¹

Abstract

Proton exchange membrane (PEM) water electrolysis coupled with renewable sources is considered one of the most practical and high-efficiency methods to produce pure hydrogen. The liquid/gas diffusion layers (LGDLs), which located between the catalyst layer (CL) and bipolar plate, are expected to transport electrons, heat, and reactants/products with minimum losses. Due to the harsh environment at anode of PEMECs, most materials, including carbon and stainless steel, can be easily corroded, which significantly affects the performance and durability of PEMECs. Titanium based thin/well-tunable LGDLs have many advantages, such as high corrosion resistance, small thickness (25 µm), well-controlled pore shape, pore size and pore distribution. Most importantly, it can achieve superior multifunctional performance in low temperature PEMECs, which significantly improves the PEMEC efficiency. In this study, the novel thin/well-tunable LGDLs with different pore morphologies and surface modifications are comprehensively investigated in order to enhance the PEMEC performance. Gold (Au) is deposited on the surface of the thin/well-tunable LGDLs by different micro/nano surface modification methods, and the surfaces of the LGDLs are both ex-situ characterized and in-situ investigated. In addition, the performance and electrochemical impedance spectroscopy (EIS) of the PEMECs with different LGDLs are experimentally investigated and analyzed.