Electrode Development of Water Electrolyzer Cells for Low-Cost and High-Efficiency Hydrogen Production

A worldwide increase in energy demand and a latent crisis in the fossil fuel supply have spurred broad research in the renewable energy. Currently, most renewable energy resources (e.g., hydro, wind, solar, tide) face supply challenges as they are known to be intermittent, unstable, and locally shackled, which calls for urgent development in energy storage and conversion. Hydrogen is regarded as an ideal energy carrier with its advantages (e.g., high energy density, environmentally friendliness, and low weight). In practice, the proton exchange membrane electrolyzer cell (PEMEC) is considered to be one of the optimal hydrogen production and energy storage devices with its superior compact design, high efficiency, preeminent hydrogen purity, and great compatibility with PEM fuel cells (PEMFCs). Although the advantages of PEMECs are apparent, the high cost holds back its large-scale application. Therefore, increasing cell efficiency, cutting down catalyst loadings, and simplifying the electrode manufacturing process are effective strategies to reduce a PEMEC’s cost and boost its commercial application. The main achievements of this dissertation include: (a) Optimize catalyst deposition method and ionomer ratio for catalyst-coated membrane (CCM). (b) Develop and compare surface treatment methods for electrode substrate. (c) Propose Ir CCLGDLs for OER in PEMECs and study CCLGDL pattern impacts. (d) Fabricate in-situ grown PtNW electrode for HER in PEMECs, indicating advantages of nano-featured catalyst structures in improving cell performance. (e) Propose all-in-one bipolar electrode concept for simplifying the fabrication process and reducing the weight, volume of the cell. (f) Synthesize in-situ grown molybdenum sulfide on carbon fiber paper for HER in PEMECs, indicating the feasibility of low-loading non-precious metal catalyst. (g) Apply thin LGDL as the GDE substrate in anion exchange membrane (AEM) electrolyzers successfully, indicating a wider application for all SPE electrochemical devices with electrode design and fabrication improvement. This research guides the future electrode design of PEMECs and other energy storage devices. Moreover, the low-cost and high-efficiency electrode designs contribute to the application and commercialization of large-scale energy storage and hydrogen production systems.