3D printing for electrochemical conversion technologies

Promovendus/a: Lore Van Looy

Promotor(en): Prof. dr. ir. Rob Ameloot, Prof. dr. Philippe Vereecken

In a time where a shift towards environmentally friendly and sustainable energy solutions is essential, three-dimensional printing (3DP) technologies offer novel opportunities for advancements in electrochemical energy conversion. This dissertation explores the application of powder-based binder jetting (BJ) to address two major challenges: the need for disposable micro power sources and the enhancement of electrolyzer efficiency.

The increasing demand for single-use portable electronic devices has highlighted the need for disposable power sources. A 3D-printed microfluidic galvanic cell (μGC) was developed, which facilitates capillary flow due to its porosity. The μGC features Pd/C paper electrodes and is powered by formic acid, with potassium permanganate serving as the oxidant. This μGC demonstrated notable performance improvements by increasing the electrode surface area and optimizing cell configuration, as demonstrated by its capability to power a glucometer. Further advancements were achieved by shifting to catalyst-free electrodes and organic quinone reagents, alongside a design that integrates electrode placement during the printing process. Ultimately, a more compact μGC design was developed, extending operational capabilities and highlighting the significant potential of 3DP in developing disposable micro power sources for point-of-care diagnostics.

Considerable research efforts have focused on improving electrode performance for the hydrogen evolution reaction (HER) using electrocatalysts. However, geometrical characteristics, including the 3D structure and surface area, significantly influence this process. 3DP offers innovative approaches for exploring intricate 3D electrodes to enhance the HER. The second part of this dissertation critically explores various 3DP techniques and metallization processes, evaluating their efficiency toward the HER. BJ 3DP combined with nickel electroless plating (ELP) proved highly effective, yielding electrodes with significantly increased surface area and improved HER performance. Various 3D electrodes were further investigated under forced flow in an electrolyzer, demonstrating superior performance compared to planar electrodes. The efficiency of bubble removal varied among different 3D structures, attributable to differences in mixing directions. Although further design optimizations are necessary, the development of 3D electrodes through BJ ELP has proven to be a straightforward and effective strategy for prototyping.

Overall, this research demonstrates the potential of 3DP technologies in developing both disposable micro power sources and advanced 3D electrodes, contributing to the broader goal of energy sustainability.