LIFT printing of deterministic porous electrodes for electrochemical systems

Abstract:
Porous electrodes are a key element of electrochemical energy conversion and storage systems like fuel cells, electrolysers and batteries. A more deterministic and flexible thin film electrode production can be expected from 3D printing technologies if these allow sufficiently high resolution. A femtosecond-Laser Induced Forward Transfer (LIFT) technique is developed, which allows constructing these deterministic three-dimensional (3D) prints of highly porous metal electrodes. Depending on the laser parameters well-organized gold structures with chip-like or droplet-like shapes are transferred as basic building blocks of the porous electrodes. With the help of a suitable printing strategy, an accumulation of the gold particles as three-dimensional ordered porous electrodes could be demonstrated in this work. By tuning the laser focus setting different micro particle shapes could be realized, as the result of the light intensity distributions in the plane of the donor thin film. To test the electrochemical activity of the printed porous electrodes for methanol oxidation reaction (MOR), an electrochemical wall-jet-electrode flow cell consisting of a three-electrode configuration was applied. In summary, the LIFT-structured gold electrode shows a higher electrochemically active surface area than the gold electrode without LIFT structure used as a reference material.