Enhanced Transport in Electrochemical Reactors Using Advanced 3D Printed Electrodes

Abstract

Water electrolyzers employ porous architectures to facilitate the transport of mass and charge. Ensuring effective transport can improve energy efficiency and unlock stable operation at higher current densities. In order to realize these improvements, however, research needs to show the relationship between pore structure and performance. Advances in 3D printing research have enabled the manufacture of functional, electrically conductive porous materials at ever finer length scales and larger build areas. Using electrodes manufactured via projection microstereolithography (PuSL), we first show how this structural control can lead to computationally optimized electrodes which minimize the total power losses of a model single phase reaction. The physics of gas bubble transport in water electrolyzers is more complicated, however. At higher operating current densities, entrained gas bubbles in the triple phase boundary can be a source of degradation by occupying active sites and impeding the flow of ions between electrodes. Using structured pores, controlled surface tension boundaries offer an unprecedented degree of control over gas bubble transport. Integrating these ordered structures into water electrolyzers has the potential to improve the stability of devices at high current densities by guiding bubbles away from the reaction zone and into designed outlets.