Development of novel hydroxyl exchange membranes for alkaline water electrolyzers

​​At imec we see the pressing challenge about global warming as a huge opportunity for new technology development towards a more  circular and sustainable society. Electrochemical technologies, and more particularly advanced electrolyzers, are a promising platform for the so-called ‘’power to molecules’’ approach, in which electrons supplied by renewable electricity are employed to transform molecules on demand, for example in the frame of renewable hydrogen production. 

​The realization of Megawatt production of pressurized hydrogen gas from renewable electricity is currently limited to two commercially available technology options: alkaline water electrolyzers (AWE) and proton-exchange-membrane (PEM) electrolysis. The alkaline technology is the most mature and can deliver stacks ranging from a few kW to 10 MW (H2 production volumes of 1-2000 Nm³/h per stack) thanks to electrodes and membranes integrated in stacks with a few square meters of active area per cell.  The PEM technology is a much younger technology that still must prove itself in the field in terms of reliability and maintenance but has single stack electrolyzers of few 200 Nm³/h already due to the higher current density it can deliver. Unfortunately, PEM technology relies on rare noble metal electrocatalysts for both the anode and cathode, which is not sustainable for gigawatt deployment of green hydrogen, in general.  Hence, both existing electrolyzer technologies still pose critical issues towards cost of hydrogen for offshore green hydrogen. Our proposed solution is to combine the best of both worlds by the development of a gas impermeable alkaline or hydroxyl exchange membrane (HEM) technology, which assembled with the novel high surface-area nanomesh (NM) electrodes developed at imec will exceed PEM in performance and stability while being free of noble metals as for the AWE. At imec, advanced ceramic-based nanocomposite HEMs are under development, with the aim of allowing operations at low alkalinity and eventually even water as for PEM technology. However, these nanocomposites require chemically stable materials organized as suitable architectures to host and integrate the expected OH- exchange functionality as well as to offer reliable integration paths for proper interplay between electrodes and the electrolyte. 

​In this PhD project, you will design and develop new nanostructured ceramics employing sol-gel chemistry combined molecular and/or hard templates and physically induced self-assembly. These nanostructured ceramics will be further combined with anionic exchange materials. You will explore and rationalize the inherent conductivity and stability of advanced HEMs in realistic environments and broad operative conditions.