New Publication: Water Transport Moder for Cathode-Vapour-Feed Electrolysers

Modelling the water flow at the heart of next-generation Water Electrolysis Propulsion

Ice2Thrust has published a new scientific paper, “Water Transport Model for Cathode-Vapour-Feed Electrolysers,” accepted for publication in the Royal Society of Chemistry’s Faraday Discussions. The work will be presented at the Faraday Discussion on “Bridging electrochemical devices across Earth and space applications,” taking place in London on 2–4 November 2026 — a meeting dedicated to the electrochemistry that links terrestrial and space technologies.

At the core of Water Electrolysis Propulsion (WEP) is a simple idea: a spacecraft is filled on the ground with pure water, which is then split onboard into hydrogen and oxygen to generate thrust. How efficiently and reliably that water is delivered to the reaction sites inside the electrolyser is decisive for the performance of the whole propulsion system.

This paper focuses on the cathode-vapour-feed (CVF) electrolyser — an architecture in which water is supplied on the cathode side of the electrolysis membrane through an additional water-feed barrier, reaching the reaction as vapour rather than as a liquid. The layout is attractive for operating in the microgravity environment of space, but it makes the transport of water through the cell’s membranes — and the losses associated with it — a central design challenge.

The new study develops a model of this water transport, describing how water diffuses through the cell to the anode, where it is decomposed. Such a model gives engineers a tool to better understand, predict, and ultimately optimise how a CVF electrolyser behaves — an essential step towards designing more efficient and reliable WEP thrusters.

The publication strengthens the scientific foundation of the Ice2Thrust EIC Pathfinder project, which proposes WEP as a safe, non-toxic, high-performance, and refillable alternative to conventional propulsion. By deepening the understanding of the electrochemistry at the heart of the electrolyser — and by bringing this work into dialogue with the wider electrochemistry community at the Faraday Discussion — the research advances the path towards efficient, scalable, water-based in-space mobility and a circular space economy.

Authors:

Sören Heizmann, Researcher, Technical University of Munich.
Prof. Chiara Manfletti, Principal Investigator, Professor for Space Mobility and Propulsion (Supervisor), Technical University of Munich.

📄 Read the full paper here: Water Transport Model for Cathode-Vapour-Feed Electrolysers within the Ice2Thrust project: https://zenodo.org/records/21997178 DOI: https://doi.org/10.1039/D6FD00123H