UK electrolyser maker ITM Power and fluoropolymer firm W. L. Gore say they have demonstrated that an ultra-thin proton exchange membrane (PEM) can deliver both higher efficiency and long-term durability in green hydrogen production.
Results published in a Gore white paper show a 50 micrometre (μm) reinforced membrane operated for 11,000 hours under “industrially relevant conditions” while maintaining low degradation rates, low hydrogen crossover and high efficiency.
The prototype is significantly thinner than many PEM membranes used in commercial electrolysers today, which are commonly around 100 to 180μm thick.
Based on multiple performance indicators, including voltage degradation, hydrogen crossover, and fluoride release rates, ITM and Gore estimate the membrane concept could achieve an operational life of approximately 80,000 hours.
The figure represents a projection based on observed degradation trends rather than an actual operating duration.
While manufacturers have sought to reduce membrane thickness to lower electrical resistance and improve efficiency, thinner membranes have traditionally been associated with increased hydrogen crossover and degradation concerns.
During a discussing the results, Gore Technical Director for Clean Energy EMEA, Dr Naima Heck, said the industry is increasingly moving away from viewing membrane design as a simple balance of advantages and disadvantages.
“The 50 μm concept under discussion actually does show the benefits of increased cell efficiency, but it also shows that stable and safe operation can be maintained over a long period of time,” she said.
The latest prototype combines a 50μm expanded polytetrafluoroethylene-reinforced PFSA membrane with an optimised recombination catalyst design. According to the white paper, the membrane was tested at 55°C, 3.3A/cm², and 20 bar differential pressure in a 130cm² active-area short stack for more than 11,000 hours.
Testing recorded a voltage degradation rate of 1.2μV/h, equivalent to less than 0.6% performance degradation per year. Hydrogen crossover remained below 0.4% throughout testing, while efficiency ranged between 48.3 and 49.5kWh/kg hydrogen.
The companies said the membrane delivered around a 40% reduction in area-specific resistance and approximately a 4% efficiency improvement compared with an earlier 85μm prototype, which accumulated 28,000 hours of testing.
During a at Shell’s Rheinland refinery – 30,000 hours in total – a 10MW ITM electrolyser reported an average efficiency of 49kWh/kg hydrogen, with a degradation rate of 0.09% per 1,000 operating hours.
The programme in response to what the companies describe as a lack of publicly available long-term durability data for PEM electrolysers operating under commercial conditions.
ITM Technology Director Frederic Marchal said membrane durability is often misunderstood within the industry.
He said the collaboration was designed to develop a deeper understanding of membrane behaviour and degradation mechanisms, allowing the companies to push performance limits while reducing technology risk.
The companies believe the work could ultimately contribute to lower hydrogen production costs by reducing the electricity required to produce each kilogramme of hydrogen.
Discussing the economic implications, Heck said, “The most obvious point for cost reduction would first of all be if you think about thin membranes, and they can help lower the energy input required, and that will translate into a reduced levelized cost of hydrogen.”
Marchal suggested the impact could extend beyond incremental improvements.
“We will expect an increase in per cent efficiency to be significant in double figures from what is achieved today in the state of the art,” he said. “So disruptive and impactful.”
While the membrane remains a development-stage technology rather than a commercial product, Gore said the findings are informing its next generation of PEM electrolyser membranes.
The companies also indicated that the results provide a platform for exploring higher-temperature operation, higher current densities and potentially even thinner membrane designs.
