2025-10-01 |
Conventional alkaline water electrolysers (AWE) typically operate at current densities of no more than 300–500 mA/cm². To produce the same amount of hydrogen, they require three to four times the space or volume compared with advanced PEM electrolysers (PEMWE). While AWE systems use cost-effective and widely available nickel-based catalysts instead of scarce and expensive platinum and iridium precious metals, a significant increase in current density remains a key target in order to secure the global competitiveness of AWE technology. However, many new approaches still rely on small amounts of precious metals or polymer membranes.
The French company Adele Hydrogen, based in Lyon, has chosen a different path: it relies on precious-metal-free high-entropy alloy catalysts (HEA), which promise both high performance and stability. Thanks to an innovative AWE laboratory cell design developed by the team led by Dr Jean-François Drillet at DECHEMA Research Institute (DFI), the 3.0 A/cm² mark at a cell voltage of less than 2.2 V was surpassed for the first time (see figure) within joint project Degrad-El3. Moreover, initial evaluations of an ongoing 1,000-hour long-term experiment also indicate outstanding stability.
The new DFI laboratory cell design ensures efficient removal of the hydrogen and oxygen products, even at very high current densities. As a result, Adele Hydrogen’s Pathfinder electrode can be fully utilized, demonstrating its impressive performance potential. Further details on this promising first laboratory breakthrough are available in the joint white paper.
Figure: Current-voltage curve of the Adele´s pathfinder electrodes in the 5 cm² AWE laboratory cell at DFI with the corresponding, calculated H2 yields at 100% energy efficiency © DFI
