Abstract
Anion-exchange membrane water electrolyzers (AeMWes) promise scalable, low-cost hydrogen production but are limited by the electrochemical instability of their anode ionomers. We report interphase engineering using inorganic-containing molecular additives that coassemble with ionomer, enabling pure water–fed AeMWes to operate with a degradation rate <0.5 millivolt per hour at 2.0 amperes per square centimeter and 70°c—a >20-fold durability improvement. Analysis of different additives and ionomers shows that the stabilization mechanism involves cross-links between metal oxo/hydroxo oligomers and ionomers. Under operation, the inorganic additive enriches, forming an interphase near the water-oxidation catalyst that passivates the anode ionomer against continuous degradation while maintaining mechanical integrity and hydroxide conductivity. this additive-based interphase-engineering strategy provides a path to durable AeMWes that operate without supporting electrolytes and is adaptable across diverse catalysts and ionomers for electrochemical technologies.
| Original language | English |
|---|---|
| Pages (from-to) | 294-298 |
| Number of pages | 5 |
| Journal | Science |
| Volume | 390 |
| Issue number | 6770 |
| DOIs | |
| State | Published - Oct 16 2025 |
Funding
We thank G. Freychet for assisting with the collection of x-ray scattering data at Brookhaven National Laboratory. R.T.H. gratefully acknowledges D. H. Marin for insightful discussions regarding the online ICP-MS measurements. The electrolyzer device work was supported by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, award DE-EE0011322. The fundamental work of understanding additive-ionomer and catalyst interface interactions was funded by the DOE Center for Ionomer-Based Water Electrolysis, award DE-AC02-05CH11231. The work made use of the Molecular Foundry, a user facility supported by the DOE under contract DE-AC02-05CH11231. R.T.H., V.C., and T.F.J. acknowledge funding from the Office of Naval Research, grant N00014-24-1-2433, for the design of the online ICP-MS system. Partial support for the online ICP-MS measurements came from the US DOE, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science Program to the SUNCAT Center for Interface Science and Catalysis. The cryo-TEM and EELS portions of this research were supported by the Center for Nanophase Materials Sciences (CNMS), which is a DOE User Facility at Oak Ridge National Laboratory. Development of x-ray scattering protocols for ionomer composites was supported by the DOE under contract no. DE-AC02-05CH11231 within the Inorganic/Organic Nanocomposites Program (KC3104). K.K.-Y.L. and G.M.S. acknowledge support from the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory, under DOE contract DE-AC02-05CH11231. This research used the Soft Matter Interfaces beamline at the National Synchrotron Light Source II, a DOE user facility operated under contract DE-SC0012704, and beamline 7.3.3 of the Advanced Light Source, which is a DOE Office of Science User Facility under contract DE-AC02-05CH11231. We thank G. Freychet for assisting with the collection of x-ray scattering data at Brookhaven National Laboratory. R.T.H. gratefully acknowledges D. H. Marin for insightful discussions regarding the online ICP-MS measurements. Funding: The electrolyzer device work was supported by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, award DE-EE0011322.The fundamental work of understanding additive-ionomer and catalyst interface interactions was funded by the DOE Center for Ionomer-Based Water Electrolysis, award DE-AC02-05CH11231.The work made use of the Molecular Foundry, a user facility supported by the DOE under contract DE-AC02-05CH11231. R.T.H.,V.C., and T.F.J. acknowledge funding from the Office of Naval Research, grant N00014-24-1-2433, for the design of the online ICP-MS system. Partial support for the online ICP-MS measurements came from the US DOE, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science Program to the SUNCAT Center for Interface Science and Catalysis.The cryo-TEM and EELS portions of this research were supported by the Center for Nanophase Materials Sciences (CNMS), which is a DOE User Facility at Oak Ridge National Laboratory. Development of x-ray scattering protocols for ionomer composites was supported by the DOE under contract no. DE-AC02-05CH11231 within the Inorganic/Organic Nanocomposites Program (KC3104). K.K.-Y.L. and G.M.S. acknowledge support from the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory, under DOE contract DE-AC02-05CH11231.This research used the Soft Matter Interfaces beamline at the National Synchrotron Light Source II, a DOE user facility operated under contract DE-SC0012704, and beamline 7.3.3 of the Advanced Light Source, which is a DOE Office of Science User Facility under contract DE-AC02-05CH11231. Author contributions: S.H. conceived and designed the experiments and completed most of the synthesis, characterization, and electrolyzer tests. S.W.B. proposed and supervised the entire project. S.H., Y.Z., and S.W.B. wrote the paper with input from all coauthors.A.S. and B.L. performed the scanning electron microscope (SEM) cross-section,GPC,and ion-exchange capacity for membrane degradation.J.O. and M.J.Z. conducted the cryo-TEM and EELS analyses. M.K. performed cross-sectional electron microscopy and x-ray photoelectron spectroscopy analysis.K.K.-Y.L.and G.M.S.performed x-ray scattering measurements and analysis.P.W.and J.F.contributed to the DLS analysis.R.T.H.,V.C.,and T.F.J.conducted the online ICP-MS experiments.A.C.E. performed the NMR measurements. H.D. and Y.Y. contributed to the hydroxide conductivity and water uptake experiments.All authors discussed the results and provided editing and comments on the manuscript. Competing interests: Patent applications were filed on the additive technology (US Provisional Application no. 63/291,295) with some of the coauthors as inventors.A.S. and B.L. are employees of Versogen and Y.Y.is chief executive officer and founder of Versogen,a company working to commercialize AEMWE technology that makes and markets PiperION membranes and ionomers used in this study.The authors declare that they have no other conflicts of interest. Data and materials availability:All data are available in the main text or supplementary materials. Polarization curves,chronopotentiometry stability data of AEMWE cells,cryo-TEM and SEM images, energy-dispersive x-ray (EDX) maps,ATR-FTIR spectra,and DLS data in the main text are available at Zenodo (68). License information: Copyright © 2025 the authors,some rights reserved; exclusive licensee American Association for the Advancement of Science.No claim to original US government works.https://www.science.org/about/science-licenses-journal-article-reuse