【Update】Dalian Institute of Chemical Physics Proposes Highly Hydrated Cation Strategy to Enhance Alkali Stability of Anion Exchange Membranes

The DNL0301 group at the Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, has made a breakthrough in improving the alkali stability of anion exchange membranes (AEMs). Led by researchers Zhigang Shao and Yun Zhao from the Fuel Cell System Science and Engineering Research Center, our group developed a novel hydrophilic silicon-oxygen network structure on cationic groups. This innovation significantly boosts the membranes' resistance to degradation under harsh alkaline conditions, addressing a longstanding challenge in advancing clean energy technologies.

AEMs, essential components for alkaline energy technologies such as fuel cells and water electrolyzers, have become a focal point of research in clean energy. Despite their promise, the poor resistance of AEMs to degradation in harsh alkaline environments continues to hinder their widespread adoption, posing a critical barrier to advancing next-generation energy systems.

In this study, by monitoring micro-region temperatures during fuel cell operation, our group simultaneously detected and calculated the local cathode λ value. Our group observed that the local cathode λ value decreased with increasing current density and decreasing relative humidity. To address this, our group engineered an innovative membrane structure: using a Menshutkin reaction, our group grafted iodomethyltrimethylsilane onto cationic functional groups, then hydrolyzed the compound to create a robust 3D silicon-oxygen network. Using two-dimensional infrared correlation spectroscopy, our group demonstrated that this modification strengthened water-binding interactions within the membrane, transitioning from moderate to tight hydrogen bonding. The AEM exhibited enhanced alkali stability in harsh ex-situ tests (λ=4). Additionally, the AEM demonstrated superior water retention under high current density and low humidity conditions, which effectively mitigated the degradation of functional groups. Accelerated aging tests further revealed that fuel cells assembled with this AEM had lower voltage decay rates. While severe degradation occurred in the cathode-side membrane and ionomer, the AEM itself demonstrated higher alkalistability. This work provides new insights for designing alkali-resistant anion exchange membranes.

In recent years, our group has been dedicated to the research of high-performance AEMs and their energy devices, achieving a series of advances in the design and preparation of AEMs (Nat. Commun., 2025; J. Membr. Sci., 2025; J. Membr. Sci., 2024), providing valuable references for the further development of anion exchange membranes.

The related study titled "Improving Alkali Stability of Anion Exchange Membranes via Super Water-retention Strategy" has been published in Advanced Functional Materials. The research received multidisciplinary funding, including:

l National Natural Science Foundation of China；

l CAS Pioneer A-class Project on grid-scale renewable energy storage technologies；

l Liaoning Province's youth scientist and talent development initiatives；

l Institutional innovation grants from the Dalian Institute of Chemical Physics；

(Authored by Zhiwei Ren and Yun Zhao)