CeOx hybrid nanoparticles were synthesized and evaluated for use as radical scavengers, in place of commercially available Ce(NO3)3 and CeO2 nanoparticles, to avoid deterioration of the initial electrochemical performance and/or spontaneous aggregation/precipitation issues encountered in polymer electrolyte membranes. When CeOx hybrid nanoparticles were used for membrane formation, the resulting membranes exhibited improved proton conductivity (improvement level = 2–15% at 30–90 °C), and thereby electrochemical single cell performance, because the –OH groups on the hybrid nanoparticles acted as proton conductors. In spite of a small amount (i.e., 1.7 mg/cm3) of introduction, their antioxidant effect was sufficient enough to alleviate the radical-induced decomposition of perfluorinated sulfonic acid ionomer under a Fenton test condition and to extend the chemical durability of the resulting reinforced membranes under fuel cell operating conditions.

In this research, a series of innovative and stable cross-linked gel polymer reinforced membranes (GPRMs), were successfully prepared and investigated for application in lithium-ion batteries. Herein, a gel directly within the commercial polyethylene (PE) separator is supported via electron-beam simultaneous irradiation cross-linking of commercial liquid electrolyte and poly(ethylene glycol) methacrylate (PEGMA) oligomers. The physical and electrochemical properties of the GPRMs were characterized by SEM, TEM, mechanical durability, heating shrinkage, and ion conductivity, etc. The GPRMs demonstrated excellent mechanical durability and high ion conductivity compared with traditional PE membranes. Moreover, coin-typed cells were assembled and cycle performance was also studied compared with same-typed cells with commercial PE membrane and liquid electrolyte. As a result, the coin-typed cells using GPRMs also showed a relatively good efficiency on the 50th cycles at a high 1.0 C -rate. These GPRMs with excellent properties present a very promising material for utilization in high-performance lithium-ion batteries with improved safety and reliability.

This study reports on an innovative press-loaded blister hybrid system equipped with gas-chromatography (PBS-GC) that is designed to evaluate the mechanical fatigue of two representative types of commercial Nafion membranes under relevant PEMFC operating conditions (e.g., simultaneously controlling temperature and humidity). The influences of various applied pressures (50 kPa, 100 kPa, etc.) and blistering gas types (hydrogen, oxygen, etc.) on the mechanical resistance loss are systematically investigated. The results evidently indicate that hydrogen gas is a more effective blistering gas for inducing dynamic mechanical losses of PEM. The changes in proton conductivity are also measured before and after hydrogen gas pressure-loaded blistering. After performing the mechanical aging test, a decrease in proton conductivity was confirmed, which was also interpreted using small angle X-ray scattering (SAXS) analysis. Finally, an accelerated dynamic mechanical aging test is performed using the homemade PBS-GC system, where the hydrogen permeability rate increases significantly when the membrane is pressure-loaded blistering for 10 min, suggesting notable mechanical fatigue of the PEM. In summary, this PBS-GC system developed in-house clearly demonstrates its capability of screening and characterizing various membrane candidates in a relatively short period of time (<1.5 h at 50 kPa versus 200 h).

Saline water electrolysis (SWE) is a representative electrochemical conversion process that produces hydrogen (H2), chlorine (Cl2), and sodium hydroxide (NaOH) at the same time, by applying electricity to saline water. SWE has been suffering from overpotentials much higher than its theoretical voltage of 2.2 V. The overpotentials come from high membrane resistance and/or interfacial resistance between its membrane and electrodes in zero-gap type. To solve this problem, water-soluble sulfonated polystyrene was chemically incorporated on both surface of chemically durable sulfonated poly (arylene ether sulfone) random copolymer via the simultaneous irradiation of electron-beam. The resulting membranes exhibited SWE performance superior to that of a commercially available Aciplex-F® membrane, owing to the synergistic effect of improved Na+ conductivity and reduced interfacial resistance.

The state-of-the-art membrane for alkaline water electrolysis is porous Zirfon®. Unfortunately, Zirfon® has been suffering from the crossover of hydrogen gas permeated through the pores, inducing safety issues including explosion. To date, there have been approaches to solve this problem. One good example is to use anion-conducting ionomer membranes with dense structures. Generally, the membranes, which are made up of hydrocarbon matrices, experience severe degradation, when they are exposed under strong basic conditions at the temperatures higher than 50 oC for high electrochemical performances. In this study, perfluorinated ionomer membranes with extremely high thermo-chemical resistances are developed via the combination of architectural design and supercritical dispersion. References [1] Zirfon perl separator for alkaline water electrolysis, AGFA, April (2016) [2] C. Y Ahn, J, Ahn, S. Y. Kang, O. H. Kim, D. W. Lee, J. H. Lee, J. G. Shim, C. H. Lee, Y. H. Cho, Y. E. Sung, Sci Adv 6, 1-9 (2020) Keywords: Alkaline water electrolysis, Perfluorinated ionomers, Anion conductivity, Thermo-chemical stability, Membrane