China's new zinc‑air batteries offer stable cycling for 200 hours

Researchers from Central South University and Xi’an Jiaotong-Liverpool University in China have developed a novel catalyst, Cl–Fe–N4, that significantly enhances the performance and stability of alkaline seawater zinc-air batteries (SZABs). Traditional Pt/C cathodes degrade rapidly in seawater due to chloride ion poisoning, which disrupts the oxygen reduction reaction (ORR). The new catalyst employs a universal oxidative-polymerization method to create a five-coordinated square pyramidal structure by axially coordinating Fe–N4 single-atom sites with heteroatoms such as chlorine or sulfur. This design repels chloride ions and doubles the reaction kinetics, resulting in a seawater-based zinc-air battery with a power density of 187.7 mW cm−2 at 245.1 mA cm−2 and stable cycling performance for 200 hours. The study, published in Nano-Micro Letters, demonstrates that Cl–Fe–N4 outperforms commercial Pt/C catalysts by achieving