Wang Liubin, Liu Ningbo, Li Qiaqia, Wang Xiaohan, Liu Jing, Xu Yinuo, Luo Zhiqiang, Zhang Ning, Li Fujun
College of Chemistry & Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, Hebei Research Center of the Basic Discipline of Synthetic Chemistry, Hebei University, Baoding, 071002, China.
Tianjin Key Lab for Photoelectric Materials & Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
Angew Chem Int Ed Engl. 2025 Jan 21;64(4):e202416392. doi: 10.1002/anie.202416392. Epub 2024 Nov 11.
Prussian blue analogues (PBAs) have been employed as host materials of aqueous zinc-ion batteries (ZIBs), however, they suffer from low capacity and poor cycling stability due to limited electron transfer and the presence of interstitial water in PBAs. Herein, a vacancy and water-free silver hexacyanoferrate KAgFe(CN) (AgHCF-3) was synthesized by adjusting the ratio of K and Ag in the framework. It offers nearly four electrons involving two sequential redox reactions, namely, Fe/Fe and Ag/Ag, to deliver a large capacity of 179.6 mAh g at 20 mA g with Coulomb efficiency of ~100 %. The Zn//AgHCF-3 cell delivers an estimated energy density of 200 Wh kg, surpassing reported PBAs-based ZIBs. The formation of Ag in the cycling process merits favorable rate performance of AgHCF-3 (156.4 mAh g at 200 mA g with 80.3 % capacity retention after 100 cycles). This investigation paves new pathways for high-capacity PBA cathodes.
普鲁士蓝类似物（PBAs）已被用作水系锌离子电池（ZIBs）的主体材料，然而，由于电子转移受限以及PBAs中存在间隙水，它们存在容量低和循环稳定性差的问题。在此，通过调整骨架中K和Ag的比例，合成了一种无空位和无水的六氰合铁酸银KAgFe(CN)（AgHCF-3）。它通过两个连续的氧化还原反应，即Fe/Fe和Ag/Ag，提供近四个电子，在20 mA g下实现了179.6 mAh g的大容量，库仑效率约为100%。Zn//AgHCF-3电池的估计能量密度为200 Wh kg，超过了已报道的基于PBAs的ZIBs。循环过程中Ag的形成有利于AgHCF-3的倍率性能（在200 mA g下为156.4 mAh g，100次循环后容量保持率为80.3%）。这项研究为高容量PBA正极开辟了新途径。
