Wang Fuxiang, Li Yanping, Zhu Wenjing, Ge Xiuli, Cui Hongtao, Feng Kai, Liu Shanshan, Yang Xin
College of Chemistry & Engineering, Yantai University, Yantai 264005, China.
ACS Appl Mater Interfaces. 2021 Jul 28;13(29):34468-34476. doi: 10.1021/acsami.1c09798. Epub 2021 Jul 14.
Prussian blue analogues (PBAs) have been considered as one kind of the most promising cathode materials for Zn-ion batteries (ZIBs) due to their low cost, high performance, high safety, and high abundance. However, owing to the low conductivity and single electron reaction, it is a great challenge to obtain a PBA cathode material with high reversible capacity, high rate capability, and good temperature adaptability. Here, a cathode material, K(VO)[Fe(CN)]·6.8HO (KVHCF), with a multielectron reaction and double conductive carbon framework (DCCF) is designed and synthesized by combining structure and morphology engineering. With the multielectron reaction and high electronic conductivity simultaneously, the KVHCF@DCCF cathode material delivers a high specific capacity (180 mAh·g @ 400 mA·g) and the best rate performance (116 mAh·g @ 8000 mA·g) of the reported PBAs. Moreover, KVHCF@DCCF presents a high specific capacity of 132 mAh·g @ 400 mA·g at 0 °C. Even at -10 °C, it still delivers specific capacities of 127 mAh·g @ 40 mA·g and 80 mAh·g @ 400 mA·g with a retention of 86% after 700 cycles. In situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS) are carried out to investigate the charge-discharge electrochemical reaction mechanism.
普鲁士蓝类似物（PBAs）因其低成本、高性能、高安全性和高丰度，被认为是锌离子电池（ZIBs）最有前景的阴极材料之一。然而，由于其低导电性和单电子反应，要获得具有高可逆容量、高倍率性能和良好温度适应性的PBA阴极材料是一项巨大挑战。在此，通过结合结构和形貌工程，设计并合成了一种具有多电子反应和双导电碳骨架（DCCF）的阴极材料K(VO)[Fe(CN)]·6.8HO（KVHCF）。由于同时具备多电子反应和高电子导电性，KVHCF@DCCF阴极材料展现出高比容量（400 mA·g时为180 mAh·g）以及已报道的PBAs中最佳的倍率性能（8000 mA·g时为116 mAh·g）。此外，KVHCF@DCCF在0°C时400 mA·g下具有132 mAh·g的高比容量。即使在-10°C时，它在40 mA·g下仍具有127 mAh·g的比容量，在400 mA·g下具有80 mAh·g的比容量，且在700次循环后保持率为86%。进行了原位X射线衍射（XRD）和非原位X射线光电子能谱（XPS）研究充放电电化学反应机理。
