材料科学
聚吡咯
阳极
化学工程
X射线光电子能谱
电导率
氧化物
热扩散率
涂层
聚合
纳米技术
电极
复合材料
聚合物
化学
物理化学
冶金
物理
量子力学
工程类
作者
Ruiqi Tian,Hehe Zhang,Zeyu Yuan,Yuehua Man,Jianlu Sun,Jianchun Bao,Mingsheng Wang,Xiaosi Zhou
标识
DOI:10.1016/j.jechem.2023.10.018
摘要
Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries (PIBs) due to their high theoretical capacity, the large volume variation remains a key issue in realizing metal oxide anodes with long cycle life and excellent rate property. In this study, polypyrrole-encapsulated Sb2WO6 (denoted Sb2WO6@PPy) microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by pyrrole. Leveraging the nanosheet-stacked Sb2WO6 microflower structure, the improved electronic conductivity, and the architectural protection offered by the PPy coating, Sb2WO6@PPy exhibits boosted potassium storage properties, thereby demonstrating an outstanding rate property of 110.3 mA h g−1 at 5 A g−1 and delivering a long-period cycling stability with a reversible capacity of 197.2 mA h g−1 after 500 cycles at 1 A g−1. In addition, the conversion and alloying processes of Sb2WO6@PPy in PIBs with the generation of intermediates, K2WO4 and K3Sb, is determined by X-ray photoelectron spectroscopy, transmission electron microscopy, and ex-situ X-ray diffraction during potassiation/depotassiation. Density functional theory calculations demonstrate that the robust coupling between PPy and Sb2WO6 endues it with a much stronger total density of states and a built-in electric field, thereby increasing the electronic conductivity, and thus effectively reduces the K+ diffusion barrier.
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