Coupling Sb_(2)WO_(6)microflowers and conductive polypyrrole for efficient potassium storage by enhanced conductivity and K^(+) diffusivity

作     者：Ruiqi Tian Hehe Zhang Zeyu Yuan Yuehua Man Jianlu Sun Jianchun Bao Ming-Sheng Wang Xiaosi Zhou Ruiqi Tian;Hehe Zhang;Zeyu Yuan;Yuehua Man;Jianlu Sun;Jianchun Bao;Ming-Sheng Wang;Xiaosi Zhou

作者机构：School of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023JiangsuChina State Key Lab of Physical Chemistry of Solid SurfacesCollege of MaterialsXiamen UniversityXiamen 361005FujianChina 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2024年第89卷第2期

页      面：250-258,I0007页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0804[工学-仪器科学与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(22075147 and 22179063)。 

主　　题：Sb_(2)WO_(6) Polypyrrole coating Anode Potassium-ion battery In-situ TEM observation 

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,polypyrroleencapsulated Sb_(2)WO_(6)(denoted Sb_(2)WO_(6)@PPy)microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by pyrrole.Leveraging the nanosheet-stacked Sb_(2)WO_(6)microflower structure,the improved electronic conductivity,and the architectural protection offered by the PPy coating,Sb_(2)WO_(6)@PPy exhibits boosted potassium storage properties,thereby demonstrating an outstanding rate property of 110.3 m A h g^(-1)at 5 A g^(-1)and delivering a long-period cycling stability with a reversible capacity of 197.2 m A h g^(-1)after 500 cycles at 1 A g^(-1).In addition,the conversion and alloying processes of Sb_(2)WO_(6)@PPy in PIBs with the generation of intermediates,K_(2)WO_(4)and K_(3)Sb,is determined by X-ray photoelectron spectroscopy,transmission electron microscopy,and exsitu X-ray diffraction during potassiation/depotassiation.Density functional theory calculations demonstrate that the robust coupling between PPy and Sb_(2)WO_(6)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.