Stabilising Cobalt Sulphide Nanocapsules with Nitrogen-Doped Carbon for High-Performance Sodium-Ion Storage

作     者：Yilan Wu Rohit RGaddam Chao Zhang Hao Lu Chao Wang Dmitri Golberg Xiu Song Zhao Yilan Wu;Rohit R. Gaddam;Chao Zhang;Hao Lu;Chao Wang;Dmitri Golberg;Xiu Song Zhao

作者机构：School of Chemical EngineeringThe University of QueenslandSt LuciaBrisbaneQLD 4072Australia School of ChemistryPhysics and Mechanical EngineeringScience and Engineering FacultyQueensland University of TechnologyBrisbaneQLD 4001Australia Institute of Materials for Energy and EnvironmentCollege of Materials Science and EngineeringQingdao University308 Ningxia RoadQingdao 266071People’s Republic of China 

出 版 物：《Nano-Micro Letters》 (纳微快报（英文版）)

年 卷 期：2020年第12卷第4期

页      面：29-40页

核心收录：

学科分类：080801[工学-电机与电器] 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）] 07[理学] 0817[工学-化学工程与技术] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 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 Australian Research Council(ARC)under project FL170100101 The University of Queensland for o ering UQI Scholarship 

主　　题：Cobalt sulphide Nitrogen-doped carbon Core–shell structure Sodium-ion capacitors 

摘      要：Conversion-type anode materials with a high charge storage capability generally su er from large volume expansion, poor electron conductivity, and sluggish metal ion transport kinetics. The electrode material described in this paper, namely cobalt sulphide nanoparticles encapsulated in carbon cages(Co9S8@NC), can circumvent these problems. This electrode material exhibited a reversible sodium-ion storage capacity of 705 mAh g^-1 at 100 mA g^-1 with an extraordinary rate capability and good cycling stability. Mechanistic study using the in situ transmission electron microscope technique revealed that the volumetric expansion of the Co9S8 nanoparticles is bu ered by the carbon cages, enabling a stable electrode–electrolyte interface. In addition, the carbon shell with high-content doped nitrogen significantly enhances the electron conductivity of the Co9S8@NC electrode material and provides doping-induced active sites to accommodate sodium ions. By integrating the Co9S8@NC as negative electrode with a cellulose-derived porous hard carbon/graphene oxide composite as positive electrode and 1 M NaPF6 in diglyme as the electrolyte, the sodium-ion capacitor full cell can achieve energy densities of 101.4 and 45.8 Wh kg^-1 at power densities of 200 and 10,000 W kg^-1, respectively.