Nb2O5 nanotubes on carbon cloth for high performance sodium-ion capacitors  

基于碳布上直接生长的Nb2O5纳米管的高性能钠离子电容器

作　　者：Rui Jia Yuan Jiang Rui Li Ruiqing Chai Zheng Lou Guozhen Shen Di Chen 贾蕊;姜源;李蕊;柴瑞青;娄正;沈国震;陈娣(School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Robert Frederick Smith School of Chemical and Biomolecular Engineering,Cornell University,Ithaca,NY 14853,USA)

机构地区：[1]School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China [2]State Key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China [3]Robert Frederick Smith School of Chemical and Biomolecular Engineering,Cornell University,Ithaca,NY 14853,USA

出　　处：《Science China Materials》2020年第7期1171-1181,共11页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(51672308;51972025 and 61888102)。

摘　　要：Hybrid sodium-ion capacitors(SICs)bridge the gap between the supercapacitors(SCs)and batteries and have huge potential applications in large-scale energy storage.However,designing appropriate anode materials with fast kinetics behavior as well as long cycle life to match with the cathode electrodes remains a crucial challenge.Herein,Nb2O5 nanotubes and nanowire-to-nanotube homo-junctions were directly grown on the carbon cloth(CC)via a simple hydrothermal process through regulating the pH value of solution.The as-prepared Nb2O5@CC nanotubes displayed a high reversible capacity of 175 mA hg-1 at the current density of 1Ag-1 with the coulombic efficiency of 97%after 1500 cycles.Besides,the SICs fabricated with Nb2O5@CC and activated carbon(AC)electrode materials showed a high energy density of 195 W h kg-1 at 120 W kg-1,a power density of 7328 W kg-1 at 28 W hkg-1and 80%of the capacitance retention after 5000 cycles.Additionally,the flexible SIC devices can operate normally at various bendable conditions.The Nb2O5@CC nanotubes in this work can be promising electrode materials in flexible and wearable energy storage devices.钠离子混合电容器是连接超级电容器与电池之间的桥梁,在大规模储能领域中具有广阔的应用前景.然而,设计出能够与正极材料相匹配,并且兼具快速动力学行为和长循环寿命的负极材料仍然是目前面临的重要挑战之一.本文通过简单的水热工艺,通过调节溶液的pH值,可以将Nb2O5纳米管以及纳米线/纳米管同质结直接生长在碳布(CC)上.所制备的Nb2O5@CC纳米管在1500次循环后,电流密度为1 A g-1时表现出175 mA h g-1的高可逆容量以及97%的库伦效率.以Nb2O5@CC为负极、活性炭为正极制备的钠离子混合电容器的能量密度和功率密度分别可达到195 W h kg-1和7328 W kg-1.即使在5000次循环后仍然具有80%的电容保持率.另外,该柔性钠离子混合电容器可以在各种可弯曲条件下正常工作.因此,Nb2O5@CC纳米管在未来有望成为一种柔性可穿戴能源存储器的理想电极材料.

关 键 词：NANOTUBES HOMOJUNCTIONS NB2O5 sodium-ion capacitors 

分 类 号：TM53[电气工程—电器] TB383.1[一般工业技术—材料科学与工程]