Reduced CoNi2S4 nanosheets decorated by sulfur vacancies with enhanced electrochemical performance for asymmetric supercapacitors  

硫空位修饰的CoNi2S4纳米片用于电化学性能增强的非对称超级电容器

作　　者：Yanpeng Liu Yuxiang Wen Yanan Zhang Xiaogang Wu Haoqian Li Hangda Chen Juanjuan Huang Guohan Liu Shanglong Peng 刘彦鹏;温昱祥;张亚男;吴晓钢;李浩乾;陈航达;黄娟娟;刘国汉;彭尚龙(National&Local Joint Engineering Laboratory for Optical Conversion Materials and Technology,School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China;Shenzhen Key Laboratory of Nanobiomechanics,Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences,Shenzhen 518055,China;Institute of Sensor Technology,Gansu Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]National&Local Joint Engineering Laboratory for Optical Conversion Materials and Technology,School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China [2]Shenzhen Key Laboratory of Nanobiomechanics,Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences,Shenzhen 518055,China [3]Institute of Sensor Technology,Gansu Academy of Sciences,Lanzhou 730000,China

出　　处：《Science China Materials》2020年第7期1216-1226,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(61376011 and 51402141);Gansu Provincial Natural Science Foundation(17JR5RA198);the Fundamental Research Funds for the Central Universities(lzujbky-2018-119 and lzujbky-2018-ct08);Shenzhen Science and Technology Innovation Committee(JCYJ20170818155813437)。

摘　　要：Nowadays,it is a matter of great concern to design electrode materials with excellent electrochemical performance for supercapacitors by a safe,efficient and simple method.And these characteristics are usually related to the vacancies and impurities in the electrode.To investigate the effect of the vacancies on the electrochemical properties of the supercapacitor cathode material,the uniform reduced CoNi2S4(r-CoNi2S4)nanosheets with sulfur vacancies have been successfully prepared by a one-step hydrothermal method.And the formation of sulfur vacancies are characterized by Raman,X-ray photoelectron spectroscopy and other means.As the electrode for supercapacitor,the r-CoNi2S4 nanosheet electrode delivers a high capacity of 1918.9 Fg-1 at a current density of 1 A g-1,superior rate capability(87.9%retention at a current density of 20 A g-1)and extraordinary cycling stability.Compared with the original CoNi2S4 nanosheet electrode(1226 F g-1at current density of 1 A g-1),the r-CoNi2S4 nanosheet electrode shows a great improvement.The asymmetric supercapacitor based on the r-CoNi2S4 positive electrode and activated carbon negative electrode exhibits a high energy density of 30.3 Wh kg-1 at a power density of 802.1 W kg-1,as well as excellent long-term cycling stability.The feasibility and great potential of the device in practical applications have been successfully proved by lightening the light emitting diodes of three different colors.如何安全、高效、简便地制备出具有优异电化学性能的超级电容器电极材料是当前人们十分关注的问题.这些特性通常与电极中的空位和杂质有关.为了研究空位对超级电容器阴极材料性能的影响,我们采用一步水热法制备了具有硫空位的CoNi2S4(r-CoNi2S4)纳米片结构电极材料.利用拉曼光谱、X射线光电子能谱(XPS)等手段对硫空位的形成进行了表征.作为超级电容器的电极,r-CoNi2S4纳米片在电流密度为1 A g-1时具有1918.9 F g-1的高容量、优异的倍率性能(在电流密度为20 A g-1时,相对于1 A g-1的保持率为87.9%)和超常的循环稳定性.与原始的CoNi2S4纳米片电极(1 A g-1时容量为1226 F g-1)相比,r-CoNi2S4电极的性能显著提高.基于r-CoNi2S4正极和活性炭负极的不对称超级电容器具有较高的能量密度.通过点亮三种不同颜色的发光二极管(LED)灯,成功证明了该器件在实际应用中的可行性和巨大潜力.

关 键 词：defect engineering sulfur vacancies electrochemical performance asymmetric supercapacitors 

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]