Layered double hydroxides with larger interlayer distance for enhanced pseudocapacitance  

层状双羟基复合金属氧化物层间距调控及其电容器性能研究（英文）

作　　者：肖元化 苏当成 王雪兆 吴诗德 周立明 方少明 李峰 

机构地区：[1]Key Laboratory of Surface and Interface Science and Technology, Zhengzhou University of Light Industry [2]Shenyang National Laboratory for Materials Science, the Institute of Metal Research, Chinese Academy of Sciences

出　　处：《Science China Materials》2018年第2期263-272,共10页中国科学（材料科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (21501152,21571159,21671178,21441003,51521091 and 51525206);China Postdoctoral Science Foundation (2017M611282);Program for Changjiang Scholars and Innovative Research Team in University (IRT15R61);Ministry of Science and Technology of China (2016YFA0200100 and 2016YBF0100100);Foundation of Zhengzhou University of Light Industry (2014BSJJ054);Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09010104);Projects for Public Entrepreneurship and Public Innovation of ZZULI (2017ZCKJ215);Key Program of Henan Province for Science and Technology (162102210212)

摘　　要：The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect of interlayer distance of layered double hydroxides（LDHs） on pseudocapacitors. Here, we obtained the CoAl-LDH with different interlayer distance via the reaction in aqueous media hydrothermally. Electrochemical characterization reveals that the CoAl（DS^-（dodecyl sulfate））-LDHs with an interlayer distance of 2.58 nm can deliver higher specific capacitance of 1481.7 F g^-1 than CoAl（SO4^2-）-LDH（0.87 nm, 1252.7 F g^-1） and CoAl（CO3^2-）-LDH（0.76 nm, 1149.2 Fg^-1） at a discharge current density of 1 A g^-1. An asymmetric supercapacitor with the CoAl（DS^-）-LDHs‖activated carbon also shows a better electrochemical performance, including a high energy density of54.2 W h kg^-1 at a power density of 0.9 kW kg^-1 and a longterm stability, in comparison with CoAl（SO4^2-）-LDH and CoAl（CO3^2-）-LDH ‖activated carbon.在电化学储能过程中,层状结构材料中较窄的层间距一般会抑制电解液离子的嵌入,进而限制其层间内部结构在电化学储能过程中的充分利用.本文分别选用3种不同尺寸的阴离子(CO_3^(2-),SO_4^(2-),DS^-(十二烷基硫酸根)),通过简单的一步水热过程,成功对CoAl-LDH(层状双羟基复合金属氧化物)进行插层,获得了3种具有不同层间距的复合材料:CoAl(CO_3^(2-))-LDH(0.76nm),CoAl(SO_4^(2-))-LDH(0.87 nm),CoAl(DS^-)-LDHs(2.58 nm).超级电容器性能研究表明,在1 A g^(-1)充放电电流密度下,3种材料单电极比电容表现出与其层间距大小的一致性,即CoAl(DS^-)-LDHs(1481.7 F g^(-1))>CoAl(SO_4^(2-))-LDH(1252.7 F g^(-1))>CoAl(CO_3^(2-)-LDH(1149.2F g^(-1)).此外,将3种材料与活性炭(AC)组建非对称超级电容器,结果表明:基于电极材料总质量,CoAl(DS^-)-LDHs‖AC展现了54.2 W h kg^(-1)的高能量密度和长循环寿命,且显著高于CoAl(SO_4^(2-))-LDH‖AC和CoAl(CO_3^(2-))-LDH‖AC非对称电容器.该方法为寻找新型高性能超级电容器用层状结构材料提供了新的途径.

关 键 词：layered double hydroxides interlayer distance HYDROTHERMAL asymmetric supercapacitors 

分 类 号：TM53[电气工程—电器]