Layered Double Hydroxides MgFe-LDH and MgAl-LDH have been prepared by th e method involving separate nucleation and ageing steps. The structure analyses for these two materials show that the values of the parameters b...Layered Double Hydroxides MgFe-LDH and MgAl-LDH have been prepared by th e method involving separate nucleation and ageing steps. The structure analyses for these two materials show that the values of the parameters both a and c of M gAl-LDH are smaller than that of MgFe-LDH though their structures are simila r, and MgAl-LDH with higher crystallinity is more easily formed than MgFe-LD H in the same preparing conditions. The IR analyses manifest that the structures of layer sheets and the orderings of the anions in the interlayer regions of Mg Al-LDH are more regular than that of MgFe-LDH. The temperature programmed XR D analyses reveal that the diffraction peak of 003 reflections for MgAl-LDH co uld be seen after calcining at 300℃, while this peak for MgFe-LDH disappears after calcining at 200℃. Together with the TG-DTA analysis it can be conclu ded that the thermal stability of MgAl-LDH is obviously higher than that of Mg Fe-LDH.展开更多
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...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.展开更多
文摘Layered Double Hydroxides MgFe-LDH and MgAl-LDH have been prepared by th e method involving separate nucleation and ageing steps. The structure analyses for these two materials show that the values of the parameters both a and c of M gAl-LDH are smaller than that of MgFe-LDH though their structures are simila r, and MgAl-LDH with higher crystallinity is more easily formed than MgFe-LD H in the same preparing conditions. The IR analyses manifest that the structures of layer sheets and the orderings of the anions in the interlayer regions of Mg Al-LDH are more regular than that of MgFe-LDH. The temperature programmed XR D analyses reveal that the diffraction peak of 003 reflections for MgAl-LDH co uld be seen after calcining at 300℃, while this peak for MgFe-LDH disappears after calcining at 200℃. Together with the TG-DTA analysis it can be conclu ded that the thermal stability of MgAl-LDH is obviously higher than that of Mg Fe-LDH.
基金financially supported by the National Natural Science Foundation of China (21501152,21571159,21671178,21441003,51521091 and 51525206)China Postdoctoral Science Foundation (2017M611282)+5 种基金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)
文摘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.
