负载Ni(OH)2/NiOOH微球碳气凝胶的水热合成与储能应用

摘要

For developing high-performance supercapacitor electrodes and extending the application area of carbon aerogels,a facile and fast hydrothermal approach was used to embed Ni(OH)2/NiOOH microspheres with a diameter of 2-4 μm into the three-dimensional carbon skeleton structure of CDCA.According to the scanning electron microscope(SEM)observations,the microsphere was formed by the different-direction aggregation and self-assembly of two-dimensional Ni(OH)2/NiOOH nanosheets with a width of 300-800 nm.The as-prepared Ni(OH)2/NiOOH/CDCA composite was mixed with acetylene black(conductive agent)and polytetrafluoroethylene(bonding agent)and then loaded onto a Ni foam.The mixture was pressed into a supercapacitor electrode.In a three-electrode mode,the area enclosed by the CV curve of this electrode was larger than that of the Ni foam-supported Ni(OH)2/NiOOH without carbon aerogels.Moreover,the electrode displayed a noticeable capacitance of 639 mF·cm-2at 1 mA·cm-2.Also,the electrode presented an excellent cycling stability with a 92.37％of capacitance retention after 5 000 cycles.%为发展高性能的超级电容器电极材料和拓展碳气凝胶的应用领域,采用温和、快速的水热合成工艺将Ni(OH)2/NiOOH微球(尺寸为2～4 μm)嵌插入纤维素衍生的碳气凝胶(CDCA)的三维碳骨架结构中.通过扫描电子显微镜(SEM)可以观察到,三维的Ni(OH)2/NiOOH微球是由众多的二维片状结构(宽度为300～800 nm)沿不同方向聚集、堆叠而形成的.将Ni(OH)2/NiOOH/CDCA纳米复合材料与乙炔黑(导电剂)和聚四氟乙烯(黏结剂)混合,然后负载在泡沫镍上,制成薄片状的超级电容器电极材料.在三电极体系下,该电极的循环伏安(CV)曲线所围面积明显大于泡沫镍支撑的Ni(OH)2/NiOOH电极的CV曲线所围的面积.此外,该电极的面电容值可达639 mF·cm-2(电流密度设定为1 mA·cm-2),且在经过5 000次连续充放电循环测试后(电流密度设定为20 mA·cm-2),该电极的电容值仍保持初始电容值的92.37％.