层状结构α-Ni(OH)_2/膨胀石墨纳米复合材料及其电化学性能

Hierarchical α-Ni(OH)_2/Expanded Graphite Nanocomposite and Its Enhanced Electrochemical Performance

以层状膨胀石墨为模板,采用化学浴沉积法首次制备了α-Ni(OH)2/膨胀石墨(α-Ni(OH)2/EG)层状结构的纳米复合材料,分别利用扫描电镜、透射电镜、X射线衍射测试其表面形貌及结构.利用热重分析来检测α-Ni(OH)2在复合材料中的负载量.使用循环伏安和恒流充放电测试等表征其电化学性能.结果表明,制备的α-Ni(OH)2/EG纳米复合材料表现出了优异的电化学性能:在6mol/L KOH电解质溶液中的比电容达到1 180F/g(0.5A/g的电流密度),对应的有效α-Ni(OH)2比电容高达1 920F/g;同时,该复合材料在10A/g的大电流密度下依然能保持较高的比电容(585F/g).优秀的循环稳定性能进一步保证了其成为超级电容器电极材料的合适选择.

The α- Ni（OH）2/expanded graphite（ α- Ni（OH）2/EG） nanocomposite was prepared by a facile chemical bath deposition （CBD） method,α-Ni（OH）2 nanosheets were vertically grown on graphite sheets in EG to form hierarchical nanostructure. The morphology and microstructure of the nanocomposite was characterized by SEM, TEM and XRD analyses. The loading mass of α- Ni（OH）2 in the composite could be characterized by thermogravimetric analyses（TG）. Its electrochemical performance was tested by cyclic voltammetry and galvanostatic charge/discharge methods. This novel structure brings the composite an electrochemical capacitance high to 1 180 F/g at the current density of 0.5 A/g, and maintained 585 F/g at 10 A/g. The effective capacitance of α- Ni（OH）2 in the composite could be 1 920 F/g at 0.5 A/g. This nanocomposite could be a promising candidate for the electrodes of high- performance supercapacitors.