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超级电容器因为具有充放电时间短的特点引起了人们的广泛关注.然而,由于电极表面的电荷积聚和化学反应,电容器的比电容及能量密度大大降低,限制了超级电容器的实际应用.本文提出了一种新颖的合成方法用以制备基于镍钴双氢氧化物的复合材料,该复合材料作为超级电容器的电极具有优异的电化学性能.利用氮掺杂石墨烯的缺陷,金属氢氧化物纳米结构在氮掺杂石墨烯表面生长,形成复合结构.通过调节并优化镍钴的元素比以及卤素离子、碳酸根离子的含量,能够改善材料的孔隙度、提高材料结构的稳定性以及促进电化学反应.金属氢氧化物的形成由钴离子的氧化反应引导,并通过定向生长方式形成一维结构.氮掺杂石墨烯有效保护镍钴双氢氧化物的纳米结构,使其在电化学测试中不被破坏,同时,氮掺杂石墨烯还能够提高电极的导电性,利于物质及离子传输.电化学测试表明,该复合材料在电流密度为1Ag-1时,比电容高达2925Fg-1,并且在高电流密度下(16Ag-1)展现出了优异的循环稳定性,在10,000次循环后比电容仍然保持在90%.在16Ag-1的电流密度下,材料的能量密度和功率密度分别达到了52Whkg-1和3191Wkg-1.该合成方法为制备基于金属氢氧化物、氧化物、硫化物等高性能超级电容器电极提供了新的途径.
Due to the short charge and discharge time, supercapacitors have drawn much attention, however, the specific capacitance and energy density of the capacitor are greatly reduced due to the charge accumulation and chemical reaction on the electrode surface, which limits the practical application of ultracapacitors.In this paper, A novel synthesis method for the preparation of nickel cobalt double hydroxides based composites with excellent electrochemical performance as electrodes for supercapacitors.Using the defects of nitrogen-doped graphene, the metal hydroxide nanostructures The surface of the nitrogen-doped graphene growth to form a composite structure by adjusting and optimizing the elemental ratio of nickel and cobalt and the content of halogen ions and carbonate ions can improve the porosity of the material to improve the stability of the material structure and to promote the electrochemical reaction . The formation of metal hydroxides is induced by the oxidation of cobalt ions and forms a one-dimensional structure by directional growth. Nitrogen-doped graphene effectively protects the nanostructures of nickel-cobalt double hydroxides from electrochemical tests Is destroyed, at the same time, nitrogen-doped graphene can also improve the conductivity of the electrode, conducive to material and ion transport. Chemical tests show that the composite has a specific capacitance of up to 2925 Fg-1 at a current density of 1 Ag-1 and an excellent cycling stability at a high current density (16Ag-1). After 10,000 cycles, the specific capacitance Remained at 90% at 16Ag-1 current density, the material energy density and power density reached 52Whkg-1 and 3191Wkg-1 The synthesis method for the preparation based on metal hydroxides, oxides, sulfides and the like High performance supercapacitor electrodes provide a new avenue.