镍钴基氧化物纳米纤维的静电纺丝法制备及电化学性能研究
发布时间：2018-12-13 08:29
【摘要】：超级电容器,已经成为一种新型的储能元件备受人们关注。超级电容器的电化学性能主要由电极材料的性质决定。过渡金属材料由于其良好的电化学性能而成为超级电容器电极最有前途的候选。本文通过静电纺丝的方法设计合成了 NiO、柠檬酸改性NiO(NiO/CA)、无P123添加的 Co3O4(Co3O4/WP)、添加 P123 的 Co3O4(Co3O4/P)和 NiO/Co3O4纳米纤维。并通过XRD、TG-DSC、TEM、SEM和N2吸脱附等手段对所得样品进行了表征和分析。采用循环伏安、恒电流充放电和交流阻抗的电化学测试手段对合成的纳米纤维进行了电化学性能的测试。研究发现,未经柠檬酸改性的NiO纳米纤维结晶性良好,存在着由片状颗粒堆积而形成的孔道,电流密度为5cmA·cm-2时的比电容可达到148 F·g-1,经过柠檬酸改性后NiO/CA纳米纤维为中空结构,并且比电容明显增大,总电阻和电荷转移电阻也有了不同程度的减小;通过Co3O4/WP纳米纤维和Co3O4/P纳米纤维的对比说明,加入P123后,使样品在焙烧后具有规则的棒状纤维形貌,颗粒排列较为紧密。颗粒之间的堆积也比较有规律,形成的堆积孔更为均匀,便于电解质的进入和渗透。Co3O4/P纳米纤维经500℃焙烧,在电流密度为5mA·cm-2时的比电容可达到401F·g-1,为Co3O4/WP纳米纤维的比电容的2.2倍;Co3O4/P纳米纤维的总电阻较小仅为0.45Ω,电荷转移电阻为0.20Ω;并且样品经过1000次循环后,其比电容仅仅下降了 6%;NiO/Co3O4纳米纤维考察了不同Ni、Co质量比,不同添加剂情况下各样品的性能。柠檬酸和P123添加后,样品具有规则的形貌,颗粒排列较为紧密,样品为中空纤维结构。颗粒之间形成的堆积孔较为均匀,便于电解质的进入和渗透。相同质量配比制备的NiO/Co3O4纳米纤维(NC-1)在电流密度为5mA·cm-2时的比电容可达到788F·g-1,较NiO纳米纤维的比电容增大几倍。NC-1纳米纤维的总电阻较小,仅为0.45Ω,电荷转移电阻为0.21Ω;并且样品经过1000次循环后,其比电容仅仅下降了 7%,表现出了很好的循环稳定性。
[Abstract]:Supercapacitors have become a new type of energy storage components. The electrochemical properties of supercapacitors are mainly determined by the properties of electrode materials. Transition metal materials are the most promising candidates for supercapacitor electrodes due to their excellent electrochemical properties. In this paper, NiO, citric acid modified NiO (NiO/CA), Co3O4 (Co3O4/WP) without P123, Co3O4 (Co3O4/P) with P123 and NiO/Co3O4 nanofibers were designed and synthesized by electrospinning. The samples were characterized and analyzed by XRD,TG-DSC,TEM,SEM and N2 adsorption and desorption. The electrochemical properties of the synthesized nanofibers were measured by cyclic voltammetry, constant current charge-discharge and AC impedance. It was found that the NiO nanofibers without citric acid modified had good crystallinity, and there were pores formed by the stacking of flake particles. The specific capacitance of NiO nanofibers with current density of 5cmA cm-2 could reach 148F g-1. The NiO/CA nanofibers modified by citric acid have hollow structure, and the specific capacitance increases obviously, and the total resistance and charge transfer resistance also decrease to some extent. The comparison of Co3O4/WP nanofibers and Co3O4/P nanofibers shows that the samples prepared by P123 have regular shape of rod fibers and compact arrangement of particles after calcination. The stacking between particles is also regular, and the stacking pore is more uniform, which facilitates the entry and permeation of electrolytes. The specific capacitance of Co3O4/P nanofibers calcined at 500 鈩，
本文编号：2376242
[Abstract]:Supercapacitors have become a new type of energy storage components. The electrochemical properties of supercapacitors are mainly determined by the properties of electrode materials. Transition metal materials are the most promising candidates for supercapacitor electrodes due to their excellent electrochemical properties. In this paper, NiO, citric acid modified NiO (NiO/CA), Co3O4 (Co3O4/WP) without P123, Co3O4 (Co3O4/P) with P123 and NiO/Co3O4 nanofibers were designed and synthesized by electrospinning. The samples were characterized and analyzed by XRD,TG-DSC,TEM,SEM and N2 adsorption and desorption. The electrochemical properties of the synthesized nanofibers were measured by cyclic voltammetry, constant current charge-discharge and AC impedance. It was found that the NiO nanofibers without citric acid modified had good crystallinity, and there were pores formed by the stacking of flake particles. The specific capacitance of NiO nanofibers with current density of 5cmA cm-2 could reach 148F g-1. The NiO/CA nanofibers modified by citric acid have hollow structure, and the specific capacitance increases obviously, and the total resistance and charge transfer resistance also decrease to some extent. The comparison of Co3O4/WP nanofibers and Co3O4/P nanofibers shows that the samples prepared by P123 have regular shape of rod fibers and compact arrangement of particles after calcination. The stacking between particles is also regular, and the stacking pore is more uniform, which facilitates the entry and permeation of electrolytes. The specific capacitance of Co3O4/P nanofibers calcined at 500 鈩，
本文编号：2376242
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