超级电容器用碳材料的制备及其电化学性能研究

发布时间：2018-02-24 09:39

本文关键词： 超级电容器碳微球生物质碳复合材料电化学储能性能　出处：《上海大学》2015年硕士论文　论文类型：学位论文

【摘要】：超级电容器是介于传统电容器与充电电池之间的一种新型储能元件,以其比功率大、充放电效率高、循环寿命长等优点,在国防、汽车工业、航天航空、电信通讯等领域都有着极为广阔的应用前景。超级电容器的性能主要由其电极材料决定,所以当前对超级电容器的研究重点之一就是寻找更为理想的电极材料。本论文以不同的制备工艺合成了多种碳材料,并对其开展了活化改性和电化学储能性能的研究。首先,本论文以葡萄糖为原料,以水热反应法和后续的高温碳化处理制备了碳微球,并用HNO3和KOH分别进行了表面活化改性处理。研究表明,实验制得的碳微球呈现良好的球状外形,且粒径分布在120 nm~450 nm的尺度范围内。经过HNO3或KOH活化处理后,碳微球粒径分布更加均匀,并减小到190 nm左右。其中,碳微球经HNO3活化后,表面含氧官能团含量增加,提升了碳微球表面的亲水性。而KOH活化则大大增加了碳微球的比表面积和介孔数量。在上述单步活化处理的基础上,本论文也对碳微球开展了HNO3和KOH的二步活化处理。虽然HNO3和KOH活化的作用机制不同,但都显著提升了碳微球的电化学储能性能。活化改性后的碳微球在KOH电解液中表现出一定的法拉第赝电容特性。HNO3活化、KOH活化和两步活化处理的碳微球在3M浓度的KOH电解液中,电流密度为0.5 A/g时,比电容分别达到195.7 F/g、206.1F/g和232.8 F/g,且经过500次充放电循环后,仍然分别保持了初始值的89%、87%和86%的比电容,表现出良好的电化学稳定性。此外,本论文也开展了以木粉为原料,通过高温碳化分解法制备生物质碳粉的研究,并用硝酸对碳粉进行活化处理。研究了不同的制备工艺和活化条件下生物质碳粉的电化学储能性能。研究表明,制备得到的生物质碳粉在6M浓度的HNO3溶液中,经过70℃水浴6 h活化得到的碳粉的电化学性能最优,在电流密度为0.5 A/g时,比电容可达到152.9 F/g,且经过500次充放电循环后,比电容维持在初始值的90%,表现出良好的循环稳定性。为了同时利用双电层电容和法拉第膺电容,本论文以活性生物质碳为载体,制备了活性生物质碳和Ni O的复合电极材料。研究表明,当Ni O的负载量为30%时,在电流密度为0.5 A/g的测试条件下,该复合电极材料的比电容达到250.5 F/g,远远高于活性生物质碳粉的比容量。复合电极材料在经过500次充放电循环后,依然保持了初始比电容的84%。
[Abstract]:Super capacitor is a new type of storage between conventional capacitors and rechargeable batteries of the element, with its high specific power, high charge discharge efficiency, long cycle life and other advantages, in the defense, automobile industry, aerospace, telecommunications and other fields have a very broad application prospect. The performance of super capacitor is mainly determined by the electrode material of super capacitor, so the current one of the key is to find more ideal electrode materials. In this paper, various carbon materials synthesis preparation technology, and the research on activation modification and electrochemical energy storage properties. Firstly, this paper using glucose as the raw material, by the hydrothermal method and subsequent high temperature carbonization preparation of carbon microspheres, and the use of HNO3 and KOH were activated surface modification. The results show that the prepared carbon microspheres showed good spherical shape and size The distribution of scale in the range of 120 nm~450 nm. After HNO3 or KOH activated carbon microspheres, particle size distribution is more uniform, and decreases to about 190 nm. Among them, the carbon microspheres were activated by HNO3, surface oxygen functional groups increased, enhance the hydrophilic surface of carbon microspheres. The activation of KOH is greatly the increase of carbon microspheres surface area and pore volume. The one-step activation in foundation treatment on the carbon microspheres carried out two step HNO3 and KOH activation. Although the mechanism of HNO3 and the activation of KOH is different, but can significantly enhance the electrochemical energy storage of carbon microspheres activation performance. After the modification of carbon microspheres in the KOH electrolyte showed.HNO3 Faraday pseudocapacitance characteristics of certain activation, activation of KOH and the two step activated carbon microspheres in KOH 3M electrolyte concentration, current density of 0.5 A/g, reached 195.7 F/g respectively than 206.1F/g and capacitor. 232.8 F/g, and after 500 cycles, still maintained the initial value of 89%, 87% and 86% of the specific capacitance exhibited good electrochemical stability. In addition, this paper also carried out with wood powder as raw material, the research preparation of biomass toner by carbonization decomposition method, and the toner activated by nitric acid was studied. The electrochemical preparation and activation under the conditions of different biomass toner performance. The results show that the prepared biomass toner in HNO3 solution 6M concentration, after 70 DEG C water bath 6 h activation toner best electrochemical performance, at a current density of 0.5 A/g, the specific capacitance can reach 152.9 F/g, and after 500 cycles, the specific capacitance remained at the initial value of 90%, showing good cycling stability. At the same time in order to use the double layer capacitance and capacitance of the pseudo Faraday, with biological activity Carbon composite electrode material as the carrier, active biomass carbon and Ni O were prepared. The results show that when the Ni load is 30% O, the current density of 0.5 A/g under the test conditions, the composite electrode specific capacitance of 250.5 F/g, far higher than the active biomass toner capacity. The electrode material after 500 cycles, still maintained the initial specific capacitance of 84%.

【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM53

【引证文献】