生物矿化多孔碳微管及其复合材料的制备与其超级电容器性能的研究
发布时间：2018-09-11 17:33
【摘要】：随着经济的快速发展,具有快速充放电,长久循环寿命,高功率密度的超级电容器逐渐作为能源储存中不可或缺的设备之一。然而其较低的容量性质以及较低的能量密度成为制约超级电容器发展的主要因素。超级电容器性能的好坏主要由电极材料自身的性质及其结构所决定。电极材料的选择以及电极结构的合理设计将有利于超级电容器性能的提高。本论文以天然生物质作为前驱体,将高温煅烧得到的中空碳微管,分别通过KOH与空气活化的方式获得具有较大比表面积的多孔材料,并与具有高导电性的金属硫化物进行复合,设计合成具有特殊结构的纳米复合材料,提高电极材料的整体性能。具体内容如下:(1)以灯芯草作为前驱体,通过高温煅烧获得三维中空的生物碳微管,在此基础上,分别通过KOH活化以及空气活化的方式得到具有高比表面积的多孔活性炭。并将其应用于对称超级电容器中,研究发现,通过空气活化得到的多孔碳管很大程度上能够保持材料原有的骨架结构,实现对双电层电容性质的改善。(2)以上述制得的生物碳微管作为基底,采用两步水热法,合成具有不同结构的C/Ni Co2S4复合材料。基于柯肯达尔效应,通过改变第二步水热的反应时间,控制合成具有管中管结构的复合材料。对该电极的结构以及组成进行详细的表征,研究发现Ni、Co、S均匀的分布在碳管的周围,而Ni Co2S4纳米管像草一样附着在碳管的内侧与外壁。通过BET表征发现其复合结构具有较大的比表面积以及丰富的孔洞分布。将其用作超级电容器电极材料,探究其电化学性能。研究表明,含特殊管状结构的C/Ni Co2S4表现出较快的反应动力学,受益于结构的优势,管中管复合材料可获得较高的容量以及较好的倍率性能和循环稳定性。这项研究为特殊形貌结构的设计以及高性能电极材料的制备提供了有价值的思路。(3)以上述制得的多孔碳微管作为基底,通过水热法以及高温硫化法,控制Ni/Co的摩尔比例,获得一系列具有不同形貌的C/NixCo1-x S1.097(0≤x1)复合材料。相关的物相表征表明,当x值为0.6时,C/Ni0.6Co0.4S1.097具有稳定的纳米线结构和较高的结晶度。将C/NixCo1-x S1.097(0≤x1)分别用作超级电容器电极材料,通过三电极体系电化学表征对比发现,C/Ni0.6Co0.4S1.097具有较好的电化学性能。将其组装为器件,结果表明C/Ni0.6Co0.4S1.097//AC表现出较高的比容量,优异的倍率性能以及较高的能量密度,可作为一种新的有前景的超级电容器器件。
[Abstract]:With the rapid development of economy, supercapacitors with rapid charge and discharge, long cycle life and high power density are becoming one of the indispensable equipments in energy storage. However, its low capacity and low energy density are the main factors restricting the development of supercapacitors. The performance of supercapacitors is mainly determined by the properties and structure of electrode materials themselves. The selection of electrode materials and the reasonable design of electrode structure will benefit the performance of supercapacitors. In this paper, the hollow carbon microtubules calcined at high temperature were used as precursors to obtain porous materials with large specific surface area by KOH and air activation, and the hollow carbon microtubules were compounded with metal sulfides with high conductivity. Nanocomposites with special structure were designed and synthesized to improve the overall properties of electrode materials. The main contents are as follows: (1) porous activated carbon with high specific surface area was obtained by KOH activation and air activation by calcination of three dimensional hollow carbon microtubules. It is found that the porous carbon tube obtained by air activation can maintain the original skeleton structure of the material to a large extent. The properties of double-layer capacitance were improved. (2) C/Ni Co2S4 composites with different structures were synthesized by two-step hydrothermal method using the biocarbon microtubules prepared above as the substrate. Based on the Kokkendal effect, the composite with tube structure was synthesized by changing the reaction time of the second step. The structure and composition of the electrode were characterized in detail. It was found that Ni,Co,S distributed uniformly around the carbon tube, while Ni Co2S4 nanotubes adhered to the inner and outer walls of the carbon tube like grass. It was found by BET that the composite structure had a large specific surface area and abundant pore distribution. It is used as electrode material of supercapacitor to study its electrochemical performance. The results show that the C/Ni Co2S4 with special tubular structure exhibits faster reaction kinetics, and can obtain higher capacity, better rate performance and better cyclic stability. This study provides valuable ideas for the design of special morphologies and the preparation of high performance electrode materials. (3) the porous carbon microtubules prepared above are used as substrates, and the molar ratio of Ni/Co is controlled by hydrothermal method and high temperature vulcanization. A series of C/NixCo1-x S1.097 (0 鈮，
本文编号：2237380
[Abstract]:With the rapid development of economy, supercapacitors with rapid charge and discharge, long cycle life and high power density are becoming one of the indispensable equipments in energy storage. However, its low capacity and low energy density are the main factors restricting the development of supercapacitors. The performance of supercapacitors is mainly determined by the properties and structure of electrode materials themselves. The selection of electrode materials and the reasonable design of electrode structure will benefit the performance of supercapacitors. In this paper, the hollow carbon microtubules calcined at high temperature were used as precursors to obtain porous materials with large specific surface area by KOH and air activation, and the hollow carbon microtubules were compounded with metal sulfides with high conductivity. Nanocomposites with special structure were designed and synthesized to improve the overall properties of electrode materials. The main contents are as follows: (1) porous activated carbon with high specific surface area was obtained by KOH activation and air activation by calcination of three dimensional hollow carbon microtubules. It is found that the porous carbon tube obtained by air activation can maintain the original skeleton structure of the material to a large extent. The properties of double-layer capacitance were improved. (2) C/Ni Co2S4 composites with different structures were synthesized by two-step hydrothermal method using the biocarbon microtubules prepared above as the substrate. Based on the Kokkendal effect, the composite with tube structure was synthesized by changing the reaction time of the second step. The structure and composition of the electrode were characterized in detail. It was found that Ni,Co,S distributed uniformly around the carbon tube, while Ni Co2S4 nanotubes adhered to the inner and outer walls of the carbon tube like grass. It was found by BET that the composite structure had a large specific surface area and abundant pore distribution. It is used as electrode material of supercapacitor to study its electrochemical performance. The results show that the C/Ni Co2S4 with special tubular structure exhibits faster reaction kinetics, and can obtain higher capacity, better rate performance and better cyclic stability. This study provides valuable ideas for the design of special morphologies and the preparation of high performance electrode materials. (3) the porous carbon microtubules prepared above are used as substrates, and the molar ratio of Ni/Co is controlled by hydrothermal method and high temperature vulcanization. A series of C/NixCo1-x S1.097 (0 鈮，
本文编号：2237380
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