超级电容器用电极材料活性炭-Co(OH)2的制备及其性能研究

论文总字数：10891字

摘 要

：采用化学水热法制得纯相Co(OH)₂和活性炭改性Co(OH)₂（C-Co(OH)₂）复合材料用于超级电容器材料。采用X射线衍射(XRD)和扫描电镜(SEM)表征了产物的结构和形貌，结果表明，150℃ 6h的水热反应条件下获得的Co(OH)₂为分散度高、形貌规则的六边形薄片状；六方形的Co(OH)₂薄片均匀分散在C-Co(OH)₂复合材料中。采用循环伏安、恒流充放电、交流阻抗等电化学方法考察其电化学性能。结果发现C-Co(OH)₂电极比Co(OH)₂电极具有更加优异的电化学性能：循环伏安分析表明， C-Co(OH)₂电极在0~0.6V（VS.SCE)，表现出良好的矩形特征；在0~0.6v充放电电位区间、0.1A/g电流密度下研究其充放电性能，发现当C与Co的质量比为16：1时电容器的充放电性能良好，比容量和储能密度均达到最大，分别为151.33F·g^-1，储能密度为0.0174Wh·kg^-1，在充放电100次后，C-Co(OH)₂的比容量没有衰减，说明产物具有较好的电化学稳定性，有望成为超级电容器的电极材料。

关键词：超级电容器，Co(OH)₂，活性炭，循环伏安，充放电，比电容

Abstract：Co(OH)₂ and Activated carbon (C) modified Co(OH)₂ (C-Co(OH)₂) used as electrode materials for supercapacitors were synthesized by hydro-thermal method under 150^oC for 6h. The structure of the products was characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that Co(OH)₂ presented as Hexagonal sheet-like structure with high dispersibility and it was uniformly dispered in active carbon. The electrochemical performances of the obtained products are investigated by cyclic voltammetry(CV), constant current charge/discharge and electrochemical impedance spectroscopy (ESR) techniques. The tests found that C-Co(OH)₂ presents better electrochemical property than that of pure Co(OH)₂.Based on Cyclic voltammograms (vs.SCE), the working voltage for C-Co(OH)₂ composites with ideal capacitor behavior were 0V-0.6 V respectively in 0.5mol·L^{- 1} Na₂SO₄. Charge and discharge behavior of the products between 0~0.6Vunder different current densities were studied, the results show that the optimum current density is 0.1 A • g^-1. Under this condition, the specific capacity and energy density reached the maximum. The specific capacity was 151.33F • g^-1, energy density is 0.0174Wh • kg^-1, respectively. After the 100 charge and discharge cycles, capacity of C-Co(OH)₂ almost maintain the same as original, indicating C-Co(OH)₂ has better electrochemical stability, which is expected to be used as the supercapacitor electrode material.

Keywords: Supercapacito, C-Co(OH)₂, Cyclic voltamper, Specific capacitance

目 录

1. 前言 4

1.1 超级电容器的简介 4

1.2 超级电容器的原理和分类 4

1.3 超级电容器的特点及应用 4

1.4 超级电容器的电极材料 4

2 实验部分 5

2.1 仪器和试剂 5

2.2 Co(OH)₂与C-Co(OH)₂复合材料的制备 5

2.3 材料表征 5

2.3.1 粉末X射线衍射 6

2.3.2 扫射电镜形貌分析 6

2.4 电极材料的制备 6

2.5 电化学测试方法 6

3 结果与讨论 6

3.1 XRD分析 6

3.2 扫射电镜图形 7

3.3 循环伏安测试 8

3.4 恒电流充放电测试 10

3.5 电化学阻抗测试 13

结 论 16

参 考 文 献 17

致 谢 18

1. 前言

环境和气候的日益恶化和化石燃料的消耗对地球的生态具有极大的影响。石油、煤、天然气等不可再生的矿物资源变得逐渐匮乏，而且化石燃料燃烧后排放出的废气体对全球生态环境造成了严重的污染。所以我们必须要大力建设新型的绿色能源和可再生资源的使用技术，削减对环境的污染，达成可持续发展的重要措施。超级电容器作为当今世界的重点发展的一种新能源，已经被许多的国家和企业单位争相研制和生产^{[1- 4]}。

1.1 超级电容器的简介

剩余内容已隐藏，请支付后下载全文，论文总字数：10891字