溶剂热法制备金属氧化物与活性炭的复合材料及其电化学性能的研究

发布时间：2018-03-24 10:41

本文选题：活性炭　切入点：Fe2O3　出处：《太原理工大学》2015年硕士论文

【摘要】：超级电容器是介于传统电容器和锂离子电池之间新型的储能元件,具有能量传递快、功率密度高、循环寿命长（105次）等优点，是一种具有竞争力的储能器件。超级电容器的一个很重要组成部分是电极，其性能是影响超级电容器性能的关键因素。本文以活性炭、金属盐和沉淀剂为原料，通过溶剂热法合成了金属氧化物与活性炭和金属氢氧化物与活性炭的复合材料。并采用XRD、SEM-EDS、FTIR、N2吸附-脱附曲线和TG-DSC等技术表征了所得复合材料的组成与结构；用循环伏安法、恒流充放电法和交流阻抗法测量了复合材料的电化学性能。主要研究内容如下：（1）采用FeCl36H2O、AC（石油焦活性炭）和沉淀剂NaOH溶剂热合成了Fe2O3负载AC复合材料。所得复合材料具有高的比电容215F/g (电流密度为1A/g)和良好的倍率特性（40A/g容量保持率达65.1%）。其优良的电化学性能主要源自于Fe2O3纳米颗粒的高赝电容特性和AC的高比表面积/导电性，为电子/离子传输和离子存储提供了高效的通道。（2）采用四种不同沉淀剂NaOH、 CH3COONa、HMT、CO(NH2)2，研究了沉淀剂种类对复合材料电化学性能的影响。XRD、SEM-EDS和TG分析表明，所制备的复合材料由α-Fe2O3（含量：48.1、47.9、44.2、44.3%）纳米粒子负载在AC颗粒（~20μm）上而形成。同时，沉淀剂的种类及其物质的量对Fe2O3/AC复合材料的比电容具有显著的影响。当CH3COONa：FeCl3的摩尔比为9时，制备出的复合材料表现出最高的比电容240F/g（电流密度1A/g）；当NaOH：FeCl3的摩尔比为1.5时，，制备出的复合材料表现出优良的倍率特性，在电流密度为1A/g时，比电容为215F/g，而电流密度为2、5、10、20和40A/g时，容量保持率高达89.3、82.3、78.1、72.6和65.1%。（3）以Co(NO3)2·6H2O、CO(NH2)2和AC为原料，利用溶剂热法合成了Co(OH)2/AC复合材料。XRD、SEM-EDS、FTIR和TG分析表明，复合材料由~2μm非晶Co(OH)2片状颗粒负载在AC颗粒上构成。电化学测试表明当电流密度为1A/g时，比电容达到301F/g，在电流密度为20A/g时，比电容为164F/g。相比之下，纯Co(OH)2或AC在同等条件下比电容很低，分别为195和33F/g。复合材料优良的电化学性能与AC的高导电性和Co(OH)2赝电容特性协同作用密切相关。
[Abstract]:Supercapacitor is a new type of energy storage element between traditional capacitor and lithium ion battery. It has the advantages of fast energy transfer, high power density, long cycle life and so on. Supercapacitor is a kind of competitive energy storage device. An important component of supercapacitor is electrode, and its performance is the key factor affecting the performance of supercapacitor. In this paper, activated carbon, metal salts and precipitators are used as raw materials, The composite materials of metal oxide and activated carbon and metal hydroxide and activated carbon were synthesized by solvothermal method. The composition and structure of the composites were characterized by XRDX SEM-EDS FTIRN 2 adsorption and desorption curves and TG-DSC, and the composition and structure of the composites were characterized by cyclic voltammetry. The electrochemical properties of composites were measured by constant current charge-discharge method and AC impedance method. The AC composites supported on Fe2O3 were prepared by the solvothermal reaction of FeCl 36 H 2O C and precipitator NaOH. The obtained composite has high specific capacitance 215F/g (current density 1 A / g) and good rate characteristic, the capacity retention rate of 40 Ar / g is 65.1%. The good electrochemical properties are mainly due to the high pseudo-capacitance characteristics of Fe2O3 nanoparticles and the high specific surface area / conductivity of AC. It provides an efficient channel for electron / ion transport and ion storage. (2) four different precipitators NaOH, CH3COONaHMTHMTHMTHMTCONH2O2 were used to study the effect of precipitators on the electrochemical properties of composites. The results of XRDX SEM-EDS and TG analysis showed that the composite was formed by 伪 -Fe _ 2O _ 3 (47.944.24.3) nanoparticles loaded on AC particles (20 渭 m). When the molar ratio of CH3COONa:FeCl3 is 9, the composite exhibits the highest specific capacitance (240F / g) (current density 1 / g), and when the molar ratio of NaOH:FeCl3 is 1.5, The prepared composites show excellent rate characteristics. When the current density is 1A/g, the specific capacitance is 215F / g, while the current density is 210g and 40A/g, the capacity retention rate is up to 82.3% 78.1% 72.6 and 65.1% respectively. Using Co(NO3)2 6H _ 2O COO _ 2 NH _ 2H _ 2 and AC as raw materials, Co(OH)2/AC composite. XRDX SEM-EDSX FTIR and TG analysis showed that the composite was supported on AC particles by amorphous Co(OH)2 flake particles of 2 渭 m. Electrochemical tests showed that the current density was 1A/g. The specific capacitance is 301F / g, and the specific capacitance is 164F / g when the current density is 20A/g. In contrast, the pure Co(OH)2 or AC has a lower capacitance under the same conditions. The excellent electrochemical properties of the composites are respectively 195 and 33F / g. The excellent electrochemical properties of the composites are closely related to the high conductivity of AC and the synergistic effect of the pseudo-capacitance characteristics of Co(OH)2.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332;TM53

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