【作者】 刘献明；

【导师】 张校刚；

【作者基本信息】 新疆大学 ， 物理化学， 2003， 硕士

【摘要】 在超级电容器的研究中，许多工作都是围绕开发在某种电解液中有较高比能量的电极材料而展开的。目前应用于超级电容器的电极材料有三种：碳基材料、贵金属氧化物材料和导电聚合物材料。碳基超级电容器比容量小，氧化时易发生腐蚀，内阻较大；过渡金属氧化物作为电极材料是利用氧化还原反应获得的准电容来存储能量，比电容大。贵金属氧化物（RuO₂）是性能优异的超级电容器电极材料，但其价格昂贵，有毒。冈此价格低廉、环境友好、具有较高氧化还原电容的过渡金属氧化物成为超级电容器最理想的电极材料。 本论文共分为五章。第一章综述了超级电容器的储能机理、特点、应用范围等，并介绍了碳基材料、金属氧化物和导电聚合物做电极材料，以及各种电解液的超级电容器的最新研究进展。最后提出了自己对超级电容器电极材料研究设想和方法。 第二章为MnO₂及其复合材料的制备和超电容特性，由四部分组成： 1．用K₂S₂O₈氧化MnSO₄·H₂O成功制得可用于电化学超级电容器电极材料的超细MnO₂。该材料制备的电极循环性能好，具有典型的电化学电容行为，单电极质量比容量达150F／g以上。 2．不同温度下热分解KMnO₄制得超级电容器电极材料MnO₂。这些材料皆有典型的电容性能，其中550℃热解产物电容特性最好，比电容量达243 F／g，充放电性能好，经200次循环电极容量保持在95％以上。 3．化学共沉淀法制得超级电容器电极材料化学掺杂Co的MnO₂。电化学测试结果得出化学掺杂的配比对电化学性能影响很大，适量掺杂的MnO₂电极比未掺杂的MnO₂电极具有更好的循环性能和电容性能。 4．化学共沉淀法制得α-MnO₂·nH₂O和活性炭的复合电极材料。循环伏安、交流阻抗以及恒流充放电等测试结果表明复合电极材料比α-MnO₂·nH₂O或活性炭电极具有更好的电化学可逆性和理想的电化学电容行为。 第三章是CoAl双氢氧化物的制备及其超电容性能，分为四部分： 1．化学共沉淀法制得含Al量不同的CoAl双氢氧化物。电化学测试结果表明CoAl双氢氧化物电极皆具有典型的电容性能，其中川C。物质的量之比为 1：2的C。AI双氢氧化物结构较稳定，循环性能较好，单电极比容量达到 400Fig。 2．AIC。物质的量之比为1：2的C。AI双氢氧化物经Xlll3、TEM、IR测试表明产物为层状结构，属于六方品系，粒径分布在6th70nm之间。该材料制备的电极只有典呗的电容性能，500次循环后电容衰减很小。 3．AIC。物质的量之比为卜 的 COA！双氢氧化物经水热处理后单电极比容量提高了15％，达 460F4，电极内阻仅数十毫欧姆。200次循环后水热处理的电极比容量衰减很小。 4．化学共沉淀法制备了掺Ni的CoAI双氢氧化物，在6mol／LKOH溶液中电化学测试表明，COnyi)AI双氢氧化物电极皆具有典型的电容性能，其中Ni取代CO物质的量之比为46的COpei川双氢氧化物结构较稳定，循环性能较好，单电极比容量达到960F／g。 第四章为＊ 及＊－RUQ的制备和超电容性能。化学共沉淀法制得＊和RU的氢氧化物共沉淀物，经热处理得到NIOIRUO；。电化学测试表明M 电极材料中引人部分RUOZ可以提高比能量和比电容，掺入 10％RUOZ的＊ 电极比能量达 26．ZW·h／kg，比电容达到210 F／g，而＊ 电极只有118F／g。200周循环后，化学引入RUO；比容量保持在95％以上，物理引入只保持在79％左右。 最后展望了超级电容器的电极材料和支持电解液未来发展方向，对如何提高超级电容器的电化学电容性能提出了点滴建议。更多还原

【Abstract】 Many researches in this area of electrochemical supercapacitors have been made focusing on the development of electrode materials that have high specific surface areas and electrochemical properties in suitable electrolytes, such as carbon, transition-metal oxide and conducting polymer. However, carbon suffers from slow deterioration by oxidation and high internal resistance; and it is uncertain to the stability and cycle property of conducting polymer as electrode materials. Many transition-metal oxides are known as excellent electrode materials for supercapacitors with charge-storage mechanisms based predominantly on pseudo-capacitance. Although the ruthenium-oxide system gives very high specific capacitance, it has the inherent disadvantage of high price and toxicity. Therefore, other cheap and environmentally benign transition-metal oxides are thought of as the most ideally substituted electrode materials for supercapacitors.This thesis consists of five chapters. The purpose of the first chapter is to survey the fundamental principles, characterizations and applications of supercapacitors, especially the recent progress of researches on supercapacitors using carbon, transition-metal oxide and conducting polymer as electrode materials in their supporting electrolytes. Based on these information I put forward my purposes and researches to solve existed questions.The second chapter shows preparation and super-capacitive properties of MnO2 and its composite materials. This chapter is divided into four parts.1.Ultrafme manganese dioxide was prepared by oxidation precipitation with potassium persulfate as oxidative reagent under the control of reaction temperature and time. By using electrochemical technique, its specific capacitance reaches over 150F/g.2.Amorphous manganese dioxides were prepared by direct thermal decomposition of KMnO4 at different temperatures. Electrochemical tests indicate that the materials prove to be excellent electrodes for supercapacitors in an unbuffered 0.5mol/L Na2SO4 aqueous electrolyte.A sample decomposed at 550 gives a specific capacitance of 243F/g.3.MnO2 chemically doped with cobalt used as electrode materials for supercapacitors were prepared by chemical co-precipitation method. Results obtained by different electrochemical measurements show that the amounts of Co in samples have great influence on their electrochemical capacities. While measured Co was doped, the electrode has better capacity property, lower impedance and higher utilization, and can be charge-discharged at high current of 40mA.4.MnO2/activated carbon composite electrode materials were prepared by chemical co-precipitation method. The results show that MnO2/activated carbon composite electrode materials have better electrochemical kinetic reversibility and ideal capacitor performance than those of -MnO2 nH2O or activated carbon electrode by CV , a.c. impedance and galvanostatic charge-discharge tests.The third chapter shows preparation and super-capacitive properties of CoAI double-layer hydroxide. It is made up of four parts.1 .Co-A! layered double hydroxides with different ratio of AI to Co have been prepared by chemical co-precipitation method. Electrochemical tests show that Co-AI LDHs as electrode material have typical capacitance . CoAl LDH(AI:Co=l:2) as electrode has a stable structure and good cyclic performance. Specific capacitance of its single electrode attains 400F/g.2.Physical properties of CoAl LDH(AI:Co=1:2) were characterized and discussed by XRD, TEM and IR measurements. The results show that it has layered structure and belongs to hexagonal system and its diameters ranges from 60nm to70nm. Electrochemical tests show that its capacitance changes few after 500 cycles.3.Co-Al LDH was treated by hydrothermal method at 130癈for 16h. Electrochemical measurements show that specific capacitance of single electrode is increased by 15% and its impedance is only tens of m . After 200 cycles its capacitance changes few.4.CoAlLDHs with different ratio更多还原