二氧化锰电极材料的制备及其超级电容器性能的研究
发布时间：2018-07-24 08:39
【摘要】：超级电容器作为一类新型能源存储器件,具有功率密度高、充放电速度快、循环寿命长等优点,因而受到广泛的关注。二氧化锰(MnO_2)因具有储量丰富、价格低廉、理论比电容量高(达到1370 F g~(-1))以及电位窗口宽等特点,是一种重要的超级电容器电极材料。然而,由于二氧化锰电极材料自身导电性差,从而限制了高电容性能二氧化锰基超级电容器的发展。本文以纳米结构的二氧化锰和高导电性材料复合来提高二氧化锰基超级电容器电化学性能作为研究内容。利用电化学沉积技术,成功制备了纳米结构的二氧化锰电极材料和三维MnO_2/AgNW复合材料,并利用循环伏安、恒流充放电、交流阻抗等测试手段对所制备电极材料的电化学性能进行系统的研究。而且,将MnO_2/AgNW复合材料组装成柔性对称型超级电容器器件,并对其组装工艺和充放电性能进行了优化探索。主要研究内容和结果如下:1.利用串联电阻计时电位法和恒流充放电过程中的二次生长技术,制备了一种具有水钠矿和斜方锰矿结构的三维牡丹花状MnO_2/FTO平板电极材料,展现了优异的电容性能,比电容量在电流密度为10 A g~(-1)条件下能够达到1260 F g~(-1),10000次恒流充放电循环后其电容保持率达到304%。不同于传统的计时电流法,利用串联电阻计时电流法制备的MnO_2电极材料在循环过程中能够进行二次生长,这种二次生长导致了MnO_2晶体结构变化,从而明显的提高了其表面/近表面及体内赝电容性能。利用交流阻抗、循环伏安和恒流程放电测试,以及第一性原理计算研究了其储能机理,发现表面电容和体电容的贡献与扫描速率的有关,主要是通过对不同扫描速率下的总电容的划分和氧化还原峰得以证明。这种特殊结构的MnO_2可用于微型超级电容器,同时其二次生长过程所展现的独特自修复特性,特别适合应用于免维修和长寿命的微型超级电容器领域。2.以银纳米线层作为导电集流体,利用电化学沉积技术将MnO_2直接生长在AgNW上,制备成三维MnO_2/AgNW复合电极材料,并对其电化学性能进行系统的研究。为了避免电沉积过程中的AgNW层的脱落问题,利用快速退火工艺将AgNW层在300 oC条件下进行焊接处理,促使相互交叉的AgNW之间形成焊接点,这能够明显的提高电极材料的导电性和循环寿命。在恒流充放电过程中,这种三维MnO_2/AgNW复合电极材料的形貌由花状结构逐渐转变为蜂窝状,从而使比容量逐渐提高,从初始的423.5 F g~(-1)增加到663.4 F g~(-1),7000次恒流充放电后其比电容提高到初始值的156.6%。3.基于上述MnO_2/AgNW复合材料所展现的优异的电化学性能,将这种电极材料制备成柔性对称性滤纸基MnO_2/AgNW超级电容器器件。为了避免AgNW层在滤纸上的脱落问题,对AgNW层进行加压处理。当扫速为10 mV/s,柔性超级电容器器件的电极材料的比电容为166.6 F g~(-1)。进行10000次恒流充放电测试过程中,其仍能展现了较好的循环稳定性。当柔性器件进行弯折处理,其比电容量仍能保持101.4 F g~(-1)的比容量。
[Abstract]:As a new type of energy storage device, supercapacitor is widely concerned because of its advantages of high power density, fast charging and discharging speed, long cycle life, and so on. Manganese dioxide (MnO_2) is an important supercapacitor because of its rich reserves, low price, high theoretical ratio (up to 1370 F g~ (-1)) and wide potential window. However, due to the poor self conductivity of the manganese dioxide electrode material, the development of the high capacitive manganese based supercapacitor is limited. This paper uses nanostructured manganese dioxide and high conductivity materials to improve the electrochemical performance of manganese based supercapacitors. The nanostructured manganese dioxide electrode materials and three dimensional MnO_2/AgNW composites were prepared successfully. The electrochemical performance of the prepared electrode materials was systematically studied by means of cyclic voltammetry, constant current charge discharge, and AC impedance, and the MnO_2/ AgNW composite was assembled into a flexible symmetric supercapacitor. The assembly process and charge discharge performance were optimized. The main contents and results were as follows: 1. a three dimensional peony shaped MnO_2/FTO plate electrode material with sodium ore and a trapezoid manganese ore structure was prepared by using the series resistance chronograph and two growth techniques in the constant current charge discharge process. With different capacitance, the specific capacitance can reach 1260 F g~ (-1) under the current density of 10 A g~ (-1). After 10000 constant current charging and discharging cycle, its capacitance retention rate is different from that of the traditional timing current method. The MnO_2 electrode material prepared by the series resistor timing current method can grow two times during the cycle process. The two growth results in the change of the MnO_2 crystal structure, which obviously improves the surface / near surface and the pseudo capacitance in the body. The energy storage mechanism is studied by the AC impedance, cyclic voltammetry and the constant flow discharge test, and the first principle calculation. It is found that the contribution of the surface capacitance and the volume capacitance is related to the scanning rate. The division of the total capacitance and the redox peak at different scanning rates are proved. The special structure of the MnO_2 can be used for micro supercapacitors, while the unique self repair characteristics presented in the secondary growth process are especially suitable for the micro supercapacitor field of the maintenance free and long life micro supercapacitor, which is guided by the silver nanowire layer as the guide. In order to avoid the loss of AgNW layer in the process of electrodeposition, the AgNW layer was welded under the condition of 300 oC to avoid the loss of AgNW layer in the process of electrodeposition, and the phase of the AgNW layer was welded on the condition of 300 oC in the process of electrodeposition. The intersecting AgNW forms the welding point, which can obviously improve the conductivity and the cycle life of the electrode material. In the constant current charge discharge process, the morphology of the three-dimensional MnO_2/AgNW composite electrode is gradually transformed from the flower structure to honeycomb, thus increasing the specific capacity gradually from the initial 423.5 F g~ (-1) to 663.4 F g~ (-1). After 7000 constant current charging and discharging, the 156.6%.3., whose specific capacitance is increased to the initial value, is based on the excellent electrochemical performance presented by the above MnO_2/AgNW composite. The electrode material is prepared into a flexible symmetric filter paper based MnO_2/AgNW supercapacitor device. In order to avoid the problem of falling off the AgNW layer on the filter paper, the AgNW layer is pressurized. When the scavenging speed is 10 mV/s, the specific capacitance of the electrode material of the flexible supercapacitor device is 166.6 F g~ (-1). During the 10000 constant current charge discharge test, it can still show good cyclic stability. When the flexible device is bent, the specific capacity of the flexible device can still maintain the specific capacity of 101.4 F g~ (-1).
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53
[Abstract]:As a new type of energy storage device, supercapacitor is widely concerned because of its advantages of high power density, fast charging and discharging speed, long cycle life, and so on. Manganese dioxide (MnO_2) is an important supercapacitor because of its rich reserves, low price, high theoretical ratio (up to 1370 F g~ (-1)) and wide potential window. However, due to the poor self conductivity of the manganese dioxide electrode material, the development of the high capacitive manganese based supercapacitor is limited. This paper uses nanostructured manganese dioxide and high conductivity materials to improve the electrochemical performance of manganese based supercapacitors. The nanostructured manganese dioxide electrode materials and three dimensional MnO_2/AgNW composites were prepared successfully. The electrochemical performance of the prepared electrode materials was systematically studied by means of cyclic voltammetry, constant current charge discharge, and AC impedance, and the MnO_2/ AgNW composite was assembled into a flexible symmetric supercapacitor. The assembly process and charge discharge performance were optimized. The main contents and results were as follows: 1. a three dimensional peony shaped MnO_2/FTO plate electrode material with sodium ore and a trapezoid manganese ore structure was prepared by using the series resistance chronograph and two growth techniques in the constant current charge discharge process. With different capacitance, the specific capacitance can reach 1260 F g~ (-1) under the current density of 10 A g~ (-1). After 10000 constant current charging and discharging cycle, its capacitance retention rate is different from that of the traditional timing current method. The MnO_2 electrode material prepared by the series resistor timing current method can grow two times during the cycle process. The two growth results in the change of the MnO_2 crystal structure, which obviously improves the surface / near surface and the pseudo capacitance in the body. The energy storage mechanism is studied by the AC impedance, cyclic voltammetry and the constant flow discharge test, and the first principle calculation. It is found that the contribution of the surface capacitance and the volume capacitance is related to the scanning rate. The division of the total capacitance and the redox peak at different scanning rates are proved. The special structure of the MnO_2 can be used for micro supercapacitors, while the unique self repair characteristics presented in the secondary growth process are especially suitable for the micro supercapacitor field of the maintenance free and long life micro supercapacitor, which is guided by the silver nanowire layer as the guide. In order to avoid the loss of AgNW layer in the process of electrodeposition, the AgNW layer was welded under the condition of 300 oC to avoid the loss of AgNW layer in the process of electrodeposition, and the phase of the AgNW layer was welded on the condition of 300 oC in the process of electrodeposition. The intersecting AgNW forms the welding point, which can obviously improve the conductivity and the cycle life of the electrode material. In the constant current charge discharge process, the morphology of the three-dimensional MnO_2/AgNW composite electrode is gradually transformed from the flower structure to honeycomb, thus increasing the specific capacity gradually from the initial 423.5 F g~ (-1) to 663.4 F g~ (-1). After 7000 constant current charging and discharging, the 156.6%.3., whose specific capacitance is increased to the initial value, is based on the excellent electrochemical performance presented by the above MnO_2/AgNW composite. The electrode material is prepared into a flexible symmetric filter paper based MnO_2/AgNW supercapacitor device. In order to avoid the problem of falling off the AgNW layer on the filter paper, the AgNW layer is pressurized. When the scavenging speed is 10 mV/s, the specific capacitance of the electrode material of the flexible supercapacitor device is 166.6 F g~ (-1). During the 10000 constant current charge discharge test, it can still show good cyclic stability. When the flexible device is bent, the specific capacity of the flexible device can still maintain the specific capacity of 101.4 F g~ (-1).
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53
【相似文献】
相关期刊论文 前10条
1 ;我国第一种国产超级电容器通过鉴定[J];测控技术;2000年12期
2 刘建新;超级电容器在直流电源系统中的应用[J];华东交通大学学报;2002年03期
3 桂长清;新型贮能单元超级电容器[J];电池工业;2003年04期
4 ;超级电容器[J];电源世界;2004年03期
5 文建国,周震涛,文衍宣;超级电容器材料研究的辩证思维[J];东莞理工学院学报;2004年01期
6 李荐,钟晖,钟海云,戴艳阳,温俊杰;超级电容器应用设计[J];电源技术;2004年06期
7 Bobby Maher;;超级电容器简介[J];今日电子;2006年01期
8 王鑫;;超级电容器在汽车启动中的应用[J];国外电子元器件;2006年05期
9 Matt Reynolds;;替代能源中的超级电容器介绍[J];今日电子;2006年07期
10 陈新丽;李伟善;;超级电容器电极材料的研究现状与发展[J];广东化工;2006年07期
相关会议论文 前10条
1 马衍伟;张熊;余鹏;陈尧;;新型超级电容器纳米电极材料的研究[A];2009中国功能材料科技与产业高层论坛论文集[C];2009年
2 张易宁;何腾云;;超级电容器电极材料的最新研究进展[A];第二十八届全国化学与物理电源学术年会论文集[C];2009年
3 钟辉;曾庆聪;吴丁财;符若文;;聚苯乙烯基层次孔碳的活化及其在超级电容器中的应用[A];中国化学会第15届反应性高分子学术讨论会论文摘要预印集[C];2010年
4 赵家昌;赖春艳;戴扬;解晶莹;;扣式超级电容器组的研制[A];第十二届中国固态离子学学术会议论文集[C];2004年
5 单既成;陈维英;;超级电容器与通信备用电源[A];通信电源新技术论坛——2008通信电源学术研讨会论文集[C];2008年
6 王燕;吴英鹏;黄毅;马延风;陈永胜;;单层石墨用作超级电容器的研究[A];2009年全国高分子学术论文报告会论文摘要集（上册）[C];2009年
7 赵健伟;倪文彬;王登超;黄忠杰;;超级电容器电极材料的设计、制备及性质研究[A];中国化学会第27届学术年会第10分会场摘要集[C];2010年
8 张琦;郑明森;董全峰;田昭武;;基于薄液层反应的新型超级电容器——多孔碳电极材料的影响[A];中国化学会第27届学术年会第10分会场摘要集[C];2010年
9 马衍伟;;新型超级电容器石墨烯电极材料的研究[A];第七届中国功能材料及其应用学术会议论文集（第7分册）[C];2010年
10 刘不厌;彭乔;孙s，
本文编号：2140828
本文链接：https://www.wllwen.com/kejilunwen/dianlidianqilunwen/2140828.html
