纳米锰氧化物及其分级结构复合材料的制备与超级电容器性能研究

发布时间：2018-06-17 08:11

本文选题：MnO_2 + 薄膜　；参考：《华中师范大学》2014年博士论文

【摘要】：锰氧化物比容量高,环保,价格低廉,被认为是最有前途的赝电容电极材料。目前,研究者们通过各种方法来提高锰氧化物的电容性能,比如将其纳米化,通过不同合成手段(比如电化学法、液相法)制备纳米线、纳米管、纳米片等多种形貌的锰氧化物。通常来说,锰氧化物可呈非晶态、弱结晶态和单晶,也容易制成薄膜,测试表明多种形态的锰氧化物都有较高的电容性能,可逆性好,并且在硫酸钠溶液中有1V的较宽的电压窗口。尽管锰氧化物如MnO2有很多优点,但其低的电导率(10-5-10-6s/cm)限制了电子的传输和电化学反应的充分进行；同时对于块体的MnO2来说,其比表面积低,块体内部并没有完全参与表面的电化学反应,也降低了其单位质量下能量的储存。所以要提升MnO2等锰氧化物的电容性能,材料的设计主要集中在将材料纳米化,掺杂以及将锰氧化物与导电性更好(碳、金属、金属氧化物)的材料进行复合。本论文工作致力于提升锰氧化物的电化学性能,采用化学浴沉积(CBD)法合成得到了纳米MnO2薄膜和CuBi2O4-掺杂的MnO2(CuBi2O4-MnO2)薄膜,设计并合成了分级的TiO2/Cu2O-Mn3O4的三元纳米片复合材料。系统研究了掺杂、基底种类、温度和时间等因素对MnO2和CuBi2O4-MnO2薄膜的结构、形貌和电化学性能的影响,并对三元复合材料TiO2/Cu2O-Mn3O4的协同效应对电化学性能的影响进行了深入分析。主要研究内容如下： (1)采用化学浴沉积(CBD)法合成得到了纳米MnO2薄膜,用XRD、SEM对薄膜的结构和形貌进行了表征。通过改变反应温度和反应时间,在导电玻璃上沉积得到了不同纳米结构的MnO2薄膜。在60℃、8小时沉积条件下,则得到了非晶的纳米花MnO2,当沉积温度更高时,在70、80、90℃下,得到了纳米线和纳米棒的MnO2。在三电极体系,0.1M硫酸钠电解液下,通过伏安曲线、充放电曲线以及电化学阻抗的测试,研究其电化学性能,研究显示,60℃下获得的纳米花有更好的电化学性能,比电容高、倍率性能好,且循环稳定,10000次循环以后还保有93%的初始容量。 (2)研究CuBi2O4掺杂对Mn02薄膜的影响。通过CBD方法分别在导电玻璃和钛片基底上沉积了不同形貌的Mn02和CuBi2O4-MnO2薄膜,研究了掺杂和基底种类对这两种薄膜电化学性能的影响。用XRD、SEM和XPS对薄膜的结构和形貌进行了表征,证明了Cu2+和Bi3+在Mn02中的成功掺杂。在三电极体系,0.1M硫酸钠电解液下,通过伏安曲线、充放电曲线以及电化学阻抗的测试,研究其电化学性能。CuBi2O4-MnO2薄膜的电容值为338Fg-1,远高于MnO2(135F g-1);另外,对于CuBi2O4-MnO2薄膜,其在导电玻璃上的CuBi2O4-MnO2薄膜要比在钛片基底上的比电容更高,且循环性和可逆性更好。 (3)设计并成功制备了分级的三元TiO2/Cu2O-Mn3O4薄膜。水热法得到TiO2褶皱纳米球阵列,然后通过新颖的连续离子层吸附与反应SILAR法在Ti02上生长得到了分级的Cu2O-Mn3O4纳米片。用XRD、SEM、TEM和XPS对薄膜的结构和形貌进行了表征,电化学性能研究表明,三元TiO2/Cu2O-Mn3O4结构的比容量相比于TiO2/Mn3O4, TiO2/Cu2O, Mn3O4都有较大的提升。在3A g-1的电流密度下,比容量高达259F g-1,这源于材料的协同效应。
[Abstract]:Manganese oxide has high specific capacity , environmental protection and low cost . It is considered to be the most promising pseudo - capacitance electrode material . At present , the researchers have adopted various methods to improve the capacitance performance of Mn oxides . For example , the manganese oxides can be made into amorphous state , weak crystalline state and single crystal .
meanwhile , for the MnO2 of the block , the specific surface area is low , the interior of the block does not fully participate in electrochemical reaction on the surface , and the storage of the energy in the unit mass is reduced ; therefore , the capacitance performance of the manganese oxide such as MnO2 is improved , and the design of the material is mainly concentrated on the compounding of the material of the material nano , the doping and the better conductivity of the manganese oxide and the conductivity ( carbon , metal , metal oxide ) .

The effects of doping , substrate species , temperature and time on the structure , morphology and electrochemical properties of MnO2 and CuBi2O4 - MnO2 films were investigated . The effects of doping , substrate species , temperature and time on the structure , morphology and electrochemical properties of MnO2 and CuBi2O4 - MnO2 films were studied .

The nano - MnO2 thin films were synthesized by chemical bath deposition ( CBD ) method . The structure and morphology of the films were characterized by XRD and SEM .

( 2 ) The influence of CuBi2O4 doping on the properties of Mn02 thin films was investigated . The effects of doping and substrate species on the electrochemical properties of the films were investigated by means of CBD method . The structure and morphology of the films were characterized by XRD , SEM and XPS . The CuBi2O4 - MnO2 thin films had a higher capacitance value than MnO2 ( 135F g - 1 ) .

The structure and morphology of TiO 2 / Cu2O - Mn 3O 4 films were characterized by XRD , SEM , TEM and XPS . The results show that the specific capacity of the ternary TiO2 / Cu2O - MnO4 structure is higher than that of TiO2 / Mn2O4 , TiO2 / Cu2O and MnO4 . The specific capacity of the ternary TiO2 / Cu2O - Mn4 structure is 259F g - 1 at the current density of 3A g - 1 , which is the synergistic effect of the material .
【学位授予单位】：华中师范大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB383.1;TM53

【共引文献】