氧化锰基超级电容器电极材料的制备与性能研究

发布时间：2018-01-26 19:43

本文关键词： 氧化锰超级电容器掺杂复合剥离　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：影响一种赝电容材料电化学性能的因素有很多,合理的结构设计和有针对性的解决方案一定是纳米材料取得突破的关键。较宽的电势窗口、廉价的原料以及优秀的理论比电容使氧化锰基的电极材料成为了超级电容器领域人们关注的焦点。而在经历了一系列石墨烯/MnO_2复合结构的热潮之后,氧化锰材料似乎遇到了瓶颈。当前这种材料在赝电容的储能机理以及离子/电荷的交换传递过程仍然存在较大的争议。基于氧化锰材料的本质特征和潜在应用,本论文提出了一系列新的解决思路,对氧化锰电极材料的电化学性能进行了有效地改进与提高。具体为：(1)利用Fe~(3+)对α-MnO_2纳米线进行了一系列的掺杂,在有效改善材料电导率的同时,晶体结构与形貌的变化使得材料的赝电容等性能获得了大幅度地提升。在杂质原子和酸蚀环境的共同作用下,独特的三相共存晶体结构的设计被认为有效地链接和疏通了电解质离子的传递通道,使得掺杂产物获得了高于纯MnO_2样品数倍的比电容值,以及2000次循环电容无衰减的优异性能。(2)利用一步法水热法成功制备了泡沫镍支撑的多级MnO_2/Ni(OH)_2纳米片复合结构薄膜。在这种由极薄的纳米片自组装构成的多孔复合结构中,高度导电的泡沫镍衬底提供了快速的电子传递通道,多级的MnO_2/Ni(OH)_2网状结构则确保了离子的扩散速率和活性材料的充分利用。优异的协同效应使得该电极具备了极高的比电容值与倍率特性。(3)利用经典的葡萄糖碳化的方式首次在泡沫铜上制备了独特的层状不定形碳模板。基于该模板在水热条件下与KMnO_4溶液发生的氧化还原反应,获得了由单层/少层MnO_2类石墨烯纳米片组装的3D网状结构。亦既是用一种全新的方法实现了对层状MnO_2材料的剥离。剥离后的产物彻底地展现出了MnO_2材料出色的赝电容潜力,获得了三倍以上于普通水钠锰矿型MnO_2纳米片的比电容值。
[Abstract]:There are many factors that affect the electrochemical performance of a pseudo-capacitor material. Reasonable structure design and targeted solution must be the key to the breakthrough of nanomaterials. Cheap raw materials and excellent theoretical capacitance make manganese oxide electrode materials become the focus of attention in the field of supercapacitors, but after a series of graphene / MNO _ 2 composite structure boom. Manganese oxide material seems to meet with a bottleneck. At present, there are still a lot of controversies in the mechanism of energy storage and ion / charge exchange transfer process of this material, based on the essential characteristics and potential application of manganese oxide material. This paper puts forward a series of new solutions. The electrochemical properties of manganese oxide electrode materials have been improved and improved effectively. (1) Fe~(3) has been used to doping 伪 -MnO _ 2 nanowires. At the same time, the changes of crystal structure and morphology have greatly improved the properties of the materials, such as pseudo-capacitance, under the combined action of impurity atoms and acid etching environment. The unique design of three-phase coexisting crystal structure is considered to effectively link and dredge the transfer channel of electrolyte ions, which makes the doped product obtain the specific capacitance value several times higher than the pure MnO_2 sample. And excellent performance of 2000 cycle capacitors without attenuation.) the multistage MNO _ 2 / NiOH supported by foamed nickel was successfully prepared by one-step hydrothermal method. In this porous composite structure composed of extremely thin nanowires self-assembled. Highly conductive nickel foam substrates provide fast electron transfer channels. Multilevel MNO _ 2 / NiOH). The Ti-2 mesh structure ensures the ion diffusion rate and the full utilization of the active materials. The excellent synergistic effect enables the electrode to have extremely high specific capacitance and rate characteristics. For the first time, a unique layered amorphous carbon template was prepared on copper foam by classical glucose carbonization. Based on the redox reaction between the template and KMnO_4 solution under hydrothermal conditions. A 3D mesh structure composed of monolayer / little layer MnO_2 graphene nanochips has been obtained. The delamination of layered MnO_2 materials has also been realized by a new method. The excellent pseudo-capacitance potential of MnO_2 materials is obtained. The specific capacitance of the MnO_2 nanocrystalline is more than three times that of the ordinary sodium manganite.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM53

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