基于非晶合金脱合金化纳米多孔构建复合型电极材料及其性能研究

A flexible method of dealloying of metallic glassy precursors followed by polarization-oxidation is carried out in order to fabricate the hybrid electrode materials for the pseudo-capacitances. During the process of dealloying, minor addition of low-surface-diffusion-coefficient metallic elements (LSDM, noble metals) inhibit the diffusion of atoms, resulting in refinement of the pores and an enrichment of noble elements on the surface of the ligaments. The relationship between the sizes of pores and ligaments with the addition of LSDM are investigated. The mechanisms of LSDM inhibiting diffusion of atoms and diffusing to the surface of the ligaments are described. In addition, the oxides mixing with noble element in metallic state are obtained by polarizing nanoporous cobalt by adjusting voltages and times. Distribution, valence of the elements as well as the thickness of oxide layer will be discussed related to polarization parameters. Noble elements in metallic state are presumed mixing with the oxidized compound supporting the good conductivity. High energy density and long cycle life of the hybrid electrode materials are expected. The mechanism of the combination of high specific capacitance and good conductivity of the hybrid materials are explored in the study. The research is necessary and important for the application of nano-structured metals.

针对当前世界对新型能源材料的迫切需求, 本项目提出以ZrAlCo系列非晶合金为前驱体，采用脱合金化及极化自氧化法原位构建纳米多孔复合型赝电容电极材料。具体利用前驱体合金中添加微量低表面扩散系数贵金属元素来降低纳米多孔特征尺寸， 并形成韧带表面贵金属富集区；系统研究低表面扩散系数元素对孔径、韧带尺寸及比表面积的影响，揭示低表面扩散系数元素抑制扩散、细化孔径及自富集机制。并采用极化自氧化法获得纳米多孔/贵金属/纳米多孔氧化物复合材料; 研究极化电压、时间对氧化物成分、厚度及元素价态与分布的影响；探讨低表面扩散系数元素在极化自氧化过程中协调扩散机制；分析复合材料比电容、工作电位窗口和循环寿命与纳米多孔的比表面积、氧化物价态及配比、贵金属在复合结构中的分布等因素之间的内在联系，阐明实现优异比电容与高效导电性的最佳耦合机制，获得具有优异性能的赝电容电极材料，推动纳米结构材料在新能源领域的应用。

纳米多孔金属及其复合材料因其大的比表面积、高导电性等特点，而在能源、催化、传感等领域有广阔的应用前景。本项目着重研究了以ZrAlCo非晶合金为前驱体的纳米多孔结构及其复合材料的设计，系统研究了低表面扩散元素添加对纳米多孔结构的调控，分析纳米结构复合型电极材料比电容、循环寿命与纳米多孔的比表面积、过渡金属氧化物价态及配比等因素之间的内在联系，阐明实现优异电容特性机制，获得了具有优异性能的赝电容电极材料，推动纳米结构材料在新能源领域的应用。并对纳米多孔结构在催化及传感领域的应用进行了拓展研究,发现在脉冲方波的作用下，纳米多孔Co呈现出优异的电化学催化降解偶氮染料特性，可应用于工业有机污水的处理领域。ZrAlCo非晶合金前驱体阳极氧化获得的管状纳米多孔及其复合材料表现出优异的葡萄糖催化传感特性，可应用于无酶葡萄糖传感器。本项目从电极材料的成分及结构设计入手，研究前驱体成分、电化学性能及纳米结构电极材料的成分、结构与性能之间的内在关联，拓展了非晶合金及纳米多孔金属的应用领域。