Nanostructured Electrode Materials for Electrochemical Supercapacitors

该赠款为电化学超级电容器的几种纳米结构电极的制造和表征提供资金，这些电极超过了目前实现的储能容量，并显示出高充电/放电速率。这些电极基于过渡金属氧化物并且由四种不同的纳米结构组成：（1）均匀尺寸和单向排列的氧化物纳米棒阵列（垂直地站立在导电基底上），（2）氧化物纳米管阵列，（3）金属-氧化物核-壳纳米电缆阵列，和（4）碳晶胶-氧化物纳米复合物。本研究将以五氧化二钒为模型体系，系统研究结晶度、纳米结构和掺杂对插层容量和充放电动力学的影响。核-壳纳米电缆阵列和碳冻凝胶-氧化物纳米复合材料具有双层超级电容器和电化学赝电容器特性，因此有望显著增强性能。碳低温凝胶-氧化物纳米复合材料的特征在于三维能量存储和释放过程，而传统的电化学电容器本质上是二维系统。存储在三维电极结构中的能量大于传统电容器中的能量。其他过渡金属氧化物包括复合氧化物、掺杂氧化物和非晶氧化物也将被探索用于进一步增强超级电容器性能。 如果成功，这项研究将导致开发具有高储能容量和快速充电/放电速率的纳米结构电极，并改善循环电阻。此外，还将开发新的制造方法，通过精心设计纳米结构或微观结构以及精确控制成分来增强材料性能。该研究将导致对制造、结构、组成、性质和性能之间的关系有更好的基本理解。该研究还将通过简单地利用纳米结构和纳米材料中的巨大表面积和改进的传输动力学来拓宽纳米结构和纳米材料的应用，而不会改变与散装材料相关的物理性质。这项工作的好处还包括教育研究生和本科生，吸引他们进入能源相关材料开发和纳米制造技术领域，从而帮助我们的国家不仅在今天而且在未来保持在这一战略领域的领先地位。

This grant provides funding for the manufacturing and characterization of several nanostructured electrodes for electrochemical supercapacitors that exceed currently achieved energy storage capacity and display high charge/discharge rates. These electrodes are based on transition metal oxides and consist of four different nanostructures: (1) uniformly sized and unidirectionally aligned oxide nanorod arrays (perpendicularly standing on conductive substrate), (2) oxide nanotube arrays, (3) metal - oxide core-shell nanocable arrays, and (4) carbon cryogel - oxide nanocomposites. This research will take vanadium pentoxide as a model system to systematically study the influences of crystallinity, nanostructure and doping on intercalation capacity and charge/discharge kinetics. Core-shell nanocable arrays and carbon cryogel-oxide nanocomposites have both double layer supercapacitor and electrochemical pseudocapacitor characteristics, and thus promise significantly enhanced performance. The carbon cryogel-oxide nanocomposite is characterized by three-dimensional energy storage and release processes, while conventional electrochemical capacitors are inherently two dimensional systems. The energy stored in a three-dimensional electrode structure is larger than that in conventional capacitors. Other transition metal oxides including complex oxides, doped oxides, and amorphous oxides will also be explored for further enhancement of supercapacitor performance. If successful, this research will lead to the development of nanostructured electrodes with high energy storage capacity and fast charge/discharge rate with improved cyclic resistance. Additionally new manufacturing methods will be developed for the enhancement of material properties by careful design of nanostructures or microstructures and by precise control of composition. The study will result in a better fundamental understanding of the relationships between manufacturing, structure, composition, properties, and performance. The research will also broaden the application of nanostructures and nanomaterials by simply capitalizing the huge surface area and improved transport kinetics in nanostructures and nanomaterials without altering the physical properties associated with bulk materials. The benefit of this work also includes educating graduate and undergraduate students and attracting them into the field of energy related materials development and nanomanufacturing technology, and thus helping our nation stay in a leading position in this strategic field not only today but also in the future.