Carbon Nanotube Based Textiles for Energy Storage Applications

解决储能系统的经济性、技术性能和设计问题需要先进的材料研究和开发。材料选择将在使存储技术负担得起，高效和可靠的选择中发挥重要作用，以应对日益增长的能源需求及其通过可再生能源的产生。目前的电池技术无法与现有能源（如汽油）的能量密度相竞争。为了在市场上与汽油汽车竞争，电动汽车（EV）中电池的能量密度必须大大提高，以使长距离EV能够广泛负担得起。此外，尽管便携式电子设备变得越来越小和灵活，但当涉及到小尺寸和高灵活性的性能时，能量管理组件往往落后于其他组件。另一个需要创新储能技术的应用领域是军事应用。将电池集成到纺织品中可以将军服变成“智能织物”，为制服提供单一电源，以确保军事行动的效率和效力。因此，提案中概述的研究将集中在推进用于储能应用的多功能碳纳米管（CNT）纺织品的科学和技术上。特别关注锂空气（Li-air）电池阴极结构的优化和全纺织柔性电化学双层超级电容器（SC）的开发。该项目开发的新型二维和三维（2D和3D）纺织品将分别基于湿纺工艺和干纺工艺制成的CNT纤维和纱线。纤维将被合股、扭曲和纹理化，以形成具有广泛机械结果的几种几何形状。将纤维捻成纱线，然后将纱线针织或编织成织物，将有助于形成具有多功能孔隙率和超高比表面积的良好限定的多孔结构，从而为能量储存提供高导电性、低密度的支架。所获得的理解和由此产生的器件性能改进可以促进碳纳米管的多种应用：储存能量的电子纺织品和具有无与伦比韧性的纤维。当与用于CNT合成的廉价工艺相结合时，用于制造连续、高性能CNT纤维的实用工艺可能会为老化的纤维工业带来重要的新产品。在锂空气电池成为高性能、商业上可行的产品之前，仍有许多科学和技术挑战必须克服。在制备用于在放电过程中在阴极处沉淀过氧化锂的结构中面临相当大的困难。如果阴极空气电极完全堵塞，则无法还原来自大气的O2，这将阻止电池运行。该提案的一个里程碑是开发和制造新的纳米结构空气阴极，其由以织物形式分层排列的CNT纤维组成，以便优化所有反应物向活性催化剂表面的运输，并为固体氧化锂产品提供适当的空间。预计该项目还将大大提高太阳能电池的能量/功率密度。尽管SC已经用于许多领域，但从可结合到服装中的可穿戴能量到空间应用的大量应用需要具有更大能量密度的更轻、更紧凑和机械柔性的能量存储装置。

Addressing energy storage system economics, technical performance, and design issues requires advanced materials research and development. Material selection will play an essential role in making storage technologies affordable, efficient, and reliable options for tackling the increasing demand for energy and its generation via renewables-based sources. Current battery technology cannot compete with energy densities associated with existing sources such as petrol. In order to compete in the market with petrol-based vehicles, the energy density of batteries in electric vehicles (EVs) will have to greatly improve to enable long-range distance EVs widely affordable. Moreover, despite portable electronic devices becoming increasingly small and flexible, the energy management components tend to lag behind the other components when it comes to performance at small size and high flexibility. Another application area that requires innovative energy storage technologies is for military applications. Batteries integrated into textiles could turn military uniforms into "smart fabrics" providing uniforms with a single power source to ensure efficiency and effectiveness of military operations. Thus, the research outlined in the proposal will be focused on advancing the science and technology for multifunctional carbon nanotube (CNT) textiles for energy storage applications. Particular focus will be placed on the optimization of the cathode structure of Lithium-air (Li-air) batteries and the development of all-textile flexible electrochemical double layer supercapacitor (SC). The novel two- and three-dimensional (2D and 3D) textiles developed during this project will be based on CNT fibers and yarns made by a wet-spinning process and a dry-spinning process respectively. Fibers will be plied, twisted and textured to form several geometries with a wide range of mechanical outcomes. Twisting fibers into yarns and then knitting or weaving the yarns into a fabric will facilitate the formation of well defined porous structures with versatile porosity and ultra-high specific surface area providing a highly conductive, low density scaffold for energy storage. The gained understanding and resulting improvements in device performance could facilitate diverse applications of CNTs: electronic textiles that store energy and fibres having unrivalled toughness. When coupled with an inexpensive process for CNT synthesis, a practical process for making continuous, high performance CNT fibres is likely to result in important new products for an aging fibre industry. Before Li-air batteries can be realized as high-performance, commercially viable products there are still numerous scientific and technical challenges that must be overcome. Considerable difficulties are faced in preparing structures for the precipitation of lithium peroxide at the cathode in the discharge process. If the cathode air electrode is fully blocked, the O2 from the atmosphere cannot be reduced which will prevent battery operation. One milestone for this proposal is to develop and fabricate new nanostructured air cathodes consisting of hierarchical arrangement of CNT fibers in a textile form so as to optimize transport of all reactants to the active catalyst surfaces and provide appropriate space for solid lithium oxide products. It is also anticipated that the project will substantially enhance the energy/power densities of SCs. Although SCs are already used in many fields, more lightweight, compact and mechanically flexible energy storage devices with greater energy densities are required for a significant number of applications from wearable energy that could be incorporated into garments to space applications.