UNS: Mechanistic Approach to Design Robust Composite Polymer Cathodes for Potassium-Air Batteries

UNS：设计用于钾空气电池的坚固复合聚合物阴极的机械方法

• 批准号: 1512405
• 负责人: Vishnu Baba Sundaresan
• 金额: $ 30万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1512405&HistoricalAwards=false
• 关键词: UNS; Mechanistic; Approach; Design; Robust

PI: Vishnu-Baba SundaresanProposal Number: 1512405Rechargeable batteries support the development of sustainable energy systems by storing electricity generated by renewable resources such as wind and solar energy, or by powering zero-emission electric vehicles charged by electricity from renewable resources. However, lithium ion batteries now in use have relatively low energy storage capacity. Metal-air batteries offer the potential for much higher energy storage capacity than lithium-ion batteries because they store electrical charge by a different process that uses oxygen in air to help transfer electrons. But this process can also increase charging times. Of the metal-air batteries, the potassium-air system is among the fastest, but is prone to failure. The goal of this project is develop a fundamental understanding of the mechanism of failure, and then use this understanding to develop a new cathode design based on conducting polymers that provides better control of oxygen atom transport. In this way, potassium-air battery systems can move forward towards eventual commercial application. As part of this research, graduate and undergraduate students will be given the skills to further develop metal-air battery systems. The principal investigators will also organize workshops on energy storage materials and smart materials to promote STEM education among middle and high school age students in greater Columbus, Ohio area. Metal-air batteries offer the potential for high electrochemical energy storage capacity that exceeds that of comparable metal ion batteries. Of the metal-air batteries, the potassium-air system uses a one-electron redox process between oxygen and superoxide to improve upon the low rates of oxygen reduction/evolution associated with other metal-air battery systems. However, the fundamental limitation of potassium-air batteries is the crossover of molecular oxygen from the cathode to potassium anode, leading to the formation of potassium superoxide on the anode surface. This process causes self-discharge and reduces the availability of metal that can participate in energy storage. The goal of the proposed research is to investigate the feasibility of a composite cathode formed from conducting polymers and carbon support materials to regulate the oxygen reduction reaction in the cathode and prevent the diffusion of molecular oxygen to the anode. The conducting polymer is a functionally graded, nanostructured polypyrrole membrane with an optimized density of redox sites, and the carbon support material is reduced graphene oxide. An electropolymerization process will be used to make the membrane so that the porosity of the cathode gradually decreases across the thickness of the membrane. It is hypothesized that the graded porous structure will block molecular oxygen crossover, thereby enhancing the performance lifetime of the potassium-air battery. The proposed research plan will develop a mechanistic understanding of charge storage of the conducting polymers within the composite cathode that accounts for mechanical stress, diffusion of gases, and electrochemical reduction reactions during faradaic processes. As part of this plan, the chemo-mechanical coefficients that relate volumetric stress generated in conducting polymers and well as their application for increasing the energy density and specific power of potassium-air batteries will be quantified. The research plan has four specific tasks: 1) electrochemical synthesis of the functionally graded, nanostructured polypyrrole membrane; 2) characterization of this membrane as the cathode for a potassium-air electrochemical cell; 3) construction of potassium-air battery containing the conducting polymer composite cathode, and 4) battery performance measurements (capacity, power, cycling). The research outcomes will advance a more generic and mechanistic understanding of energy storage and conversion in conducting polymers for metal-air battery systems, and concepts derived from the research will be introduced into an energy storage materials course.

主要研究者：Vishnu-Baba SundaresanProposal编号：1512405可充电电池通过储存风能和太阳能等可再生资源产生的电力，或为零排放电动汽车提供动力，这些汽车由可再生资源的电力充电，从而支持可持续能源系统的发展。 然而，现在使用的锂离子电池具有相对低的能量存储容量。 金属空气电池提供了比锂离子电池更高的储能容量，因为它们通过不同的过程存储电荷，该过程使用空气中的氧气来帮助转移电子。 但这个过程也会增加充电时间。 在金属-空气电池中，钾-空气系统是最快的，但容易出现故障。 该项目的目标是对失效机制有一个基本的了解，然后利用这种了解开发一种基于导电聚合物的新阴极设计，以更好地控制氧原子的传输。 通过这种方式，钾空气电池系统可以朝着最终的商业应用迈进。 作为这项研究的一部分，研究生和本科生将获得进一步开发金属空气电池系统的技能。主要研究人员还将组织关于储能材料和智能材料的研讨会，以促进俄亥俄州大哥伦布地区初中和高中学生的STEM教育。金属-空气电池提供了超过可比金属离子电池的高电化学能量存储容量的潜力。 在金属-空气电池中，钾-空气系统使用氧和超氧化物之间的单电子氧化还原过程，以改善与其他金属-空气电池系统相关的低氧还原/放出速率。 然而，钾-空气电池的根本限制是分子氧从阴极到钾阳极的跨越，导致在阳极表面上形成超氧化钾。 这一过程会导致自放电，并降低了可以参与储能的金属的可用性。该研究的目的是研究由导电聚合物和碳支撑材料形成的复合阴极的可行性，以调节阴极中的氧还原反应并防止分子氧扩散到阳极。 导电聚合物是具有优化的氧化还原位点密度的功能梯度的纳米结构聚吡咯膜，并且碳载体材料是还原的氧化石墨烯。 将使用电聚合工艺来制造膜，使得阴极的孔隙率在膜的厚度上逐渐减小。 据推测，梯度多孔结构将阻止分子氧交叉，从而提高钾-空气电池的性能寿命。 拟议的研究计划将开发一个机械的理解的电荷存储的导电聚合物内的复合阴极，占机械应力，气体的扩散，和电化学还原反应在法拉第过程。作为该计划的一部分，将量化与导电聚合物中产生的体积应力相关的化学机械系数及其在提高钾空气电池的能量密度和比功率方面的应用。 该研究计划有四个具体任务：1）功能梯度，纳米结构聚吡咯膜的电化学合成; 2）该膜作为钾-空气电化学电池阴极的表征; 3）含有导电聚合物复合阴极的钾-空气电池的构建;以及4）电池性能测量（容量，功率，循环）。 研究成果将促进对金属-空气电池系统导电聚合物中能量储存和转换的更一般和更机械的理解，并且从研究中得出的概念将被引入储能材料课程。