EAGER: Continuous, Catalyzed Thermopower Wave Generators Powered by Renewable Biofuels: A New Fuel Cell Concept

strano, Michael s .技术基础便携式能量存储和传输是现代运输系统和便携式电子设备扩散的基石，是一个快速发展的领域。此外，最新的自主和移动传感器、机器人和离网无线网络的发展，特别是在微纳米尺度上，经常受到缺乏类似尺寸的高功率密度能量系统的阻碍。当今的每一种便携式能源技术都有其独特的缺点。电池是人们最熟悉的电能储存形式，但与储存在燃料化学键中的能量相比，电化学能量密度从根本上是有限的。此外，多年来电池会慢慢失去电量，这使得它们不太适合长期储存能量。超级电容器提供了更高的功率密度（在重量和体积方面），但以能量密度为代价。此外，它们甚至不能像电池一样长时间充电。燃料电池和发动机可以使用化学燃料的高能量密度，但在小范围内制造起来更复杂，因此它们的功率密度到目前为止是有限的。麻省理工学院的迈克尔·斯特拉诺教授已经对一种替代能源装置进行了一些初步研究，这种装置提供了取代这些现有装置的可能性。基于热电波的能量装置可以将便携式功率装置的能量密度显著提高10倍以上，并具有零存储损耗和电荷衰减等其他优点。高导电性支架，如碳纳米管（CNTs），沿着其长度引导热化学反应波；这种波还推动电荷载体产生高功率的脉冲电流。根据斯特拉诺的说法，这种快速波意味着热电波通常可以在功率密度方面优于使用静态热梯度的传统热电，并且可能没有相同的效率限制（通常约为1-5%）。要测试的概念是是否可以制造出热电燃料电池，这种电池可以持续发电；以前的设备只能产生短于一秒的电脉冲。本项目介绍了在碳纳米管热电管道中添加金属催化剂纳米颗粒的新方面。通过专注于生物衍生的甲酸和甲醇等燃料，这些发电机可以使用可再生能源。这是一个理想的EAGER项目，因为必须成功地展示几个高风险方面。首先，使用甲酸和甲醇的波传播必须使用低到中等活性的催化材料来证明它们沿着热管材料的长度分解，包括碳纳米管纤维、无机纳米线或石墨烯薄膜。对这些波的理论认识的进步将伴随着这一努力。催化剂的选择必须优化活化能；太低的话，燃料就会自发反应而不受纳米管的控制；太高的话，所需的起始能量就会太大，从而降低效率。液体燃料twg要实用，更常见的金属，如Au、Fe或Cu必须是活性催化剂金属。除此之外，目标将是制造一个工作装置并证明延长的使用寿命。这显然是为EAGER奖项所设想的高风险-高潜在回报项目。对于这个项目，PI打算利用本科生和研究生的研究人员，作为促进工程多样性的一种手段。PI指出，组成这个项目的实验似乎非常适合本科生，他们适应并快速学习如何制备热电波基板，并学习如何使用仪器。PI过去曾与大量本科生广泛合作，其中许多是性别和种族少数群体。在一个短暂的EAGER项目中发展这些方面是困难的，因此PI在这方面的努力值得赞扬。

Abstract#1239073Strano, Michael S.Technical BasisPortable energy storage and delivery is the cornerstone of modern transportation systems and the of the proliferation of portable electronic devices and is a rapidly growing field. Additionally, the development of the newest autonomous and mobile sensors, robots, and off-grid wireless networks, particularly at the micro- and nanoscale, is often hampered today by the lack of high power density energy systems of similar size. Each of todays portable energy technologies has its distinct shortcomings. Batteries are the most familiar form of electrical energy storage, but electrochemical energy density is fundamentally limited compared to storing energy in the chemical bonds of fuels. In addition, batteries slowly lose their charge over years, making them less desirable for long-term energy storage. Supercapacitors offer substantially higher power density (in weight and volume terms), but at the expense of energy density. Moreover, they cannot hold their charge even as long as batteries. Fuel cells and engines can use the large energy density of chemical fuels but are more complicated to fabricate at the small scale, so their power density has been limited so far. Professor Michael Strano of the Massachusetts Institute of Technology has performed some initial studies on an alternative energy device that offers the possibility of supplanting these existing devices.Thermopower wave based energy devices may dramatically increase the energy density of portable power devices more than a factor of 10, with other advantages such as zero storage losses and charge decay. High-conductivity scaffolds, like carbon nanotubes (CNTs), direct a hot chemical reaction wave along their length; the wave also pushes charge carriers to create a high-power pulse of electricity. This fast wave means that thermopower waves can often outperform conventional thermoelectrics using static thermal gradients in terms of power density and may not have the same limits on efficiency (usually about 1-5%)according to Strano. The concept to be tested is whether thermopower fuel cells can be created, which could be operated to generate power continuously; previous devices could only make electrical pulses shorter than a second. This project introduces the new aspect of the addition of metal catalyst nanoparticles to the CNT thermoelectric conduits. By focusing on fuels like formic acid and methanol that can be biologically derived, these generators can use renewable energy sources. This is an ideal EAGER project in that several high risk aspects must be successfully demonstrated. First, wave propagation using formic acid and alternatively methanol must be demonstrated using low- to medium-activity catalytic materials for their decomposition along the length of thermal conduit materials, including carbon nanotube fibers, inorganic nanowires, or grapheme films. Advances in theoretical understanding of these waves will accompany this effort. The choice of catalyst(s) must optimize the activation energy; too low and the fuel will react spontaneously without being controlled by the nanotubes, too high and the required initiation energy will be too large, sapping the efficiency. For liquid-fueled-TWGs to be practical, more common metals like Au, Fe, or Cu must be the active catalyst metal. Beyond this, a target would be to fabricate a working device and demonstrate extended operating life. This is clearly the high risk-high potential return project envisioned for EAGER awards. Broader Impacts For this project, the PI intends to utilize undergraduate and graduate researchers, as a means of fostering diversity in Engineering. The PI notes that the experiments that make up this project seem to be well suited for undergraduates, who adapt and learn quickly how to prepare thermopower wave substrates, and learn how to use the instrumentation. The PI has extensively worked with a large body of undergraduate students in the past, many of whom are gender and racial minorities. It is difficult to develop these aspects in a short EAGER project, so the PI is to be commended for making this effort.