Continuous, Roll-to-Roll Manufacturing and Assembly of Yeast-derived Carbon Nanotube-based Lithium-Sulphur Batteries

在便携和移动电子产品的世界里，用于电能存储的电池已经无处不在。然而，目前的锂离子电池技术存在几个关键的局限性，如成本高、储能密度有限、耐久性差以及对环境的严重影响。这些缺点限制了许多重要的新兴技术的可行性，例如电动汽车和可再生能源发电系统的非峰值存储。基于锂硫（li -硫）化学的电池理论上可以实现比传统锂离子（Li-ion）电池高6倍的能量密度，但通常只有100次充电循环的寿命。该奖项研究的是制造锂硫电池电极的新方法，这种电池具有长寿命且价格合理。初步结果表明，电池阴极可以通过小麦面团的高温碳化制造多孔碳网络。由此产生的碳泡沫结构被碳纳米管覆盖，这使得硫纳米颗粒的密集负载能够增加能量容量。多孔碳/碳纳米管支架结构防止了活性硫材料的降解，延长了电池的耐用性，超过4000次循环。电池组件通过可扩展、连续和高通量的低成本前体组装，这也有助于提高环境的可持续性。本研究为储能器件的设计和纳米制造提供了新的范例。这些研究进展通过有针对性的课程、研讨会和出版物传播给K-12、本科生和研究生以及公众。该项目的研究目标是解决关键技术和工程障碍，以实现高通量制造具有极高能量和功率密度以及超长寿命的电池。这种方法是从一种现成的、低成本的、环保的材料，特别是小麦面团中提取电极材料。该项目解决了诸如严重的容量退化、不完全的硫利用以及电化学反应过程中可溶中间体严重的“穿梭效应”等研究空白。研究活动的特点是系统级的重点跨越(1)介孔活性炭/碳纳米管支架的合成，(2)开发的锂- s电池阴极的卷对卷制造，以及(3)电极材料的结构和力学表征，以评估结构对电池降解的作用。这项工作的主要贡献是通过将硫纳米颗粒嵌入高导电性的活性炭/碳纳米管支架中来提高硫阴极的有效导电性，并研究该结构如何通过抑制“穿梭效应”和限制反应体积变化来阻碍电极降解。研究了以小麦面团为原料，在碳化酵母上一步合成碳纳米管的基本机理。设计了用于生产高性能锂电池的自动卷对卷制造工艺的原型。

Batteries for electrical energy storage have become ubiquitous in a world of portable and mobile electronics. However, current lithium-ion battery technology suffers from several key limitations, such as, high cost, limited energy storage density, poor durability, and severe environmental impact. These shortcomings limit the viability of many important emerging technologies, such as electric vehicles and off-peak storage for renewable energy generation systems. Batteries based on a lithium-sulphur (Li-S) chemistry can theoretically achieve energy densities six times greater than conventional lithium-ion (Li-ion) batteries but have typical lifetimes of only 100 recharge cycles. This award studies new approaches to the manufacture of electrodes for lithium-sulphur batteries that have long lifespan and are affordable. Preliminary results have demonstrated that a battery cathode can be manufactured by high temperature carbonization of wheat dough creating a porous carbon network. The resulting carbon foam structure is covered with carbon nanotubes, which enables a dense loading of sulphur nanoparticles to increase energy capacity. The porous carbon/carbon nanotube scaffold structure prevents the degradation of the active sulphur material, extending the durability of the battery to over 4000 cycles. The battery components are assembled through a scalable, continuous, and high-throughput process from low-cost precursors, which also contributes to improved environmental sustainability. This research develops new paradigms for design and nanomanufacturing of energy storage devices. These research advances are disseminated to K-12, undergraduate, and graduate students, as well as the general public through targeted courses, seminars, and publications.The research objective of the project is to address key technological and engineering barriers to achieving high-throughput manufacturing of batteries with exceptionally high energy and power densities and ultra-long lifespan. The approach is to derive electrode materials from a readily available, low cost, environmentally-benign material, specifically, wheat dough. The project addresses research gaps such as severe capacity degradation, incomplete sulfur utilization, and the severe 'shuttle effect' of dissolvable intermediates during the electrochemical reaction process. Research activities feature a systems-level focus spanning (1) synthesis of the mesoporous activated carbon/carbon nanotube scaffolds, (2) roll-to-roll manufacturing of the developed cathode into Li-S batteries, and (3) structural and mechanical characterization of electrode materials to evaluate the role of structure on battery degradation. The primary contributions of this work are to improve the effective conductivity of the sulphur cathode by embedding sulphur nanoparticles within a highly-conductive activated carbon/carbon nanotube scaffold and to study how the structure impedes electrode degradation by inhibiting the 'shuttle effect' and limiting reaction volume changes. The fundamental mechanism of the one-step synthesis of carbon nanotubes on carbonized yeast from wheat dough is determined. A prototype automated roll-to-roll manufacturing process is devised to produce high-performance Li-S batteries.