Nanofiber-based Novel Electrode Architecture for Lithium-Air batteries

PI：Kalra，Vibha提议编号：1236466机构：Drexel University标题：基于纳米纤维的锂空气电池新型电极结构尽管最先进的锂离子电池最近取得了进展，但它们的能量和功率密度不足以满足交通应用。这个项目将研究一种新的电池化学，即锂-空气，它的理论能量密度可以比锂离子电池高出近两个数量级。然而，在锂空气电池的前景成为现实之前，一个需要克服的严峻挑战将是这项工作的重点是开发纳米结构空气正极？它优化了所有反应物(氧、锂离子和电子)到活性催化剂表面的传输，并为电池放电过程中固体锂氧化物产品的掺入提供了足够的空间。本方案的具体目标是在一种新型的、分级有序的纳米纤维结构中制备和研究工艺-结构-性能相关性，目的是开发高效的锂空气电池正极。将使用一种独特的三轴静电纺丝技术，允许核-壳结构通过简单的合成过程实现良好控制的定向材料组装。除了提供定义明确的多相反应表面外，所建议的电极设计还将显示分层的两级孔结构；从纤维间间距到电纺丝固有的大孔和中孔，这些孔将通过受控的纳米材料组装在碳芯中产生。这种结构将有助于优化氧气的质量传输和表面积，并提供足够的孔隙空间，以并入必要的固体放电产品，以最大限度地提高放电潜力。由于所提出的体系结构的复杂性，Pi？S的方法是首先独立地了解核壳纳米纤维各功能层的电纺行为和过程-结构相关性，然后利用这些知识来研究完整的体系结构。如果成功，这项工作将开发出比目前最先进的锂离子电池具有更高储能密度的电池。这种能力将使他们能够在运输领域成功竞争，并实现令人满意的行驶里程。此外，通过这项工作获得的材料加工、结构和电极设计方面的基础知识也将使超级电容器和其他电池化学制品受益。该项目将通过讲习班、基于研究的课程和实践研究经验，让1名博士研究生、几名本科生和K-12学生/教师，特别是女性和来自代表性不足的少数群体的学生/教师参与跨学科研究活动。

PI: Kalra, VibhaProposal Number: 1236466Institution: Drexel UniversityTitle: Nanofiber-based Novel Electrode Architecture for Lithium-Air batteries Despite recent advances in the state-of-the-art lithium ion batteries, their energy and power densities are insufficient for transportation applications. This project will examine a novel battery chemistry, namely, Lithium-air, which can exhibit a theoretical energy density of almost 2 orders of magnitude higher than lithium-ion batteries. However, before the promise of Li-air batteries can become a reality, a serious challenge that needs to be overcome and will be the focus of this work is the development of ?nanostructured air cathodes? that optimize transport of all reactants (oxygen, Li+ ions, and electrons) to the active catalyst surfaces and provide enough spaces for incorporation of solid lithium oxide products during battery discharge.The specific objective of this proposal is to fabricate and study process-structure-performance correlation in a novel, hierarchically-ordered nanofiber-based architecture with the aim to develop efficient cathodes for Li-air batteries. A unique triaxial electrospinning technique will be used that will allow core-shell architecture to achieve well-controlled directed material assembly via a simple synthesis procedure. In addition to providing well-defined multi-phase reaction surfaces, the proposed electrode design will exhibit a hierarchical two-level pore structure; macropores from inter-fiber spacing inherent to electrospinning and mesopores, which will be created in the carbon core via controlled nanoscale material assembly. This structure will help optimize oxygen mass transport and surface area and provide sufficient pore space for incorporation of solid discharge products necessary to maximize discharge potential. Owing to the complexity of the proposed architecture, PI?s approach is to first independently understand the electrospinning behavior and process- structure correlation in each of the functional layers of the core-shell nanofiber and then leverage these learnings to study the complete architecture. If successful, this work will develop batteries that possess significantly higher energy storage density than the current state-of-the-art Li-ion batteries. Such ability will allow them to successfully compete in the transportation sector and achieve a satisfactory driving range. In addition, the fundamental knowledge gained through this work on materials processing, structure and electrode design will also benefit supercapacitors and other battery chemistries. This project will involve 1 PhD graduate, several undergraduates and K-12 students/teachers, particularly females and those from under-represented minorities in interdisciplinary research activities via workshops, research-based course and hands-on research experiences.