Nanofiber-based Novel Electrode Architecture for Lithium-Air batteries

PI: Kalra， vibha提案号：1236466机构：德雷克塞尔大学标题：基于纳米纤维的新型锂空气电池电极结构尽管最近在最先进的锂离子电池方面取得了进展，但其能量和功率密度不足以用于运输应用。该项目将研究一种新的电池化学物质，即锂-空气，它的理论能量密度比锂离子电池高出近2个数量级。然而，在锂-空气电池的前景成为现实之前，需要克服的一个严峻挑战将是这项工作的重点。纳米结构空气阴极？优化所有反应物（氧、Li+离子和电子）到活性催化剂表面的传输，并在电池放电过程中为固体氧化锂产品的结合提供足够的空间。本提案的具体目标是在一种新颖的、层次有序的纳米纤维结构中制造和研究工艺-结构-性能的相关性，目的是开发锂空气电池的高效阴极。将使用一种独特的三轴静电纺丝技术，该技术将允许核-壳结构通过简单的合成程序实现良好控制的定向材料组装。除了提供定义良好的多相反应表面外，所提出的电极设计将呈现分层的两级孔结构；由静电纺丝固有的纤维间距产生的大孔和中孔，将通过可控的纳米级材料组装在碳芯中产生。这种结构将有助于优化氧质量运输和表面积，并提供足够的孔隙空间，以纳入必要的固体放电产物，以最大限度地提高放电潜力。由于所提议的体系结构的复杂性，PI？我们的方法是首先独立地了解核-壳纳米纤维每个功能层的静电纺丝行为和工艺-结构相关性，然后利用这些知识来研究完整的结构。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能量存储密度的电池。这样的能力将使他们能够在交通运输领域成功竞争，并达到令人满意的行驶里程。此外，通过这项工作获得的材料加工，结构和电极设计的基础知识也将有利于超级电容器和其他电池化学。该项目将包括1名博士研究生、几名本科生和K-12学生/教师，特别是女性和少数族裔学生/教师，通过研讨会、研究课程和实践研究经验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.