UNS: Ion transport in semicrystalline solid polymer electrolytes

#1510092 Li，Christopher虽然目前最先进的锂离子电池（LIB）已经广泛应用于消费电子产品中，但由于理论容量相对较低，它们无法满足诸如电动汽车、自主飞行器、等。通过用锂金属代替石墨作为阳极来制造锂金属电池，可以大大提高LIB的理论容量（LMB）。要实现LMB，最大的障碍是相关的火灾或爆炸危险。为了实现LMB的安全运行，需要具有良好的室温离子电导率和高剪切模量的固体聚合物电解质（SPE）。这项研究的目的是了解半结晶SPE的能量器件应用中的离子输运机制。所提出的半结晶SPE可能是制造下一代安全LMB的可行候选物。 在这个建议中，通过对过去四十年的SPE研究的批判性分析，一个被忽视的问题，在SPE中的结晶形态对离子电导率的影响的详细机制已被提出。为了回答这个具有挑战性的问题，PI提出了一系列具有精确控制的晶体尺寸，取向和链折叠的半结晶SPE。这种新的方法，第一次，在SPE中的离子输运的internapolites结构（曲折）和动态（拴链限制）的影响。它还表明，曲折度与结晶形态起着至关重要的作用，在半结晶SPE的离子输运。拟议的研究将为能源设备应用设计SPE提供一种新的策略：与现有SPE相比，所提出的具有受控晶体形态和取向的半结晶SPE是有利的，因为结晶聚合物比无定形橡胶聚合物机械强度高3-4个数量级，内禀两相模型与半结晶SPE相关的（结晶和非结晶）解决了两个性能测量的需要，机械性能和高离子电导率。 这项研究旨在解决能源研究领域的一个具有挑战性的问题。如果成功，该项目将导致一种新型的SPE，使锂金属电池能够安全运行，这是能源研究界面临的巨大挑战。这些拟议的教育活动具有广泛的影响。首先，拟议的计划将有助于弥合教育发展水平之间的现有差距，通过一些指导方案使高中学生和教师参与研究活动。第二，由于费城地区代表性不足的群体人口众多，拟议的外联方案将专门针对鼓励代表性不足的人口的参与。第三，将通过科学媒体和公共讲习班宣传拟议的研究。这一信息的传播沿着中学教师的实践经验，将使更多的教师能够通过与费城周边地区的学区建立合作努力来教育未来。

#1510092Li, ChristopherAlthough the current state-of-the-art lithium ion batteries (LIBs) have been widely used in consumer electronics, because of the relatively low theoretical capacity, they cannot meet the need of applications such as electrical vehicles, autonomous aircrafts, etc. The theoretical capacity of LIBs can be greatly improved by replacing graphite with lithium metal as the anode to fabricate a lithium metal battery (LMB). To materialize LMB, the biggest obstacle is the associated fire or explosion hazards. In order to achieve safe operation for LMB, solid polymer electrolytes (SPEs) with good room temperature ionic conductivity and high shear modulus are needed. The goal of this proposed research is to understand the ion transport mechanism in semicrystalline SPEs for energy device applications. The proposed semicrystalline SPEs could be a viable candidate for fabricating next generation safe LMBs. In this proposal, through critical analysis of the past four decades of research on SPE, an overlooked question regarding the detailed mechanism of the crystalline morphology effect on ionic conductivity in SPEs has been raised. To answer this challenging question, the PI proposes a series of semicrystalline SPEs with precisely controlled crystal size, orientation, and chain folding. This novel approach, for the first time, decouples the intertwine structural (tortuosity) and dynamic (tethered chain confinement) effects on ion transport in SPE. It also demonstrates that tortuosity associated with crystalline morphology plays a critical role on ion transport in semicrystalline SPEs. The proposed research will provide a new strategy to design SPEs for energy device applications: Compared with existing SPEs, the proposed semicrystalline SPE with controlled crystal morphology and orientation is advantageous because crystalline polymer is mechanically 3-4 orders of magnitude stronger than amorphous rubbery polymers, the intrinsic two-phase model (crystalline and amorphous) associated with semicrystalline SPE addresses the needs for two performance measures, the mechanical properties and the high ionic conductivity, respectively. The proposed research aims to tackle a challenging problem in the energy research field. If successful, the project will lead to a new type of SPEs, which enables safe operation of lithium metal batteries, a grand challenge facing the energy research community. These proposed educational activities encompass a broad impact. First, the proposed plan will help bridge the existing gap between levels of educational developments by involving high school students and teachers in research activities through a number of mentoring programs. Second, due to the high population of under-represented groups in the Philadelphia region, the proposed outreach program will be specifically geared towards encouraging the participation of under-represented populations. Third, the proposed research will be publicized through scientific media and public workshops. The dissemination of this information along with hands-on experiences for secondary education teachers will result in more informed teachers capable of educating the future by establishing collaborative efforts with school districts in the surrounding Philadelphia region.