Multifunctional solid polymer electrolytes for all-solid-state batteries

锂离子电池存在于许多日常使用的设备中，如智能手机、笔记本电脑和平板电脑、无线工具和电动汽车。然而，这些电池存在安全问题，因为这些设备的故障可能会导致火灾。为了安全高效地运行，锂离子电池组件对离子导电性、电化学稳定性、机械坚固性、加工性和阻燃性等提出了许多要求。在这个研究项目中，研究人员将使用一个可调的化学平台来满足这些同时的要求。该电池系统包括由链状分子粘合在一起形成高度连接的支架的聚合物网络基座。该系统还包括由从网络支架上延伸出来的聚合物组成的梳状结构。可以将稳定剂或阻燃剂等其他组件添加到梳子的末端，以赋予系统相应的性能。通过改变网络支架的结构或组成，调查人员将研究如何改变材料属性，以优化系统的整体性能。利用在这个项目中学到的概念，参与者将为纳米结构聚合物材料课程开发两个课程模块。此外，高中学生和教师，特别是来自STEM领域中代表性不足的群体，将通过Drexel项目的夏季工程体验参与研究活动。在这个研究项目中，研究人员旨在设计、合成和实现一系列多功能和多功能的梳链交联剂网络固体聚合物电解质(ConSPE)。多功能性元素来自链和交联剂末端的大量官能团，这些官能团提供了快速的交联剂和添加更多组分的机会。使用该平台，研究人员将调整网络化学、体系结构、机械和电化学性质，以满足高性能电解液的需求。具体地说，将添加组分以针对给定的、所需的固体电解质性能。例如，聚碳酸亚丙酯可以改善材料的电压稳定性和迁移数，而接枝的卤代部分则可以改善材料的阻燃性能、固体电解质界面的形成和循环性能。研究人员将使用振荡剪切和经典拉伸力学测量来表征材料，并将通过原子力显微镜使用定量纳米机械作图来评估依赖于小长度尺度的机械性能。电化学表征包括电化学阻抗测定的离子导电性和循环伏安测定的循环稳定性。在建立了ConSPE材料的资料库后，研究人员将选择两种不同的材料，并将它们组合成双层结构。这种非对称双层材料可能比均匀材料更有能力满足固体电解质面向阳极和面向阴极的不同要求。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Lithium ion batteries are found in many daily use devices such as smartphones, laptop and tablet computers, cordless tools, and electric vehicles. However, there are safety concerns about these batteries, because failure in these devices can lead to a fire. For safe and efficient operation, lithium ion battery components have many requirements such as ionic conductivity, electrochemical stability, mechanical robustness, processability and fire retardance. In this research project, the investigators will use a tunable chemical platform to address these simultaneous requirements. This battery system includes a polymer network base that is made of chain-like molecules bonded together to form a highly connected scaffold. The system also includes comb-like structures that consist of polymers extending off the network scaffold. Additional components, such as stabilizers or fire retardants, can be added to the end of the combs to impart the corresponding properties to the system. By changing the structure or composition of the network scaffold, the investigators will study how the material properties can be altered to optimize the overall performance of the system. Using the concepts learned during this project, the participants will develop two class modules for a course on nanostructured polymeric materials. Additionally, high school students and teachers, particularly from groups under-represented in STEM fields, will be involved in the research activities via the Summer Engineering Experience at Drexel Program.In this research project the investigators aim to design, synthesize, and implement a series of multifunctional and versatile comb-chain crosslinker based network solid polymer electrolytes (ConSPEs). The versatility element comes from the large number of functional groups found on the ends of the chains and cross-linkers, which provide fast cross-linking and an opportunity to add further components. Using this platform the investigators will tune network chemistry, architecture, mechanical and electrochemical properties to address the high performance electrolyte needs. Specifically, components will be added to target a given, desired solid electrolyte property. For example, poly(propylene carbonate) would improve voltage stability and transference number, while grafted halogenated moieties would improve fire retardance, solid electrolyte interface formation and cycling performance. The investigators will characterize the materials using oscillatory shear and classical tensile mechanical measurements, and small-length scale dependent mechanical properties will be assessed using quantitative nanomechanical mapping via atomic force microcopy. Electrochemical characterizations include ion conductivity via electrochemical impedance and cycling stability via cyclic voltammetry. After establishing a library of ConSPE materials, the investigators will select two differing materials and combine them into bilayer structures. Such asymmetric bilayer materials might be more capable than a uniform materials of meeting the different requirements of the anode- and cathode-facing sides of the solid electrolyte.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.