Collaborative Research: SusChEM: Perfluoroether-based Polymer Electrolytes for Lithium Batteries

Nitash Balsara/Joseph DeSimone 1505669/1510579尽管电动和混合动力汽车有潜力减少对化石燃料的运输依赖，但目前为它们提供动力的可充电锂电池存在许多问题。目前的设计可以容纳10%的理论能量含量，含有高度易燃的有机液体电解液，相对昂贵，而且寿命不如典型的汽车。需要新的电池材料来解决这些问题。该项目的目标是为不含易燃成分的锂电池开发高性能电解液，潜在地提高安全性。这些电解液将基于不可燃的氟化聚合物，旨在溶解锂离子并保持高离子导电性，以提高充放电速度。这项拟议的研究将制造和测试这些用于电池应用的新聚合物材料，并试图了解其性能背后的基础科学。与该项目相关的拟议教育活动包括为奥克兰-伯克利地区未得到充分服务的高中生举办工程夏令营，该夏令营的特色是与锂电池有关的动手项目。拟议研究的总体目标是开发用于锂电池的全氟聚醚(PFPE)基电解液。人们认为这种材料是一种很有前途的新电解液，主要有两个原因。首先，全氟聚乙烯材料是一类本质上不可燃的含氟聚合物，具有低蒸汽压以及热稳定性、化学稳定性和氧化稳定性。其次，对于锂离子电池应用，基于PFPE的电解液还可以将锂盐与含氟阴离子溶解。由于PFPE材料的玻璃化转变温度较低，以及含氟聚合物对含氟阴离子的溶剂化作用使阴离子固定在聚合物上，该电解质体系具有以分子锂离子(Li+)传输为主的高电导率。这项研究将合成功能化的全氟聚醚和锂盐，表征这些电解液的电化学性质，并在电化学储能测试装置中评估它们的离子传输和循环性能。选定的研究成果将用于支持一家初创公司的发展，并为参与该项目的学生提供创业培训。与加州大学伯克利分校的专业发展计划和研究三角电化学学会学生分会协调，还计划开展更多的教育和外展活动。

Nitash Balsara / Joseph DeSimone 1505669 / 1510579 Although electric and hybrid vehicles have the potential to reduce dependence on fossil fuels for transportation, the rechargeable lithium batteries that currently power them suffer from many problems. Current designs can hold 10% of their theoretical amount of energy content, contain highly flammable organic liquid electrolytes, are relatively costly, and do not last as long as a typical automobile. New battery materials are needed to address these problems. The objective of this project is to develop high-performance electrolytes for lithium batteries that have no flammable components, potentially leading to improved safety. These electrolytes will be based on nonflammable fluorinated polymers designed to dissolve lithium ions and maintain high ion conductivity for improved charging and discharging rates. The proposed research will make and test these new polymer materials for battery applications, and try to understand the fundamental science underlying their performance. The proposed educational activities associated with this project include an engineering summer camp for underserved high school students in the Oakland-Berkeley area that features hands-on projects related to lithium batteries. The overall goal of the proposed research is to develop perfluoropolyether (PFPE)-based electrolytes for lithium batteries. It is believed that this material is a promising new electrolyte for two principal reasons. First, PFPE materials are a class of fluoropolymers that are intrinsically nonflammable and exhibit low vapor pressure as well as thermal, chemical and oxidative stability. Second, for lithium ion battery applications, PFPE-based electrolytes also can dissolve lithium salts with fluoridated anions. This electrolyte system possesses high conductivity dominated by molecular lithium ion (Li+) transport, owing to the low glass transition temperature of the PFPE materials, and the solvation of fluorinated anions by fluorinated polymers, which immobilizes the anion on the polymer. The proposed research will synthesize functionalized homo- and block co-polymer perfluoropolyethers and lithium salts, characterize the electrochemical properties of these electrolytes, and assess their ion transport and cycling performance in electrochemical energy storage test devices. Selected research outcomes will be used to support the development of a start-up company and provide entrepreneurial training for students involved on the project. Additional education and outreach activities are also planned in coordination with the Professional Development Program at UC Berkeley and with the Research Triangle Electrochemical Society Student Chapter.