Fabrication and characterization of PEO-based solid electrolytes for thin-film flexible battery applications

Abstract

Due to the tremendous progresses in the technological field of energy storage, there is a wide interest in flexible batteries with all solid-state materials to power portable devices for aerospace applications[1]. Lithium ion batteries (LIB) for such applications can be achieved by utilizing unique characteristics of certain materials such as conductive polymer materials. Polyethylene oxide (PEO) based solid polymer electrolytes have been considered to be an interesting candidate as an electrolyte in the field of thin film solid-state flexible batteries due to several advantages, such as safety, relative ease of fabrication in large scale processes, high energy density, electrochemical stability and good mechanical properties. However, there is a need to address a better understanding in how to improve the ionic conductivity of PEO electrolyte[2]. The conductivity of PEO electrolytes is found to be in the range of (10-4 Scm-1) at (65-78 °C) [2]from my preliminary study; In this thesis, I investigate the scalability of processing polymer electrolyte in a cost effective way by using a safer and cheaper solvent such as methanol, as well as simplifying the process further by fabricating the polymer sheets in ambient conditions, instead of inside a glove box. Another goal of this study is to investigate the ionic conductivity enhancements by implementing the following strategies: (II) varying the thickness, (II) investigating the effect of different salts such as lithium bis(oxalato)borate (LiBOB) and lithium bis(trifluorosulfonyl)imide LITFSI, (III) studying the effect of hot pressing the electrolyte composite.

Date of Award	May 2019
Original language	American English
Supervisor	Daniel Choi (Supervisor)