Polyfluorinated Electrolyte Solutions and Additives for High Voltage Non-Flammable Lithium Batteries

Abstract

The highly flammable nature of current lithium battery electrolyte solution (hydrocarbons) presents a major challenge for operation at large scale, though significant efforts are being made to improve the battery safety and capacity. One of the key challenges for safe high voltage lithium batteries is to develop new electrolyte systems that are non-flammable and possess wide electrochemical windows. Here, we report the synthesis and fundamental electrochemical characterization of polyfluorinated electrolyte solutions and additives that could potentially be used in high voltage non-flammable lithium batteries. Our results show that the polyfluorinated electrolyte solutions we tested possess wider electrochemical windows than their hydrocarbon analogs, and are non-flammable. We further find that use of perfluorinated alcohol additives improves the reversibility of lithium ion reduction which is important for rechargeable lithium batteries. Together, polyfluorinated ethers and perfluorinated alcohols exhibit great potential in developing high voltage lithium batteries.