Acyclic Acetals in Propylene Carbonate-Based Electrolytes for Advanced and Safer Graphite-Based Lithium Ion Batteries

In this work, we investigate the electrochemical and safety performance of the glyoxalic acyclic acetals, namely 1,1,2,2-tetramethoxyethane (TME) and 1,1,2,2 tetraethoxyethane (TEE) as substituted solvents for linear organic carbonates in propylene carbonate (PC)-based electrolytes in LiNi0.6Mn0.2Co0.2O2 parallel to graphite cells. By means of conductivity measurements and under consideration of PC-intercalation suppression, an optimized electrolyte was formulated with excellent thermal properties and electrochemical performance. The optimized electrolyte shows excellent cycling performance at the level of established organic carbonate-based electrolyte consisted ethylene carbonate, ethyl methyl carbonate and with lithium hexafluorophosphate as conducting salt with an extended operating cycling temperature window, good C-rate behavior and promising safety properties, clearly demonstrating the application potential of this new solvent class for lithium ion battery electrolytes. (c) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.