(Digital Presentation) Effects of Solvents and Additives in Non-Conventional Liquid Electrolytes for Lithium-Ion Batteries

Abstract

Lithium (Li)-ion batteries (LIBs) have now been the major power sources in consumer electronic devices and electric vehicles. To further enhance the battery performances, more efforts are required to address significant challenges in improving cycle life, rate capability, energy density, working temperature range and safety of state-of-the-art LIBs. The conventional LiPF6/carbonate electrolytes have been found unable to meet all the requirements for advanced LIBs with high-capacity cathodes and anodes although proper additives can improve the battery performances in certain aspects. For instance, the presence of acidic species like HF in LiPF6 electrolytes and specifically at elevated temperatures is still detrimental to the layered oxide cathodes and the electrode/electrolyte interphases, and the issue of electrochemical oxidation stability of conventional electrolytes at voltages over 4.3 V needs to be addressed for the high-voltage cathodes and batteries. In response to the challenges facing to the conventional LiPF6/carbonate electrolytes in LIBs, especially the long-term cycling stability, non-conventional electrolytes based on functional localized high-concentration electrolytes (LHCEs) have been developed for LIBs in recent years. Due to the unique solvation structures of LHCEs, LHCEs lead to formation of thin, compact and uniform electrode/electrolyte interphases, thus greatly improve LIB performances. In this work, we comparatively studied the effects of solvating solvents and additives in LHCEs on the solvation structures and properties of LHCEs as well as the battery performance of LIBs with nickel-rich cathode and graphite anode. More details will be reported during the presentation.