Developing high-voltage carbonate-ether mixed electrolyte via anode-free cell configuration

Abstract

Here, an anode-free cell (Cu//LiNi1/3Mn1/3Co1/3O2) with all irreversible features is employed as a tool to develop non-flammable and highly fluorinated interphase forming carbonate-ether mixed high-voltage electrolyte. The two extreme electrolytes are chosen for comparing and understanding the fundamental science behind. The best electrolyte developed (lithium hexafluorophosphate (LiPF6) in a mixture of fluoroethylene carbonate and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether) shows stable cycling for more than 65 cycles with >50% retention capacity and average coulombic efficiency (Av.CE) of ~98.67% in an anode-free cell at 0.5 mAcm−2. The cell with 1 M LiPF6 in ethylene carbonate (EC) and diethyl carbonate (DEC), (EC/DEC electrolyte) can only cycle for 5 cycles >50% retention capacity with Av. CE of 84.59%. The best electrolyte developed also shows much better cycling performance in high-voltage lithium-metal batteries (HVLMBs) and high-voltage lithium-ion batteries (HVLIBs) compared to the commercial electrolyte, indicating the anode-free configuration is a powerful tool to develop electrolytes not only for HVLMBs but also for HVLIBs. Anode-free cell configuration can be scaled up as a tool to design electrolytes within short period of time and less cost at industrial levels.