Performance of lithium tetrafluorooxalatophosphate (LiFOP) electrolyte with propylene carbonate (PC)

The cycling performance of LiPF 4(C 2O 4) (LiFOP) electrolyte with propylene carbonate (PC) as a cosolvent is compared with LiPF 6 electrolyte with ethylene carbonate (EC) as a cosolvent in the presence of different cathode materials, such as LiNi 1/3Co 1/3Mn 1/3O 2 and LiFePO 4. The cycling performance of cells with LiFOP and PC is similar to cells with LiPF 6 with EC at room temperature and superior at low temperature (-10 °C). After thermal abuse the room temperature performance of cells with LiFOP electrolyte and PC is worse than cells with LiPF 6 and EC. A detailed analysis of the surface films on both the anode and the cathode via X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Fourier transfer infrared spectroscopy (FT-IR) in the attenuated total reflection (ATR) mode was conducted to provide a better understanding of performance differences. © 2012 Elsevier B.V. All rights reserved