Iron-Based Cathode Material for Lithium Ions and Metal Batteries

Abstract

Metal oxyfluoride conversion cathodes are very attractive as high energy material due to their high redox reactions because of the high electronegativity of fluorine atom. It has been demonstrated that the rutile structure of FeOF has been obtained, but there are only a few reports about the cubic phase of FeOF. In this study, we are demonstrated a cubic phase of FeOF can be obtained after charging and discharging a mixture of ball milled LiF/FeO at 750 rpm for 12 hours. Although, X-ray diffraction did not show the presence of Fe+3 in the starting material, X-ray-photo electron spectroscopy revealed the presence of Fe+3 suboxides. Excellent cycling stability was obtained and a cell was cycled at 50 mA/g in liquid electrolyte. We also demonstrate long-cycle stability for over 200 cycles at 40 °C when a solid electrolyte was used. The solid electrolyte was embedded with a cross-linked composite polymer electrolyte to improve transport of lithium ion inside the cathode. The electrochemical properties of both the lithium ion and the lithium metal properties will be compared. Figure 1