2003 Volume 71 Issue 12 Pages 1172-1176
A mixture of α-fluoro and β fluoro-γ-butyrolactone (30 : 70 mol%; F-γ-BLmix) was prepared by the direct fluorination of γ-butyrolactone (γ-BL) and its physical properties and its performances as an electrolyte solvent were examined for lithium rechargeable cell application. Its relative permittivity and viscosity was more than two times of those of γ-BL. Its lithium cycling efficiency on a Ni electrode was compared with γ-BL and propylene carbonate (PC) using LiClO4, LiBF4, and LiPF6. Among every combination, LiPF6/F-γ-BLmix electrolyte afforded the best cycling efficiency due to the smoothest surface formation, however, the cycle performance of Li/LiCoO2 cell using LiPF6/F-γ-BLmix was not as good as the one using LiPF6/PC presumably due to its higher film resistance.
