On the Relation Between the Overpotentials and Structures of Graphite Fluoride Electrode in Nonaqueous Lithium Cell

Abstract

A study was made of the relation between the cathode overpotentials and structures of two kinds of graphite fluorides, (CF)nand (C2F)nin nonaqueous lithium battery. The overpotential of (CF)nelectrode decreased with increasing interlayer spacing and decreasing thickness of the crystallite along the C axis. However, it was found that the overpotential of (C2F)nelectrode primarily depended on the amount of the defects which would be present in the form of polynuclear aromatic carbon rings in (C2F)n. The defects in (C2F)nwould give the short circuiting paths for the transfer of a lithium ion in diffusion layer. The higher discharge potential of (C2F)nthan that of (CF)„ was mainly attributed to the effect of the defects contained in (C2F)n. © 1984, The Electrochemical Society, Inc. All rights reserved.