CHARGE DISCHARGE CYCLING BEHAVIOR OF PITCH-BASED CARBON-FIBER IN ORGANIC ELECTROLYTE-SOLUTIONS

Pitch-based carbon fiber in which a graphite structure is highly oriented in the radial direction from its central axis has been examined as a negative electrode matrix of a rechargeable lithium battery. The cyclic voltammograms for the fiber electrode showed that a reversible process of lithium intercalation/deintercalation occurred in propylene carbonate (PC)-based solutions containing various lithium salts. A high discharge capacity of about 220 Ah kg carbon-1 and a nearly 100% coulombic efficiency were observed in PC dissolving LiClO4 (1 mol dm-3) under constant-current charge/discharge cycling. The effects of the electrolyte salt on the cycling behavior of the carbon fiber electrode were investigated by means of an ac impedance technique. The battery performance of the carbon fiber was tested using model full cells with lithiated manganese oxide and vanadium oxide cathodes.