J. Phys. IV France 07 (1997) C1-161-C1-162
K+-β-Ferrite as a New Cathode Active Material for Lithium Secondary BatteryS. Ito, K. Ui, N. Hoshi, H. Kurosawa, N. Koura and K. Akashi
Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo, Noda Chiba 278, Japan
The possibility of K+-β-ferrite (Kl.33Fe11O17) as a cathode active material for lithium secondary battery was investigated. It was confirmed that lithium ions certainly inserted into K+-β-ferrite. Li content y in LiyK1,33Fe11O17 was increased up to 6.79. Most of lithium ions seem to enter into γ-Fe2O3 layers of K+-β-ferrite, because alkali layers could contain only 2 alkali ions for Fe11O17. According to the cyclic voltammogram, good reversibility was observed in insertion and extraction of lithium ions. The discharge potential decreased to 1.5V vs. Li/Li+ and the charge potential increased to 4.5V vs. Li/Li+. The capacity of K+-β-ferrite has reached 200Ah/kg.
© EDP Sciences 1997