SYNTHESIS AND ELECTROCHEMICAL PROPERTIES OF LITHIUM IRON-OXIDES WITH LAYER-RELATED STRUCTURES

Two modifications of layered lithium iron oxides were synthesized and characterized by X-ray diffractometry and electrochemical measurements . LiFeO2 with alpha-NaFeO2 structure was synthesized by the ion-exchan ge reaction in molten salts; cationic distribution in the host, alpha- NaFeO2, affects the disordering in the reaction product. However, lith ium de-intercalation was not confirmed. The ion-exchange reaction in m olten salts gave a whole range of solid solution, Li(Fe1-xNix) O-2, us ing the alpha-Na(Fe1-xNix)O-2 hosts, and their electrochemical propert ies were determined, Lithium iron oxide, LiFeO2, with a corrugated lay er structure, was synthesized by an ion-exchange reaction between gamm a-FeOOH and LiOH . H2O. Lithium cells consisting of LiFeO2 cathodes an d lithium anodes showed good charge and discharge reversibility in the voltage 1.5-3.0 V range. (C) 1997 Published by Elsevier Science S.A.