RECHANGING TYPE ELECTROCHEMICAL CELL HAVING LICHIUM ANODE

摘要

PURPOSE: To improve the cycle of a rechargeable electrochemical battery by forming its cathode substance out of manganese dioxide which includes lithium ions and has an alpha manganese dioxide crystal structure called Cryptomelane. CONSTITUTION: A cathode substance is composed of manganese dioxide which includes lithium ions and has an alpha manganese dioxide crystal structure called Cryptomelane. The cathode substance is formed out of a mixture of alpha manganese dioxide and a lithium compound heated at 300 to 400 deg.C. The mole ratio of lithium to manganese is between 0.1 to 0.5 to 1.0. The heat treatment causes chemical reaction between alpha MnO2 and the lithium compound. The resultant product after the reaction is washed in water to remove an unconverted lithium compound therefrom. The period of the heat treatment is determined such that solids other than alpha dioxide of MnO2 , especially LiMn2 O4 and Li2 MnO3 are never formed in the reaction, for example to about 12 hours.