PURPOSE: To obtain a lithium-manganese dioxide battery having a flat electric- discharge potential and great electric-discharge capacity by using as the positive active material, manganese dioxide displaying a diffraction peak near the d level of 3.60 when X-ray diffraction is performed at the end of electric discharge.
CONSTITUTION: Manganese dioxide with which a diffraction peak appears near the diffractional crystalline surface distance (d) of 3.60 when X-ray diffraction analysis is performed at the end of electric discharge, is used as an active material for the positive electrode 1 of a lithium-manganese dioxide battery. For the above manganese dioxide, β-MnO2 and the like prepared by thermally treating electrolytic manganese dioxide or chemically-synthesized manganese dioxide at high temperature before nitric acid is added to the thus obtained product and then the mixture is thermally treated can be used. However, the above manganese dioxide is not restricted to these compounds and various types of manganese dioxide which display the above diffraction peak after the end of the electric discharge test can be specifically used as the positive active material.
SAMEJIMA TOSHIKO
TAMURA HIDEMASA