Electrolytic manganese dioxide, and method for its production and its application

Abstract

An object of the present invention is to provide electrolytic manganese dioxide to be used as a cathode active material for an alkali-manganese dry cell, which has a high alkali potential and is provided with a high reactivity and packing efficiency as a cathode for the cell, and which is excellent in the middle rate discharge characteristic, and electrolytic manganese dioxide excellent in the high rate discharge characteristic and the middle rate discharge characteristic, which will not cause corrosion of metal materials, and a method for its production. In the present invention, electrolytic manganese dioxide having an alkali potential of at least 280 mV and less than 310 mV, and FWHM of at least 2.2° and at most 2.9°, is used. It is preferred that of the electrolytic manganese dioxide, the (110)/(021) peak intensity ratio in the X-ray diffraction peaks is at least 0.50 and at most 0.80, and the (110) interplanar spacing is at least 4.00 Å and at most 4.06 Å. Further, electrolytic manganese dioxide wherein the JIS-pH (JIS K1467) is at least 1.5 and less than 2.6, the sodium content is at least 0.02 wt % and less than 0.10 wt %, the sulfate group content is less than 1.30 wt %, the median diameter is at least 30 μm and at most 50 μm, and the BET specific surface area is at least 20 m/g and at most 50 m/g, is preferred.