Alkaline battery

Abstract

An alkaline battery has a positive electrode mixture containing manganese dioxide and a conductive material filling a tubular positive electrode can that is closed at one end. A negative electrode mixture containing a zinc powder filling on an inner peripheral side of a separator is disposed on an inside of the positive electrode mixture. The negative electrode mixture contains zinc particles with a granularity of 75 μm or less at 25 to 40 mass %. The positive electrode mixture has a plurality of tubular pellets stacked inside the positive electrode can coaxially with the positive electrode can. A sum s of lengths of gaps between the pellets is set at 1 to 14% with respect to a sum d of lengths of the pellets. Thus, a sufficient amount of the electrolyte is held in the gaps and between the pellets in the positive electrode.

1 . An alkaline battery comprising:
 a positive electrode mixture filling a tubular positive electrode can closed at one end;   a separator disposed on an inner peripheral side of the positive electrode mixture;   a negative electrode mixture filling an inner peripheral side of the separator, the negative electrode mixture containing a powder mainly containing zinc;   a negative electrode current collector inserted into the negative electrode mixture;   a negative electrode terminal plate to seal an opening of the positive electrode can; and   an alkaline electrolyte,   the positive electrode mixture containing manganese dioxide and a conductive material,   the powder containing particles with a granularity of 75 μm or less in a range of 25 to 40 mass %,   the positive electrode mixture constituted of a plurality of tubular pellets, the plurality of tubular pellets stacked and loaded inside the positive electrode can in such a manner as to be stacked coaxially with the positive electrode can,   a gap disposed between the pellets, the gaps and the pellets having a ratio of a sum s of length of the gaps axially along the positive electrode can to a sum d of lengths of the pellets axially along the positive electrode can, the ratio being 1 to 14%.   
     
     
         2 . The alkaline battery according to  claim 1 , wherein
 the pellets have a density in a range of 3.0 to 3.7 g/cm 3 ,   
     
     
         3 . The alkaline battery according to  claim 1 , wherein
 the pellets contain graphite as the conductive material in a range of 5 to 20 mass % with respect to the manganese dioxide.