Advancing trend of Manufacturing Method Of Alkaline Battery
The alkaline battery has a structure in which a cylindrical positive electrode mixture is arranged in a positive electrode case serving as a positive terminal to closely adhere to the positive electrode case, and a gelled negative electrode is placed in the center thereof with a separator interposed therebetween. Recently, the load of devices powered by such batteries has been increasing, and thus batteries having excellent high-load discharge characteristics are required.
For example, Patent Document 1 suggests the following battery. The positive electrode mixture containing nickel oxyhydroxide is formed into a cylindrical shape. A negative electrode is placed in the positive electrode mixture with a separator interposed therebetween, thereby forming an electrode assembly. The electrode assembly was placed in a cylindrical battery case with a bottom, and a sealing member was tightly sealed at the opening of the battery case. Considering the expansion of nickel oxyhydroxide contained in the positive electrode mixture during overdischarge, a space corresponding to 5-10% of the height of the positive electrode mixture is provided between the sealing member and the positive electrode mixture.
However, if the ratio of the negative electrode capacity to the positive electrode capacity is too high, hydrogen gas is generated during overdischarge, thereby increasing the internal pressure of the battery, which may cause leakage.