| 摘要 |
PURPOSE:To obtain a battery having a battery case with excellent mechanical strength, friction resistance and corrosion resistance by forming a layer consisting of a nitride of an element chosen from the IVa, the Va and the VIa groups on the outer surface of the metallic base body of a positive case. CONSTITUTION:An alkaline battery is constituted by packing a positive mixture 2 in the bottom portion of a positive case 1 before a separator 3 and an electrolyte-holding member 4 are stacked over the positive mixture 2, being followed by sealing the opening of the case 1 by means of a negative case 6 packed with a negative mixture 5. The positive case 1 is made by subjecting a steel plate as an example used as a base body to press work to form a case body, then forming a layer consisting of a nitride of an element chosen from the IVa, the Va and the VIa groups on the outer surface of the case body. The nitride layer consists of titanium nitride, hafnium nitride or zirconium nitride for example. The formation of the nitride layer is carried out by a so-called PVD method such as a plasma CVD method, iron plating or sputtering. Among these methods, it is specially desirable that a plasma CVD method be used since a coating surface having a homogeneous stable luster is easily obtained. |
