SURFACE-TREATED STEEL SHEET FOR BATTERY CASE, BATTERY CASE COMPRISING THE SAME, METHODS FOR PRODUCING THEM, AND BATTERY

摘要

A surface-treated steel sheet for a battery case having a good alkali-resistance and capable of maintaining a high discharge level for a longe time, a battery case, and methods for producing them are disclosed. After a nickel-bismuth alloy layer is formed on a steel sheet, the steel sheet is heated at 300 to 650 DEG C for 240 to 600 min in an inert or non-oxidizing gas atmosphere to form iron-nickel and nickel-bismuth diffusion layers at their interfaces. Using a steel sheet on which one or more layers out of an iron-nickel diffusion layer, a nickel metallic layer, a nickel-bismuth diffusion layer, an iron-nickel-bismuth alloy layer as a case material, a battery is produced.