MATERIAL FOR METALLIC OUTER CASE FOR SECONDARY BATTERY UTILIZING NON-AQUEOUS ELECTROLYTE, METALLIC OUTER CASE, SECONDARY BATTERY, AND PROCESS FOR PRODUCTION OF MATERIAL FOR METALLIC OUTER CASE

The material for metal cases of secondary batteries using a non-aqueous electrolyte includes a steel sheet; and a plated layer that has a Ni layer, and a Cu-Ni layer, which is disposed between the Ni layer and the steel sheet and is in contact with the Ni layer, and is in contact with the steel sheet.