BATTERY

PROBLEM TO BE SOLVED: To provide a battery capable of improving a cycle characteristic while reducing the weight thereof even when an armoring can is used as a negative electrode. SOLUTION: A battery element 20 having a laminate structure of a positive electrode 21, a negative electrode 22 and a separator 23 is housed in the armoring can 11. The armoring can 11 is formed of a metal material containing aluminum, and a reaction suppression layer 31 formed of copper or nickel is formed on its inside surface. An alloying reaction of lithium included in an electrolyte held to the separator 23 with aluminum included in the armoring can 11 is suppressed by the reaction suppression layer 31. Since the inside surface of the armoring can 11 faces a positive electrode collector 21A positioned at an end on a rolling outer periphery side of the battery element 20 through the reaction suppression layer 31 and the separator 23, excessive heat generation is suppressed in abnormality such as breakage. COPYRIGHT: (C)2009,JPO&INPIT