NOVELTY - The battery (100) has a battery case (50) equipped with an electric current interruption mechanism (30) operated at time of inner pressure rise of the case. A positive electrode (10) is equipped with a positive electrode electrical power collector and a positive electrode active material layer containing positive electrode active material formed on the positive electrode electrical power collector. An ion conduction layer (16) is provided between the positive electrode active material layer and a separator (40), and includes ion conductor, which does not have electronic conductivity.    USE - Non-aqueous-electrolyte secondary battery i.e. lithium ion secondary battery, for use on a vehicle e.g. plug-in hybrid motor vehicle, hybrid vehicle, electric vehicle, electric truck, bicycle with a power engine, electric-power assisted bicycle, electric wheelchair and electric railway. Can also be used as a nickel-hydrogen battery and for a personal computer and a portable terminal.    ADVANTAGE - The battery allows non-aqueous electrolyte and gas forming agent to be fully infiltrated in the positive electrode active material layer such that electroconductivity in the positive electrode active material layer can be kept favorable, so that increase of battery resistance can be suppressed, thus exhibiting battery characteristic outstanding at time of normal use and rapidly oxidatively decomposing gas forming agent at time of overcharge, and hence operating the current interruption mechanism rapidly and improving reliability and output performance of the battery.    DETAILED DESCRIPTION - The battery case is a flat box type battery case formed in parallelepiped shape.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a non-aqueous-electrolyte secondary battery.    Positive electrode (10)    Ion conduction layer (16)    Electric current interruption mechanism (30)    Separator (40)    Battery case (50)    Non-aqueous-electrolyte secondary battery (100)