A non-aqueous secondary battery having an electrode group comprising a portion of exposed metal foil electrically connected to the positive electrode collector and covering the entire outer surface of the electrode group. Separator material is sandwiched between the foil and the negative electrode, which is positioned outwardly of the positive electrode, and separator material is also positioned between the foil covering of the electrode group and a negative polarity cell container. The positioning of the metal foil is such that if the battery is crushed, the separator material on the outermost side of the metal foil or between the metal foil and the negative electrode is broken first, so that the metal foil short-circuits with the inner wall of the cell container or the negative electrode, respectively.