Non-aqueous electrolyte secondary battery

Abstract

The invention aims to allow carbon dioxide, which is generated upon decomposition of lithium carbonate contained in a positive electrode mixture layer, to easily flow toward the outside of a flat wound electrode body, and further aims to rapidly raise the pressure inside a battery and to reliably operate a pressure-sensitive current interrupt mechanism before the temperature inside the battery rises to such an extent as causing an abnormal state, e.g., smoking, firing, or a burst. A nonaqueous electrolyte secondary battery () according to one embodiment of the present invention includes a pressure-sensitive current interrupt mechanism. An insulating tape () is bonded onto a positive electrode mixture layer () in at least one of a winding start-side edge portion and a winding end-side edge portion of a positive electrode plate () in a flat wound electrode body () at a position opposing to a separator (), the insulating tape extending in a widthwise direction of the positive electrode mixture layer ().