A nonaqueous electrolyte secondary battery of the present invention includes a nonaqueous electrolyte and a positive electrode 13 that occludes lithium ions reversibly. The positive electrode 13 includes active material layers 13b and a sheet-like collector 13a that supports the active material layers 13b. The collector 13a contains aluminum and at least one element other than aluminum. The average composition that is obtained by averaging the ratio of the elements composing the collector 13a in the direction of the thickness of the collector 13a is equal to the composition of an alloy whose liquidus temperature is 630° C. or lower. The present invention makes it possible to prevent heat from being generated due to an internal short circuit in the nonaqueous electrolyte secondary battery.