Secondary battery having a non-aqueous electrolyte

A secondary battery with non-aqueous electrolyte comprises: a pressure-based current interrupt device (30) which is arranged in a conduction path, in order to interrupt the conduction path when an inner pressure exceeds a working pressure; a nonaqueous electrolyte; and a positive electrode composite material layer (10b). The non-aqueous electrolyte contains a gas generating agent that generates a gas in an overload region, and the positive electrode composite material layer (10b) contains a particle of a first as a positive electrode acting material, the lithium iron phosphate contains, and a particle of a second as a positive electrode acting material that includes a lithium nickel composite. A proportion of the particle of the first positive electrode active material to a total mass of the particle of the first electrode as a positive-acting material and the particle of the second electrode as a positive-acting material is 5 mass% or more and 20 mass% or less.