Abstract: A secondary battery includes an outer package member, a battery device, and a non-aqueous solution. The outer package member includes iron. The battery device and the non-aqueous solution are contained inside the outer package member. The battery device includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode and the negative electrode are opposed to each other and are wound. The positive electrode and the negative electrode are each impregnated with the electrolytic solution. The negative electrode is electrically coupled to the outer package member, and includes at least one selected from the group consisting of polyvinylidene difluoride, a polyacrylic acid, a polyacrylic acid salt, polyacrylonitrile, and derivatives thereof. The non-aqueous solution is disposed in at least a portion of a space around the battery device inside the outer package member. The electrolytic solution and the non-aqueous solution each include a dinitrile compound.