Secondary battery and dendrite formation inhibitor used in the secondary battery

Disclosed is a secondary battery in which a sulfide compound represented by general formula (1) is contained in an electrolyte solution and a negative electrode is formed from a metal. In general formula (1), R1 represents a 1-naphthyl group or a 2-naphthyl group and a hydrogen atom in the 1-naphthyl group or the 2-naphthyl group may be substituted by a halogen atom or the like; R2 represents a phenyl group or a benzyl group and a hydrogen atom in the phenyl group or the benzyl group may be substituted by a halogen atom or the like; and x represents 1 or 2.