NOVELTY - A secondary battery comprises a positive electrode (21) and a negative electrode (22) that are laminated through a separator (23), and electrolyte solution, where the positive electrode, negative electrode and the separator contain a high molecular compound, the electrolyte solution contains an oxidation reduction compound, the oxidation-reduction potential of the oxidation reduction compound is higher than electric potential of the positive electrode, and lower than oxidation potential of high molecular compound.    USE - Secondary battery i.e. lithium ion secondary battery, for use in an electric tool, an electric vehicle, an electric power storage system and an electronic device (all claimed) such as video camera, digital still camera, mobile telephone, notebook personal computer, cordless telephone apparatus, headphone stereo cassette tape recorder, portable radio, portable TV, portable information terminal electric shaver, backup power supply, memory card, pacemaker or hearing aid.    ADVANTAGE - The battery has improved high temperature characteristic by inhibiting the decomposition reaction of electrolyte solution in high-temperature environment with an oxidation reduction compound even if chlorine exists in electrolyte solution.    DETAILED DESCRIPTION - A secondary battery comprises a positive electrode and a negative electrode that are laminated through a separator, and electrolyte solution, where the positive electrode, negative electrode, and the separator contain a high molecular compound, the electrolyte solution contains an oxidation reduction compound, the oxidation-reduction potential of the oxidation reduction compound in the electrolyte solution is higher than the electric potential of the positive electrode of the charge final voltage in the electrolyte solution, and lower than the oxidation potential of the high molecular compound in the electrolyte solution, and the chlorine content in the electrolyte solution is 100 ppm or less.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of secondary battery.'(Drawing includes non-English language text)'    Winding electrode body (20)    Positive electrode (21)    Positive electrode active material layer (21B)    Negative electrode (22)    Separator (23)