NOVELTY - A secondary battery comprises positive electrode (21), negative electrode (22), and electrolyte solution consisting of 1st-5th amino-containing aromatic compounds, wherein 1st amino-containing aromatic compound (1) contains naphthalene structure with 2 rings, 2 tertiary amino groups bonded with 1,8-position of naphthalene structure, and greater than or equal to 1 substituents bonded with naphthalene structure, and 2nd amino-containing aromatic compound (2) contains naphthalene structure and 2 tertiary amino groups which form a ring bonded with nitrogen while bonding with 1,8-position of naphthalene structure.    USE - A secondary battery for electronic device, electric tool, electric vehicle, and electric power storage system (all claimed).    ADVANTAGE - Decomposition reaction of electrolyte solution is inhibited in high-temperature environment, increase in resistance inside a battery is suppressed, and high-temperature characteristic is improved.    DETAILED DESCRIPTION - A secondary battery comprises positive electrode (21), negative electrode (22), and electrolyte solution consisting of 1st-5th amino-containing aromatic compounds, wherein 1st amino-containing aromatic compound (1) contains naphthalene structure with 2 rings, 2 tertiary amino groups (-NR2) bonded with 1,8-position of naphthalene structure, and greater than or equal to 1 substituents bonded with naphthalene structure, 2nd amino-containing aromatic compound (2) contains naphthalene structure and 2 tertiary amino groups which form a ring bonded with nitrogen while bonding with 1,8-position of naphthalene structure, 3rd amino-containing aromatic compound (3) contains naphthalene structure and 2 tertiary amino groups bonded to positions other than 1,8-position of naphthalene structure, 4th amino-containing aromatic compound (4) contains naphthalene structure and greater than or equal to 3 tertiary amino groups bonded with naphthalene structure, and 5th amino-containing aromatic compound (5) contains aromatic skeleton, except naphthalene, which has greater than or equal to 2 rings and greater than or equal to 1 tertiary amino groups bonded to every ring.    R=H, C, N, O, S, F, Cl, Br, and/or I.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional diagram of an expanded part of winding electrode body. (Drawing includes non-English language text).    Winding electrode body (20)    Positive electrode (21)    Positive electrode collector (21A)    Negative electrode (22)    Separator (23)