NOVELTY - Secondary battery (11) comprises a positive electrode (21), a negative electrode (22), and an electrolytic solution containing a nitrogen-containing aryl compound, where the nitrogen-containing compound comprising an aryl skeleton containing one or two or more aryl rings and one or two or more nitrogen-containing functional groups bonded to the aryl rings (I).    USE - The secondary battery, preferably a lithium ion secondary battery, is useful in an electronic appliance, a power tool, an electric vehicle and an electric power storage system (all claimed), preferably household electric power servers, power drills, electric cars, video camera, digital still camera, mobile phone, laptop computer, cordless phone, headphone stereo player, portable radio, portable TV, personal digital assistant, electric shaver, backup electric power source, memory card, pacemaker and hearing aid.    ADVANTAGE - The secondary battery exhibits high durability, high energy density than lead battery or nickel-cadmium battery and high cycle characteristics even at high temperature, hence swelling and leakage of the battery are avoided.    DETAILED DESCRIPTION - Secondary battery (11) comprises a positive electrode (21), a negative electrode (22), and an electrolytic solution containing a nitrogen-containing aryl compound, where the nitrogen-containing compound comprising contains an aryl skeleton containing one or two or more aryl rings and one or two or more nitrogen-containing functional groups bonded to the aryl rings of formula ((Y1a)z-X=N-) (I).    X = C or P;    Y1a = a group constituted of one kind or two or more kinds of elements consisting of H, C, N, O, S, F, Cl, Br or I, provided that arbitrary two or more of X and Y1 may be bonded to each other to form a ring structure, where Y1 is at least one of dialkylamino group or aryl group; and    z = 2 or 3.    An INDEPENDENT CLAIM is included for the electrolytic solution comprising the nitrogen-containing aryl compound.    DESCRIPTION OF DRAWING(S) - The figure shows a sectional view of the secondary battery (cylindrical type).    Secondary battery (11)    Battery lid (14)    Positive electrode (21)    Negative electrode (22)    Separator. (23)