NOVELTY - Secondary battery comprises a cathode, an anode (22) and an electrolytic solution, where the electrolytic solution includes a cyano cyclic ester carbonate (I).    USE - The secondary battery is useful in a battery pack, an electric vehicle, an electric power storage system, an electric power tool and an electronic device, where the secondary battery is lithium ion secondary battery (all claimed). The secondary battery is useful: for machine, device, instrument, apparatus and system; as a driving electric power source and an electric power storage source for electric power storage; in mobile electronic devices (such as video camcoder, digital still camera, mobile phone, notebook personal computer, cordless phone, headphone stereo, portable radio, portable television and personal digital assistant); in mobile lifestyle electric appliance (such as electric shaver), memory device (such as backup electric power source and memory card), electric drill and electric saw, electric power source of notebook personal computer, medical electronic device (such as pacemaker and hearing aid), and electric automobile (including a hybrid automobile).    ADVANTAGE - The secondary battery is small in size and weight, thus improving long life of the battery, and has improved electrochemical characteristics and high energy density.    DETAILED DESCRIPTION - Secondary battery comprises a cathode, an anode and an electrolytic solution, where the electrolytic solution includes a cyano cyclic ester carbonate of formula (I).    R1-R3 = H, halo, CN, monovalent hydrocarbon group, monovalent halogenated hydrocarbon group, monovalent oxygen-containing hydrocarbon group, and monovalent halogenated oxygen-containing hydrocarbon group, where arbitrary two or more of the R1-R3 are allowed to be bonded to each other, and when the total number of cyano groups is 1, one or more of R1-R3 each are a halogen group, a monovalent halogenated hydrocarbon group, or a monovalent halogenated oxygen-containing hydrocarbon group.    INDEPENDENT CLAIMS are included for:    (1) an electrolytic solution including (I);    (2) a battery pack comprising the secondary battery, a control section controlling a usage state of the secondary battery, and a switch section switching the usage state of the secondary battery according to an instruction of the control section;    (3) an electric vehicle comprising the secondary battery, a conversion section converting electric power supplied from the secondary battery to drive power, a drive section operating according to the drive power, and a control section controlling a usage state of the secondary battery;    (4) an electric power storage system comprising the secondary battery, one, or two or more electric devices supplied with electric power from the secondary battery, and a control section controlling the supply of the electric power from the secondary battery to the electric device;    (5) an electric power tool comprising a secondary battery, and a movable section being supplied with electric power from the secondary battery;    (6) and an electronic device comprising the secondary battery as an electric power supply source.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional configuration of a secondary battery.    Battery can (11)    Insulating plates (12)    Battery cover (14)    Anode (22)    Separator. (23)