NOVELTY - A secondary battery comprises: a cathode; an anode; and an electrolytic solution, where the anode includes an anode active material layer on an anode current collector, the anode active material layer includes a carbon material, the anode active material layer has a thickness of 30-100 micrometers both inclusive, and the electrolytic solution includes an unsaturated cyclic ester carbonate (I).    USE - As secondary battery used in an electric vehicle, an electric power storage system, an electric power tool, and an electronic apparatus (claimed). The secondary battery is used in an electronic apparatuses (including portable electronic apparatuses) such as video camcorder, 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 an electric shaver; in memory device such as backup electric power source and memory card; in an electric power tool such as electric drill and electric saw; in battery pack used as an electric power source of notebook personal computer; in medical electronic apparatus such as pacemaker and hearing aid; in electric vehicle such as electric automobile (including hybrid automobile); and in an electric power storage system such as home battery system for storing electric power for emergency.    ADVANTAGE - The secondary battery has superior battery characteristics; has prolonged long life; is small and light-weight; and provides high energy density.    DETAILED DESCRIPTION - A secondary battery comprises: a cathode; an anode; and an electrolytic solution, where the anode includes an anode active material layer on an anode current collector, the anode active material layer includes a carbon material, the anode active material layer has a thickness of 30-100 micrometers both inclusive, and the electrolytic solution includes an unsaturated cyclic ester carbonate of formula (I).    X=divalent group in which m-number of -C=CR1R2 or n-number of -CR3R4 are bonded in any order;    R1-R4=H, halo, monovalent hydrocarbon group, monovalent halogenated hydrocarbon group, monovalent oxygen-containing hydrocarbon group, and monovalent halogenated oxygen-containing hydrocarbon group;    m= greater than or equal to 1;    n=0.    INDEPENDENT CLAIMS are included for the following:    (1) a battery pack comprising: a secondary battery; a control section controlling a used state of the secondary battery; and a switch section switching the used state of the secondary battery according to an instruction of the control section;    (2) an electric vehicle comprising: a secondary battery; a conversion section converting electric power supplied from the secondary battery into drive power; a drive section operating according to the drive power; and a control section controlling a used state of the secondary battery;    (3) an electric power storage system comprising: a secondary battery; at least one electric device supplied with electric power from the secondary battery; and a control section controlling the supplying of the electric power from the secondary battery to the electric device;    (4) an electric power tool comprising: a secondary battery; and a movable section being supplied with electric power from the secondary battery; and    (5) an electronic apparatus comprising a secondary battery as an electric power supply source.