NOVELTY - Secondary battery comprises: cathode (21); anode (22); and electrolytic solution, where the cathode includes lithium composite oxide, first compound, and second compound, the composite oxide includes lithium and transition metal element as constituent elements, the first compound includes first metal element different from the transition metal element as a constituent element and exists on surface and inside the composite oxide, and the second compound includes second metal element different from the first metal element as constituent element and exists on the surface of the composite oxide.    USE - The secondary battery is useful as lithium ion secondary battery and electric power supply source in an electronic apparatus, and in battery pack, electric vehicle, electric power storage system and electric power tool (all claimed) comprising e.g. refrigerator, an air conditioner, TV, electric automobile, electric shaver, electric drill, electric saw, hearing aid and home battery system, and mobile electronic apparatus (e.g. digital still camera, mobile phone, notebook personal computer, cordless phone and headphone stereo).    ADVANTAGE - The secondary battery: exhibits superior battery characteristics (high energy density, superior cycle characteristics, superior conservation characteristics, and high battery capacity); lowers discharge capacity and resistance, even if charge and discharge are repeated; suppresses liquid leakage of the electrolytic solution and battery swollenness; and achieves electro-chemical stability of the cathode active material and suppression of decomposition reaction of electrolytic solution.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) an electrode comprising: the lithium composite oxide; the first compound; and the second compound;    (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 the control section;    (4) an electric power storage system comprising: the secondary battery; at least one electric device supplied with electric power from the secondary battery; and the control section controlling the supplying of the electric power from the secondary battery to the electric device; and    (5) an electric power tool comprising: the secondary battery; and a movable section being supplied with electric power from the secondary battery.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-sectional view of configuration of the secondary battery (cylindrical type) including electrode.    Battery can (11)    Insulating plates (12)    Gasket (17)    Cathode (21)    Anode (22)