NOVELTY - A lithium ion secondary battery has positive electrode (2), negative electrode (4), separator (7) and organic electrolyte. Organic electrolyte contains solvent, additive and electrolyte. Solvent contains cyclic carbonate (I) and linear carbonate. Additive is halogenated cyclic carbonate (II). Amount of halogenated cyclic carbonate with respect to solvent is 0.4-3.2 wt.%. Electrolyte contains lithium salt chosen from hexafluoro lithium phosphate or tetrafluoro lithium borate. Concentration of electrolyte with respect to total amount of solvent and additive is 0.5-2 mol/L.    USE - Lithium ion secondary battery is used as power supply for hybrid vehicles.    ADVANTAGE - The lithium ion secondary battery has high output characteristics, favorable durability and reduced size.    DETAILED DESCRIPTION - A lithium ion secondary battery has a positive electrode (2) capable of occluding and discharging lithium ion, a negative electrode (4) capable of occluding and discharging lithium ion, a separator (7) provided between electrodes, and an organic electrolyte. The average face distance of (002) plane of carbon material contained in negative electrode by X-ray diffraction is 0.38-0.4 nm. The organic electrolyte contains a solvent, an additive and an electrolyte. The solvent contains cyclic carbonate (18-30 volume%) of formula (I) and linear carbonate (70-82 volume%) of formula: R5-O-C(=O)-O-R6. The additive is halogenated cyclic carbonate of formula (II). The amount of halogenated cyclic carbonate with respect to solvent is 0.4-3.2 wt.%. The electrolyte contains lithium salt chosen from hexafluoro lithium phosphate or tetrafluoro lithium borate. The concentration of electrolyte with respect to total amount of solvent and additive is 0.5-2 mol/L.    R1-R6=H or 1-3C alkyl;and    R7-R9=H, 1-3C alkyl, vinyl or halo.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of winding-type battery.    Positive electrode collector (1)    Positive electrode (2)    Negative electrode (4)    Separator (7)    Negative electrode lead (9)