NOVELTY - A lithium ion secondary cell (1) has an anode (2), a cathode (3) and a non-aqueous electrolyte obtained by dissolving an electrolyte and normal temperature fused salt into mixed solvent of an organic solvent. The anode contains an anode active material consisting oxide containing lithium and transition metal element or poly anionic compound. The cathode contains a cathode active material consisting of carbon material capable of occluding and discharging lithium. The electrolyte is lithium hexafluorophosphate and salt of anion compound (1).    USE - For motor vehicles, mobile telephone and personal computer.    ADVANTAGE - The lithium ion secondary cell has favorable charging-and-discharging characteristics and flame retardance.    DETAILED DESCRIPTION - A lithium ion secondary cell has an anode, a cathode and non-aqueous electrolyte obtained by dissolving an electrolyte and normal temperature fused salt into mixed solvent of an organic solvent. The anode contains an anode active material consisting oxide containing lithium and transition metal element or poly anionic compound. The cathode contains a cathode active material consisting of carbon material capable of occluding and discharging lithium. The electrolyte is lithium hexafluorophosphate and salt of anion compound of formula (1).    M=transition metal, III group element, IV group element or V group element;    b=1-3;    m=1-4;    n=0-8;    q=0 or 1;    R1=1-10C alkylene, 1-10C halogenated alkylene, 6-20C arylene or 6-20C halogenated arylene, each optionally having substituent and hetero atom;    R2=1-10C alkyl, halogen, 1-10C alkyl halide, 6-20C aryl, 6-20C halogenated aryl or X3R3, and alkyl and aryl groups optionally have substituent and hetero atom;    X1-X3=oxygen, sulfur or NR4;and    R3,R4=H and group (G) chosen from 1-10C alkyl, 1-10C alkyl halide, 6-20C aryl or 6-20C halogenated aryl, each optionally having substituent and heteroatom, and optionally couple to form ring.    DESCRIPTION OF DRAWING(S) - The figure shows the explanatory drawing of structure of lithium ion secondary cell. (Drawing includes non-English language text)    Lithium ion secondary cell (1)    Anode (2)    Cathode (3)    Separator (4)    Battery case (6)