NOVELTY - Non-aqueous electrolyte lithium ion secondary cell (1) has an anode (2), a cathode (3), and a non-aqueous electrolyte formed by dissolving an electrolyte in a non-aqueous solvent. The anode active material essentially contains iron-lithium phosphate. The electrolyte has lithium hexafluoro phosphate as main component. The non-aqueous solvent has mixed solvent of ethylene carbonate and diethyl carbonate, or mixed solvent of ethylene carbonate and ethylmethyl carbonate as main component along with 0.2-5 wt.% of vinylene carbonate and/or vinyl ethylene carbonate.    USE - Non-aqueous electrolyte lithium ion secondary cell is used for personal computer, mobile telephone, hybrid vehicles and electric vehicles.    ADVANTAGE - The non-aqueous electrolyte lithium ion secondary cell is lightweight and has high output, excellent charging and discharging characteristics, and high capacitance which is maintained even at high temperature. The reduction in output of cell at low temperature is prevented.    DETAILED DESCRIPTION - Non-aqueous electrolyte lithium ion secondary cell has an anode, a cathode, and a non-aqueous electrolyte formed by dissolving an electrolyte in a non-aqueous solvent. The anode contains an anode active material which consists of a compound that occludes and releases lithium ion. The cathode contains a cathode active material which consists of a carbon type material that occludes and releases lithium ion. The anode active material contains iron-lithium phosphate (LiFePO4) of olivine structure as main component. The electrolyte has lithium hexafluorophosphate as main component. The non-aqueous solvent has mixed solvent of ethylene carbonate and diethyl carbonate, or mixed solvent of ethylene carbonate and ethylmethyl carbonate as main component along with 0.2-5 wt.% of vinylene carbonate and/or vinyl ethylene carbonate. The content of ethylene carbonate in the non-aqueous solvent is 15-40 wt.%. The non-aqueous solvent preferably has mixed solvent of ethylene carbonate and ethylmethyl carbonate along with 0.5-1.5 wt.% of vinyl ethylene carbonate. The content of ethylmethyl carbonate in the non-aqueous solvent is 60-80 wt.%.    DESCRIPTION OF DRAWING(S) - The drawing shows the structure of non-aqueous electrolyte lithium ion secondary cell.(Drawing includes non-English language text)    Non-aqueous electrolyte lithium ion secondary cell (1)    Anode (2)    Cathode (3)    Separator (4)    Battery case (6)