NOVELTY - A non-aqueous electrolyte contains lithium phosphorus hexafluoride, anion compound (1), and additional positive ions chosen from sodium ion, potassium ion, rubidium ion, cesium ion and/or tetra alkyl ammonium ion. The electrolyte contains lithium ion and phosphorus hexafluoride ion in non-aqueous solvent. The anion compound is contained in an amount of 1-30 mol% with respect to total amount of phosphorus hexafluoride and anion compound. The additional positive ion is contained in an amount of 0.1-20 mol% with respect to total amount of lithium ion and additional positive ion.    USE - For lithium secondary battery (claimed) used as power supply of personal computer, mobile telephone, electric vehicle and hybrid electric vehicle.    ADVANTAGE - The non-aqueous electrolyte provides secondary battery with improved battery characteristics such as output, capacitance maintenance factor and initial state discharge capacitance.    DETAILED DESCRIPTION - A non-aqueous electrolyte contains lithium phosphorus hexafluoride, anion compound of formula (1), and additional positive ions chosen from sodium ion, potassium ion, rubidium ion, cesium ion and/or tetra alkyl ammonium ion. The electrolyte contains lithium ion and phosphorus hexafluoride ion in non-aqueous solvent. The anion compound is contained in an amount of 1-30 mol% with respect to the total amount of phosphorus hexafluoride and anion compound. The additional positive ion is contained in an amount of 0.1-20 mol% with respect to the total amount of lithium ion and additional positive ion.    M=transition metal, metal of group III, IV or V;    b=1-3;    m=1-4;    n=0-8;    q=0 or 1;    R1=1-10C (halo)alkylene, 6-20C (halo)arylene, optionally substituted with hetero atom;    R2=halogen, 1-10C (halo)alkyl, 6-20C (halo)aryl or X3R3, optionally substituted with hetero atom;    X1-X3=oxygen, sulfur or NR4;and    R3,R4=1-10C (halo)alkyl, 6-20C (halo)aryl, optionally substituted with hetero atom.    m R1 may couple to form a ring. n R2 may couple to form a ring. R3 and R4 may couple to form a ring. An INDEPENDENT CLAIM is included for lithium secondary battery (1), which consists of anode (2) comprising anode active material provided on collector containing aluminum, cathode (3) comprising cathode active material and electrolyte liquid formed by dissolving the non-aqueous electrolyte in an organic solvent, provided in a battery case (6).    DESCRIPTION OF DRAWING(S) - The figure shows the explanatory drawing of the lithium secondary battery. (Drawing includes non-English language text)    Lithium secondary battery (1)    Anode (2)    Cathode (3)    Separator (4)    Battery case (6)