NOVELTY - A lithium salt-containing non-electrolyte for a lithium secondary battery using a lithium manganese metal oxide as a cathode active material and non-graphite carbon as anode material, comprises an alkyl ammonium or phosphonium borate/phosphate salt (1 - 20 wt.%).    USE - As an electrolyte for a lithium secondary battery used in unit cell for a high power, large-capacity battery or battery pack, which is useful as a power source for an electric vehicle or a hybrid electric vehicle (all claimed).    ADVANTAGE - The electrolyte exhibits excellent low-temperature properties and is thus capable of providing excellent properties even when it is used under severe conditions, particularly at low temperatures, such as in electric vehicles (EVs) and hybrid electric vehicles (HEVs). The non-graphitic carbon material enables use of propylene carbonate (PC) exhibiting a relatively low viscosity at a low temperature while having a high dielectric constant as an electrolyte solvent. The lithium secondary battery improves low-temperature properties of the battery by increasing the lithium ion-electrode reactivity and decreasing the electrode-interface resistance, via the formation of a charge double layer at the cathode-anode interface upon charging/discharging of the battery at a low temperature, and therefore can be preferably used in medium/large battery systems such as power sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs) forced to be in operation under severe conditions.    DETAILED DESCRIPTION - A lithium salt-containing non-electrolyte for a lithium secondary battery using a lithium manganese metal oxide as a cathode active material and non-graphite carbon as anode material, an alkyl ammonium or phosphonium borate/phosphate salt (1 - 20 wt.%) of formula (R)4X+Y1-(Z)n (I) (1 - 20 wt.%).    R=3-10C alkyl;    X=N or P;    Y1=B or P;    Z=3-10C alkyl, 4-10C cyclic or aromatic group or halo;    n=4 or 6 (depending on oxidation number of Y1).    Provided that X and Y1 are not identical.