TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The lithium salt comprises at least one selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO4, LiAlCl4, LiCl and/or LiI. The positive active material is selected from lithium based compound of formulae LiaA'1-bB'bD'2, LiaE'1-bB'bO2-cF'c, LiCO2-bO4-cFc, LiMn2-bO4-cF'c, LiaNi1-b-cCobB'cD'~a, LiaNi1-b-cCObO2-~aF'~a, LiaNi1-b-cCObO2-~aF'2, LiaNi1-b-cMnbB'cD'~a, LiaNi1-b-cMnbO2-~aF'~a, LiaNi1-b-cMnbO2-~aF'2, LiaNibE'cG'dO2, LiaNibCocMndG'eO2, LiaNiG'bO2, LiaCoG'bO2, LiaMnG'bO2, LiaMn2G'bO4, HO2, HS2, LiHS2, V2O5, LiV2O5, LiI'O2, LiNiVO4, Li3-fJ'2(PO4)3, Li3-f'Fe2(PO4)3.a=0.95-1.1;b=0-0.5;c=0-0.05;alpha =greater than 0 and less than 2;d and e=0.001-0.1;f=0-3;f'=0-2;A'=Ni, Co and/or Mn;B'=Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V and/or rare earth element;D'=O, F, S and/or P;E'=Co and/or Mn;F'=F, S and/or P;G'=Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and/or lanthanide element;Q'=Ti, Mo and/or Mn;I'=Cr, V, Fe, Sc and/or Y;andJ'=V, Cr, Mn, Co, Ni and/or Cu.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The compound (I) is present in an amount of 0.01-10 wt.% based on the total weight of the electrolyte. The lithium salt comprises at least one selected from LiCF3SO3, LiC4F9SO3, LiN(CF3SO2)2, LiN(C2F5SO2)2, LiN(CpF2p+1SO2)(CqF2q+qSO2) and/or LiSO3CF3. The lithium salt is present at a concentration of 0.7-2M. The non-aqueous organic solvent comprises at least one selected from carbonate-based solvent, ester-based solvent, ether-based solvent, and/or ketone-based solvent, and optionally an aromatic hydrocarbon-based solvent. The non-aqueous organic solvent comprises a carbonate-based solvent comprised of a mixture of a cyclic carbonate and a linear carbonate in a volume ratio of 1:1-1:9. The cyclic carbonate comprises at least one selected from ethylene carbonate, propylene carbonate, butylene carbonate and/or gamma -butyrolactone, and the linear carbonate comprises at least one selected from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate and/or methylethyl carbonate. The non-aqueous organic solvent comprises the carbonate-based solvent and the aromatic hydrocarbon-based solvent. The carbonate-based solvent and the aromatic hydrocarbon-based solvent are in a volume ratio of 1:1-30:1. The aromatic hydrocarbon-based solvent is of formula phenyl substituted at 1-6 positions by R1-R6 respectively. The negative active material is at least one selected from carbonaceous material, metal being capable of alloying lithium and/or composite of a metal and a carbonaceous material.p and q=natural numbers;andR1-R6=H, halo, 1-10C alkyl and/or haloalkyl. SPECIFIC COMPOUNDS - Use of tris(trimethylsilyl)phosphite, tris(triethylsilyl)phosphite, tris(trimethylsilyl)borate and tris(triethylsilyl)borate are specifically claimed as (I).    EXAMPLE - 1M LiPF6 was added to a non-aqueous organic solvent in which ethylene carbonate/ethylmethyl carbonate/dimethyl carbonate were mixed at a volume ratio of 3/4/3, and then the tris(trimethylsilyl)borate (I') (2 wt.%) was added to it to provide an test electrolyte solution. An comparative electrolyte solution was prepared in accordance with the same procedure as in above-mentioned for test electrolyte solution, except that the compound (I') was not added. The test and comparative rechargeable lithium battery cells including test and comparative electrolytes were charged at -30 degrees C, an initial voltage of 3.74V, and a 5 C constant current discharge for 2 seconds, then measured for the low temperature (LT) Power based on the low temperature discharge. The test/comparative rechargeable lithium battery cells showed LT power (W/cell) of 5.35/3.74. The test rechargeable lithium battery cell showed most improved output characteristic than that comparative rechargeable lithium battery cell.