TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Electrolyte: The electrolyte further comprises boron containing lithium salt. Preferred Components: The additive has a reduction potential higher than 0.7 V and an oxidation potential higher than 5.0 V, and is selected from fluorine-containing carbonates and/or fluorine-containing ethers. The additive is present in an amount of 0.1-20 parts by weight (pbw). The additive is fluorine-containing carbonate present in an amount of 3-10 pbw, and boron containing lithium salt present in an amount of 0.1-5 pbw based on 100 pbw of the electrolyte. The weight ratio of the ionic liquid to the additive is 6:0.5 to 6:4. The fluorine-containing carbonate is a compound of formula (I) and R'2-O-C(O)-O-R'1 (II). The fluorine-containing ether is compound of formula C(R)3-(O-C(R)2-C(R)2)n-OC(R)3. The ionic liquid of 5-70 (preferably 5-40) pbw is a combination of a cation selected from ammonium, imidazolium, oxazolium, piperidinium, pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolinium, thriazolium, triazolium, and guanidinium cations, and an anion selected from halo, sulfate, sulfonate, amide, imide, borate, phosphate, antimonate, decanoate and cobalt tetracarbonyl anions. The non-aqueous organic solvent is selected from carbonates (preferably dimethyl carbonates, diethyl carbonates, dipropyl carbonates, methyl propyl carbonates, ethyl propyl carbonates, ethyl methyl carbonates, ethylene carbonates, propylene carbonates, butylene carbonates and/or pentylene carbonates), esters (preferably n-methyl acetate, n-ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, .gamma.-butyrolactone, decanolide, valerolactone, mevalonolactone and/or caprolactone), ethers (preferably dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran and/or tetrahydrofuran) and/or ketones (preferably cyclohexanone and/or polymethyl vinyl ketone).R1 and R2=H, fluoro or fluorinated 1-5C alkyl;R'1 and R'2=1-5C alkyl or fluorinated 1-5C alkyl;R=H or fluoro;andn=1-3.Where both R1 and R2 are not H, and either R'1 or R'2 is fluorinated 1-5C alkyl.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The boron-containing lithium salt is selected from lithium bis(oxalato)borate and/or lithium fluoro(oxalato)borate. The lithium salt is selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiAlO4, LiAlCl4, LiN(CpF2p+1SO2)(CqF2q+1SO2), LiCl and/or LiI.p and q=natural numbers. EXAMPLE - Lithium hexafluorophosphate (LiPF6) was added to a mixed solvent of ethylene carbonate and ethyl methyl carbonate at (3:7 (v/v)) until the final concentration reached 1.3 M, and N-methyl propylpiperidinium bis(trifluoromethylsulfonyl)imide (40 parts by weight (pbw)) as an ionic liquid and fluoroethylene carbonate (FEC) (5 pbw) were added to prepare an electrolyte.