TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The compound (I) is preferably chosen from methyl acetylsalicylate and methyl-2-methoxybenzoate. The concentration of compound (I) is 0.1-20 wt.%. The electrolyte composition further contains an additive chosen from solid electrolyte interphase forming additive and additional overcharge protection additive. The solid electrolyte interphase forming additive is chosen from vinylene carbonate and its derivatives, fluorinated ethylene carbonate and its derivatives, propane sultone and its derivatives, ethylene sulfite and its derivatives, oxalate-containing compounds, and ionic compounds containing a cation of formula (II) and anion chosen from bis(oxalato)borate, difluoro(oxalato)borate, (FzB(CmF(2m+1)4-z))-, (FyP(CmF(2m+1)6-y))-, ((CmF(2m+1))2P(O)O)-, (CmF(2m+1)P(O)O2)2-, (O-C(O)-CmF(2m+1))-, (O-S(O)2-(CmF(2m+1)))-, (N(C(O)- CmF(2m+1))2)-, (N(S(O)2-CmF(2m+1))2)-, (N(C(O)-CmF(2m+1))(S(O)2-CmF(2m+1)))-, (N(C(O)-CmF(2m+1))(C(O)F))-, (N(S(O)2-CmF(2m+1))(S(O)2F))-, (N(S(O)2F)2)-, (C(C(O)-CmF(2m+1))3)- and (C(S(O)2-CmF(2m+1))3)-. The additional overcharge protection additive is of formula (III). The electrolyte composition contains aprotic organic solvent(s) chosen from cyclic and acyclic carbonates, di-1-10C-alkylethers, di-1-4C-alkyl-2-6C-alkylene ethers and polyethers, cyclic ethers, cyclic and acyclic acetal and ketal, orthocarboxylic acids esters, cyclic and acyclic esters of carboxylic acids, cyclic and acyclic sulfones, and cyclic and acyclic nitriles and dinitriles.X=CH2 or NR';R3,R'=1-6C alkyl;R4=-(CH2)u-SO3-(CH2)v-R";-SO3-=-O-S(O)2- or -S(O)2-O-;u,m=1-8;v,Z=1-4;R"=1-20C alkyl, 2-20C alkenyl, 2-20C alkynyl, 6-12C aryl, or 6-24C aralkyl (optionally substituted by 1 or more F and optionally having 1 or more CH2 which is not directly bonded to SO3 replaced by O);y=1-6;R5=cyclohexyl or 6-12C aryl optionally substituted by F, Cl, Br, I or 6-12C aryl or 1-6C alkyl (both optionally substituted by F, Cl, Br or I);andR6-R10=H, F, Cl, Br, I, or 6-12C aryl, or 1-6C alkyl (both optionally substituted by F, Cl, Br or I).(i) CH2 groups of -(CH2)u-alkylene chain are not directly bonded to the N-atom or SO3 group, are optionally replaced by O; and (ii) two adjacent CH2 groups of -(CH2)u- alkylene chain are optionally replaced by a C-C double bond.