An electrolyte solution comprising (i) a compound of formula: wherein R 101 and R 102 each individually are - a substituent selected from H, F, C 1-7 -alkyl, C 2-7 -alkenyl, C 2-7 -alkynyl, C 6-15 -aryl, - a group of the formula -O p101 -(SiR 103 2 O) n101 -SiR 104 3, wherein R 103 and R 104 each individually are alkyl, alkenyl, alkynyl or aryl, each obtained by optionally replacing at least one H by F; n101 is an integer of ≥ 0; and p101 is 0 or 1, - -SO 2 X 101 or -SO 3 X 102 wherein X 101 and X 102 each independently are H, F, or alkyl obtained by optionally replacing at least one H by F, or - a C 2-7 -hydrocarbon group that, by bonding of R 101 and R 102, forms a cyclic structure optionally containing a multiple bond, and the substituent optionally contains at least one di-to hexavalent heteroatom in its structure or optionally has a structure obtained by replacing at least one H by F or a C 0-7 -functional group, and (ii) at least one compound selected from the formulae to: wherein R 111 and R 112 each independently are H, F or an alkyl group optionally containing a fluorine atom, and R 113 is fluorine-free alkyl or an organic group containing an unsaturated carbon-carbon bond; wherein R 121 is C 1-7 -alkyl, C 2-8 -alkenyl, C 2-9 -alkynyl or C 6-12 -aryl, each optionally fluorinated and optionally containing at least one of O, Si, S, and N in its structure; wherein R 131 and R 132 (i) each individually are H, F, or C 1-7 -alkyl, C 2-8 -alkenyl, C 2-9 -alkynyl or C 6-12 -aryl,each optionally fluorinated, or (ii) are hydrocarbon groups binding to each other to form a 5- or 6-membered hetero ring with a nitrogen atom, and R 131 and R 132 each optionally contain at least one of O, S, and N in the structure, wherein Rf 141 is CF 3 -, CF 2 H-, or CFH 2 -, and R 141 is C 2-5 -alkenyl or C 2-8 -alkynyl, each optionally fluorinated and optionally containing Si in its structure; CH 3 CFX 151 COOR 151 wherein R 151 is a C 1-4 -alkyl, and X 151 is H or F. (i) a compound of formula: wherein R 101 and R 102 each individually are - a substituent selected from H, F, C 1-7 -alkyl, C 2-7 -alkenyl, C 2-7 -alkynyl, C 6-15 -aryl, - a group of the formula -O p101 -(SiR 103 2 O) n101 -SiR 104 3, wherein R 103 and R 104 each individually are alkyl, alkenyl, alkynyl or aryl, each obtained by optionally replacing at least one H by F; n101 is an integer of ≥ 0; and p101 is 0 or 1, - -SO 2 X 101 or -SO 3 X 102 wherein X 101 and X 102 each independently are H, F, or alkyl obtained by optionally replacing at least one H by F, or - a C 2-7 -hydrocarbon group that, by bonding of R 101 and R 102, forms a cyclic structure optionally containing a multiple bond, and the substituent optionally contains at least one di-to hexavalent heteroatom in its structure or optionally has a structure obtained by replacing at least one H by F or a C 0-7 -functional group, and - a substituent selected from H, F, C 1-7 -alkyl, C 2-7 -alkenyl, C 2-7 -alkynyl, C 6-15 -aryl, - a group of the formula -O p101 -(SiR 103 2 O) n101 -SiR 104 3, wherein R 103 and R 104 each individually are alkyl, alkenyl, alkynyl or aryl, each obtained by optionally replacing at least one H by F; n101 is an integer of ≥ 0; and p101 is 0 or 1, - -SO 2 X 101 or -SO 3 X 102 wherein X 101 and X 102 each independently are H, F, or alkyl obtained by optionally replacing at least one H by F, or - a C 2-7 -hydrocarbon group that, by bonding of R 101 and R 102, forms a cyclic structure optionally containing a multiple bond, and (ii) at least one compound selected from the formulae to: wherein R 111 and R 112 each independently are H, F or an alkyl group optionally containing a fluorine atom, and R 113 is fluorine-free alkyl or an organic group containing an unsaturated carbon-carbon bond; wherein R 121 is C 1-7 -alkyl, C 2-8 -alkenyl, C 2-9 -alkynyl or C 6-12 -aryl, each optionally fluorinated and optionally containing at least one of O, Si, S, and N in its structure; wherein R 131 and R 132 (i) each individually are H, F, or C 1-7 -alkyl, C 2-8 -alkenyl, C 2-9 -alkynyl or C 6-12 -aryl,each optionally fluorinated, or (ii) are hydrocarbon groups binding to each other to form a 5- or 6-membered hetero ring with a nitrogen atom, and R 131 and R 132 each optionally contain at least one of O, S, and N in the structure, wherein Rf 141 is CF 3 -, CF 2 H-, or CFH 2 -, and R 141 is C 2-5 -alkenyl or C 2-8 -alkynyl, each optionally fluorinated and optionally containing Si in its structure; CH 3 CFX 151 COOR 151 wherein R 151 is a C 1-4 -alkyl, and X 151 is H or F.