An electrolyte composition containing at least one conducting salt selected from lithium salts and at least one compound of formula (I) wherein X 1 and X 2 are N; R 1 and R 2 are selected independently from each other from R 4 , OR 4 , SR 4 , S(O)R 4 , S(O) 2 R 4 , OS(O) 2 R 4 , S(O) 2 OR 4 , OSiR 8 3 , and NR 5 R 6 , R 4 is selected from C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, alkynyl, (hetero)aryl, and (hetero)aralkyl may be substituted by one or more substituents selected from F, CN, C(O)OR 7 , OC(O)R 7 , OR 7 , and SR 7 ; R 5 and R 6 are selected independently from each other from H, C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, alkynyl, (hetero)aryl, and (hetero)aralkyl may be substituted by one or more substituents selected from F and CN; or R 5 and R 6 may be combined to form together with the C- or N-atom a 5- to 7-membered heterocycle which may be substituted by one or more substituents selected from F, CN, C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, alkynyl, (hetero)aryl, and (hetero)aralkyl may be substituted by one or more substituents selected from F and CN; R 7 is selected from C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl which may be substituted by one or more substituents selected from F and CN; and R 8 is independently selected from R 4 and OR 4 . X 1 and X 2 are N; R 1 and R 2 are selected independently from each other from R 4 , OR 4 , SR 4 , S(O)R 4 , S(O) 2 R 4 , OS(O) 2 R 4 , S(O) 2 OR 4 , OSiR 8 3 , and NR 5 R 6 , R 4 is selected from C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, alkynyl, (hetero)aryl, and (hetero)aralkyl may be substituted by one or more substituents selected from F, CN, C(O)OR 7 , OC(O)R 7 , OR 7 , and SR 7 ; R 5 and R 6 are selected independently from each other from H, C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, alkynyl, (hetero)aryl, and (hetero)aralkyl may be substituted by one or more substituents selected from F and CN; or R 5 and R 6 may be combined to form together with the C- or N-atom a 5- to 7-membered heterocycle which may be substituted by one or more substituents selected from F, CN, C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, alkynyl, (hetero)aryl, and (hetero)aralkyl may be substituted by one or more substituents selected from F and CN; R 7 is selected from C 1 to C 12 alkyl, C 3 -C 6 (hetero)cycloalkyl, C 2 to C 12 alkenyl, C 2 to C 12 alkynyl, C 5 to C 12 (hetero)aryl, and C 6 to C 24 (hetero)aralkyl which may be substituted by one or more substituents selected from F and CN; and R 8 is independently selected from R 4 and OR 4 . <EOS>