An electrolyte composition containing at least one conducting salt selected from lithium salts and at least one compound of formula 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 R 4, S 2 R 4, OS 2 R 4, S 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 OR 7, OC 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 R 4, S 2 R 4, OS 2 R 4, S 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 OR 7, OC 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.