Oxiranyl-acyl derivatives as additives for electrolytes in lithium ion batteries

A method for preparing an electrolyte for an electrochemical cell, the method comprising:

• introducing a conducting lithium salt and a compound of formula (I)
• into the electrolyte as an additive,
• wherein
• X is carbon, S(O) or P(OR8);
• n is 0 or 1;
• R1 is selected from the group consisting of C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C3-C6 (hetero)cycloalkenyl, C2-C6 alkynyl, C5-C7 (hetero)aryl, and C6-C13 aralkyl, wherein alkyl, (hetero)cycloalkyl, aralkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, and (hetero)aryl are each optionally substituted by one or more substituents selected from the group consisting of F, CN, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C5-C7 (hetero)aryl, ORS, C(O)R5, C(O)OR5, OC(O)R5, OC(O)OR5, OC(O)C(O)OR5, OS(O)2R5, and S(O)2OR5;
• R2 is selected from the group consisting of H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C3-C6 (hetero)cycloalkenyl, C2-C6 alkynyl, C5-C7 (hetero)aryl, C6-C13 aralkyl, C(O)R6, C(O)OR6, and S(O)2OR6, wherein alkyl, (hetero)cycloalkyl, aralkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, and (hetero)aryl are each optionally substituted by one or more substituents selected from the group consisting of F, CN, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C5-C7 (hetero)aryl, OR7, C(O)R7, C(O)OR7, OC(O)R7, OC(O)OR7, OC(O)C(O)OR7, OS(O)2R7, and S(O)2OR7;
• R3 and R4 are independently selected from the group consisting of H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C3-C6 (hetero)cycloalkenyl, C2-C6 alkynyl, C5 or C7 (hetero)aryl, C6-C13 aralkyl, C(O)R6, C(O)OR6, and S(O)2OR6, wherein alkyl, (hetero)cycloalkyl, aralkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, and (hetero)aryl are each optionally substituted by one or more substituents selected from the group consisting of F, CN, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C5-C7 (hetero)aryl, OR7, C(O)R7, C(O)OR7, OC(O)R7, OC(O)OR7, OC(O)C(O)OR7, OS(O)2R7 and S(O)2O R7;
• or R2 and R3 are combined with each other and form together with a C—C single bond of an oxirane cycle a 5 to 7 membered hydrocarbon cycle which is substituted by at least one group selected from the group consisting of O and oxiranyl, and/or two adjacent C-atoms of the hydrocarbon carbon cycle form together with an O-atom an additional oxirane cycle;
• R5, R6, R7 and R8 are independently selected from the group consisting of H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C3-C6 (hetero)cycloalkenyl, C2-C6 alkynyl, C5-C7 (hetero)aryl, and C6-C13 aralkyl, wherein alkyl, (hetero)cycloalkyl, aralkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, and (hetero)aryl are each optionally substituted by one or more substituents selected from the group consisting of F, CN, and oxiranyl.