Acrylonitrile derivatives as additive for electrolytes in lithium ion batteries

The electrolyte composition (A) according to claim 1, wherein the aprotic organic solvent (i) is selected from the group consisting of

• (a) cyclic and noncyclic organic carbonates, which may be optionally partly halogenated,
• (b) di-C1-C10-alkylethers, optionally partly halogenated,
• (c) di-C1-C4-alkyl-C2-C6-alkylene ethers and polyethers, optionally partly halogenated,
• (d) cyclic ethers, optionally partly halogenated.
• (e) cyclic and acyclic acetals and ketals, optionally partly halogenated,
• (f) orthocarboxylic acids esters, optionally partly halogenated,
• (g) cyclic and noncyclic esters of carboxylic acids, optionally partly halogenated,
• (h) cyclic and noncyclic sulfones, optionally partly halogenated,
• (i) cyclic and noncyclic nitriles and dinitriles, optionally partly halogenated, and
• (j) ionic liquids, optionally partly halogenated.

The electrolyte composition (A) according to claim 1, wherein the conducting salt (ii) is selected from the group consisting of

• Li[F6−xP(CyF2y+1)x], wherein x is an integer in the range from 0 to 6 and y is an integer in the range from 1 to 20;
• Li[B(RI)4], Li[B(RI)2(ORIIO)] and Li[B(ORIIO)2] wherein each RI is independently F, Cl, Br, I, C1-C4 alkyl, C2-C4 alkenyl, or C2-C4 alkynyl, wherein alkyl, alkenyl, and alkynyl may be substituted by one or more ORIII, wherein RIII is selected from the group consisting of C1-C6 alkyl, C2-C6 alkenyl, and C2-C6 alkynyl and (ORIIO) is a bivalent group derived from a 1,2- or 1,3-diol, a 1,2- or 1,3-dicarboxlic acid or a 1,2- or 1,3-hydroxycarboxylic acid, wherein the bivalent group forms a 5- or 6-membered cycle via the both oxygen atoms with the central B-atom;
• LiClO4;
• LiAsF6;
• LiCF3SO3;
• Li2SiF6;
• LiSbf6;
• LiAlCl4, lithium tetrafluoro (oxalato) phosphate;
• lithium oxalate;
• and
• salts of formula Li[Z(CnF2n+1SO2)m], wherein
• m=1 when Z is selected from oxygen and sulfur,
• m=2 when Z is selected from nitrogen and phosphorus,
• m=3 when Z is selected from carbon and silicon, and
• n is an integer in the range from 1 to 20.

A method to prepare an electrolyte for an electrochemical cell, comprising:

• adding a compound of formula (I) to the electrolyte:
• wherein
• X1 and X2 are each independently N(R1), P(R1), O, or S;
• R1 is H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C3-C6 (hetero)cycloalkenyl, C2-C6 alkynyl, C5-C7 (hetero)aryl, C7-C13 aralkyl, OR3, C(O)R3, C(NR3)R4, or C(O)OR3, wherein alkyl, (hetero)cycloalkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, (hetero)aryl, and aralkyl may be 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, S(O)2OR3a, OS(O)2R3a, S(O)2R3a, OR3a, C(O)R3a, C(O)OR3a, NR3aR3b, and NC(O)R3aR3b;
• Y1 and Y2 are each independently (O), (S), (PR2) or (NR2),
• R2 is H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, (hetero)C3-C6 cycloalkenyl, C2-C6 alkynyl, C5-C7 (hetero)aryl, C7-C13 aralkyl, OR2a or C(O)R2a, wherein alkyl, (hetero)cycloalkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, (hetero)aryl, and aralkyl may be 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, S(O)2OR2b, OS(O)2R2b, S(O)2R2b, OR2b, C(O)R2b, C(O)OR10b, NR2bR2c, and NC(O)R2bR2c;
• and
• R2a, R2b and R2c are each independently H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, or C5-C7 (hetero)aryl, wherein alkyl, (hetero)cycloalkyl, alkenyl, and (hetero)aryl may be substituted by one or more substituents selected from F and CN,
• R3, R4, R3a, and R3b are each independently H, C1-C6 alkyl, C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, C3-C6 (hetero)cycloalkenyl, C2-C6 alkynyl, C5-C7 (hetero)aryl, or C7-C13 aralkyl, wherein alkyl, (hetero)cycloalkyl, alkenyl, (hetero)cycloalkenyl, alkynyl, (hetero)aryl, and aralkyl may be 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, S(O)2OR3c, OS(O)2R3c, S(O)2R3c, OR3c, C(O)R3c, C(O)OR3c, NR3cR3d, and NC(O)R3cR3d;
• R3c and R3d are each independently H, C1-C6 alkyl C3-C6 (hetero)cycloalkyl, C2-C6 alkenyl, or C5-C7(hetero)aryl, wherein alkyl, (hetero)cycloalkyl, alkenyl, and (hetero)aryl may be substituted by one or more substituents selected from F and CN.