Electrolyte and battery

An electrolyte, comprising an additive, wherein the additive is selected from a group consisting of multi-cyano six-membered N-heterocyclic compounds represented by Formula I-1, Formula I-2 and Formula I-3, and combinations thereof,

• wherein R1, R2, R3 and R4 are each independently selected from a group consisting of hydrogen, halogen, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C1-C12 alkoxy, substituted or unsubstituted C1-C12 amine group, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C26 aryl, and substituted or unsubstituted C4-C12 heterocyclic group;
• the substituent for the above groups, if present, is independently selected from a group consisting of halogen, cyano, C1-C6 alkyl, C2-C6 alkenyl, C1-C6 alkoxy, and combinations thereof;
• x, y and z are each an integer independently selected from 0-8;
• and
• m, n and k are each an integer independently selected from 0-2.