Lithium-ion battery and apparatus

A lithium-ion battery comprising an electrode assembly and an electrolyte, the electrode assembly comprising a positive electrode sheet, a negative electrode sheet and a separation film;

• wherein
• a positive active material in the positive electrode sheet comprises Lix1Coy1M1-y1O2-z1Qz1, 0.5≤x1≤1.2, 0.8≤y1<1.0, 0≤z1≤0.1, M is selected from one or more of the group consisting of Al, Ti, Zr, Y, and Mg, and Q is selected from one or more of the group consisting of F, Cl, and S;
• the electrolyte comprises an additive A and an additive B, the additive A is selected from one or more of the group consisting of
• Formula I-1, and Formula I-3,
• in Formula I-1, and Formula I-3:
• R1, R2, R3 and R4 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted C1-C12 alkyl group, a substituted or unsubstituted C1-C12 alkoxy group, a substituted or unsubstituted C1-C12 amine group, a substituted or unsubstituted C2-C12 alkenyl group, a substituted or unsubstituted C2-C12 alkynyl group, a substituted or unsubstituted C6-C26 aryl group, and a substituted or unsubstituted C2-C12 heterocyclic group, wherein a substituent group is selected from one or more of the group consisting of a halogen atom, a nitrile group, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C1-C6 alkoxy group;
• x, y, and z are each independently selected from integers of 0-8;
• and m, n, and k are each independently selected from integers of 0-2;
• and the additive B is selected from one or more of the group consisting of compounds represented by Formula II-1 and Formula II-2;
• in Formula II-1 and Formula II-2:
• R5 is selected from the group consisting of a substituted or unsubstituted C1-C12 alkylene group, a substituted or unsubstituted C2-C12 alkenylene group, and a substituted or unsubstituted C2-C12 alkynylene group, and R6, R7, and R8 are each independently selected from the group consisting of substituted or unsubstituted C1-C12 alkylene group, substituted or unsubstituted C2-C12 alkenylene group, and substituted or unsubstituted C2-C12 alkynylene group, wherein a substituent group is selected from one or more of the group consisting of a halogen atom, a nitrile group, a C1-C6 alkyl group, a C2-C6 alkenyl group, and a C1-C6 alkoxy group, wherein a mass percentage of the additive A in the electrolyte is 0.1-10, and a mass percentage of additive B in the electrolyte is 0.1-10.