Lithium-ion battery and apparatus

A lithium-ion battery, comprising an electrode assembly and an electrolyte, wherein the electrode assembly comprises a positive electrode plate, a negative electrode plate, and a separator, wherein

• a positive active material of the positive electrode plate comprises Lix1Coy1M1-y1O2-z1Qz1, where 0.5≤x1≤1.2, 0.8≤y1≤1.0, 0≤z1≤0.1, M is one or more selected from the group consisting of Al, Ti, Zr, Y, and Mg, and Q is one or more selected from the group consisting of F, Cl, and S;
• the electrolyte contains an additive A represented by Formula I-2 in an amount of 0.1%-10% by mass based on the total mass of the electrolyte;
• and
• in the Formula 1-2, R1, R2, R3, and R4 each are independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted C1-C3 linear or branched alkyl group, a substituted or unsubstituted C5-C7 cyclic alkyl group, a substituted or unsubstituted C1-C3 alkoxy group, a substituted or unsubstituted C1-C3 amine group, a substituted or unsubstituted C2-C3 alkenyl group, a substituted or unsubstituted C2-C3 alkynyl group, a substituted or unsubstituted C6-C8 aryl group, and a substituted or unsubstituted C2-C7 heterocyclic group, wherein a substituent group is one or more selected from the group consisting of halogen atoms;
• x and y each are independently selected from 0, 1, or 2;
• and m and n each are independently selected from 1 or 2.