A lithium-ion battery, comprising an electrode assembly and an electrolyte, the electrode assembly comprises a positive electrode sheet, a negative electrode sheet and a separation film; characterized in that, a positive active material in the positive electrode sheet comprises Li x1 Co y1 M 1-y1 O 2-z1 Q z1, 0.5≤x1≤1.2, 0.8≤y1<1.0, 0≤z1≤0.1, M is selected from one or more of Al, Ti, Zr, Y, and Mg, Q is selected from one or more of F, Cl, S; the electrolyte also contains an additive A and an additive B, the additive A is selected from one or more of compounds represented by Formula I-1, Formula I-2, and Formula I-3, and the additive B is selected from one or more of compounds represented by Formula II-1 and Formula II-2; in Formula I-1, Formula I-2, and Formula I-3: R 1, R 2, R 3, and R 4 are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 -C 12 alkyl group, a substituted or unsubstituted C 1 -C 12 alkoxy group, a substituted or unsubstituted C 1 -C 12 amine group, a substituted or unsubstituted C 2 -C 12 alkenyl group, a substituted or unsubstituted C 2 -C 12 alkynyl group, a substituted or unsubstituted C 6 -C 26 aryl group, a substituted or unsubstituted C 2 -C 12 heterocyclic group, wherein a substituent group is selected from one or more of a halogen atom, a nitrile group, a C 1 -C 6 alkyl group, a C 2 -C 6 alkenyl group, a C 1 -C 6 alkoxy group; x, y, z are each independently selected from integers of 0-8; and m, n, k are each independently selected from integers of 0-2; in Formula II-1 and Formula II-2: R 5 is selected from a substituted or unsubstituted C 1 -C 12 alkylene group, a substituted or unsubstituted C 2 -C 12 alkenylene group, a substituted or unsubstituted C 2 -C 12 alkynylene group, R 6, R 7, and R 8 are each independently selected from substituted or unsubstituted C 1 -C 12 alkylene group, substituted or unsubstituted C 2 -C 12 alkenylene group, substituted or unsubstituted C 2 -C 12 alkynylene group, wherein a substituent group is selected from one or more of a halogen atom, a nitrile group, a C 1 -C 6 alkyl group, a C 2 -C 6 alkenyl group, and a C 1 -C 6 alkoxy group. a positive active material in the positive electrode sheet comprises Li x1 Co y1 M 1-y1 O 2-z1 Q z1, 0.5≤x1≤1.2, 0.8≤y1<1.0, 0≤z1≤0.1, M is selected from one or more of Al, Ti, Zr, Y, and Mg, Q is selected from one or more of F, Cl, S; the electrolyte also contains an additive A and an additive B, the additive A is selected from one or more of compounds represented by Formula I-1, Formula I-2, and Formula I-3, and the additive B is selected from one or more of compounds represented by Formula II-1 and Formula II-2; in Formula I-1, Formula I-2, and Formula I-3: R 1, R 2, R 3, and R 4 are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 -C 12 alkyl group, a substituted or unsubstituted C 1 -C 12 alkoxy group, a substituted or unsubstituted C 1 -C 12 amine group, a substituted or unsubstituted C 2 -C 12 alkenyl group, a substituted or unsubstituted C 2 -C 12 alkynyl group, a substituted or unsubstituted C 6 -C 26 aryl group, a substituted or unsubstituted C 2 -C 12 heterocyclic group, wherein a substituent group is selected from one or more of a halogen atom, a nitrile group, a C 1 -C 6 alkyl group, a C 2 -C 6 alkenyl group, a C 1 -C 6 alkoxy group; x, y, z are each independently selected from integers of 0-8; and m, n, k are each independently selected from integers of 0-2; in Formula II-1 and Formula II-2: R 5 is selected from a substituted or unsubstituted C 1 -C 12 alkylene group, a substituted or unsubstituted C 2 -C 12 alkenylene group, a substituted or unsubstituted C 2 -C 12 alkynylene group, R 6, R 7, and R 8 are each independently selected from substituted or unsubstituted C 1 -C 12 alkylene group, substituted or unsubstituted C 2 -C 12 alkenylene group, substituted or unsubstituted C 2 -C 12 alkynylene group, wherein a substituent group is selected from one or more of a halogen atom, a nitrile group, a C 1 -C 6 alkyl group, a C 2 -C 6 alkenyl group, and a C 1 -C 6 alkoxy group.