A lithium-ion battery, comprising an electrode assembly and an electrolytic solution, wherein the electrode assembly comprises a positive electrode sheet, a negative electrode sheet, and a separation film; wherein 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, and Q is selected from one or more of F, Cl, and S; the positive electrode active material is a mixture of large particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1 and small particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1, wherein an average particle size D50 of the large particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1 is 10 μm-17 μm, and an average particle size D50 of the small particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1 is 2 μm-7 μm; the electrolytic solution contains an additive A that is selected from one or more of compounds represented by Formula I-1, Formula I-2, and Formula I-3; in the Formula I-1, the Formula I-2, and the Formula I-3, R 1, R 2, R 3, and R 4 each are 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, or 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, and a C 1 -C 6 alkoxy group; x, y, and z each are independently selected from integers 0-8; and m, n, and k each are independently selected from integers 0-2. 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, and Q is selected from one or more of F, Cl, and S; the positive electrode active material is a mixture of large particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1 and small particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1, wherein an average particle size D50 of the large particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1 is 10 μm-17 μm, and an average particle size D50 of the small particles Li x1 Co y1 M 1-y1 O 2-z1 Q z1 is 2 μm-7 μm; the electrolytic solution contains an additive A that is selected from one or more of compounds represented by Formula I-1, Formula I-2, and Formula I-3; in the Formula I-1, the Formula I-2, and the Formula I-3, R 1, R 2, R 3, and R 4 each are 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, or 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, and a C 1 -C 6 alkoxy group; x, y, and z each are independently selected from integers 0-8; and m, n, and k each are independently selected from integers 0-2.