A secondary battery comprising a positive electrode plate, a negative electrode plate, an electrolyte and a separator, the negative electrode plate comprising a negative current collector and a negative film, the negative film being provided on at least one surface of the negative current collector and comprising a negative active material; wherein the negative active material comprises graphite; the negative active material is obtained by the process of being tested in a button half battery: the button half battery is discharged to 5 mV at a constant current of 0.05 C, and the obtained capacity is recorded as X; then the button half battery is discharged to 5 mV at a constant current of 50 μA, and the obtained capacity is recorded as A; then the button half battery is discharged to 5 mV at a constant current of 10 μA, and the obtained capacity is recorded as B; and the polarisation of the negative active material satisfies 0.02≤(A+B)/X≤0.50; wherein the negative electrode plate satisfies a relationship: 0.05≤(A/X)×CW≤2.00, CW represents a coating weight of the negative electrode plate per unit area with a unit of mg/cm 2; and wherein the positive electrode plate comprises a positive current collector and a positive film, the positive film is provided on at least one surface of the positive current collector and comprises a positive active material, the positive active material is one or more selected from a group consisting of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and olivine-type lithium-containing phosphate. wherein the negative active material comprises graphite; the negative active material is obtained by the process of being tested in a button half battery: the button half battery is discharged to 5 mV at a constant current of 0.05 C, and the obtained capacity is recorded as X; then the button half battery is discharged to 5 mV at a constant current of 50 μA, and the obtained capacity is recorded as A; then the button half battery is discharged to 5 mV at a constant current of 10 μA, and the obtained capacity is recorded as B; and the polarisation of the negative active material satisfies 0.02≤(A+B)/X≤0.50; wherein the negative electrode plate satisfies a relationship: 0.05≤(A/X)×CW≤2.00, CW represents a coating weight of the negative electrode plate per unit area with a unit of mg/cm 2; and wherein the positive electrode plate comprises a positive current collector and a positive film, the positive film is provided on at least one surface of the positive current collector and comprises a positive active material, the positive active material is one or more selected from a group consisting of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and olivine-type lithium-containing phosphate. the button half battery is discharged to 5 mV at a constant current of 0.05 C, and the obtained capacity is recorded as X; then the button half battery is discharged to 5 mV at a constant current of 50 μA, and the obtained capacity is recorded as A; then the button half battery is discharged to 5 mV at a constant current of 10 μA, and the obtained capacity is recorded as B; and the polarisation of the negative active material satisfies 0.02≤(A+B)/X≤0.50; wherein the negative electrode plate satisfies a relationship: 0.05≤(A/X)×CW≤2.00, CW represents a coating weight of the negative electrode plate per unit area with a unit of mg/cm 2; and wherein the positive electrode plate comprises a positive current collector and a positive film, the positive film is provided on at least one surface of the positive current collector and comprises a positive active material, the positive active material is one or more selected from a group consisting of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and olivine-type lithium-containing phosphate.