Secondary battery and apparatus including the secondary battery

A secondary battery, comprising a negative electrode plate, a positive electrode plate, a separator, and an electrolyte, wherein the electrolyte comprises an organic solvent and an electrolyte salt, the negative electrode plate comprises a negative current collector and negative film layers, wherein the negative film layers comprise a first negative film layer and a second negative film layer, the first negative film layer is disposed on at least one surface of the negative current collector and comprises a first negative active material, and the second negative film layer is disposed on the first negative film layer and comprises a second negative active material;

• the first negative active material comprises natural graphite, and the second negative active material comprises artificial graphite;
• the first negative active material has a powder orientation index (OI) value COI1 satisfying 4.7≤COI1≤5.0;
• and
• the second negative active material has a powder orientation index (OI) value COI2 satisfying 2.8≤COI2≤3.0, and
• the first negative active material and the second negative active material further satisfy 1.1≤COI1/COI2≤2.5,
• wherein
• COI1 is a ratio of peak area of 004 characteristic diffraction peak to peak area of 110 characteristic diffraction peak in an X-ray diffraction pattern of the first negative active material;
• and
• COI2 is a ratio of peak area of 004 characteristic diffraction peak to peak area of 110 characteristic diffraction peak in an X-ray diffraction pattern of the second negative active material;
• and
• wherein the first negative active material has a particle diameter distribution satisfying 0.8≤(DV90−DV10)/DV50≤1.5, and the second negative active material has a particle diameter distribution satisfying 0.9≤(DV90−DV10)/DV50≤2.