Lithium-ion secondary battery

1. A lithium-ion secondary battery comprising a positive electrode plate, a negative electrode plate, a separator and an electrolyte, the electrolyte comprising a lithium salt and an organic solvent;

wherein

the lithium-ion secondary battery satisfies a relationship:

2.13≤(m×C)/(ρ×Cap)<2.63, m represents a total mass of the electrolyte inside the lithium-ion secondary battery with a unit of g, ρ represents a density of the electrolyte with a unit of g/cm 3 , C represents a concentration of the lithium salt in the electrolyte with a unit of mol/L, Cap represents a rated capacity of the lithium-ion secondary battery with a unit of Ah,

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 comprises one or more selected from the group consisting of Li x Ni a Co b M c O 2 and a doping and/or coating modified compound thereof, M is one or two selected from the group consisting of Mn and Al, 0.95≤x≤1.2, 0<a<1, 0<b<1, 0<c<1, and

the density of the electrolyte represented by ρ is 1.1 g/cm 3 -1.25 g/cm 3 .

2. The lithium-ion secondary battery according to claim 1 , wherein the negative electrode plate comprises a negative current collector and a negative film, the negative film is provided on at least one surface of the negative current collector and comprises a negative active material, the negative active material at least comprises graphite.

3. The lithium-ion secondary battery according to claim 2 , wherein a coating weight of the negative film per unit area on one surface of the negative current collector represented by CW is 0.006 g/cm 2 -0.012 g/cm 2 .

4. The lithium-ion secondary battery according to claim 3 , wherein the coating weight of the negative film per unit area on one surface of the negative current collector represented by CW is 0.007 g/cm 2 -0.009 g/cm 2 .

5. The lithium-ion secondary battery according to claim 2 , wherein an OI value of the negative film represented by V OI is 11-30,

wherein

V OI =C 004 /C 110 ,

C 004 represents a characteristic diffraction peak area of (004) crystal plane in X-ray diffraction pattern of the negative film, and

C 110 represents a characteristic diffraction peak area of (110) crystal plane in X-ray diffraction pattern of the negative film.

6. The lithium-ion secondary battery according to claim 5 , wherein the OI value of the negative film represented by V OI is 14-30.

7. The lithium-ion secondary battery according to claim 6 , wherein the OI value of the negative film represented by V OI is 16-30.

8. The lithium-ion secondary battery according to claim 2 , wherein a pressing density of the negative film is 1.0 g/cm 3 -1.6 g/cm 3 .

9. The lithium-ion secondary battery according to claim 2 , wherein an average particle diameter of the negative active material represented by D50 is 4 μm-15 μm.

10. The lithium-ion secondary battery according to claim 1 , wherein the concentration of the lithium salt in the electrolyte represented by C is 0.6 mol/L-1.2 mol/L.

11. The lithium-ion secondary battery according to claim 10 , wherein the concentration of the lithium salt in the electrolyte represented by C is 0.8 mol/L-1.17 mol/L.

12. The lithium-ion secondary battery according to claim 1 , wherein m/Cap is 2 g/Ah-6 g/Ah.

13. The lithium-ion secondary battery according to claim 12 , wherein m/Cap is 2 g/Ah-3.0 g/Ah.

14. The lithium-ion secondary battery according to claim 1 , wherein a pressing density of the positive film is 3.3 g/cm 3 -3.55 g/cm 3 .

15. The lithium-ion secondary battery according to claim 1 , wherein a+b+c=1.