Lithium-ion battery
The present disclosure provides a lithium-ion battery, the lithium-ion battery comprises a positive electrode plate, a negative electrode plate, a separator and an electrolyte, the positive active material comprises a layered lithium-containing compound, the negative active material comprises graphite, the positive film and the negative film satisfy a relationship 0.3≤(OI c ×PD c )/(OI a ×PD a )≤20.0. The present disclosure can make the lithium-ion battery have smaller swelling and higher charging capability, and also make the lithium-ion battery have excellent cycle life and excellent safety performance during the long-term fast charging process.
1. A lithium-ion battery comprising a positive electrode plate, a negative electrode plate, a separator and an electrolyte, the positive electrode plate comprising a positive current collector and a positive film, the positive film being provided on at least one surface of the positive current collector and comprising a positive active material, 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 positive active material comprises a layered lithium-containing compound, the layered lithium-containing compound is one or more selected from a group consisting of lithium nickel cobalt manganese oxide and lithium nickel cobalt aluminum oxide;
the negative active material comprises graphite;
the positive film and the negative film satisfy a relationship 1.71≤(OI c ×PD c )/(OI a ×PD a )≤7.51;
OI c represents an OI value of the positive film, and OI c =C 003 /C 110 , C 003 represents characteristic diffraction peak area of (003) crystal plane in X-ray diffraction pattern of the positive electrode plate, C 110 represents characteristic diffraction peak area of (110) crystal plane in X-ray diffraction pattern of the positive electrode plate;
PD c represents a pressing density of the positive film with a unit of g/dm 3 ;
OI a represents an OI value of the negative film, and OI a =C 004 /C 110 , C 004 represents characteristic diffraction peak area of (004) crystal plane in X-ray diffraction pattern of the negative electrode plate, C 110 represents characteristic diffraction peak area of (110) crystal plane in X-ray diffraction pattern of the negative electrode plate;
PD a represents a pressing density of the negative film with a unit of g/dm 3 ,
the OI value of the positive film represented by OI c is 26-52,
the negative film satisfies a relationship 20000≤OI a ×PD a ≤50250; and
the pressing density of the negative film represented by PD a is 1.4×10 3 g/dm 3 -1.65×10 3 g/dm 3 .
2. The lithium-ion battery according to claim 1 , wherein
the positive film and the negative film satisfy a relationship 2.64≤(OI c ×PD c )/(OI a ×PD a )≤6.0.
3. The lithium-ion battery according to claim 2 , wherein
the positive film and the negative film satisfy a relationship 3.68≤(OI c ×PD c )/(OI a ×PD a )≤6.0.
4. The lithium-ion battery according to claim 1 , wherein
the positive film satisfies a relationship 79200≤OI c ×PD c ≤323840.
5. The lithium-ion battery according to claim 4 , wherein
the positive film satisfies a relationship 110400≤OI c ×PD c ≤182000.
6. The lithium-ion battery according to claim 1 , wherein
the negative film satisfies a relationship 20000≤OI a ×PD a ≤30000.
7. The lithium-ion battery according to claim 1 , wherein
an upper limit of the OI value of the negative film represented by OI a is 40.
8. The lithium-ion battery according to claim 1 , wherein
the pressing density of the positive film represented by PD c is 3.3×10 3 g/dm 3 -3.5×10 3 g/dm 3 .
9. The lithium-ion battery according to claim 1 , wherein
the positive film and the negative film satisfy a relationship 1.78≤(OI c ×ρ c )/(OI a ×ρ a )≤6.0;
ρ c represents an areal density of the positive film with a unit of g/cm 2 ; and
ρ a represents an areal density of the negative film with a unit of g/cm 2 .
10. The lithium-ion battery according to claim 9 , wherein
the positive film and the negative film satisfy a relationship 2.52≤(OI c ×ρ c )/(OI a ×ρ a )≤6.0.
11. The lithium-ion battery according to claim 9 , wherein
the positive film satisfies a relationship 0.173≤OI c ×ρ c ≤0.845; and/or
the negative film satisfies a relationship 0.080≤OI a ×ρ a ≤0.360.
12. The lithium-ion battery according to claim 11 , wherein
the positive film satisfies a relationship 0.353≤OI c ×ρ c ≤0.845; and/or
the negative film satisfies a relationship 0.140≤OI a ×ρ a ≤0.20.
13. The lithium-ion battery according to claim 9 , wherein
the areal density of the positive film represented by ρ c is 0.01 g/cm 2 -0.02 g/cm 2 ; and/or
the areal density of the negative film represented by ρ a is 0.007 g/cm 2 -0.013 g/cm 2 .
14. The lithium-ion battery according to claim 13 , wherein
the areal density of the positive film represented by ρ c is 0.015 g/cm 2 -0.02 g/cm 2 ; and/or
the areal density of the negative film represented by ρ a is 0.007 g/cm 2 -0.009 g/cm 2 .
15. The lithium-ion battery according to claim 1 , wherein
an average particle size D50 of the positive active material is 2 μm-10 μm; and/or
an average particle size D50 of the negative active material is 4 μm-15 μm.
16. The lithium-ion battery according to claim 15 , wherein
the average particle size D50 of the positive active material is 2.5 μm-7.3 μm; and/or
the average particle size D50 of the negative active material is 5.5 μm-12 μm.
17. The lithium-ion battery according to claim 1 , wherein at least a part of the positive active material is a single particle.