Negative electrode plate and secondary battery comprising the same
The disclosure relates to a secondary battery comprising a negative electrode plate the same. Specifically, the present disclosure provides secondary battery, comprising a negative electrode plate, the negative electrode plate comprises a negative electrode current collector and a negative electrode layer coated on at least one surface of the negative electrode current collector, the negative electrode layer comprising a negative electrode active material, wherein the negative electrode active material comprises a graphite material, and the negative electrode layer fulfills the condition: 0.75≤7.8/D50+1.9*D50/(V OI ) 2 ≤2.0, wherein D50 represents a volume distribution average particle diameter of particles of the negative electrode active material in micron; V OI represents the OI value of the negative electrode layer. The secondary battery has the combination of high energy density, fast charge, and long cycle life.
1. A secondary battery, comprising a negative electrode plate, the negative electrode plate comprises a negative electrode current collector and a negative electrode layer coated on at least one surface of the negative electrode current collector, the negative electrode layer comprising a negative electrode active material, wherein the negative electrode active material comprises a graphite material, and the negative electrode layer fulfills the condition:
0.75≤7.8/ D 50+1.9× D 50/( V OI ) 2 ≤2.0
Wherein
D50 represents a volume distribution average particle diameter of particles of the negative electrode active material in micron,
V OI represents the OI value of the negative electrode layer, and V OI =C 004 /C 110 , wherein C 004 was the peak area of the 004 characteristic diffraction peak, and C 110 is the peak area of the 110 characteristic diffraction peak in X-ray diffraction spectrum of the negative electrode plate, and
wherein the volume distribution average particle diameter D50 of the negative electrode active material is 4-15 μm.
2. The secondary battery according to claim 1 , wherein the negative electrode layer fulfills the condition:
0.75≤7.8/ D 50+1.9× D 50/( V OI ) 2 ≤1.31.
3. The secondary battery according to claim 1 , wherein the negative electrode active material fulfills the condition:
6.5≤ D 50×0.625+ G× 3≤12
wherein D50 represents a volume distribution average particle diameter of particles of the negative electrode active material in micron,
G represents the degree of graphitization of the negative electrode active material.
4. The secondary battery according to claim 3 , wherein the negative electrode active material fulfills the condition:
8.95≤ D 50×0.625+ G× 3≤11.45.
5. The secondary battery according to claim 1 , wherein the negative electrode layer fulfills the condition:
0.055≤ A/B≤ 0.31
wherein A=7.8/D50+1.9×D50/(V OI ) 2
B=D 50×0.625+ G× 3
D50 represents a volume distribution average particle diameter of particles of the negative electrode active material in micron,
V OI represents the OI value of the negative electrode layer,
G represents the degree of graphitization of the negative electrode active material.
6. The secondary battery according to claim 5 , wherein the negative electrode layer fulfills the condition:
0.061≤ A/B≤ 0.097.
7. The secondary battery according to claim 1 , wherein the volume distribution average particle diameter D50 of the negative electrode active material is 5-15 μm.
8. The secondary battery according to claim 1 , wherein the volume distribution average particle diameter D50 of the negative electrode active material is 10-15 μm.
9. The secondary battery according to claim 1 , wherein the OI value V OI of the negative electrode layer is 1.5-50.
10. The secondary battery according to claim 1 , wherein the OI value V OI of the negative electrode layer is 6-20.
11. The secondary battery according to claim 1 , wherein the OI value V OI of the negative electrode layer is 15-20.
12. The secondary battery according to claim 1 , wherein the degree of graphitization G of the negative electrode active material is 80%-98%.
13. The secondary battery according to claim 12 , wherein the degree of graphitization G of the negative electrode active material is 90%-95%.
14. The secondary battery according to claim 1 , wherein the powder OI value G OI of the negative electrode active material is 2-4.5.
15. The secondary battery according to claim 1 , wherein the press density PD of the negative electrode layer is 1.0 g/cm 3 -1.6 g/cm 3 .
16. The secondary battery according to claim 1 , wherein the graphite material comprises artificial graphite.
17. The secondary battery according to claim 1 , wherein the secondary battery comprises a positive electrode plate, the positive electrode plate comprises a positive electrode current collector and a positive electrode layer disposed on the surface of the positive electrode current collector, the positive electrode layer comprises a positive electrode active material, and the positive electrode active material comprises lithium nickel cobalt manganese oxide.