Negative active material, electrochemical device that uses same, and electronic device
A negative active material includes a carbon material. The carbon material satisfies the following relationship: 6<Gr/K<16, Gr is a graphitization degree of the carbon material, measured by X-ray diffraction; and K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm −1 to 1650 cm −1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm −1 to 1650 cm −1 , and is measured by using Raman spectroscopy, and K is 0.06 to 0.15.
1. A negative active material, comprising: a carbon material; and 6<Gr/K<16,
wherein, Gr is a graphitization degree of the carbon material, measured by means of X-ray diffraction; and
K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm −1 to 1650 cm −1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm −1 to 1650 cm −1 , and is measured by using Raman spectroscopy, and K is 0.09 to 0.15; and
wherein
La/S> 20,
wherein
La is a size of a crystal of the carbon material along a horizontal axis as measured by X-ray diffraction, and is measured in units of nm;
S is a ratio of a peak area C004 of a (004) surface to a peak area C110 of a (110) surface of the negative active material as measured by using an X-ray diffraction pattern; and
50 <La< 250.
2. The negative active material according to claim 1 , wherein Gr is 0.92 to 0.96.
3. The negative active material according to claim 1 , wherein
Lc/S< 9
wherein
Lc is a size of a crystal of the carbon material along a vertical axis as measured by X-ray diffraction, and is measured in units of nm; and
Lc is less than 45.
4. The negative active material according to claim 1 , wherein a Dv10 value and a Dv90 value of the negative active material in μm satisfy the following relationship: Dv90/Dv10+Dv90>23.0.
5. An electrochemical device, comprising a positive electrode, an electrolytic solution, and a negative electrode; wherein the negative electrode comprises a negative active material layer and a negative current collector, and the negative active material layer comprises the negative active material;
wherein, the negative active material comprises a carbon material; and 6<Gr/K<16,
wherein, Gr is a graphitization degree of the carbon material, measured by X-ray diffraction; and
K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm −1 to 1650 cm −1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm −1 to 1650 cm −1 , and is measured by using Raman spectroscopy, and K is 0.06 to 0.15; and
wherein
La/S> 20,
wherein
La is a size of a crystal of the carbon material along a horizontal axis as measured by X-ray diffraction, and is measured in units of nm;
S is a ratio of a peak area C004 of a (004) surface to a peak area C110 of a (110) surface of the negative active material as measured by using an X-ray diffraction pattern; and
La is greater than 50; and
wherein the electrolytic solution comprises fluoroethylene carbonate, 1,3-propane sultone, and succinonitrile.
6. The electrochemical device according to claim 5 , wherein Gr is 0.92 to 0.96.
7. The electrochemical device according to claim 5 , wherein Gr is 0.93 to 0.95.
8. The electrochemical device according to claim 5 , wherein
Lc/S< 9;
Lc is a size of a crystal of the carbon material along a vertical axis as measured by X-ray diffraction, and is measured in units of nm; and
Lc is less than 45.
9. The electrochemical device according to claim 5 , wherein a Dv10 value and a Dv90 value of the negative active material in μm satisfy the following relationship: Dv90/Dv10+Dv90>23.0.
10. The electrochemical device according to claim 5 , wherein 7<Gr/K<14.
11. The electrochemical device according to claim 5 , wherein 9<Gr/K<12.
12. The electrochemical device according to claim 5 , wherein K is 0.07 to 0.12.
13. The electrochemical device according to claim 5 , wherein K is 0.08 to 0.15.
14. The electrochemical device according to claim 8 , wherein 3<Lc/S<11.
15. The electrochemical device according to claim 5 , wherein 22<La/S<45.
16. The electrochemical device according to claim 5 , wherein an area density of the negative active material layer is 0.077 mg/mm 2 to 0.121 mg/mm 2 , a compacted density of the negative active material layer is 1.70 g/cm 3 to 1.92 g/cm 3 .
17. The electrochemical device according to claim 5 , wherein, in a fully discharged state, as measured by an X-ray diffraction pattern, a ratio S′ of a peak area C004′ of a (004) surface to a peak area C110′ of a (110) surface of the negative active material layer is 10 to 20.
18. The electrochemical device according to claim 5 , wherein a peel-off strength between the negative active material layer and the negative current collector is 6 N/m to 15 N/m.
19. The electrochemical device according to claim 5 , wherein a porosity of the negative active material layer is 20% to 40%.
20. The electrochemical device according to claim 5 , wherein, in a fully charged state of the electrochemical device, a thermal decomposition temperature of the negative active material layer is greater than or equal to 280° C.
21. The electrochemical device according to claim 5 , wherein, in a fully discharged state of the electrochemical device, a thermal decomposition temperature of the negative active material layer is greater than or equal to 130° C.
22. An electronic device, comprising the electrochemical device; the electrochemical device comprising a positive electrode, an electrolytic solution, and a negative electrode, wherein the negative electrode comprises a negative active material layer and a negative current collector, and the negative active material layer comprises the negative active material;
wherein, the negative active material comprises a carbon material; and 6<Gr/K<16,
wherein, Gr is a graphitization degree of the carbon material, measured by X-ray diffraction; and
K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm −1 to 1650 cm −1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm −1 to 1650 cm −1 , and is measured by using Raman spectroscopy, and K is 0.06 to 0.15; and
wherein
La/S> 20,
wherein
La is a size of a crystal of the carbon material along a horizontal axis as measured by X-ray diffraction, and is measured in units of nm;
S is a ratio of a peak area C004 of a (004) surface to a peak area C110 of a (110) surface of the negative active material as measured by using an X-ray diffraction pattern; and
La is greater than 50; and
wherein the electrolytic solution comprises fluoroethylene carbonate, 1,3-propane sultone, and succinonitrile.
23. The negative active material according to claim 1 , wherein 9≤Gr/K≤14.
24. The negative active material according to claim 3 , wherein 20≤Lc≤43.
25. The negative active material according to claim 1 , wherein 80≤La≤180.
26. The negative active material according to claim 3 , wherein 4.3≤Lc/S≤8.9.
27. The negative active material according to claim 1 , wherein 22≤La/S≤45.
28. The electrochemical device according to claim 5 , wherein K is 0.09 to 0.15.
29. The electrochemical device according to claim 8 , wherein 20≤Lc≤43.
30. The electrochemical device according to claim 5 , wherein 80≤La≤180.
31. The electrochemical device according to claim 17 , wherein the ratio S′ is 11-16.