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: 6.1<Gr/K≤15.3, 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 0.09 to 0.15; and a Dv10 value and a Dv90 value of the negative active material in μm satisfy: 23. < Dv 90 / Dv 10 + Dv 90 ≤ 50.
1 . A negative active material, comprising: a carbon material; and 6.1<Gr/K≤15.3,
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;
wherein a Dv10 value and a Dv90 value of the negative active material in μm satisfy: 23.0<Dv90/Dv10+Dv90≤50;
wherein 4.3≤Lc/S<13,
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;
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;
Lc is less than 45.
2 . The negative active material according to claim 1 , wherein Gr is 0.92 to 0.97.
3 . The negative active material according to claim 1 , wherein
La/S> 17,
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; and
La is greater than 50.
4 . The negative active material according to claim 3 , wherein 9≤Gr/K≤14.
5 . The negative active material according to claim 3 , wherein 20≤Lc≤43, and/or 80≤La≤180.
6 . The negative active material according to claim 3 , wherein 4.3≤Lc/S≤12.
7 . The negative active material according to claim 3 , wherein 22≤La/S≤40.
8 . 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 6.1<Gr/K≤15.3,
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 0.09 to 0.15;
wherein a Dv10 value and a Dv90 value of the negative active material in μm satisfy: 23.0<Dv90/Dv10+Dv90≤50;
wherein 4.3≤Lc/S<13,
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;
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;
Lc is less than 45.
9 . The electrochemical device according to claim 8 , wherein Gr is 0.92 to 0.97.
10 . The electrochemical device according to claim 8 , wherein
La/S> 17,
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; and
La is greater than 50.
11 . The electrochemical device according to claim 8 , wherein 7<Gr/K<14.
12 . The electrochemical device according to claim 8 , wherein 9<Gr/K<15.
13 . The electrochemical device according to claim 8 , wherein 23.0<Dv90/Dv10+Dv90<35.
14 . The electrochemical device according to claim 10 , wherein 4.3≤Lc/S≤12.
15 . The electrochemical device according to claim 10 , wherein 25≤La/S≤45.
16 . The electrochemical device according to claim 8 , wherein an areal 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 8 , wherein the electrochemical device satisfies at least one of the following conditions:
(1) a peel-off strength between the negative active material layer and the negative current collector is 6 N/m to 15 N/m; or
(2) a porosity of the negative active material layer is 20% to 40%.
18 . The electrochemical device according to claim 8 , wherein, in a fully charged state, the electrochemical device satisfies at least one of the following conditions:
(1) 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; or
(2) a thermal decomposition temperature of the negative active material layer is greater than or equal to 280° C.
19 . The electrochemical device according to claim 8 , 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.
20 . 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 0.09 to 0.15;
wherein a compacted density of the negative active material layer is 1.70 g/cm 3 to 1.92 g/cm 3 ;
wherein 4.3≤Lc/S<13,
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;
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;
Lc is less than 45.