Secondary battery, apparatus, artificial graphite and preparation method thereof
The present application discloses a secondary battery comprising a negative electrode plate, an apparatus including the secondary battery, an artificial graphite and a preparation method thereof, the negative electrode plate comprising a negative active material, wherein the negative active material comprises an artificial graphite having a volume average particle size D v 50 of 12 μm to 22 μm, and satisfying: 12≤D v 50×SSA≤25, in which SSA is the specific surface area of artificial graphite, in m 2 /g; the negative electrode plate has a compaction density of 1.6 g/cm 3 to 1.75 g/cm 3 and an OI value of at most 15, wherein the OI value represents a ratio C 004 /C 110 , in which C 004 is the peak area of the diffraction peak of 004 crystal plane of artificial graphite in the negative electrode plate and C 110 is the peak area of the diffraction peak of 110 crystal plane of artificial graphite in the negative electrode plate.
1 . A secondary battery comprising a negative electrode plate, the negative electrode plate comprising a negative active material, wherein the negative active material comprises an artificial graphite having a volume average particle size D v 50 of 12 μm to 22 μm and an SSA of 0.56 to 1.35, and the artificial graphite satisfies: 12≤D v 50×SSA≤25, in which SSA is the specific surface area of the artificial graphite, in m 2 /g;
the artificial graphite has a particle size span (D v 90−D v 10)/D v 50 of 1.1 to 1.5;
the artificial graphite has a volume particle size D v 10 satisfying 6.2 μm≤D v 10≤10.8 μm;
the artificial graphite has a numerical particle size D n 10 satisfying: 0.43 μm≤D n 10≤1.8 μm;
the negative electrode plate has a compaction density of 1.6 g/cm 3 to 1.75 g/cm 3 , and
the negative electrode plate has an OI value from 6 to 15, wherein the OI value of the negative electrode plate represents a ratio C 004 /C 110 , in which C 004 is the peak area of the diffraction peak of 004 crystal plane of the artificial graphite in the negative electrode plate and C 110 is the peak area of the diffraction peak of 110 crystal plane of the artificial graphite in the negative electrode plate.
2 . The secondary battery according to claim 1 , wherein the artificial graphite has a volume average particle diameter D v 50 of 15 μm to 18 μm.
3 . The secondary battery according to claim 1 , wherein the artificial graphite satisfies: 15≤D v 50×SSA≤22.
4 . The secondary battery according to claim 1 , wherein the negative electrode plate has a compaction density of 1.6 g/cm 3 to 1.7 g/cm 3 .
5 . The secondary battery according to claim 1 , wherein the OI value of the negative electrode plate is from 8 to 12.
6 . The secondary battery according to claim 1 , wherein:
the artificial graphite has a volume particle size D v 10 satisfying: D v 10≥6 μm.
7 . The secondary battery according to claim 1 , wherein artificial graphite has a graphitization degree of 90% to 95%;
the artificial graphite has a tap density of 0.85 g/cm 3 to 1.35 g/cm 3 ;
the artificial graphite has a powder compaction density of 1.65 g/cm 3 to 1.85 g/cm 3 under a pressure of 2000 kg;
the artificial graphite has a D peak intensity I D and a G peak intensity I G , and the ratio I D /I G satisfies: I D /I G ≤0.25;
the artificial graphite has a gram capacity of 350 mAh/g to 359 mAh/g.
8 . The secondary battery according to claim 1 , wherein the artificial graphite has a numerical particle size D n 10 satisfying: 1 μm≤D n 10≤1.8 μm.
9 . The secondary battery according to claim 1 , wherein the artificial graphite comprises secondary particles formed by agglomeration of primary particles; a proportion of a number of the secondary particles in the artificial graphite is at least 60%.
10 . The secondary battery according to claim 9 , wherein a proportion of a number of the secondary particles in the artificial graphite is from 70% to 90%.
11 . The secondary battery according to claim 1 , wherein at least one of the following conditions is satisfied:
(1) the artificial graphite satisfies: 16≤D v 50×SSA≤21; or
(2) the artificial graphite has a volume particle size D v 10 satisfying: 6.5 μm≤D v 10≤10.5 μm; or
(3) the artificial graphite has a particle size span (D v 90−D v 10)/D v 50 of 1.2 to 1.5; or
(4) the artificial graphite has a graphitization degree of 92% to 94%; or
(5) the artificial graphite has a tap density of 0.95 g/cm 3 to 1.15 g/cm 3 ; or
(6) the artificial graphite has a powder compaction density of 1.68 g/cm 3 to 1.83 g/cm 3 under a pressure of 2000 kg; or
(7) the artificial graphite has a D peak intensity I D and a G peak intensity I G , and the ratio I D /I G satisfies: 0.1≤I D /I G ≤0.2; or
(8) the artificial graphite has a gram capacity of 352 mAh/g to 355 mAh/g.
12 . An artificial graphite, wherein the artificial graphite has a volume average particle size D v 50 of 12 μm to 22 μm and an SSA of 0.56 to 1.35, the artificial graphite has a particle size span (D v 90−D v 10)/D v 50 of 1.1 to 1.5, and the artificial graphite satisfies: 12≤D v 50×SSA≤25, in which SSA is the specific surface area of the artificial graphite, in m 2 /g; wherein the artificial graphite has a volume particle size D v 10 satisfying 6.2 μm≤Dv10≤10.8 μm; the artificial graphite has a numerical particle size D n 10 satisfying: 0.43 μm≤D n 10≤1.8 μm; when the artificial graphite is used in a negative electrode with a compaction density of 1.6 g/cm 3 to 1.75 g/cm 3 , the artificial graphite has a peak area C 004 of the 004 crystal plane and a peak area C 110 of the 110 crystal plane satisfying 6≤C 004 /C 110 ≤15.
13 . A method for preparing an artificial graphite, comprising the following steps:
(1) crushing green coke materials and classifying them;
(2) shaping the product obtained in step (1);
(3) granulating the product obtained in step (2), wherein the amount of binder added during the granulation process does not exceed 5% of the total weight of the green coke materials;
(4) subjecting the product obtained in step (3) to a graphitization treatment at a temperature of 2800° C.˜3200° C. to obtain the artificial graphite;
wherein the artificial graphite has a volume average particle size D v 50 of 12 μm to 22 μm and an SSA of 0.56 to 1.35, and the artificial graphite satisfies: 12≤D v 50×SSA≤25, in which SSA is the specific surface area of the artificial graphite, in m 2 /g; when the artificial graphite is used in a negative electrode with a compaction density of 1.6 g/cm 3 to 1.75 g/cm 3 , the artificial graphite has a peak area C 004 of the 004 crystal plane and a peak area Clio of the 110 crystal plane satisfying 6≤C 004 /C 110 ≤15; and wherein the artificial graphite has a numerical particle size D n 10 satisfying: 0.43 μm≤D n 10≤1.8 μm; wherein the artificial graphite has a particle size span (D v 90−D v 10)/D v 50 of 1.1 to 1.5, the artificial graphite has a volume particle size D v 10 satisfying 6.2 μm≤D v 10≤10.8 μm.
14 . The method according to claim 13 , wherein the green coke comprises one or more of green petroleum coke, green pitch coke and metallurgical coke.
15 . The method according to claim 13 , wherein the green coke is non-needle coke.
16 . The method according to claim 13 , wherein the green coke has a volatile content of 6%-12%; and/or,
the green coke has a sulfur content of ≤2%.
17 . The method according to claim 13 , wherein in step (3), the product obtained in step (2) is granulated without adding a binder.
18 . The method according to claim 13 , wherein the step (2) further comprises removing fine powder after shaping; preferably, the number particle size D n 10 of the granular product after step (2) is controlled to be ≥0.5 μm, through a fine powder removal treatment.
19 . The method according to claim 13 , wherein the product obtained in step (3) is graphitized at a temperature of 2900° C. to 3100° C.