ARTIFICIAL GRAPHITE AND PREPARATION METHOD AND APPLICATION THEREOF
A preparation method of an artificial graphite includes heat-treating a graphite raw material to obtain artificial graphite, where an ambient atmosphere of the heat treatment is a mixed gas including a gas that is at least one of oxygen or water vapor and including a chemically inert gas, and, during the heat treatment, the graphite raw material is in a motion state.
1 . A preparation method of artificial graphite, comprising:
heat-treating a graphite raw material to obtain artificial graphite;
wherein:
an ambient atmosphere of the heat treatment is a mixed gas comprising a gas that is at least one of oxygen or water vapor and comprising a chemically inert gas; and
during the heat treatment, the graphite raw material is in a motion state.
2 . The preparation method according to claim 1 , wherein:
the heat treatment is performed at a temperature of 400° C. to 900° C.; or
the heat treatment is performed at a temperature of 400° C. to 900° C. and for duration of 10 to 60 minutes.
3 . The preparation method according to claim 1 , wherein the motion state of the graphite raw material is at least one of a continuous fluidizing state or a tumbling state.
4 . The preparation method according to claim 3 , wherein the tumbling state is implemented by rotation of a furnace tube or rotation of a mechanical rod, and a rotation speed of the furnace tube or the mechanical rod is 1 to 8 r/min.
5 . The preparation method according to claim 1 , wherein:
in the mixed gas, the gas that is at least one of oxygen or water vapor accounts for 5% to 40% of a total volume of the mixed gas; and/or
during the heat treatment, the mixed gas is fed in at a flow rate of 0 to 10 m 3 /h.
6 . The preparation method according to claim 1 , wherein:
a particle diameter Dv 50 of the graphite raw material is 16.0 to 24.0 μm; and/or
the graphite is an artificial graphite material.
7 . The preparation method according to claim 6 , further comprising:
crushing a solid-state carbon source to obtain a granular solid-state carbon source;
shaping the granular solid-state carbon source to obtain shaped particles; and
graphitizing the shaped particles to obtain an artificial graphite raw material.
8 . The preparation method according to claim 7 , wherein:
a particle diameter Dv 50 of the granular solid-state carbon source is 16.0 to 24.0 μm; and/or
the solid-state carbon source comprises at least one of petroleum coke, needle coke, pitch coke, or metallurgical coke; and/or
the graphitization is performed at a temperature of 2800° C. to 3200° C.; and/or
before the shaped particles are graphitized, the preparation method further comprises granulating the shaped particles.
9 . The preparation method according to claim 8 , wherein granulating the shaped particles comprises:
mixing a carbon source binder with the shaped particles, and then performing granulation and molding.
10 . An artificial graphite, prepared by the preparation method according to claim 1 .
11 . The artificial graphite according to claim 10 , wherein a compaction density and a particle diameter of the artificial graphite satisfy the following relationships:
ks=P 5k /( Dv 50 ×G ), and 100≤ ks≤ 150,
wherein, P 5k is a compaction density of powder of the artificial graphite at a pressure of 5000 kg, measured in units of g/cm 3 ; Dv 50 is an average particle diameter of the artificial graphite, measured in units of m; G is a graphitization degree of the artificial graphite; and ks is measured in units of kg/cm 4 .
12 . The artificial graphite according to claim 10 , wherein ks satisfies 110≤ks≤130.
13 . The artificial graphite according to claim 10 , wherein:
P 5k is 1.80 to 2.10 g/cm −3 ; and/or
Dv 50 is 16.0 to 24.0 μm; and/or
G is 91% to 96%.
14 . The artificial graphite according to claim 10 , wherein:
P 5k is 1.85 to 2.05 g/cm −3 ; and/or
Dv 50 is 16.0 to 18.0 μm; and/or
G is 92% to 95%.
15 . The artificial graphite according to claim 10 , wherein:
a volume average diameter Dv 10 of the artificial graphite is 4.0 to 15.0 μm; and/or
a volume average diameter Dv 90 of the artificial graphite is 20.0 to 40.0 μm; and/or
a number average diameter Dn 10 of the artificial graphite is 2.0 to 8.0 μm.
16 . The artificial graphite according to claim 10 , wherein the artificial graphite exhibits at least one of the following characteristics:
a gravimetric capacity of the artificial graphite is 340 to 365 mAh/g;
a specific surface area of the artificial graphite is 1.5 to 2.5 m 2 /g; and
a tap density of the artificial graphite is 0.80 to 1.20 g/cm 3 .
17 . The artificial graphite according to claim 10 , wherein the artificial graphite exhibits at least one of the following characteristics:
a gravimetric capacity of the artificial graphite is 345 to 363 mAh/g;
a specific surface area of the artificial graphite is 1.6 to 2.3 m 2 /g; and
a tap density of the artificial graphite is 0.82 to 1.18 g/cm 3 .
18 . A negative electrode material, comprising the artificial graphite according to claim 10 .
19 . A negative electrode, comprising the negative electrode material according to claim 18 .
20 . A battery, comprising the negative electrode according to claim 19 .