Artificial graphite negative-pole material, preparation method therefor and lithium-ion battery

[0028] Example 1

[0029] The needle coke with a volatile content of 0.5% is crushed and shaped by a roller mill-shaping machine to obtain primary particles A, and the average particle size D50 of the primary particles A is controlled to 8 μm. Take part of the primary particles A and the pyrolysis oil coating agent into the vacuum kneader according to the mass ratio of 100:8, knead at 120°C at normal pressure for 2 hours, then switch to vacuum mode for kneading at 250°C for 4 hours, and put the kneaded material into the vertical In a reactor, under the protection of nitrogen, heat up at 5°C/min to 400°C for 2 hours, then heat up at 3°C/min to 550°C for 4 hours, and sieving after cooling to obtain primary particles B; Particle A and petroleum pitch with a softening point of 250°C and an average particle size of 7μm are mixed uniformly according to a mass ratio of 100:10, and then put into a drum furnace. Under the protection of nitrogen, the temperature is raised at 5°C/min to 600°C for 4 hours. Granules are reacted and sieved after cooling to obtain secondary granules C. The primary particles B and the secondary particles C are graphitized at 2800° C. for 24 hours, and then sieved to obtain graphitized primary particles B and graphitized secondary particles C. The graphitized primary particles B and the graphitized secondary particles C are uniformly mixed according to a mass ratio of 30:70, and then sieved again to obtain a high-energy density magnification type artificial graphite product.

[0030] Example 2

[0031] The needle coke with a volatile content of 1% is crushed and shaped by a roller mill-shaping machine to obtain primary particles A, and the average particle size D50 of the primary particles A is controlled to 8 μm. Take part of the primary particles A and the sucrose coating agent into the vacuum kneader at a mass ratio of 100:5, knead at 120°C for 2 hours at normal pressure, then switch to vacuum mode for kneading at 250°C for 4 hours, and put the kneaded material into the vertical type In the reactor, under the protection of nitrogen, heat up at 5°C/min to 400°C for 2 hours, then heat up at 3°C/min to 600°C for 2 hours. After cooling, sieving to obtain primary particles B; take part of the primary particles A and petroleum pitch with a softening point of 150°C and an average particle size of 7μm are mixed uniformly according to a mass ratio of 100:15 and then put into a drum furnace. Under the protection of nitrogen, the temperature is raised at 5°C/min to 600°C for 4 hours for granulation. After reaction, sieving after cooling to obtain secondary particles C. The primary particles B and the secondary particles C are graphitized at 2800° C. for 24 hours, and then sieved to obtain graphitized primary particles B and graphitized secondary particles C. The graphitized primary particles B and the graphitized secondary particles C are uniformly mixed according to a mass ratio of 40:60, and sieved again to obtain a high-energy-density-multiplying artificial graphite product.

[0032] Example 3

[0033] The needle coke with a volatile content of 5% is roughly broken to below 5 mesh, then modified and modified at a high temperature of 900°C for 4 hours, and then crushed and shaped by a roller mill-shaping machine to obtain primary particles A, and control the primary particle A The average particle size D50 is 8 μm. Take part of the primary particles A and the phenolic resin oil coating agent into the vacuum kneader at a mass ratio of 100:8, knead at 120°C under normal pressure for 2 hours, then switch to vacuum mode for kneading at 250°C for 4 hours, and put the kneaded material into it In the vertical reactor, under the protection of nitrogen, heat up at 5°C/min to 400°C for 2 hours, then heat at 3°C/min to 600°C for 2 hours. After cooling, sieving to obtain primary particles B; The primary particles A and the petroleum resin with a softening point of 150°C and an average particle size of 9μm are uniformly mixed according to a mass ratio of 100:12, and then put into the drum furnace. Under the protection of nitrogen, the temperature is raised at 5°C/min to 550°C for 4 hours. Granulation reaction, sieving after cooling to obtain secondary granules C. The primary particles B and the secondary particles C are graphitized at 2800° C. for 24 hours, and then sieved to obtain graphitized primary particles B and graphitized secondary particles C. The graphitized primary particles B and the graphitized secondary particles C are uniformly mixed according to a mass ratio of 50:50, and then sieved again to obtain a high-energy density magnification type artificial graphite product.