A continuous coating and granulation method and device for lithium ion battery negative electrode material

Abstract

The application provides a continuous coating granulation preparation method and device for a lithium ion battery negative electrode material, a process path of which comprises a low-temperature reaction section and a high-temperature reaction section; the low-temperature reaction section adopts two groups of half helical blades which are intermeshed to strongly stir the coated material, the material is strongly dispersed, and the material is pushed forward by the helical blade rise angle while rotating to complete the continuous heating coating process, and the heating interval of the low-temperature reaction section is 550±50 DEG C; the coated material exceeding 550 DEG C does not have a secondary agglomeration phenomenon, and the high-temperature reaction section is connected in series at the discharging end of the low-temperature reaction section, and the high-temperature reaction section is an indirect heating rotary kiln, and the heating interval is 1000±50 DEG C. The application has the beneficial effects that continuous production is met, and the physical and chemical properties of the coated material reach the level of a periodical reaction kettle, and continuous, automatic, low-energy-consumption, low-pollution, high-yield and high-quality are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the negative material production technical field, especially to a lithium ion battery negative material continuous coating granulation preparation method and device. BACKGROUND

[0002] In the production process of lithium ion battery negative material, carbon coating or coating of graphite with pitch-based substances needs heating treatment to make the coating material carbonize uniformly in the coated material particles, and improve the electrical properties of the coated material. At present, the coating process of negative material mostly uses periodic reaction kettles for production, which has obvious shortcomings of high energy consumption, low yield and heavy pollution. Some people have tried to use a rotary kiln for continuous production, but the effect is not ideal. Although the yield is improved and the power consumption is reduced, the quality is also significantly reduced. The pitch-based substances do not have strong stirring during heating in the rotary kiln, and it is also impossible to rotate at a very high speed, which will lead to the agglomeration of molten pitch-based substances and coated materials. If secondary crushing is performed again, it will damage the surface and internal structure of the coated material, affecting the performance of the coated material. SUMMARY

[0003] The present application provides a lithium ion battery negative material continuous coating granulation preparation method and device, which not only meets continuous production but also meets the physical and chemical properties of the coated material reaching the level of the periodic reaction kettle, realizing continuous, automatic, low-energy consumption, low pollution, high yield and high quality.

[0004] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0005] A lithium ion battery negative material continuous coating granulation preparation method, the process path includes a low-temperature reaction section and a high-temperature reaction section, the low-temperature reaction section adopts two groups of half-spiral blades intermeshing, strongly stirring the coated material, strongly dispersing the material, and at the same time, pushing the material forward by the spiral blade rise angle while rotating, completing the continuous heating coating process, the heating interval of the low-temperature reaction section is 550±50℃; The coated material at about 550℃ does not have secondary agglomeration phenomenon, the high-temperature reaction section is connected in series at the discharge end of the low-temperature reaction section, and the high-temperature reaction section is an indirect heating rotary kiln, and the heating interval is 1000±50℃.

[0006] The device for a lithium ion battery negative material continuous coating granulation preparation method comprises a spiral blade strong heating device and an indirect heating rotary kiln, the spiral blade strong heating device comprises a self-purification rotary heating transmission device, a transmission shaft, self-purification blades, a self-purification heating device, heat insulation refractory material and a furnace tank, the self-purification blades are two groups of spiral blades respectively installed on two transmission shafts, the two groups of spiral blades are both small semicircle spiral blades, and the two groups of spiral blades are arranged in a staggered mode and meshed with each other, the two transmission shafts are rotationally connected through a gear transmission, and one of the transmission shafts is in transmission connection with the self-purification rotary heating transmission device, the self-purification blades are in the furnace tank, the self-purification heating device is arranged outside the furnace tank, and the heat insulation refractory material is arranged outside the self-purification heating device; the indirect heating rotary kiln is connected in series at the discharging end of the spiral blade strong heating device, and the indirect heating rotary kiln comprises a rotary kiln cylinder, a rotary kiln heating device and a rotary kiln heat insulation refractory furnace body, the rotary kiln heat insulation refractory furnace body is wrapped outside the rotary kiln cylinder, and the rotary kiln heating device is arranged between the rotary kiln heat insulation refractory furnace body and the rotary kiln cylinder.

[0007] The feeding port of the spiral blade strong heating device is connected with a feeder, and the feeder is connected with a feeding tank.

[0008] The furnace tank is fixed through external support, bearing seats are fixed at two ends of the furnace tank, the transmission shaft is supported through the bearing seats, and the self-purification rotary heating transmission device is in transmission connection with one of the transmission shafts through a transmission sprocket.

[0009] The indirect heating rotary kiln is arranged below the spiral blade strong heating device, a discharging chute is arranged at the discharging end of the spiral blade strong heating device, and the discharging chute is inserted into the charging fixed end of the indirect heating rotary kiln.

[0010] The indirect heating rotary kiln is arranged below the spiral blade strong heating device, a discharging chute is arranged at the discharging end of the spiral blade strong heating device, and the discharging chute is inserted into the charging fixed end of the indirect heating rotary kiln.

[0011] Compared with the prior art, the lithium ion battery negative material continuous coating granulation preparation method and device have the following beneficial effects:

[0012] The lithium ion battery negative material continuous coating granulation preparation method and device can not only meet continuous production but also meet the physical and chemical performance of coated materials reaching the level of a periodic reaction kettle, and continuous, automatic, low-energy-consumption, low-pollution, high-yield and high-quality are realized. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the whole schematic view of the lithium ion battery negative material continuous coating granulation device of the present application;

[0014] Figure 2 is an enlarged view of the spiral blade strong heating device.

[0015] Figure 3 is the internal cross-sectional view of the spiral blade strong heating device furnace tank.

[0016] Figure 4 is the dynamic static sealing schematic diagram.

[0017] In the figure: 1 - feeding tank, 2 - spiral feeder, 3 - self-cleaning rotary heating transmission device, 4 - transmission sprocket, 5 - gear, 6 - bearing seat, 7 - transmission shaft, 8 - self-cleaning blade, 9 - self-cleaning heating device, 10 - heat-insulating refractory material, 11 - furnace tank, 12 - discharging chute, 13 - charging fixed end, 14 - charging end dynamic static sealing, 15 - guide wheel group support, 16 - rotary kiln transmission device, 17 - rotary kiln cylinder, 18 - rotary kiln heating device, 19 - rotary kiln refractory heat-insulating furnace body, 20 - discharging fixed end, 21 - discharging end dynamic static sealing, 22 - rotary kiln discharging device, 23 - material cooler, 24 - material discharging device after cooling, 25 - flexible sealing ring, 26 - corrugated expander, 27 - inner sealing tube, 28 - lead screw. DETAILED DESCRIPTION

[0018] The specific embodiments of the application will be further described below in combination with the drawings:

[0019] See Figures 1-4 A continuous coating granulation preparation method of lithium ion battery negative electrode material, the process path includes a low temperature reaction section and a high temperature reaction section, the low temperature reaction section adopts two groups of half spiral blades intermeshing, strongly stirring the coated material, strongly dispersing the material, and simultaneously pushing the material to rotate and advance by the spiral blade rise angle, completing the continuous heating coating process, the heating interval of the low temperature reaction section is from 550±50℃; The coated material at about 550℃ does not have a secondary agglomeration phenomenon, the high temperature reaction section is connected in series at the discharging end of the low temperature reaction section, and the high temperature reaction section is an indirect heating rotary kiln, and the heating interval is 1000±50℃.

[0020] A continuous coating granulation preparation method of lithium ion battery negative electrode material adopts a device, including a spiral blade strong heating device and an indirect heating rotary kiln, the spiral blade strong heating device includes a self-cleaning rotary heating transmission device 3, a transmission shaft 7, a self-cleaning blade 8, a self-cleaning heating device 9, a heat-insulating refractory material 10, and a furnace tank 11, the self-cleaning blade 8 is two groups of spiral blades respectively installed on two transmission shafts 7, and the two groups of spiral blades are both small semicircular spiral blades (such as Figure 3The two groups of spiral blades are staggered and meshed with each other, and the two transmission shafts 7 are rotationally driven through the gear 5, one of which is in transmission connection with the self-cleaning rotary heating transmission device 3, the self-cleaning blades 8 are in the furnace tank 11, the outside of the furnace tank 11 is provided with the self-cleaning heating device 9, and the outside of the self-cleaning heating device 9 is provided with the heat-insulating refractory material 10; the indirect heating rotary kiln is connected in series at the discharging end of the spiral blade strong heating device, and comprises a rotary kiln cylinder 17, a rotary kiln heating device 18 and a rotary kiln refractory heat-insulating furnace body 19, the rotary kiln refractory heat-insulating furnace body 19 is wrapped outside the rotary kiln cylinder 17, and the rotary kiln heating device 18 is between the rotary kiln refractory heat-insulating furnace body 19 and the rotary kiln cylinder 17. The self-cleaning heating device 9 and the rotary kiln heating device 18 can both adopt electric heating. An end cover is arranged at the upper end of the furnace tank 11, and an anti-explosion exhaust pipeline is arranged on the end cover.

[0021] The feeding port of the spiral blade strong heating device is connected with the screw feeder 2, and the screw feeder 2 is connected with the feeding tank 1.

[0022] The furnace tank 11 is fixed through external support, both ends of the furnace tank 11 are fixed with bearing seats 6, the transmission shafts 7 are supported through the bearing seats 6, and the self-cleaning rotary heating transmission device 3 is in transmission connection with one of the transmission shafts 7 through the transmission sprocket 4.

[0023] The indirect heating rotary kiln is arranged below the spiral blade strong heating device, the discharging end of the spiral blade strong heating device is provided with a discharging chute 12, and the discharging chute 12 is inserted into the charging fixed end 13 of the indirect heating rotary kiln.

[0024] Both ends of the indirect heating rotary kiln are respectively provided with the charging fixed end 13 and the discharging fixed end 20, and dynamic and static seals are arranged between the charging fixed end 13 and the discharging fixed end 20 and the rotary kiln cylinder 17.

[0025] The whole indirect heating rotary kiln has an inclination angle of 1°-5°, the rotary kiln cylinder 17 is driven to rotate by the rotary kiln transmission device 16, the rotary kiln transmission device 16 adopts frequency conversion speed regulation, and the rotary kiln cylinder 17 is provided with a guide wheel set support 15.

[0026] See Figure 4 The dynamic and static seals (discharging end dynamic and static seal 21 and charging end dynamic and static seal 14) are composed of a flexible sealing ring 25, an inner sealing pipe 27, a distance adjusting lead screw 28 and a corrugated expander 26, the inner sealing pipe 27 is connected with the rotary kiln cylinder 17 through the distance adjusting lead screw, and the rotary kiln cylinder 17 and the inner sealing pipe 27 are further provided with the corrugated expander 26 for sealing. The flexible sealing ring 25 is connected with the charging fixed end 13 or the discharging fixed end 20 and wrapped outside the inner sealing pipe 27 for sealing.

[0027] The middle of the distance adjusting screw 28 is a nut, and the two ends are screw rods with positive and reverse threads. The length of the distance adjusting screw 28 is adjusted by screwing the nut, so that the radial distance between the inner sealing pipe 27 and the rotary kiln cylinder 17 is adjusted. In the circumferential direction, the sealing surface and the rotary kiln are concentric through the adjustment of the screw rod. The corrugated expander 26 plays a sealing role between the inside and outside of the kiln and can provide position compensation during debugging.

[0028] The process of the present application is as follows:

[0029] The material from the feeding tank 1 is sent into the spiral blade strong heating device through the plug valve, air lock and quantitative screw feeder 2. Under the pushing of the transmission shaft 7 and the self-cleaning blade 8, the material moves from the low temperature section to the high temperature section. The self-cleaning rotary heating transmission device 3 is frequency conversion and speed regulation. The transmission shaft 7 is supported on the bearing seat 6 and rotates under the driving of the meshing gear. The furnace tank 11 is made of heat-resistant steel material. The heating device 9 is arranged outside the furnace tank 11 to indirectly heat the furnace tank 11. The heating temperature is controlled according to the process requirements. The self-cleaning blade 8 has a set spiral pitch angle. Through the joint action of the frequency conversion transmission device, the predetermined material conveying speed is achieved. The material reaching the first section temperature heating setting value is sent into the second set of equipment "indirect heating rotary kiln" through the (corrugated expansion pipe, air lock valve) discharge chute 12. The heating temperature is adjustable from 550 DEG C to 1000 DEG C. The material conveying in the indirect heating rotary kiln is consistent with the upper "spiral blade strong heating device". The well-heated material in the rotary kiln is sent into the material cooler 23 through the discharge fixed end 20 and the rotary kiln discharge device 22 for indirect cooling. The material cooler 24 is a spiral feeder with circulating water cooling wall. The central shaft of the spiral feeder is also connected with the cooling circulating water. The material is cooled to 100 DEG C and then sent to the material discharge device 24, so that the whole material coating and heating process is completed.

[0030] The present application realizes the continuous, automatic, low energy consumption, low pollution, high yield and high quality production of the continuous coating and granulation process of the negative electrode material. Under the same investment, the energy consumption is reduced by more than 30%, and the yield is increased by more than 50%.

Claims

1. A method for preparing a lithium-ion battery anode material through continuous coating and granulation, characterized in that, The process includes a low-temperature reaction section and a high-temperature reaction section. The low-temperature reaction section uses two sets of semi-spiral blades that mesh with each other to stir and disperse the material to be coated. At the same time, the spiral blades push the material forward while rotating, completing the continuous heating and coating process. The heating range of the low-temperature reaction section is 550℃. At 550℃, the coated material no longer exhibits secondary agglomeration. The high-temperature reaction section is connected in series at the discharge end of the low-temperature reaction section. The high-temperature reaction section is an indirect heating rotary kiln with a heating range of 1000±50℃. The overall tilt angle of the indirect heating rotary kiln is 1°-5°; The indirect heating rotary kiln is provided with a charging fixed end and a discharging fixed end at both ends. The charging fixed end and the discharging fixed end are provided with dynamic and static seals between themselves and the rotary kiln body. The dynamic and static seals are composed of a flexible sealing ring, an inner sealing tube, an adjusting screw, and a corrugated expander. The inner sealing tube is connected to the rotary kiln body through the adjusting screw. A corrugated expander for sealing is also provided between the rotary kiln body and the inner sealing tube. The flexible sealing ring is connected to the charging fixed end or the discharging fixed end and is wrapped around the outside of the inner sealing tube for sealing. The apparatus used in the continuous coating and granulation preparation method of lithium-ion battery anode material includes a helical blade high-intensity heating device and an indirect heating rotary kiln. The helical blade high-intensity heating device includes a self-cleaning rotary heating transmission device, a transmission shaft, self-cleaning blades, a self-cleaning heating device, heat-insulating refractory material, and a furnace. The self-cleaning blades are two sets of helical blades respectively mounted on two transmission shafts. Both sets of helical blades are small semi-circular helical blades, and the two sets of helical blades are staggered and meshed with each other. The two transmission shafts rotate through gear transmission. A drive shaft is connected to a self-cleaning rotary heating drive device. The self-cleaning blades are inside the furnace jar, and the self-cleaning heating device is located outside the furnace jar. The self-cleaning heating device is also equipped with heat-insulating refractory material. The indirect heating rotary kiln is connected in series at the discharge end of the spiral blade high-power heating device. The indirect heating rotary kiln includes a rotary kiln cylinder, a rotary kiln heating device, and a rotary kiln refractory heat-insulating furnace body. The rotary kiln refractory heat-insulating furnace body is wrapped around the rotary kiln cylinder, and the rotary kiln heating device is located between the rotary kiln refractory heat-insulating furnace body and the rotary kiln cylinder.

2. The method for continuous coating and granulation preparation of lithium-ion battery anode material according to claim 1, characterized in that, The feed inlet of the powerful heating device for the spiral blades is connected to a feeder, and the feeder is connected to a loading tank.

3. The method for continuous coating and granulation preparation of lithium-ion battery anode material according to claim 1, characterized in that, The furnace is fixed by external support, and bearing seats are fixed at both ends of the furnace. The drive shaft is supported by the bearing seats, and the self-cleaning rotary heating transmission device is connected to one of the drive shafts through a transmission sprocket.

4. The method for continuous coating and granulation preparation of lithium-ion battery anode material according to claim 1, characterized in that, The indirect heating rotary kiln is located below the spiral blade high-intensity heating device. The discharge end of the spiral blade high-intensity heating device is provided with a discharge chute, which is inserted into the charging and fixing end of the indirect heating rotary kiln.

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