Sintering device and preparation method of battery positive electrode material
By introducing multi-stage overflow plates and built-in ventilation fans into the pusher-plate tunnel resistance furnace, the problems of low waste heat recovery efficiency and material cracking were solved, achieving uniform temperature control and efficient sintering, thus improving the quality of battery cathode materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-05
- Publication Date
- 2026-03-27
AI Technical Summary
Existing pusher-plate tunnel resistance furnaces have problems such as low waste heat recovery efficiency, uneven material drying leading to cracking, and vibration affecting density during the sintering process of battery cathode materials, which affect the sintering quality.
A sintering device was designed, comprising a tunnel furnace body, an electric pusher system, an over-temperature protection mechanism, a drying mechanism, and a heat exchanger. Through components such as multi-stage overflow plates, ventilation slots, and built-in ventilation fans, waste heat recovery and uniform temperature control are achieved, preventing cracking and improving density.
It improves energy efficiency, ensures temperature uniformity of materials during drying and sintering, prevents cracking, and enhances sintering quality and density.
Smart Images
Figure CN121739738A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of battery material production, in particular to a sintering device for battery positive electrode material and a preparation method thereof. BACKGROUND
[0002] The push plate tunnel type resistance furnace is a kind of efficient industrial heating equipment, which is widely used in metal processing, casting, heat treatment and other fields. The device is suitable for the production of lithium cobalt oxide, tricobalt tetraoxide, ternary material, lithium manganate, ferrite and electronic material, and the smoothing of alumina ceramic substrate. The device is generally composed of furnace body, resistance heating element, push plate system and control system. The device has the following characteristics: 1. Continuous operation: the push plate tunnel type resistance furnace adopts continuous production mode, and the workpiece moves in the furnace through the push plate system to realize efficient heating and processing. 2. Uniform heating: the resistance heating elements in the furnace are uniformly distributed, so that the temperature distribution in the whole furnace chamber is uniform, which can ensure the consistency and stability of the workpiece in the heating process. 3. Energy saving and environmental protection: compared with traditional furnaces, the push plate tunnel type resistance furnace has higher thermal efficiency, which can effectively reduce energy consumption, and the design usually considers waste gas treatment and environmental protection measures. 4. Adjustable temperature control: the device automatically controls the furnace temperature and monitors the running condition through computer, realizes precise control of heating temperature, and meets the requirements of different materials and processes.
[0003] The existing push plate tunnel type resistance furnace is generally a tunnel furnace, and when sintering the positive electrode material of the battery, the tunnel furnace and the push plate system connected therewith have the following defects: because the waste gas temperature is high, a heat exchanger is generally arranged to recover the waste heat, but the heat generated by the waste heat recovery is difficult to use directly, and a lot of energy is lost during transmission. In addition, the existing tunnel furnace generally sets the material drying process in the preheating part of the tunnel furnace, and the temperature of the preheating part of the tunnel furnace is too high, which causes the temperature and humidity inside and outside the sintered material to be inconsistent, resulting in cracking of the outer surface of the sintered material and affecting the sintering quality. In addition, during the drying process, the sintered material is vibrated under the transmission of the push plate system, which can cause the internal structure of the sintered material to be loose, affect the density of the material, and further affect the quality of the final product. SUMMARY
[0004] In view of the deficiencies of the prior art, the present application provides a sintering device for battery positive electrode material and a preparation method thereof, which can recover excess heat, improve energy utilization, automatically and uniformly dry the blank, improve sintering quality, and prevent the blank from cracking during drying.
[0005] In order to achieve the above object, the present application provides the following technical scheme: a sintering device for battery positive electrode material, comprising a tunnel furnace body, an electric push plate system matched with the tunnel furnace body, an over-temperature protection mechanism arranged at the top of the tunnel furnace body, and a drying treatment mechanism mounted on the electric push plate system, the inside of the tunnel furnace body is divided into three parts, namely a heating zone arranged at the end of the tunnel furnace body, a sintering zone arranged at the middle of the tunnel furnace body, and a heat preservation zone arranged at the tail of the tunnel furnace body, the inside of the tunnel furnace body is provided with a heat preservation layer, a heating layer and a furnace body lining, the electric push plate system is composed of three parts, namely a feeding zone arranged outside the tunnel furnace body, a high-temperature resistant zone arranged inside the tunnel furnace body, and a feeding and discharging zone connecting the feeding zone and the sintering zone, the over-temperature protection mechanism is composed of an exhaust pipe, an external electromagnetic valve and a heat exchanger, the heat exchanger is composed of an inner shell and an outer shell, the drying treatment mechanism is composed of a drying preheating pipeline and an air venting groove, and a sintering box is arranged on the electric push plate system. The inside of the tunnel furnace body is provided with an air venting stabilizing mechanism, the air venting stabilizing mechanism is composed of an air inlet pipe and a jet plate, the jet plate is mounted inside the furnace body lining, and the jet plate is connected with the exhaust end of the air inlet pipe. The bottom of the exhaust pipe is communicated with the inside of the tunnel furnace body, the heat exchanger is mounted at the top of the exhaust pipe, and the inner shell is communicated with the top of the exhaust pipe.
[0006] Preferably, a side air venting groove is arranged on the outer side wall of the sintering box, a bottom insertion hole is arranged at the bottom of the side air venting groove, a top insertion block is arranged at the top of the side air venting groove, the bottom insertion hole is matched with the top insertion block, the bottom of the sintering box is provided as an inclined surface, and the top insertion block and the bottom insertion hole are both provided as a taper.
[0007] Preferably, the inner shell is arranged inside the outer shell, a sectional partition plate is mounted on the inner wall of the inner shell, the sectional partition plate is composed of a plurality of symmetrically distributed blocking pieces with different radii, there is a gap between the bottom of the blocking piece and the inner wall of the inner shell, the gap between the blocking piece closer to the middle of the inner shell and the inner wall of the inner shell is smaller, and a waste gas pipe is mounted at the center of the inner shell.
[0008] Preferably, a first water inlet pipe is mounted at the front end of the outer shell, a first water outlet pipe is mounted at the rear end of the outer shell, the first water inlet pipe and the first water outlet pipe are arranged between the outer shell and the inner shell, a steam pipe is mounted at the center of the outer shell, and the waste gas pipe penetrates through the steam pipe.
[0009] Preferably, the outer part of the exhaust pipe is provided with an external electromagnetic valve, the exhaust pipe is provided with two groups, and the two groups of exhaust pipes are symmetrically distributed on the top of the tunnel furnace body, each group of exhaust pipes is provided with a plurality of exhaust pipes, and a part of each group of exhaust pipes is arranged inside the sintering area of the tunnel furnace body, the other part of the two groups of exhaust pipes is arranged inside the heating area and the heat preservation area of the tunnel furnace body, and the inner part of the two outermost exhaust pipes is provided with an internal ventilation fan, and the external electromagnetic valve outside the two outermost exhaust pipes is set to be always open.
[0010] Preferably, an elastic shock pad is installed on the fixed slide rail in the loading area of the electric push plate system, and the sintering pot is arranged on the top of the elastic shock pad and at the center of the fixed slide rail in the loading area of the electric push plate system.
[0011] Preferably, the drying and preheating pipeline is erected on the electric push plate system, the cross section of the drying and preheating pipeline is arranged in a meandering shape, a plurality of multi-stage overflow plates are uniformly arranged on the inner wall of the drying and preheating pipeline, a drain valve plate is arranged at the bottom of the multi-stage overflow plates, a second drain pipe and a waste water discharge pipe are arranged at the front end of the drying and preheating pipeline, the waste water discharge pipe is arranged at the bottom of the end of the drying and preheating pipeline, a second water inlet pipe is arranged at the rear end of the drying and preheating pipeline, the rear end of the drying and preheating pipeline is close to one side of the heating area of the tunnel furnace body, and the front end of the drying and preheating pipeline is close to one side of the heat preservation area of the tunnel furnace body.
[0012] Preferably, the ventilation groove is provided with two groups and is symmetrically arranged on the inner wall of the drying and preheating pipeline, a fan is arranged on the top of the drying and preheating pipeline, a ventilation pipe is arranged at the exhaust end of the fan, the ventilation pipe is connected with the end of the ventilation groove, a plurality of ventilation openings are arranged on the outer wall of the ventilation groove in a linear distribution, and a plurality of exhaust openings are arranged on the top of the drying and preheating pipeline in a linear array.
[0013] Preferably, a preparation method of a battery positive electrode material comprises the following steps: S1: raw material preparation: Co304 and Li2CO3 are used as raw materials, and are matched in a proportion of n(Li) / n(Co)=1.01-1.08 according to stoichiometric ratio, 300-3000PPm of an additive (one or more of ZrO2, TiO2, magnesium oxide, and aluminum oxide) is added, the above-mentioned raw materials are placed in a ball mill, and are ball milled for 6-12h to obtain a mixture; S2: blank preparation and potting: the raw material prepared in S1 is pressed and formed in a sintering pot through a mold to form a 2.5cm*2.5cm*1cm preform, the number of the preforms is 9*9, and the preforms are uniformly arranged, then two sintering pots are stacked one on top of the other; S3: drying treatment: the sintering box of S2 is placed in the loading area of the electric push plate system of the sintering device, and the multiple groups of sintering boxes are pushed into the drying preheating pipeline in sequence through the electric push plate system, and the drying treatment is carried out, and the drying treatment time is 4-6h: S4: primary sintering: the sintering box after S3 drying is pushed into the heating zone inside the tunnel furnace main body through the feeding area of the electric push plate system under the action of the electric push plate system, so that the prefabricated blank is preheated, and then the prefabricated blank is pushed into the sintering zone inside the tunnel furnace main body through the high-temperature-resistant area of the electric push plate system, the pushing speed of the electric push plate system is adjusted, the time of the prefabricated blank passing through the sintering zone is 6-12h, and the sintering is carried out at 900-1100 DEG C for 6-12h to form a sintered material, after the sintering is completed, the sintering box containing the prefabricated blank enters the heat preservation zone of the tunnel furnace main body, and after a period of heat preservation, it is pushed out of the tunnel furnace main body; S5: crushing and re-loading, the sintered material in the sintering box is taken out for crushing, and then re-loaded through S2 to form a blank in the sintering box, and the blank is formed by directly pressing the mold; S6: secondary sintering: the sintering box in S5 is pushed again through the electric push plate system, dried in the drying preheating pipeline, and then subjected to secondary sintering through S3, wherein the sintering temperature is controlled at 600-900 DEG C, and the sintering time is the same as that of S4 primary sintering, and finally stable LiCo02 is obtained; S7: discharging: the LiCo02 block in the sintering box after secondary sintering in S6 is taken out from the sintering box.
[0014] Compared with the prior art, the present application provides a sintering device for a battery positive electrode material and a preparation method thereof, which has the following beneficial effects: 1: by arranging the drying treatment mechanism and the multiple overflow plates in the drying treatment mechanism, the temperature of the blank gradually increases during the pushing process of the sintering box by the electric push plate system, and the slow air blowing by the air vent groove can uniformly discharge the solvent in the blank, prevent the blank from cracking due to uneven drying or large temperature changes during drying, and improve the sintering quality.
[0015] 2: by using the hot water in the heat exchanger to flow into the drying preheating pipeline, the energy can be efficiently recycled, and by adjusting the opening degree of the drainage valve plate at the bottom of the multiple overflow plates, the temperature at different positions of the drying preheating pipeline can be adjusted to accurately control the drying effect.
[0016] 3、The application, through the setting of the built-in ventilation fan, in use, waste gas can be sucked into the heat exchanger through the built-in ventilation fan, in addition, when the internal temperature of the tunnel furnace body is too high, a plurality of exhaust pipes can be opened to quickly exhaust heat, so that the sintering temperature is in a stable state, the segmented partition plate makes the high-temperature hot gas entering the inside of the heat exchanger can be fully heat-exchanged in the heat exchanger, and the waste heat utilization rate is improved. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is a schematic diagram of the overall structure of the application; Figure 2 It is a schematic diagram of the drying treatment mechanism structure of the application; Figure 3 It is a schematic diagram of the drying treatment mechanism structure of the application; Figure 4 It is a layout sectional view of the drying preheating pipeline of the application; Figure 5 It is a sectional view of the heat exchanger of the application; Figure 6 It is a schematic diagram of the top view structure of the application; Figure 7 It is a three-dimensional schematic diagram of the sintering sagger of the application; Figure 8 It is a side sectional view of the sintering sagger of the application; Figure 9 It is a partial schematic diagram of the ventilation stabilizing mechanism inside the tunnel furnace body of the application; Figure 10 It is a schematic diagram of the application Figure 9 The bottom view.
[0018] In the figure: 1, tunnel furnace body; 101, heat preservation layer; 102, heating layer; 103, furnace body lining; 104, air inlet pipe; 105, air injection plate; 2, electric push plate system; 3, exhaust pipe; 4, external electromagnetic valve; 5, heat exchanger; 51, inner layer shell; 52, outer layer shell; 6, segmented partition plate; 7, waste gas pipe; 8, steam pipe; 9, first water inlet pipe; 10, first water outlet pipe; 11, built-in ventilation fan; 12, drying preheating pipeline; 13, multi-stage overflow plate; 14, water drainage valve plate; 15, ventilation groove; 16, fan; 17, ventilation pipe; 18, ventilation opening; 19, exhaust port; 20, second water inlet pipe; 21, second water outlet pipe; 22, waste water discharge pipe; 23, waste water discharge pipe; 24, side ventilation groove; 25, bottom insertion hole; 26, top insertion block; 27, shock absorbing fixing frame; 28, elastic shock absorbing pad. DETAILED DESCRIPTION
[0019] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.
[0020] Embodiment 1 In an embodiment of the present application, referring to Figure 1 , Figure 2 and Figures 6 to 10 , a sintering device for a battery positive electrode material comprises a tunnel furnace body 1, an electric push plate system 2 matched with the tunnel furnace body 1, an over-temperature protection mechanism arranged at the top of the tunnel furnace body 1, and a drying treatment mechanism mounted on the electric push plate system 2. The inside of the tunnel furnace body 1 is divided into three parts, i.e., a heating-up zone arranged at the end of the tunnel furnace body 1, a sintering zone arranged at the middle of the tunnel furnace body 1, and a heat preservation zone arranged at the tail of the tunnel furnace body 1. The inside of the tunnel furnace body 1 is provided with a heat preservation layer 101, a heating layer 102, and a furnace body lining 103. The electric push plate system 2 is composed of three parts, i.e., a feeding zone arranged outside the tunnel furnace body 1, a high-temperature resistant zone arranged inside the tunnel furnace body 1, and a feeding and discharging zone connecting the feeding zone and the sintering zone. The over-temperature protection mechanism is composed of an exhaust pipe 3, an external electromagnetic valve 4, and a heat exchanger 5. The heat exchanger 5 is composed of an inner layer shell 51 and an outer layer shell 52. The drying treatment mechanism is composed of a drying preheating pipeline 12 and an air venting groove 15.
[0021] The inside of the tunnel furnace body 1 is provided with an air venting stabilizing mechanism. The air venting stabilizing mechanism is composed of an air inlet pipe 104 and a jet plate 105. The jet plate 105 is mounted inside the furnace body lining 103, and the jet plate 105 is connected with the exhaust end of the air inlet pipe 104.
[0022] The bottom of the exhaust pipe 3 is connected with the inside of the tunnel furnace body 1. The heat exchanger 5 is mounted at the top of the exhaust pipe 3. The inner layer shell 51 is connected with the top of the exhaust pipe 3.
[0023] The electric push plate system 2 is provided with a sintering box 23. The lateral wall of the sintering box 23 is provided with a lateral air venting groove 24. The bottom of the lateral air venting groove 24 is provided with a bottom insertion hole 25. The top of the lateral air venting groove 24 is provided with a top insertion block 26. The bottom insertion hole 25 is matched with the top insertion block 26. The bottom of the sintering box 23 is provided with an inclined surface. The top insertion block 26 and the bottom insertion hole 25 are both provided with a conical shape.
[0024] Specifically, before sintering, the raw materials need to be prepared and the green body processing is needed. The raw materials are prepared by taking Co3O4 and Li2CO3 as raw materials, matching them in a stoichiometric ratio of n(Li) / n(Co)=1.01-1.08, and adding 300-3000PPm of additives (one or more of ZrO2, TiO2, magnesium oxide, and aluminum oxide). The above-mentioned raw materials are placed in a ball mill for 6-12 hours to obtain a mixture. Then, the prepared raw materials are mixed with water and sintered in the sintering kiln 23, and then pressed into a 2.5cm*2.5cm*1cm preform by a mold, and the preform is arranged in a 9*9 format.
[0025] Then, the two sintering kilns 23 are stacked on top of each other and placed at the loading area of the electric push plate system 2. By starting the electric push plate system 2 and setting the conveying speed of the electric push plate system 2, the sintering kiln 23 enters the drying preheating pipeline 12 for drying treatment. During the drying process, the sintering kiln 23 is blown with gas through the air slot 15. The side air slot 24 on the sintering kiln 23 can be used for ventilation treatment of the preform. In combination with the inclined surface arranged at the bottom of the sintering kiln 23, it can prevent water vapor from adhering to the surface of the preform during drying, thereby preventing the problem of uneven internal and external humidity causing the preform to crack, thereby improving the sintering quality.
[0026] After passing through the drying preheating pipeline 12, the sintering kiln 23 is conveyed from the loading area to the feeding area of the feeding and discharging area, and then conveyed by the conveying mechanism of the feeding area to the high-temperature-resistant area of the electric push plate system 2 located inside the tunnel furnace main body 1 for sintering.
[0027] During sintering, the sintering kiln 23 first passes through the heating zone of the tunnel furnace main body 1 to uniformly heat the preform inside the sintering kiln 23, and then enters the sintering zone, which is controlled at a temperature of 900-1100℃, and then sintered for 6-12h. During this period, the tunnel furnace main body 1 is generally provided with a control system including a temperature sensor, a PLC controller, etc., which can monitor and adjust the operating parameters in the furnace. During sintering, oxygen is needed for the reaction: 2Co304+3Li2C03+1 / 202=6LiCo02+3C02. However, due to the high temperature in the sintering zone, it is difficult for external air to enter. Therefore, an air stabilizing mechanism is provided to supply stable air to the sintering zone through the air inlet pipe 104 and the air injection plate 105 by using external air pump and other air supply equipment, so as to ensure the oxygen supply and improve the sintering quality.
[0028] When sintering, carbon dioxide is produced, so exhaust gas needs to be discharged, and the exhaust gas is discharged through the exhaust pipe 3. The high-temperature gas discharged can be collected through the heat exchanger 5 to collect the waste heat and can be used as power for other equipment, thereby improving energy utilization. In addition, when discharging carbon dioxide, the effect of the ventilation stabilizing mechanism and the built-in ventilation fan 11 arranged inside the exhaust pipe 3 can quickly guide the carbon dioxide, reduce the time of carbon dioxide in the tunnel furnace body 1, and make the air introduced by the ventilation stabilizing mechanism also flow quickly, improve the effect of air circulation and diffusion, keep the oxygen distribution uniform in the sintering area, and further improve the sintering quality.
[0029] The blank inside the sintering box 23 passing through the sintering area has completed sintering, at this time, enters the holding area, and after a period of holding, is discharged from the tunnel furnace body 1, at this time, completes one sintering.
[0030] The material after one sintering is crushed, and then the sintering device is used for secondary sintering. The secondary sintering is consistent with the process of one sintering.
[0031] Example 2 As an embodiment of the present application, please refer to 5, a sintering device for a battery positive electrode material, based on example 1, further comprising, the front end of the outer shell 52 is provided with a first water inlet pipe 9, the rear end of the outer shell 52 is provided with a first drain pipe 10, the first water inlet pipe 9 and the first drain pipe 10 are arranged between the outer shell 52 and the inner shell 51 respectively, the center of the outer shell 52 is provided with a steam pipe 8, and the exhaust pipe 7 penetrates the steam pipe 8; The outer part of the exhaust pipe 3 is provided with an external electromagnetic valve 4. The exhaust pipe 3 is provided with two groups, and the two groups of exhaust pipes 3 are symmetrically distributed on the top of the tunnel furnace body 1. Each group of exhaust pipes 3 is provided with a plurality of exhaust pipes 3, and a part of each group of exhaust pipes 3 is arranged inside the sintering area of the tunnel furnace body 1. The other part of the two groups of exhaust pipes 3 is arranged inside the heating area and the holding area of the tunnel furnace body 1. The inner part of the two exhaust pipes 3 located at the outermost side is provided with a built-in ventilation fan 11, and the external electromagnetic valve 4 outside the two exhaust pipes 3 located at the outermost side is set as always open.
[0032] Specifically, during sintering, the gas inside the tunnel furnace body 1 can flow quickly through the built-in ventilation fan 11 inside the two outermost exhaust pipes 3, the carbon dioxide generated by the sintering reaction can be introduced into the inner shell 51 of the heat exchanger 5, participate in heat exchange of the heat exchanger 5, preheat and recover the sintering waste gas, in addition, when the temperature sensor at different positions inside the tunnel furnace body 1 senses a temperature exceeding the set temperature, the outer electromagnetic valve 4 of the exhaust pipe 3 closest to the temperature sensor can be opened through the control hole arranged outside the tunnel furnace body 1, then the exhaust pipe 3 is connected with the internal space of the tunnel furnace body 1, the airflow direction caused by the built-in ventilation fan 11 makes the top airflow of the exhaust pipe 3 flow, then the exhaust pipe 3 can smoothly inhale the airflow from the bottom of the exhaust pipe 3 to the inner shell 51 of the heat exchanger 5, participate in heat exchange, and cool down the inside of the tunnel furnace body 1, and due to the arrangement of the sectional partition plate 6, the time of the high-temperature waste gas introduced from the tunnel furnace body 1 inside the inner shell 51 is increased, further improving the heat exchange efficiency.
[0033] Example 3 As an embodiment of the present application, please refer to Figure 3 and Figure 4 , a sintering device for a battery positive electrode material, based on example 2, further comprising a elastic damping pad 28 installed on the fixed slide rail of the feeding area of the electric push plate system 2, and the sintering box 23 is arranged on the top of the elastic damping pad 28 and at the center of the fixed slide rail of the feeding area of the electric push plate system 2.
[0034] Specifically, during the movement of the sintering box 23 on the feeding area of the electric push plate system 2, the elastic damping pad 28 is used for damping, preventing the blank inside the sintering box 23 from being shaken too hard and affecting the tightness of the material inside the blank, and improving the sintering quality during subsequent sintering.
[0035] The drying and preheating pipeline 12 is arranged on the electric push plate system 2, the cross section of the drying and preheating pipeline 12 is arranged in a meandering shape, a plurality of multi-stage overflow plates 13 are uniformly arranged on the inner wall of the drying and preheating pipeline 12, a drain valve plate 14 is arranged at the bottom of the multi-stage overflow plates 13, a second drain pipe 21 and a waste water discharge pipe 22 are arranged at the front end of the drying and preheating pipeline 12, the waste water discharge pipe 22 is arranged at the bottom of the end of the drying and preheating pipeline 12, a second water inlet pipe 20 is arranged at the rear end of the drying and preheating pipeline 12, the rear end of the drying and preheating pipeline 12 is close to the side of the temperature maintaining area of the tunnel furnace body 1, and the front end of the drying and preheating pipeline 12 is close to the side of the temperature rising area of the tunnel furnace body 1.
[0036] In use, the first water inlet pipe 9 is connected with the first water outlet pipe 10, and then the second water outlet pipe 21 and the waste water discharge pipe 22 are connected with the first water inlet pipe 9 through an external pump body, so that the waste heat energy collected by the heat exchanger 5 can be directly used, the energy utilization efficiency is improved, and energy waste is reduced.
[0037] Specifically, when the sintering sagger 23 enters the drying preheating pipeline 12, the drying preheating pipeline 12 is internally provided with multiple overflow plates 13, so that the temperature inside the drying preheating pipeline 12 gradually increases from left to right, and the sintering sagger 23 enters from the left side of the drying preheating pipeline 12, so that the temperature gradually increases inside the sintering sagger 23. Since there is moisture in the air, the blank inside the blank will also have a certain amount of moisture when it is formed, so it needs to be removed. In the process of gradually increasing the temperature, the moisture inside gradually decreases, which can effectively prevent the moisture from evaporating unevenly due to the sudden increase in the temperature of the blank, prevent cracks from occurring on the surface of the blank, and improve the sintering quality in the later stage. The drain valve plate 14 can be externally connected to an external electric control system, and multiple temperature sensors can be arranged at different positions inside the drying preheating pipeline 12. Since the time and temperature required for different sintering are different, the time and drying temperature experienced by the sintering sagger 23 when passing through the drying preheating pipeline 12 are inconsistent, so the temperature gradient inside the drying preheating pipeline 12 needs to be adjusted. At this time, by controlling the angle at which the drain valve plate 14 is opened, the overflow amount and overflow speed are adjusted, and then the temperature change at different positions inside the drying preheating pipeline 12 is adjusted, so that the purpose of adjusting the drying efficiency according to the pushing speed of the electric push plate system 2 is achieved.
[0038] The air vent groove 15 is provided with two groups and is symmetrically installed on the inner wall of the drying preheating pipeline 12. The top of the drying preheating pipeline 12 is provided with a fan 16, the exhaust end of the fan 16 is provided with an air vent pipe 17, the air vent pipe 17 is connected with the end of the air vent groove 15, multiple linearly distributed air vents 18 are formed in the outer wall of the air vent groove 15, and the top of the drying preheating pipeline 12 is provided with linearly arrayed exhaust ports 19.
[0039] Specifically, when the blank inside the sintering sagger 23 is dried, water vapor will be generated on the surface of the blank. At this time, in the drying process, the fan 16 performs ventilation treatment on the blank inside the sintering sagger 23 through the air vent pipe 17 and the air vents 18 on the air vent groove 15, so that the dry evaporated gas is discharged through the exhaust port 19, preventing the water vapor from sticking to the surface of the blank and affecting the drying effect.
[0040] In summary, when the positive electrode material of the battery is prepared, the preparation method is as follows: First step, first preparation of raw materials, with Co304 and Li2C03 as raw materials, according to the stoichiometric ratio, according to n(Li) / n(Co)=1.01-1.08 ratio, add 300-3000PPm of additives (one or more of ZrO2, TiO2, magnesium oxide, aluminum oxide), the above raw materials are placed in the ball mill, ball milling 6-12h, get mixed material; Second step, blanking and boxing: the raw materials prepared in the first step are put into the sintering box 23, and the preform blank is formed by pressing molding through the mold, which is 2.5cm*2.5cm*1cm, and the blank quantity is 9*9 format, uniform setting, then the two sintering box 23 are stacked up and down.
[0041] Third step, drying treatment, the loaded sintering box 23 is put into the loading area of the electric push plate system 2 of the sintering device, and the multiple groups of sintering box 23 are pushed into the drying preheating pipeline 12 in turn through the electric push plate system 2, and the drying treatment time is 4-6h, during drying, the hot water generated by heat exchange of heat exchanger 5 is introduced into drying preheating pipeline 12, and multi-stage overflow plate 13 is used, so that the sintering box 23 can gradually increase the temperature when passing through the drying preheating pipeline 12, and then uniformly dry, in addition, the fan 16 cooperates with the ventilation groove 15 to ventilate the blank inside the sintering box 23, prevent the blank from cracking on the surface when drying, and improve the sintering quality.
[0042] Fourth step, once sintering, the dried sintering box 23 is put into the heating zone inside the tunnel furnace body 1 under the action of the electric push plate system 2 through the feeding area of the electric push plate system 2, so that the preform blank is preheated, then the preform blank is pushed into the sintering zone inside the tunnel furnace body 1 through the high temperature resistant zone of the electric push plate system 2, the pushing speed of the electric push plate system 2 is adjusted, so that the preform blank stays in the sintering zone for 6-12h, and sintering at 900-1100℃ for 6-12h to form a sintered material, after sintering, the sintering box 23 containing the preform blank enters the heat preservation zone of the tunnel furnace body 1, and after a period of heat preservation, it is pushed out of the tunnel furnace body 1; When sintering, oxygen is consumed to produce carbon dioxide, at this time, the external air is introduced into the sintering area of the tunnel furnace body 1 through the air inlet pipe 104 and the air injection plate 105 by the ventilation stabilizing mechanism, participates in the high-temperature chemical reaction to prevent oxygen deficiency, and the produced carbon dioxide is introduced into the inner shell 51 of the heat exchanger 5 by the built-in ventilation fan 11, heat exchange treatment is performed, recycling is realized, and when the sintering temperature is too high, the exhaust pipe 3 of the sintering area is opened, then the gas in the interior of the sintering area is introduced into the heat exchanger 5 for waste heat recovery, the sintering temperature is reduced, the sintering temperature is kept in a stable state, water is introduced into the heat exchanger 5, water vapor and hot water are produced by heat exchange, the water vapor is discharged and used for other power input, and the hot water can be introduced into the drying preheating pipeline 12 to provide heat energy for drying the blanks, the water temperature after passing through the drying preheating pipeline 12 is reduced, and the water can be introduced into the heat exchanger 5 again to realize energy recycling and efficient use of energy.
[0043] The fifth step is to crush and re-load the case. The sintered material in the sintering case 23 is taken out for crushing, and then re-loaded into the sintering case 23 by S2 to form blanks. This time, only pressing is needed, and the pressing is performed by using a metal mold with specifications of 9*9 and a size of 2.5cm*2.5cm*1cm.
[0044] The fifth step is to sinter again. The sintering case 23 of the fifth step is again passed through the drying preheating pipeline 12 by the electric push plate system 2 for drying treatment, and then sintered again by S3. In the second sintering, the sintering temperature needs to be controlled at 600-900℃, and the sintering time is consistent with that of the first sintering. Finally, a stable LiCo02 bulk body is obtained.
[0045] It should be noted that the relational terms herein such as first and second are used only to differentiate one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including one" does not exclude the presence of another identical element in the process, method, article or equipment including the element.
[0046] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.
Claims
1. A sintering device for a battery cathode material, comprising a tunnel furnace main body, an electric push plate system arranged in a supporting manner with the tunnel furnace main body, an over-temperature protection mechanism arranged on the top of the tunnel furnace main body, and a drying treatment mechanism installed on the electric push plate system, wherein: The interior of the tunnel furnace body is divided into three parts: a heating zone at the end of the tunnel furnace body, a sintering zone in the middle of the tunnel furnace body, and a heat preservation zone at the tail of the tunnel furnace body. The interior of the tunnel furnace body is equipped with a heat preservation layer, a heating layer, and a furnace lining. The electric pusher system consists of three parts: a feeding zone outside the tunnel furnace body, a high-temperature resistant zone inside the tunnel furnace body, and a feeding and discharging zone connecting the feeding zone and the sintering zone. The over-temperature protection mechanism consists of an exhaust pipe, an external solenoid valve, and a heat exchanger. The heat exchanger consists of an inner shell and an outer shell. The drying treatment mechanism consists of a drying preheating pipe and a ventilation trough. The electric pusher system is equipped with a sintering sagger. The tunnel furnace body is equipped with an internal ventilation stabilization mechanism, which consists of an air inlet pipe and an air jet plate. The air jet plate is installed inside the furnace lining and is connected to the exhaust end of the air inlet pipe. The bottom of the exhaust pipe is connected to the interior of the tunnel furnace body, the heat exchanger is installed on the top of the exhaust pipe, and the inner shell is connected to the top of the exhaust pipe.
2. The sintering apparatus for a battery positive electrode material according to claim 1, characterized in that: The outer wall of the sintering sagger is provided with a side ventilation groove, the bottom of the side ventilation groove is provided with a bottom insertion hole, the top of the side ventilation groove is provided with a top insertion block, the bottom insertion hole is adapted to the top insertion block, the bottom of the sintering sagger is provided with an inclined surface, and both the top insertion block and the bottom insertion hole are conical.
3. The sintering apparatus for a battery positive electrode material according to claim 2, characterized in that: The inner shell is located inside the outer shell. The inner wall of the inner shell is equipped with segmented baffles, which are composed of multiple baffles of different curvatures that are symmetrically distributed. There is a gap between the bottom of the baffle and the inner wall of the inner shell. The gap between the baffle and the inner wall of the inner shell is smaller the closer it is to the middle of the inner shell. An exhaust pipe is installed at the center of the inner shell.
4. The sintering apparatus for a battery positive electrode material according to claim 3, characterized in that: The front end of the outer shell is equipped with a first water inlet pipe, and the rear end of the outer shell is equipped with a first drain pipe. The first water inlet pipe and the first drain pipe are respectively located between the outer shell and the inner shell. A steam pipe is installed at the center of the outer shell, and an exhaust pipe passes through the steam pipe.
5. The sintering apparatus for a battery positive electrode material according to claim 4, characterized in that: External solenoid valves are installed on the exterior of the exhaust pipes. There are two sets of exhaust pipes, which are symmetrically distributed on the top of the tunnel furnace body. Each set of exhaust pipes has multiple exhaust pipes. Part of each set of exhaust pipes is located inside the sintering zone of the tunnel furnace body, and the other part of each set of exhaust pipes is located inside the heating zone and the heat preservation zone of the tunnel furnace body. Built-in ventilation fans are installed inside the two outermost exhaust pipes. The external solenoid valves on the two outermost exhaust pipes are normally open.
6. The sintering apparatus for a battery positive electrode material according to claim 5, characterized in that: Elastic damping pads are installed on the fixed slide rails in the feeding area of the electric pusher system. The sintering sagger is placed on top of the elastic damping pads and at the center of the fixed slide rails in the feeding area of the electric pusher system.
7. The sintering apparatus for a battery positive electrode material according to claim 6, characterized in that: The drying and preheating pipe is installed on the electric push plate system. The cross-section of the drying and preheating pipe is U-shaped. The inner wall of the drying and preheating pipe is equipped with a multi-stage overflow plate that is evenly distributed. The bottom of the multi-stage overflow plate is equipped with a drain valve plate. The front end of the drying and preheating pipe is equipped with a second drain pipe and a wastewater discharge pipe. The wastewater discharge pipe is located at the bottom of the end of the drying and preheating pipe. The rear end of the drying and preheating pipe is equipped with a second water inlet pipe. The rear end of the drying and preheating pipe is close to the heating zone of the tunnel furnace body, and the front end of the drying and preheating pipe is close to the insulation zone of the tunnel furnace body.
8. The sintering apparatus for a battery positive electrode material according to claim 7, characterized in that: There are two sets of ventilation slots, which are symmetrically installed on the inner wall of the drying and preheating pipe. A fan is installed at the top of the drying and preheating pipe, and a ventilation pipe is installed at the exhaust end of the fan. The ventilation pipe is connected to the end of the ventilation slot. Multiple ventilation openings are linearly distributed on the outer wall of the ventilation slot. Exhaust openings are linearly arrayed on the top of the drying and preheating pipe.
9. The method for preparing a battery cathode material according to claim 1, characterized in that: Using the sintering apparatus for a battery positive electrode material as described in claim 8, the process includes the following steps: S1: Raw material preparation: Co3O4 and Li2CO3 are used as raw materials and are mixed in a stoichiometric ratio of n(Li) / n(Co) = 1.01-1.
08. Add 300-3000 ppm of additives (one or more of ZrO2, TiO2, magnesium oxide, and aluminum oxide). Place the above raw materials in a ball mill and ball mill for 6-12 hours to obtain a mixture. S2: Blank preparation and saggar loading: The raw materials prepared in S1 are pressed into shape in the sintering saggar by a mold to form a pre-made blank of 2.5cm*2.5cm*1cm, and the blanks are evenly arranged in a 9*9 format. Then, two sintering saggars are stacked one on top of the other. S3: Drying treatment: Place the sintering saggers prepared in S2 into the feeding area of the electric pusher system of the sintering device. The electric pusher system will then push multiple sets of sintering saggers into the drying and preheating pipes for drying treatment. The drying treatment time is 4-6 hours. S4: First sintering: After drying in S3, the sintering sagger enters the heating zone inside the tunnel furnace body through the feeding zone of the electric pusher system, which preheats the precast blank. Then, through the high-temperature zone of the electric pusher system, the precast blank is pushed into the sintering zone inside the tunnel furnace body. The pushing speed of the electric pusher system is adjusted so that the time for the precast blank to pass through the sintering zone is 6-12 hours. It is sintered at 900-1100℃ for 6-12 hours to form a sintered material. After sintering, the sintering sagger holding the precast blank enters the heat preservation zone of the tunnel furnace body. After a period of heat preservation, it is pushed out of the tunnel furnace body. S5: Crushing and reloading into the sintering sagger. The sintering material inside the sintering sagger is taken out and crushed. Then it passes through S2 again to form a blank inside the sintering sagger. This time, the blank is formed by direct pressing with a mold. S6: Secondary sintering: The sintering sagger in S5 is dried again through the drying and preheating pipe by the electric pusher system, and then sintered again through S3. In the secondary sintering, the sintering temperature needs to be controlled at 600-900℃, and the sintering time is the same as the sintering time of the first sintering in S4, so as to finally obtain stable LiCoO2. S7: Discharge: Remove the LiCoO2 blocks from the sintering sagger after the second sintering in S6.