Lithium battery positive electrode material sintering kiln

Abstract

The utility model discloses a lithium battery positive electrode material sintering kiln which comprises an atmosphere sintering furnace body, a heating area, a sintering area and a cooling area are arranged in the atmosphere sintering furnace body, the heating area, the sintering area and the cooling area are separated through partition plates, and air curtains are arranged on the partition plates. Air inlets are formed in the two sides and the middle of the bottoms of the heating area, the sintering area and the cooling area; the gas inlet device is arranged at the bottom of the atmosphere sintering furnace body, connected with the gas inlet and used for conveying gas into the atmosphere sintering furnace body; and the exhaust device is arranged on the atmosphere sintering furnace body and used for exhausting water vapor and waste gas in the atmosphere sintering furnace body. Compared with a traditional atmosphere sintering furnace, the problems of poor product uniformity, high residual alkali content, large hearth atmosphere fluctuation and high nickel energy consumption in multi-layer sagger sintering are effectively solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of kilns, and in particular relates to a kiln for sintering positive electrode materials of lithium batteries. Background Art

[0002] With increasing demands for new energy vehicle range, the demand for high-energy-density lithium batteries has increased significantly. The solid-phase method is a key method for synthesizing cathode materials, offering advantages such as ease of operation, zero wastewater discharge, and low production costs, making it readily adaptable to industrial production. However, in nickel-cobalt-manganese ternary cathode materials, increasing nickel content complicates the process and places higher demands on roller kiln equipment and the environment.

[0003] Roller hearth kilns are currently the primary method for synthesizing lithium battery cathode materials due to their rapid heating rate, uniform temperature distribution, ease of control, ease of ignition and shutdown, and simple operation. These kilns are suitable for rapid sintering, reduce costs, and require minimal floor space. These kilns are categorized as air kilns and atmosphere kilns. Low- to medium-nickel ternary cathode materials, lithium manganese oxide (LMM) cathode materials, and lithium cobalt oxide (LCO) cathode materials are primarily sintered in air kilns; lithium iron phosphate (LFP) cathode materials are primarily sintered in nitrogen atmosphere kilns; and high-nickel ternary cathode materials are sintered in oxygen atmosphere kilns.

[0004] At present, the air intake and exhaust system of atmosphere sintering furnaces is usually set up to intake air near the sides and bottom of the kiln, and exhaust is provided at the top. To increase production capacity while reducing costs, the feeding method is usually designed to be multi-row and multi-layer. The calcination process of ternary cathode materials consumes a large amount of oxygen and emits a large amount of water vapor and alkaline waste gas. Currently, the air sintering of medium and high nickel is low-cost, but the product uniformity and high-temperature performance are poor, the structure is unstable, and the cost of oxygen atmosphere is high. In addition, the air intake on the side of the kiln, coupled with the loss of some heat energy through the ends of the rollers, leads to uneven furnace temperature and a large temperature difference between the side and the center of the furnace, which in turn leads to unstable and poor product uniformity. Utility Model Content

[0005] In order to solve the technical defects of poor product uniformity, uneven furnace temperature and high residual alkali in the multi-row and multi-layer sagger sintering, the utility model provides a lithium battery positive electrode material sintering kiln.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A lithium battery positive electrode material sintering kiln, comprising: an atmosphere sintering furnace body, wherein a heating zone, a sintering zone, and a cooling zone are provided inside the atmosphere sintering furnace body, wherein the heating zone, the sintering zone, and the cooling zone are separated by partitions, and an air curtain is provided on the partitions. Air inlets are provided on both sides and in the middle of the bottom of the heating zone, the sintering zone, and the cooling zone;

[0008] An air intake device is provided at the bottom of the atmosphere sintering furnace body, the air intake device is connected to the air inlet, and the air intake device is used to transport gas into the atmosphere sintering furnace body;

[0009] The exhaust device is arranged on the atmosphere sintering furnace body and is used for exhausting water vapor and waste gas in the atmosphere sintering furnace body.

[0010] Furthermore, the wind curtain is arranged in the middle of the partition and located on the top of the atmosphere sintering furnace body. The wind curtain is provided with an impeller and a motor. The impeller is arranged on the driving end of the motor. The motor drives the impeller to rotate to block the exchange of gas inside and outside the partition.

[0011] Furthermore, the internal pressure of the air curtain is higher than the furnace pressure at both ends of the air curtain.

[0012] Furthermore, the heating zone, the sintering zone and the cooling zone are each provided with two air intake flow meters, the two air intake flow meters are arranged at intervals, and the two air intake flow meters are both connected to the air intake device.

[0013] Furthermore, the bottom of each of the heating zone, the sintering zone, and the cooling zone is provided with two air inlets, the air inlet flowmeter is provided in the air inlet, and a third air inlet branch pipe is provided at the end of the air inlet, and the first air inlet branch pipe and the second air inlet branch pipe are connected to the third air inlet branch pipe;

[0014] The air intake device includes a first air intake main pipe, a second air intake main pipe and a third air intake main pipe. The first air intake main pipe is connected to the first air intake branch pipe, and the second air intake main pipe and the third air intake main pipe are connected to the second air intake branch pipe.

[0015] Furthermore, an air preheating groove is provided above the air inlet.

[0016] Furthermore, the heating zone, sintering zone and cooling zone are all provided with exhaust devices.

[0017] Furthermore, the exhaust device includes an exhaust port and an exhaust motor, and the exhaust port and the exhaust motor cooperate with each other.

[0018] Furthermore, a small gas discharge hole is provided at the bottom of the heating zone, the sintering zone and the cooling zone, and a regulating valve is provided on the gas discharge hole.

[0019] Furthermore, the front end of the atmosphere sintering furnace body is provided with a furnace air inlet, and the rear end is provided with a furnace air outlet.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The gas enters the atmosphere sintering furnace from the bottom and is discharged from the top, avoiding low temperatures on both sides of the furnace and large temperature differences in each temperature zone in the furnace, reducing the loss of heat energy in the furnace, and thus ensuring the uniformity of the temperature field in the furnace; at the same time, the kiln is divided into three sections by partitions, namely the heating zone, the sintering zone, and the cooling zone. Each section is separated by partitions and air curtains to prevent the mixing of different gases in the two sections. More importantly, the same product can react under different atmospheres at different reaction stages, changing the oxygen atmosphere environment in the furnace, reducing high nickel oxygen consumption, and improving product quality. Compared with traditional atmosphere sintering furnaces, it effectively solves the problems of poor product uniformity, high residual alkali, large fluctuations in furnace atmosphere, and high high nickel energy consumption in multi-layer sagger sintering. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is an overall schematic diagram of the lithium battery positive electrode material sintering kiln provided by the utility model;

[0024] Among them: 11. Atmosphere sintering furnace body; 12. First air inlet main pipe; 13. Second air inlet main pipe; 14. Third air inlet main pipe; 15. First air inlet branch pipe; 16. Second air inlet branch pipe; 17. Third air inlet branch pipe; 18. Air inlet; 19. Air inlet flowmeter; 20. Air outlet hole; 21. Air inlet preheating groove; 22. Partition; 23. Impeller; 24. Motor; 25. Exhaust port; 26. Kiln bottom; 27. Kiln top; 28. Roller; 29. ​​Sagger; 30. Exhaust motor; 31. Heating zone; 32. Sintering zone; 33. Cooling zone; 34. Sintering furnace air inlet; 35. Sintering furnace air outlet. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. These terms are only used to facilitate the description of the present invention and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be understood as indicating or implying relative importance.

[0029] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] This embodiment will be described in detail below with reference to the accompanying drawings.

[0032] This embodiment provides a sintering kiln for lithium battery positive electrode materials.

[0033] like Figure 1As shown, a lithium battery positive electrode material sintering kiln includes an atmosphere sintering furnace body 11, and a heating zone 31, a sintering zone 32 and a cooling zone 33 are provided inside the atmosphere sintering furnace body 11. The heating zone 31, the sintering zone 32 and the cooling zone 33 are separated by a partition 22, and an air curtain is provided on the partition 22. Air inlets 18 are provided on both sides and in the middle of the bottom of the heating zone 31, the sintering zone 32 and the cooling zone 33; an air intake device is provided at the bottom of the atmosphere sintering furnace body 11, that is, the bottom 26 of the kiln, and the air intake device is connected to the air intake 18. The air intake device is used to transport gas to the inside of the atmosphere sintering furnace body 11; an exhaust device is provided in the atmosphere sintering furnace body 11, and is used to discharge water vapor and exhaust gas in the atmosphere sintering furnace body 11. During use, the gas enters the atmosphere sintering furnace body 11 from the bottom 26 of the kiln and is discharged from the top 27 of the kiln, avoiding low temperatures on both sides of the kiln and large temperature differences in the temperature zones in the furnace, reducing the loss of heat energy in the kiln, and thus ensuring the uniformity of the temperature field in the furnace; at the same time, the kiln is divided into three sections by the partition 22, namely the heating zone 31, the sintering zone 32, and the cooling zone 33. Each section is separated by the partition 22 and the wind curtain to prevent the mixing of different gases in the two sections. More importantly, the same product can react under different atmospheres at different reaction stages, changing the oxygen atmosphere environment in the furnace, reducing high nickel oxygen consumption, and improving product quality. Compared with traditional atmosphere sintering furnaces, it effectively solves the problems of poor product uniformity, high residual alkali, large fluctuations in furnace atmosphere, and high high nickel energy consumption caused by sintering of multi-layer saggers 29.

[0034] like Figure 1As shown, the air curtain is installed in the middle of the partition 22 and is located at the top of the atmosphere sintering furnace body 11, that is, the kiln top 27. The air curtain is equipped with an impeller 23 and a motor 24. The impeller 23 is installed at the drive end of the motor 24. The motor 24 drives the impeller 23 to rotate to block the exchange of gases inside and outside the partition 22. Because the air curtain is installed in the middle of the partition 22, the internal pressure of the air curtain is higher than the furnace pressure at both ends of the air curtain. Two air intake flow meters 19 are installed in the heating zone 31, sintering zone 32, and cooling zone 33 of the atmosphere sintering furnace body 11. The two air intake flow meters 19 are spaced apart and connected to the air intake device. Furthermore, two air inlets 18 are provided at the bottom of the heating zone 31, the sintering zone 32 and the cooling zone 33. An air flow meter 19 is arranged in the air inlet 18, and a third air inlet branch pipe 17 is provided at the end of the air inlet 18. The third air inlet branch pipe 17 is connected to the first air inlet branch pipe 15 and the second air inlet branch pipe 16; the air intake device includes a first air inlet main pipe 12, a second air inlet main pipe 13 and a third air inlet main pipe 14, the first air inlet main pipe 12 is connected to the first air inlet branch pipe 15, and the second air inlet main pipe 13 and the third air inlet main pipe 14 are connected to the second air inlet branch pipe 16; the atmosphere transported by the first air inlet main pipe 12, the second air inlet main pipe 13 and the third air inlet main pipe 14 to the atmosphere sintering furnace body 11 is one of oxygen, air and inert gas. During the transportation of the atmosphere, one or more types can be selected for simultaneous transportation according to the operating conditions.

[0035] In this embodiment, an air preheating groove 21 is provided above the air inlet 18. The gas entering through the air inlet 18 needs to enter the air preheating groove 21 for preheating before entering each zone.

[0036] In this embodiment, exhaust devices are provided in the heating zone 31 , the sintering zone 32 and the cooling zone 33 . The exhaust devices include an exhaust port 25 and an exhaust motor 30 . The exhaust port 25 cooperates with the exhaust motor 30 .

[0037] In this embodiment, a gas outlet hole 20 is provided at the bottom of the temperature rising zone 31 , the sintering zone 32 and the cooling zone 33 , and a regulating valve is provided on the gas outlet hole 20 .

[0038] In this embodiment, a furnace air inlet 34 is provided at the front end of the atmosphere sintering furnace body 11 , and a furnace air outlet 35 is provided at the rear end. Rollers 28 and a sagger 29 are also provided in the atmosphere sintering furnace body 11 .

[0039] The atmosphere sintering furnace body 11 uses four groups of partitions 22 to divide the body into three parts. Each part can be introduced into three different gases or a mixed gas in a certain proportion through the first air inlet main pipe 12, the second air inlet main pipe 13, the third air inlet main pipe 14, the first air inlet branch pipe 15, the second air inlet branch pipe 16 and the third air inlet branch pipe 17. When one gas is introduced alone, they do not interfere with each other. This not only ensures that the raw materials react fully, the residual lithium on the surface is low, and the product performance is better, but also takes into account the compatibility of the preparation of multiple products, providing a certain guarantee for improving production capacity and reducing high nickel oxygen consumption.

[0040] The air intake volume of the first main air intake conduit 12, the second main air intake conduit 13, the third main air intake conduit 14, the first branch air intake conduit 15, the second branch air intake conduit 16, and the third branch air intake conduit 17 is controlled by valves and air flowmeters 19 in air inlet ports 18. Each gas conduit is equipped with a pressure reducing valve, and the mixing ratio of the various gases can be adjusted using ball valves. Several air inlets 18 leading into the atmosphere sintering furnace body 11 are located on both sides and in the center of the furnace bottom in the heating zone 31, sintering zone 32, and cooling zone 33. Each air inlet 18 is equipped with an air inlet valve and air flowmeter 19 to control the amount of air intake. An air preheating groove 21 is provided above the air inlet 18 of the atmosphere sintering furnace body 11, and an exhaust hole 20 is provided at the lower part of the furnace at the air supply port of each temperature zone, and the gas is discharged at multiple points. The gas is sent into the air preheating groove 21 of the furnace body through the air intake flow meter 19. After being heated and the temperature is basically consistent, the fresh gas comes into contact with the product through the air intake channel at the bottom, thereby achieving the purpose of uniform furnace temperature and gas replenishment. The atmosphere sintering furnace body 11 is not provided with side air intake, and all air inlets 18 are at the bottom 26 of the kiln, which effectively avoids the low temperature on both sides of the kiln, resulting in uneven furnace temperature field and large differences in product indicators. An exhaust motor 30 and an exhaust port 25 are provided at the top 27 of the kiln to adjust the exhaust gas emission. Adjustable pumping valves are installed on the exhaust ports 25 to control the exhaust volume. The raw materials react in the sagger 29 under a certain atmosphere, and the generated water vapor and exhaust gas are discharged through the exhaust port 25. One exhaust port 25 is provided for each temperature zone on the top of the furnace in the heating section. The exhaust volume can be adjusted by a regulating valve, and the exhaust volume of each branch is controlled by a plug-in regulating valve.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A lithium battery positive electrode material sintering kiln, characterized in that: include: An atmosphere sintering furnace body (11), wherein a heating zone (31), a sintering zone (32) and a cooling zone (33) are provided inside the atmosphere sintering furnace body (11), wherein the heating zone (31), the sintering zone (32) and the cooling zone (33) are separated by a partition (22), and an air curtain is provided on the partition (22); air inlets (18) are provided on both sides and in the middle of the bottom of the heating zone (31), the sintering zone (32) and the cooling zone (33); An air intake device is provided at the bottom of the atmosphere sintering furnace body (11), the air intake device is connected to the air inlet (18), and the air intake device is used to transport gas into the atmosphere sintering furnace body (11); An exhaust device is provided on the atmosphere sintering furnace body (11) and is used for exhausting water vapor and waste gas in the atmosphere sintering furnace body (11).

2. The kiln according to claim 1, characterized in that The wind curtain is arranged in the middle of the partition (22) and is located at the top of the atmosphere sintering furnace body (11). An impeller (23) and a motor (24) are provided on the wind curtain. The impeller (23) is arranged on the driving end of the motor (24). The motor (24) drives the impeller (23) to rotate, so as to block the exchange of gas inside and outside the partition (22).

3. The kiln according to claim 2, characterized in that The internal pressure of the air curtain is higher than the furnace pressure at both ends of the air curtain.

4. The kiln according to claim 1, characterized in that The temperature rising zone (31), the sintering zone (32) and the cooling zone (33) are each provided with two air intake flow meters (19), the two air intake flow meters (19) are arranged at intervals, and the two air intake flow meters (19) are both connected to the air intake device.

5. The kiln according to claim 4, characterized in that The bottoms of the heating zone (31), the sintering zone (32) and the cooling zone (33) are each provided with two air inlets (18), the air inlet flowmeter (19) being arranged in the air inlet (18), and the ends of the air inlet (18) being provided with a third air inlet branch pipe (17), the third air inlet branch pipe (17) being connected to the first air inlet branch pipe (15) and the second air inlet branch pipe (16); The air intake device comprises a first air intake main pipe (12), a second air intake main pipe (13) and a third air intake main pipe (14); the first air intake main pipe (12) is connected to the first air intake branch pipe (15); the second air intake main pipe (13) and the third air intake main pipe (14) are connected to the second air intake branch pipe (16).

6. The kiln according to claim 5, characterized in that An air preheating groove (21) is provided above the air inlet (18).

7. The kiln according to claim 1, 4 or 5, characterized in that: The temperature rising zone (31), the sintering zone (32) and the cooling zone (33) are all provided with exhaust devices.

8. The kiln according to claim 7, characterized in that The exhaust device comprises an exhaust port (25) and an exhaust motor (30), and the exhaust port (25) and the exhaust motor (30) cooperate with each other.

9. The kiln according to claim 7, characterized in that A gas discharge hole (20) is provided at the bottom of the temperature rising zone (31), the sintering zone (32) and the cooling zone (33), and a regulating valve is provided on the gas discharge hole (20).

10. The kiln according to claim 1, characterized in that The front end of the atmosphere sintering furnace body (11) is provided with a furnace air inlet (34), and the rear end is provided with a furnace air outlet (35).

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