A positive electrode material storage device and system

Abstract

The utility model discloses a kind of positive electrode material storage device and system, belong to lithium ion battery positive electrode material manufacturing field.The device includes warehouse body, the stirring device of being set in warehouse body, temperature measuring device and the circulating fluid cooling device of being set on the outer wall of warehouse body.The system includes the fixed temporary storage bin connected with production line and the mobile bin that can be handled by fork truck.When high-temperature material enters warehouse body, through the synergistic effect of stirring device, cooling device and temperature measuring device, the temperature of material can be controlled, effectively solve the technical problem that carbonization combustion of lithium iron phosphate positive electrode material is prone to occur due to heat accumulation, improve production safety.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery cathode material manufacturing technology, and more specifically, to a cathode material storage device and system. Background Technology

[0002] Lithium iron phosphate (LFP), as an important cathode material for lithium-ion batteries, typically requires several processes in its production, including mixing, dispersing, grinding, spray drying, and high-temperature sintering of raw materials such as precursors, lithium sources, and sugar sources. After spray drying, the high-temperature cathode material powder needs to be conveyed to the next step of sintering in a crucible.

[0003] However, in actual production, downstream equipment in the spray drying system may malfunction, preventing the timely processing of freshly dried, high-temperature materials. These materials typically require temporary storage. Because the cathode material contains a carbon source, internal heat accumulates when the temperature exceeds 120°C, easily leading to carbonization of the carbon source and even combustion. This not only results in material loss but also poses serious safety hazards. Current conventional practices involve storing these materials in bulk bags or ordinary containers, relying on manual periodic turning to aid heat dissipation. However, this method is labor-intensive, has low heat dissipation efficiency, and cannot effectively monitor the internal temperature of the material, especially the core of the material pile, posing a high safety risk.

[0004] Therefore, how to provide a storage device and system that can effectively cool down the positive electrode material after spray drying and prevent it from carbonizing and burning has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] The purpose of this invention is to provide a cathode material storage device and system to solve the technical problem in the prior art that cathode materials are prone to carbonization and combustion due to high temperature heat accumulation during temporary storage.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A cathode material storage device includes: a chamber for containing spray-dried cathode material; a stirring device rotatably disposed within the chamber for stirring the cathode material; a temperature measuring device disposed on the inner wall or inside the chamber for monitoring the temperature of the cathode material within the chamber; and a circulating fluid cooling device disposed on the outer wall of the chamber for cooling the cathode material within the chamber.

[0008] The beneficial effects of this invention are as follows: by combining the stirring device, temperature measuring device, and circulating fluid cooling device, an integrated temperature-controlled storage solution is achieved. When the high-temperature cathode material enters the silo, the external circulating fluid cooling device can actively and efficiently remove the heat from the material; the internal stirring device can slowly and continuously agitate the material pile, on the one hand, turning the internal heat to the area near the silo wall, accelerating the heat conduction to the cooling device, and on the other hand, effectively preventing the material from clumping due to local overheating; the temperature measuring device monitors the temperature inside the silo in real time, providing data for controlling the cooling power of the cooling device and the start, stop, and speed of the stirring device, thereby ensuring that the material temperature inside the entire silo is always within a safe and controllable range, fundamentally avoiding the risk of high-temperature carbonization and combustion, and improving the safety of the production process and the qualification rate of the material.

[0009] Optionally, the circulating fluid cooling device includes a cooling coil or cooling jacket disposed on the outer wall of the chamber, and cooling fluid flows through the cooling coil or cooling jacket.

[0010] This application features a cooling coil or jacket installed on the outer wall of the chamber, resulting in a simple, compact, and easy-to-implement structure. The cooling medium circulates within a closed pipeline, preventing direct contact with the positive electrode material inside the chamber and avoiding the risk of material contamination, thus ensuring the purity of the material.

[0011] Optionally, the stirring device is a spiral stirring device.

[0012] This application uses a spiral stirring device that can lift and tumble the material from bottom to top, forming a circulating flow. Compared with ordinary stirring blades, it can stir more evenly and without dead corners.

[0013] Optionally, the mixing device also includes a wall scraper connected to the outer edge of the spiral mixing device for scraping the inner wall of the chamber.

[0014] This application, by adding a wall scraper, can scrape off the material adhering to the inner wall of the silo that has slow heat dissipation and mix it into the main material, further improving the uniformity of stirring and heat exchange, and effectively preventing the material from caking on the silo wall.

[0015] Optionally, a secondary cooling system is also included, comprising an inert gas supply unit and an air distribution plate. The air distribution plate is located on the side wall or bottom of the silo, and has multiple air holes with air caps on the air holes. The side walls of the air caps have airflow holes, or there are gaps between adjacent air caps. The inert gas supply unit is connected to the air distribution plate, and inert gas is introduced into the silo through the air distribution plate to form a cooling airflow channel. When the secondary cooling system is running, taking the air distribution plate located at the bottom of the silo as an example, the airflow in the air duct enters the lower part of the air cap through the air holes, and then flows out horizontally or obliquely upward from the airflow holes (or gaps) on the side walls of the air cap. In this application, the air caps on the air distribution plate can effectively prevent material leakage, and the airflow direction helps to agitate the particles. In this application, the air caps can be mushroom-shaped, bell-shaped, or directional (slanted) air caps. This application prefers bell-shaped air caps, which have excellent anti-leakage, anti-wear, and uniform airflow effects. The air distribution plate and air cap can be made of high-performance austenitic stainless steel (316L and above grade). 316L has low carbon content, less carbide precipitation, good resistance to intergranular corrosion, contains molybdenum (Mo), which can improve the resistance to chloride pitting corrosion and crevice corrosion, has good processing performance, and the cost is relatively controllable. The use of 316L in the silo basically meets the standards for metal ion precipitation of cathode materials. However, if it is used in a high-temperature and highly corrosive environment for a long time, high-quality and high-purity 316L must be selected, and the surface needs to be specially treated. Of course, 316L VM, 317L, 904L, duplex steel, etc. can also be used. These materials have higher molybdenum, chromium, and nickel content, stronger corrosion resistance, and thus further reduce the risk of metal ion precipitation. Alternatively, nickel-based alloys (Hastelloy C-22, C-276, Inconel 625, etc.) can be used. They have unparalleled corrosion resistance and can resist corrosion from almost all chemical media, fundamentally eliminating the risk of metal contamination. At the same time, they have excellent high-temperature strength and are suitable for production lines of ultra-high nickel ternary materials (such as NCMA, N90) or solid-state battery cathode materials with impurity control requirements at the ppb (parts per billion) level, or for processes with extremely corrosive atmospheres.

[0016] Optionally, the inert gas is selected from nitrogen, and the temperature of the inert gas is from -10°C to -40°C; preferably from -20°C to -30°C.

[0017] This application provides a two-stage or alternative cooling solution by adding an inert gas cooling channel. The low-temperature inert gas (such as nitrogen) uniformly penetrates the material layer, which not only removes heat and achieves gentle cooling, but also provides an atmosphere protection for the cathode material, preventing it from oxidizing upon contact with air, thereby further improving the safety and quality of material storage.

[0018] Optionally, the chamber is provided with an exhaust port, and the secondary cooling system also includes a gas recovery and cooling regeneration unit connected to the exhaust port, which is used to recover and cool the gas discharged from the chamber and circulate it to the inert gas supply unit.

[0019] This application constructs a closed-loop gas circulation system by recovering, cooling, and recycling inert gases, which greatly saves the consumption of inert gases, reduces operating costs, and realizes waste heat recovery, meeting the requirements of energy-saving and environmentally friendly production.

[0020] Optionally, the temperature measuring device is a distributed temperature sensor used to monitor the core and multiple points of the positive electrode material within the chamber. For example, the distributed temperature sensor can consist of multiple temperature sensing units, which can be distributed in different parts of the chamber, such as on the stirring device or on the side or bottom walls of the chamber, to monitor the temperature of the positive electrode material at different locations, such as the core.

[0021] This application uses distributed temperature sensors, which can more accurately and comprehensively grasp the temperature distribution inside the material pile, especially the core area that is most prone to heat accumulation and other arbitrary locations. Compared with traditional single-point temperature measurement, it can detect local hot spots earlier, thereby achieving more precise temperature control and stronger early warning and protection capabilities.

[0022] Optionally, the silo body is a movable silo, and the outer wall of the silo body is provided with a forklift access port.

[0023] This application designs the device in a mobile form, greatly improving the flexibility of production scheduling. When the production line fails, the mobile hopper can be easily transported by forklift to the discharge port of the spray drying system to receive materials and transferred to a safe area for cooling and storage. After production resumes, the materials can be easily transferred and fed back, making it a multi-purpose and easy-to-operate device.

[0024] Optionally, the storage unit is a fixed temporary storage unit connected to a positive pressure conveying system.

[0025] This application directly applies the temperature control technology to a fixed temporary storage bin on the production line, providing safety assurance for online materials without altering the main production process. Even if materials remain in the temporary storage bin for an extended period, the device ensures that their temperature remains controllable, preventing material loss due to unexpected shutdowns and improving the stability and reliability of the entire production line.

[0026] This utility model also provides a cathode material storage system, including two cathode material storage devices as described in any of the first aspects of this utility model. One cathode material storage device is connected to the production line for online temporary storage of cathode materials; the other cathode material storage device has a movable hopper for offline storage of cathode materials when the production line fails.

[0027] This application provides a complete, dual-protection material buffering and safe storage solution by combining a fixed temporary storage bin and a mobile storage bin into a single system. The fixed temporary storage bin handles normal fluctuations and short-term downtime during the production process, while the mobile storage bin serves as an emergency measure for handling prolonged failures or large-scale material transfers. The two work together to greatly improve the operational stability, flexibility, and safety of the entire production line. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present invention and, together with their description, serve to explain the principles of the present invention.

[0029] Figure 1 This is a schematic diagram of the positive pressure conveying temporary storage bin in an embodiment of this utility model.

[0030] Figure 2 This is a schematic diagram of the structure of the mobile hopper assembly in another embodiment of the present invention.

[0031] Figure 3 yes Figure 2 A schematic diagram of the structure of the mobile silo.

[0032] Figure 4 yes Figure 2 A schematic diagram of the structure of the central silo frame.

[0033] Explanation of reference numerals in the attached figures:

[0034] 11. Temporary storage bin inlet; 12. Temporary storage bin outlet; 13. Temporary storage bin exhaust port; 14. Temporary storage bin agitator motor; 15. Temporary storage bin agitator blades; 16. Temporary storage bin cooling water coil; 17. Temporary storage bin cooling water inlet; 18. Temporary storage bin cooling water outlet;

[0035] 21. Mobile hopper feed inlet; 22. Mobile hopper exhaust outlet; 23. Forklift bay; 24. Mobile hopper mixing motor; 25. Mobile hopper mixing blades; 26. Mobile hopper cooling water coil; 27. Mobile hopper cooling water inlet; 28. Mobile hopper cooling water outlet;

[0036] 30. Hopper frame; 31. Casters; 32. Positioning bar. Detailed Implementation

[0037] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0038] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0039] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0040] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0042] This invention provides a cathode material storage device and system. The device includes a silo with active temperature control, an internal stirring device for agitating the material, an external circulating fluid cooling device for cooling, and a temperature measuring device for real-time temperature monitoring. This system combines a fixed online storage silo with a mobile offline silo, providing the production line with dual and flexible material safety buffering capabilities.

[0043] In practical applications, the device described in this utility model has two specific product forms, and these two forms together constitute the storage system of this utility model:

[0044] Example 1: Fixed temporary storage bin.

[0045] like Figure 1 As shown, in this embodiment, the storage device is specifically implemented as a fixed temporary storage bin connected to the positive pressure conveying system on the production line. The bin has a conical structure and specifically includes the following components:

[0046] The top of the silo is provided with a temporary storage silo inlet 11 and a temporary storage silo exhaust outlet 13, and the bottom is provided with a temporary storage silo outlet 12, which is connected to the downstream positive pressure conveying equipment.

[0047] Inside the temporary storage chamber, a stirring device is rotatably installed. The stirring device includes a temporary storage chamber stirring motor 14 located at the top of the chamber and a temporary storage chamber stirring blade 15 extending into the chamber.

[0048] A circulating fluid cooling device is installed on the outer wall of the temporary storage chamber. Specifically, the device is a temporary storage chamber cooling water coil 16 arranged around the outer wall of the chamber. The cooling water coil has a temporary storage chamber cooling water inlet 17 and a temporary storage chamber cooling water outlet 18. The temporary storage chamber cooling water outlet 18 is located above the temporary storage chamber cooling water inlet 17.

[0049] The chamber also has an inert gas inlet and an inert gas outlet (not shown in the figure) for connection to the secondary cooling system, so as to introduce low-temperature inert gas for auxiliary cooling and atmosphere protection.

[0050] In addition, a temperature measuring device (not shown in the figure) is installed on the inner wall or inside the temporary storage compartment.

[0051] In practical applications, this temporary storage bin serves as a fixed link in the production process, providing a safe buffer for materials in the production line. When a downstream equipment failure occurs, the material is temporarily stored in the bin. At this time, the stirring device and the circulating fluid cooling device are activated, and the temperature is monitored by a temperature measuring device to ensure that the material does not carbonize due to high temperatures during the waiting period.

[0052] Example 2: Mobile hopper.

[0053] like Figures 2 to 4 As shown, in this configuration, the storage device is specifically implemented as a movable hopper. This movable hopper can be used in conjunction with a matching hopper frame 30.

[0054] The mobile hopper also has a conical structure. The top of the hopper has a mobile hopper inlet 21 and a mobile hopper vent 22, and the bottom has a discharge outlet. On the lower outer wall of the hopper, there is a forklift slot 23 for forklift operation.

[0055] Similar to Embodiment 1, the mobile silo is equipped with a rotating agitator inside, including a mobile silo agitator motor 24 and a mobile silo agitator blades 25; its outer wall is equipped with a circulating fluid cooling device, specifically a mobile silo cooling water coil 26, having a mobile silo cooling water inlet 27 and a mobile silo cooling water outlet 28; a temperature measuring device (not shown in the figure) is also installed inside or on the inner wall. Similar to Embodiment 1, the mobile silo body is also provided with an inert gas inlet and an inert gas outlet (not shown in the figure).

[0056] The hopper frame 30 is used to support the moving hopper, and its bottom is equipped with casters 31. The hopper frame 30 is also equipped with positioning strips 32, which are used to guide and limit the movement of the moving hopper to ensure stable placement.

[0057] When the production line malfunctions, a forklift can flexibly transport the mobile hopper to the discharge port via the forklift slot 23 to receive the material, and then transfer it to a safe area for cooling and storage. When material needs to be discharged, the forklift can be used to place it on the hopper frame 30, and the material can be easily discharged from the discharge port at the bottom.

[0058] Example 3: Storage system.

[0059] This utility model also provides a positive electrode material storage system, which is composed of a fixed temporary storage bin as described in Embodiment 1 and a mobile storage bin as described in Embodiment 2.

[0060] During production, fixed temporary storage silos are used to handle normal production fluctuations and short-term equipment downtime, providing online temporary storage and temperature control for materials. When a prolonged or severe production line failure occurs, resulting in a large backlog of materials, mobile silos are activated for offline storage and temperature control. These two types of storage devices work together to form a complete and flexible storage system.

[0061] Example 4:

[0062] This utility model provides a specific application scenario to illustrate the working process and effects of the storage device and system of this utility model.

[0063] During the production of cathode materials, after the spray drying process, the material temperature exceeds 120°C. At this point, the downstream loading equipment experiences a sudden malfunction, requiring an estimated 3 hours for repair. To prevent carbonization of the high-temperature material, the movable silo described in Example 2 is used for emergency handling.

[0064] The specific steps are as follows:

[0065] 1. Transport the mobile silo to the standby discharge port of the spray drying tower to receive approximately 5 cubic meters of powder material at a temperature of 150°C.

[0066] 2. Use a forklift to transfer the mobile silo filled with materials to the designated safe temporary storage area, and connect the cooling water pipes and power supply.

[0067] 3. Start the circulating fluid cooling device of the mobile silo and introduce circulating cooling water into the cooling water coil 26 of the mobile silo.

[0068] 4. Start the mobile silo mixing device and set the mobile silo mixing motor to 24 low-speed intermittent mixing.

[0069] 5. The temperature changes in the core and edges of the material pile are monitored in real time by distributed temperature sensors installed inside the silo.

[0070] After a period of cooling and stirring, the maximum temperature of the material inside the silo steadily decreased to below 80℃, completely eliminating the carbonization hazard zone above 120℃. Once the downstream equipment returned to normal, a forklift was used to place the mobile silo on the silo frame 30, and the bottom outlet of the mobile silo was opened to smoothly transfer the intact and temperature-safe material to the next process, avoiding material loss and safety accidents.

[0071] In a preferred embodiment, the aforementioned temporary storage bin stirring blade 15 and moving hopper stirring blade 25 can be specifically configured as a spiral stirring device. Furthermore, to improve stirring uniformity and prevent material caking, a wall scraper can be connected to the outer edge of the spiral stirring device for scraping the inner wall of the bin. Those skilled in the art will recognize that the spiral stirring device and the wall scraper are conventional configurations in the field, and their specific structures can be selected according to actual needs, and will not be elaborated further here.

[0072] To achieve more accurate temperature monitoring, especially for monitoring the temperature of the core of the material pile, the temperature measuring device in the two embodiments described above can preferably be a distributed temperature sensor. For example, the distributed temperature sensor can consist of multiple temperature sensing units, which can be distributed in different parts of the silo, such as on the stirring device or on the side or bottom walls of the silo, to monitor the temperature of the cathode material at different locations, such as the core of the silo. Alternatively, the temperature measuring device can be used in combination with an infrared thermal imaging module, which can be installed outside the silo to perform non-contact, large-area real-time monitoring of the material surface temperature. Those skilled in the art will recognize that distributed temperature sensors and infrared thermal imaging modules are conventional detection components in the field, and their specific models and arrangements can be selected according to the measurement accuracy and silo structure, which will not be elaborated further here.

[0073] In addition, to further improve the cooling effect and provide atmosphere protection for the cathode material, the devices in the above two embodiments can also be equipped with a secondary cooling system. This secondary cooling system includes an inert gas supply unit and an air distribution plate; the air distribution plate is located on the side wall or bottom of the chamber, and has multiple air holes with air caps on the air holes. The side walls of the air caps have airflow holes, or there are gaps between adjacent air caps; the inert gas supply unit is connected to the air distribution plate, and inert gas is introduced into the chamber through the air distribution plate to form a cooling airflow channel. When the secondary cooling system is running, taking the air distribution plate located at the bottom of the silo as an example, the airflow in the duct enters the lower part of the air cap through the air holes, and then flows out horizontally or obliquely upward from the airflow holes (or gaps) on the side wall of the air cap. In this application, the air cap on the air distribution plate can effectively prevent material leakage, and the air outlet direction helps to agitate the particles. The air cap can be a mushroom-shaped air cap, a bell-shaped air cap, or a directional air cap (slanted air cap), etc., with the bell-shaped air cap being preferred, thus providing excellent anti-leakage, anti-wear, and uniform air distribution effects. The air distribution plate and air cap can be made of high-performance austenitic stainless steel (316L and above grade) or nickel-based alloys (Hastelloy C-22, C-276, Inconel 625, etc.) to cope with the high temperature and corrosion problems in different cathode material production environments, fundamentally eliminating the risk of metal contamination. Preferably, the inert gas can be selected from nitrogen, with a temperature of -10℃ to -40℃, preferably -20℃ to -30℃. Preferably, the chamber is provided with exhaust vents. The secondary cooling system may also include a gas recovery and cooling regeneration unit connected to the exhaust vents, which is used to recover and cool the gas discharged from the chamber and circulate it to the inert gas supply unit, thereby saving energy.

[0074] In summary, this utility model, by organically combining the aforementioned functional components into a single chamber, can effectively solve the risk of carbonization and combustion of cathode materials due to heat accumulation after spray drying, whether used as a fixed online temporary storage device or a flexible offline storage container. It is simple to operate, safe and reliable, and has high industrial practical value.

[0075] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A positive electrode material storage device, characterized in that, include: The chamber is used to hold the positive electrode material after spray drying; A stirring device is rotatably mounted inside the chamber and is used to stir the positive electrode material; A temperature measuring device is installed on the inner wall or inside the chamber to monitor the temperature of the positive electrode material inside the chamber. A circulating fluid cooling device is installed on the outer wall of the chamber to cool the positive electrode material inside the chamber.

2. The positive electrode material storage device according to claim 1, characterized in that, The circulating fluid cooling device includes a cooling coil or cooling jacket disposed on the outer wall of the chamber, and cooling fluid flows through the cooling coil or cooling jacket.

3. The positive electrode material storage device according to claim 1 or 2, characterized in that, The stirring device is a spiral stirring device.

4. The positive electrode material storage device according to claim 3, characterized in that, The stirring device also includes a wall scraper, which is connected to the outer edge of the spiral stirring device and is used to scrape the inner wall of the chamber.

5. The positive electrode material storage device according to claim 1, characterized in that, It also includes a secondary cooling system, which comprises an inert gas supply unit and an air distribution plate; The air distribution plate is disposed on the side wall or bottom of the silo body. The air distribution plate has multiple air holes, and the air holes are provided with air caps. The side wall of the air caps is provided with airflow holes or there is a gap between adjacent air caps. The inert gas supply unit is connected to the air distribution plate, and inert gas is introduced into the chamber through the air distribution plate to form a cooling airflow channel.

6. The positive electrode material storage device according to claim 5, characterized in that, The chamber is provided with an exhaust port. The secondary cooling system also includes a gas recovery and cooling regeneration unit connected to the exhaust port, which is used to recover and cool the gas discharged from the chamber and circulate it to the inert gas supply unit.

7. The positive electrode material storage device according to claim 1, characterized in that, The temperature measuring device is a distributed temperature sensor used to monitor the core and multiple points of the positive electrode material inside the chamber.

8. The positive electrode material storage device according to claim 1, characterized in that, The silo is a movable silo, and the outer wall of the movable silo is provided with an insertion port for forklift operation.

9. The positive electrode material storage device according to claim 1, characterized in that, The storage chamber is a fixed temporary storage chamber connected to the upstream positive pressure conveying system.

10. A positive electrode material storage system, characterized in that, The device includes two cathode material storage devices as described in any one of claims 1-7, one of which is connected to the production line for online temporary storage of cathode materials; the other of which has a movable silo for offline storage of cathode materials in the event of a production line failure.

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