A preparation system and method for silicon-oxygen anode materials for lithium-ion batteries

Abstract

This invention relates to the field of lithium battery material production technology, specifically to a preparation system and method for lithium-ion battery silicon-oxygen anode materials. The system includes a horizontally arranged furnace body with a preheating zone and a high-temperature zone inside. It also includes a bidirectional conveyor, a drive assembly, and a gas guiding assembly. The bidirectional conveyor is coaxially mounted on the furnace body, and the drive assembly is mounted on the furnace body and connected to the bidirectional conveyor. This invention, through the bidirectional conveyor, drive assembly, and gas guiding assembly, can preheat the carrier particles before they enter the high-temperature zone, preventing excessive thermal stress on the surface of the carrier particles due to sudden temperature differences upon entering the high-temperature zone, which could lead to micro-cracks. Simultaneously, during the rotation of the bidirectional conveyor, the carrier particles undergo a continuous "climb-slide-climb" motion, ensuring sufficient contact between the carrier particles and the reactant gas, thus providing dual protection for the lithium battery's endurance performance.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lithium battery material production, in particular to a preparation system and method of a silicon-oxygen negative electrode material of a lithium ion battery. BACKGROUND

[0002] Methods or devices for directly converting chemical energy into electrical energy, such as battery packs, are the most important accessories for new energy electric vehicles. Among them, lithium batteries are widely used due to their high energy, long service life, easy use and environmental protection. The negative electrode of the lithium battery includes a silicon-based negative electrode (including pure silicon, silicon-oxygen and silicon-carbon, etc.), but the silicon-oxygen negative electrode is not a "whole piece" electrode, but a composite electrode structure assembled by an active material as the main body, in combination with a conductive agent, a binder and a current collector. The most core role is to greatly improve the energy density of the battery, thereby increasing the driving mileage of the electric vehicle.

[0003] At present, the chemical vapor deposition method is one of the mainstream methods for preparing the silicon-oxygen negative electrode material. However, in the traditional horizontal or vertical fixed bed reactor, the carrier particles are in a static stacking state, which makes it difficult for the reaction gas to penetrate into the interior of the particles. As a result, the outer particles are excessively deposited while the inner particles are insufficiently deposited, resulting in extremely uneven distribution of the stoichiometric ratio and the loading amount in the product, and ultimately reducing the high capacity advantage of the silicon-oxygen negative electrode material and the endurance performance of the lithium battery. In view of the above problems, there are good solutions in the prior art, such as using a rotary tube furnace, a fluidized bed or a spouted bed CVD, which can eliminate the above defects by forcing the carrier particles to move to make the reaction gas penetrate into the interior of the carrier particles, thereby improving the endurance performance of the lithium battery. However, there are still the following defects: since the simple rotary tube furnace, fluidized bed or spouted bed CVD is usually a single temperature zone and a unified atmosphere, it is impossible to control the different stages (such as preheating, reaction and annealing) of the carrier particles in the furnace, and the carrier particles will adsorb moisture and oxygen in the air when entering from the normal temperature bin. The sudden temperature difference during high-temperature reaction will cause excessive thermal stress on the surface of the carrier particles and produce tiny cracks, which will damage the integrity of the carrier particles. In the subsequent charging and discharging process of the lithium battery, the electrons in the electrode will encounter a large resistance when crossing these tiny cracks, which will cause the internal resistance of the entire electrode to rise sharply, and will also affect the endurance performance of the lithium battery. SUMMARY

[0004] The application aims to provide a preparation system and method of a lithium ion battery silicon-oxygen negative electrode material, solve the problem of heat flow transfer in different areas of the furnace body and the problem of the surface of the carrier particles generating micro cracks when entering the high temperature area due to moisture and oxygen, thereby affecting the endurance performance of the lithium battery. The bidirectional conveying element, the driving assembly, the gas guiding assembly and the preheating area and high temperature area in the furnace body are arranged, so that the carrier particles can be preheated before entering the high temperature area, the surface thermal stress of the carrier particles is prevented from being too large due to the sudden temperature difference during high temperature reaction, the endurance performance of the lithium battery is ensured, the cooperation between the stirring groove and the air nozzle arranged on the surface of the outer spiral blade is used to make the carrier particles continuously move in the mode of "climbing-sliding-climbing" during the conveying process, the full contact between the carrier particles and the reaction gas is ensured, and the endurance performance of the lithium battery is further ensured.

[0005] To achieve the above object, the application provides the following technical scheme.

[0006] A preparation system of a lithium ion battery silicon-oxygen negative electrode material, comprising a horizontally arranged furnace body, a preheating area and a high temperature area are arranged in the furnace body, further comprising a bidirectional conveying element, a driving assembly and a gas guiding assembly, the bidirectional conveying element is coaxially arranged on the furnace body, the driving assembly is arranged on the furnace body and connected with the bidirectional conveying element, the driving assembly drives the bidirectional conveying element to rotate when being powered on, the bidirectional conveying element rotates to convey the carrier particles from the preheating area to the high temperature area for reaction, then conveys the reacted carrier particles from the high temperature area to the preheating area for cooling and finally discharges the carrier particles to the outside of the furnace body, the gas guiding assembly is arranged on the furnace body, the gas guiding assembly conveys inert gas and high temperature reaction gas into the furnace body when being powered on, the inert gas enters the preheating area after being preheated in the high temperature area, and the high temperature reaction gas remains in the high temperature area, the gas guiding assembly comprises an air nozzle, the air nozzle is arranged on the bidirectional conveying element, and the air nozzle rotates synchronously with the bidirectional conveying element when the bidirectional conveying element rotates and stirs the carrier particles in the gap of the bidirectional conveying element.

[0007] Preferably, the driving assembly comprises a motor, a driving shaft, a gear ring and a conveying cylinder, the motor is arranged on the furnace body, the driving shaft is arranged at one end of the furnace body, two gear rings are arranged on the motor and the driving shaft respectively, the two gear rings are engaged with each other, and the conveying cylinder is coaxially arranged in the furnace body and connected with the driving shaft, the bidirectional conveying element comprises an outer spiral blade and an inner spiral blade, the outer spiral blade is arranged outside the conveying cylinder, the inner spiral blade is arranged inside the conveying cylinder, and the spiral directions of the outer spiral blade and the inner spiral blade are opposite.

[0008] It can be known that there are many ways to prolong the reaction time of the carrier particles in the high-temperature zone of the furnace body, including but not limited to reducing the moving speed of the carrier particles in the high-temperature zone or enlarging the range of the high-temperature zone, but due to the fact that the carrier particles need to go through the preheating, high-temperature and annealing three stages inside the furnace body, which leads to the problem that the furnace body needs to be divided into three regions for preheating, high-temperature and annealing operations respectively, but after the increase of the regions, the temperature and gas between different regions will flow each other, that is, part of the moisture and oxygen in the air enters the high-temperature zone, which will also cause the problem of too large thermal stress on the surface of the carrier particles and produce tiny cracks, which still affects the endurance performance of the lithium battery, so the scheme is adopted. By setting the outer spiral blade and the inner spiral blade with opposite spiral directions, the carrier particles inside and outside the conveying cylinder can be conveyed in different directions in the process of rotating the outer spiral blade and the inner spiral blade driven by the conveying cylinder, which can prolong the reaction time while reducing the partition inside the furnace body, effectively avoiding the situation that the temperature and gas between different regions flow each other, thereby avoiding the tiny cracks on the surface of the carrier particles due to too large thermal stress, which not only ensures the integrity of the carrier particles, but also ensures the endurance performance of the lithium battery.

[0009] Preferably, the internal space of the conveying cylinder is greater than or equal to the space between the furnace body and the conveying cylinder.

[0010] By adopting the above technical scheme, when the carrier particles are conveyed from the inside of the conveying cylinder to the outside by the inner spiral blade (i.e. the process of conveying the carrier particles from the high-temperature zone to the preheating zone and finally discharging through the conveying cylinder), the carrier particles originally crowded between the conveying cylinder and the inner wall of the furnace body become loose, thereby accelerating the diffusion speed of the residual reaction gas molecules accumulated in the carrier particles, making the residual reaction gas continue to react with the carrier particles, on the one hand, avoiding the waste of the reaction gas, on the other hand, also ensuring the quality of the carrier particles after the reaction, which can also ensure the endurance performance of the lithium battery.

[0011] Preferably, the inner spiral blade is provided with variable pitch, the pitch of the inner spiral blade decreases and then increases from right to left, and the pitch of the section of the inner spiral blade located in the high-temperature zone is the same as the pitch of the outer spiral blade.

[0012] It can be known that, because the temperature of the carrier particles just after the reaction is very high, the structure is in a metastable state, and if directly exposed to air, it will be rapidly oxidized, at the same time, rapid cooling will generate huge stress between the coating and the substrate, which may cause the coating to crack, peel off, and still cause the carrier particle surface to appear cracks, so the scheme is adopted. By setting the inner spiral blade with variable pitch, the conveying cylinder utilizes the pitch change of the inner spiral blade when rotating to rapidly transport the carrier particles entering the inside of the conveying cylinder from the high temperature zone to the preheating zone, and after the carrier particles are transported to the preheating zone, the pitch of the inner spiral blade is reduced to prolong the transport time of the carrier particles in the preheating zone, on the one hand, the low temperature effect of the preheating zone can be utilized to cool the carrier particles removed from the high temperature zone and prolong the cooling time, on the other hand, the heat carried by the carrier particles after being removed from the high temperature zone can be utilized to heat the preheating zone inside the furnace body, without additionally setting a heating source for the preheating zone, the carrier particles in the preheating zone can be preheated, thereby reducing the oxygen and moisture adsorbed by the carrier particles after entering the furnace body, ensuring the quality of the carrier particles after the reaction, and further ensuring the endurance performance of the lithium battery.

[0013] Preferably, the air guide assembly further comprises an air outlet pipe one, an air outlet pipe two, an air inlet pipe one and an air inlet pipe two, the air outlet pipe one and the air outlet pipe two are arranged on the inner spiral blade, the outer spiral blade is hollow inside, the air outlet pipe one arranged in the high temperature zone is provided with a branch pipe one in communication, the air outlet pipe two arranged in the preheating zone is provided with a branch pipe two in communication, the branch pipe one and the branch pipe two penetrate the conveying cylinder and extend to the inside of the outer spiral blade, the driving shaft is hollow and the right end is rotatably sleeved with a connecting block, the right ends of the air outlet pipe one and the air outlet pipe two penetrate into the inside of the driving shaft, the right end of the air outlet pipe two is coaxial with the driving shaft and penetrates the connecting block, the air inlet pipe one is arranged on the connecting block and penetrates into the inside of the driving shaft, so that the connecting block plays the role of a multi-channel rotary pneumatic joint, and the air inlet pipe two is sleeved on the right end of the air outlet pipe two.

[0014] By adopting the above scheme, the first gas inlet pipe is used to deliver high-temperature reaction gas to the inside of the furnace body, the second gas inlet pipe is used to deliver normal-temperature inert gas to the inside of the furnace body, the high-temperature reaction gas enters the high-temperature zone inside the furnace body after being discharged through the first gas outlet pipe, the branch pipe and the corresponding gas nozzle, and reacts with the carrier particles, the normal-temperature inert gas enters the preheating zone inside the furnace body after being discharged through the second gas outlet pipe, the branch pipe and the corresponding gas nozzle, and the oxygen in the preheating zone is discharged under the action of the inert gas. At the same time, since the second gas outlet pipe is arranged through the furnace body, the end of the second gas outlet pipe in the high-temperature zone will heat the normal-temperature inert gas due to the heat conduction effect of the high-temperature reaction gas, so that the normal-temperature inert gas carries heat when entering the preheating zone, thereby achieving the effect of preheating the carrier particles in the preheating zone, and the heat of the preheating can be used to assist the discharge of water in the preheating zone, further avoiding the case that the sudden temperature difference of the carrier particles entering the high-temperature zone causes excessive thermal stress on the surface of the carrier particles and generates micro cracks, thereby further ensuring the endurance performance of the lithium battery on the basis of avoiding damage to the integrity of the carrier particles.

[0015] Preferably, the driving assembly further comprises a material guide plate, the material guide plate is arranged at the right end of the outer spiral blade and connected with the conveying cylinder, and the conveying cylinder is provided with a feeding port close to the material guide plate.

[0016] By adopting the above scheme, the carrier particles can be guided to the inside of the conveying cylinder when the conveying cylinder rotates, thereby avoiding the carrier particles from being accumulated at the right end position inside the furnace body, and thereby realizing continuous production of the carrier particles, which can ensure the quality of the carrier particles after reaction and improve the work efficiency.

[0017] Preferably, the hollow area inside the outer spiral blade is arranged as two sections which are not connected, the gas nozzle in the preheating zone is arranged at the left side of the outer spiral blade, the gas nozzle in the high-temperature zone is arranged at the right side of the outer spiral blade, and an exhaust pipe is further arranged at the right end position of the furnace body, which can be used to discharge the residual gas in the furnace body after reaction, thereby avoiding the high-temperature reaction gas from flowing to the preheating zone after gathering in the high-temperature zone.

[0018] By adopting the above technical scheme, the high-temperature zone and the preheating zone can be controlled separately, so that the high-temperature reaction gas remains in the high-temperature zone after being sprayed from the corresponding gas nozzle, and the normal-temperature inert gas remains in the preheating zone after being sprayed from the corresponding gas nozzle after being preheated in the high-temperature zone, thereby avoiding the gases in the preheating zone and the high-temperature zone from flowing to each other, which can further ensure the endurance performance of the lithium battery on the basis of avoiding cracks on the surface of the carrier particles.

[0019] Preferably, a plurality of stirring grooves are arranged on the left side surface of the one section of the outer spiral blade in the high-temperature zone, and the groove depth of the stirring grooves increases from inside to outside along the radial direction of the furnace body.

[0020] By adopting the above scheme, when the outer spiral blade rotates with the conveying cylinder, the carrier particles in the stirring tank can be guided. At the same time, the protruding action of the air nozzle on the surface of the outer spiral blade can stir the carrier particles in the spiral gap of the outer spiral blade, avoiding the carrier particles in the spiral gap of the outer spiral blade from being in a relatively static state. This effectively solves the problem of excessive deposition of outer layer carrier particles and insufficient deposition of inner layer carrier particles, and further ensures the endurance performance of lithium battery.

[0021] On the other hand, this application also provides a method for preparing a silicon-oxygen anode material for lithium-ion batteries, applied to the preparation system for a silicon-oxygen anode material for lithium-ion batteries as described above; the preparation method includes:

[0022] S10: Inert gas at room temperature is conveyed into the interior of the furnace body, so that the inert gas at room temperature is heated by the high temperature zone. The heated inert gas, along with the heat, is sent into the interior of the bidirectional conveyor and finally discharged into the preheating zone inside the furnace body through the corresponding gas nozzle.

[0023] S20: Add carrier particles to the preheating zone inside the furnace body to preheat the carrier particles so as to remove oxygen and moisture from the preheating zone.

[0024] S30: Transports high-temperature reaction gas into the gas guide assembly, so that the high-temperature reaction gas entering the gas guide assembly enters the interior of the bidirectional conveyor under the diversion action, and is finally discharged into the high-temperature zone inside the furnace body through the corresponding gas nozzle.

[0025] S40: Start the drive assembly to make the bidirectional conveyor rotate to transport the carrier particles in the preheating zone to the high-temperature zone, so that the carrier particles can come into contact with the high-temperature reaction gas in the high-temperature zone and react.

[0026] Preferably, the starting drive assembly causes the bidirectional conveyor to rotate, thereby conveying the carrier particles from the preheating zone to the high-temperature zone, allowing the carrier particles to contact and react with the high-temperature reaction gas in the high-temperature zone, and the subsequent steps include:

[0027] Driven by the drive component, the carrier particles gathered at the right end of the furnace body are guided into the drive component, thereby transporting the reacted carrier particles from the high temperature zone to the preheating zone. The heat attached to the carrier particles is used to assist in heating the preheating zone to ensure the preheating effect of the preheating zone on the carrier particles.

[0028] As the bidirectional conveyor continues to rotate, the agitator on the opposite side of the gas nozzle drives the carrier particles to continuously "climb-slide-climb again," achieving full contact and reaction between the carrier particles and the reactive gas.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. By using the drive assembly and bidirectional conveyor, the different helical directions of the outer and inner helical blades of the bidirectional conveyor can be utilized to transport the carrier particles from the preheating zone to the high-temperature zone when the conveying cylinder rotates. After the carrier particles have fully contacted and reacted with the high-temperature reaction gas, they are discharged. Based on the continuous production operation of carrier particles in the furnace, the heat generated when the carrier particles are output can be used to heat the preheating zone. This avoids excessive surface thermal stress caused by the sudden temperature difference when the carrier particles enter the high-temperature zone. It also ensures the battery's endurance performance by preventing the formation of micro-cracks on the surface of the carrier particles and thus protecting their integrity.

[0031] 2. Through the set gas guiding components and corresponding gas nozzles, room temperature inert gas can be delivered to the preheating zone and high temperature reaction gas can be delivered to the high temperature zone respectively. While avoiding the mutual flow between the room temperature inert gas in the preheating zone and the high temperature reaction gas in the high temperature zone, the room temperature inert gas flowing in the second gas outlet in the high temperature zone can be preheated. This allows the inert gas to preheat the carrier particles in the preheating zone after entering the preheating zone, further preventing the carrier particles from developing micro-cracks on the surface due to the sudden temperature difference when entering the high temperature zone, and further ensuring the battery's endurance performance.

[0032] 3. By hollowing out the outer spiral blades and creating agitation grooves on their surface, the high-temperature reaction gas directly heats the outer spiral blades upon entering them, keeping their surface at a high temperature. This expands the heating range of the high-temperature zone, ensuring sufficient contact between the carrier particles and the high-temperature reaction gas. Simultaneously, during the rotation of the bidirectional conveyor, the agitation grooves on its surface, along with the provided nozzles, agitate the carrier particles within the spiral gaps of the outer spiral blades. This causes the carrier particles in the high-temperature zone to continuously undergo a "climb-slide-climb" motion as the outer spiral blades rotate, ensuring full contact between the carrier particles and the high-temperature reaction gas within the spiral gaps, further guaranteeing the lithium battery's endurance. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0034] Figure 2 This is a partial cross-sectional view of the connection structure between the drive assembly, the furnace body, and the bidirectional conveyor of the present invention.

[0035] Figure 3 This is a cross-sectional view of the connection structure between the air guide assembly, the inner spiral blade, and the outer spiral blade of the present invention.

[0036] Figure 4This is an exploded view of the inner spiral blade, the first exhaust pipe, and the second exhaust pipe of the present invention.

[0037] Figure 5 For the present invention Figure 3 Enlarged view of part A in the middle section.

[0038] Figure 6 This is a schematic diagram of the connection structure between the conveying cylinder and the outer spiral blade of the present invention.

[0039] Figure 7 This is a cross-sectional view of the connection structure between the outer spiral blade and the first and second air outlets of the present invention.

[0040] In the diagram: 1. Furnace body; 11. Preheating zone; 12. High temperature zone; 2. Bidirectional conveyor; 21. Outer spiral blade; 211. Agitator; 22. Inner spiral blade; 3. Drive assembly; 31. Motor; 32. Drive shaft; 321. Connecting block; 33. Gear ring; 34. Conveying cylinder; 341. Feed inlet; 35. Guide plate; 4. Air guide assembly; 41. Air nozzle; 42. Air outlet pipe one; 421. Branch pipe one; 43. Air outlet pipe two; 431. Branch pipe two; 44. Air inlet pipe one; 45. Air inlet pipe two. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] Please see Figures 1 to 7 This invention provides a system for preparing silicon-oxygen anode materials for lithium-ion batteries, the technical solution of which is as follows:

[0044] For details, please refer to Figure 1 , Figure 2 , Figure 3 and Figure 6 A preparation system for silicon-oxygen anode materials for lithium-ion batteries includes a horizontally arranged furnace body 1, with a preheating zone 11 and a high-temperature zone 12 inside the furnace body 1.

[0045] The preheating zone 11 is used to preheat the carrier particles before the reaction and to cool the carrier particles after the reaction. The high temperature zone 12 is used to react the carrier particles that have been preheated in the preheating zone 11 and have had oxygen and moisture removed.

[0046] The preparation system also includes a bidirectional conveyor 2, a drive assembly 3, and a gas guiding assembly 4. The bidirectional conveyor 2 is coaxially mounted on the furnace body 1 and rotatably connected to the end of the furnace body 1 via a sealed bearing. The drive assembly 3 is mounted on the furnace body 1 and connected to the bidirectional conveyor 2.

[0047] The drive assembly 3 includes a motor 31, a drive shaft 32, a gear ring 33, and a conveyor cylinder 34. The motor 31 is mounted on the furnace body 1, and the drive shaft 32 is located at one end of the furnace body 1. Two gear rings 33 are provided and respectively mounted on the motor 31 and the drive shaft 32, and the two gear rings 33 mesh with each other. The conveyor cylinder 34 is coaxially mounted inside the furnace body 1 and connected to the drive shaft 32.

[0048] The bidirectional conveyor 2 includes an outer spiral blade 21 and an inner spiral blade 22. The outer spiral blade 21 is disposed outside the conveying cylinder 34, and the inner spiral blade 22 is disposed inside the conveying cylinder 34. The spiral directions of the outer spiral blade 21 and the inner spiral blade 22 are opposite. The internal space of the conveying cylinder 34 is greater than or equal to the space between the furnace body 1 and the conveying cylinder 34.

[0049] The drive assembly 3 also includes a guide plate 35, which is located at the right end of the outer spiral blade 21 and connected to the conveying cylinder 34. The conveying cylinder 34 has a feed inlet 341 that is close to the guide plate 35. When the outer spiral blade 21 conveys the carrier particles to the right end of the furnace body 1, the carrier particles are guided by the guide plate 35 to the feed inlet 341 on the conveying cylinder 34, and thus enter the interior of the conveying cylinder 34.

[0050] Under the above conditions, carrier particles to be reacted are added to the preheating zone 11 of the furnace body 1. The motor 31 is powered on and started. The output end of the motor 31 drives the conveying cylinder 34 to rotate through the meshing connection between the two toothed rings 33. When the conveying cylinder 34 rotates, it drives the outer spiral blade 21 to rotate. When the outer spiral blade 21 rotates, it conveys the carrier particles from the preheating zone 11 to the high-temperature zone 12, so that the carrier particles react with the reaction gas in the high-temperature zone 12. As the conveying cylinder 34 continues to rotate, the carrier particles will accumulate at the right end of the furnace body 1. Since the conveying cylinder 34 has a feed inlet 341 and a guide plate 35 is provided on one side of the feed inlet 341, the guide plate 35 will rotate synchronously with the conveying cylinder 34, thereby guiding the carrier particles accumulated at the right end of the furnace body 1 into the interior of the conveying cylinder 34. Since the conveying cylinder 34 is equipped with an inner spiral blade 22, and the outer spiral blade 21 has the opposite spiral direction to the inner spiral blade 22, the inner spiral blade 22 will transport the carrier particles from the high temperature zone 12 to the preheating zone 11 and finally discharge them as the conveying cylinder 34 rotates.

[0051] As one embodiment of the present invention, refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 ,Figure 5 and Figure 7 The gas guiding component 4 is disposed on the furnace body 1. The gas guiding component 4 includes a gas nozzle 41, which is disposed on the bidirectional conveyor 2.

[0052] The air guiding assembly 4 also includes an outlet pipe 42, an outlet pipe 43, an inlet pipe 44, and an inlet pipe 45. Both outlet pipes 42 and 43 are mounted on the inner spiral blade 22, while the outer spiral blade 21 is hollow. Outlet pipe 42 has a connecting branch pipe 421 in the high-temperature zone 12, and outlet pipe 43 has a connecting branch pipe 431 in the preheating zone 11. Both branch pipes 421 and 431 penetrate the conveying cylinder 34 and extend into the outer spiral blade 21.

[0053] The hollow area inside the outer spiral blade 21 is designed as two non-connected sections (physical separation can be achieved by welding a sealing partition inside the outer spiral blade 21) to prevent the ambient temperature inert gas and high temperature reaction gas in the outer spiral blade 21 from mixing. The gas nozzle 41 located in the preheating zone 11 is located on the left side of the outer spiral blade 21, and the gas nozzle 41 located in the high temperature zone 12 is located on the right side of the outer spiral blade 21. An exhaust pipe is also provided at the right end of the furnace body 1. This exhaust pipe (not shown in the attached figure) can be used to discharge the gas remaining in the high temperature zone 12 inside the furnace body 1 after the reaction, preventing the high temperature reaction gas from flowing through the carrier particles into the preheating zone 11.

[0054] The drive shaft 32 is hollow, with a connecting block 321 rotatably fitted at its right end. The right ends of both the first exhaust pipe 42 and the second exhaust pipe 43 extend into the drive shaft 32. The right end of the second exhaust pipe 43 is coaxial with the drive shaft 32 and extends through the connecting block 321. The first intake pipe 44 is mounted on the connecting block 321 and extends into the drive shaft 32. The second intake pipe 45 is rotatably fitted onto the right end of the second exhaust pipe 43 via a sealed bearing, preventing cross-contamination between the room-temperature inert gas and the high-temperature reactive gas. The connecting block 321 is rotatably fitted to the end of the drive shaft 32 via a sealed bearing and fixed by a fastener to prevent rotation of the connecting block 321, ensuring proper installation of the first intake pipe 44 and the second intake pipe 45.

[0055] Under the above-mentioned conditions, the opening and closing of the first inlet pipe 44 and the second inlet pipe 45 can be controlled by an electronically controlled valve to automatically deliver high-temperature reactive gas into the first inlet pipe 44 and room-temperature inert gas into the second inlet pipe 45. Since the right end of the first outlet pipe 42 extends into and connects with the interior of the drive shaft 32, the inert gas will first fill the interior of the drive shaft 32 before entering the first outlet pipe 42, and finally be delivered to the high-temperature zone 12 inside the furnace body 1 by the corresponding branch pipe 421 and the corresponding nozzle 41, so that the carrier particles can come into contact with the high-temperature reactive gas and react. Since the exhaust pipe 43 and the inlet pipe 45 are rotatably connected by a sealed bearing, the room temperature inert gas will first pass through the high temperature zone 12 for preheating during the flow inside the exhaust pipe 43. Finally, after being discharged through the exhaust pipe 43, the branch pipe 431 and the corresponding gas nozzle 41, it enters the preheating zone 11 inside the furnace body 1. This will remove the moisture and oxygen that follow the carrier particles into the preheating zone 11, and prevent the carrier particles from developing micro-cracks due to excessive thermal stress on their surface caused by the sudden temperature difference when entering the high temperature zone 12. This ensures the integrity of the carrier particles and also guarantees the battery's endurance performance.

[0056] As one embodiment of the present invention, refer to Figure 1 , Figure 3 and Figure 4 The inner spiral blade 22 is configured with a variable pitch. The pitch of the inner spiral blade 22 decreases from right to left and then increases. The pitch of a section of the inner spiral blade 22 located in the high-temperature zone 12 is the same as that of the outer spiral blade 21.

[0057] Under the aforementioned conditions, when the inner spiral blade 22 rotates with the conveying cylinder 34, its right end will convey the carrier particles inside the conveying cylinder 34 to the left at the same speed as the outer spiral blade 21. When the carrier particles inside the conveying cylinder 34 are conveyed to the area where the pitch of the inner spiral blade 22 decreases, the movement speed of the carrier particles in this area will decrease. That is, after the high-temperature carrier particles after the reaction are quickly conveyed from the high-temperature zone 12 to the preheating zone 11, the conveying time of the carrier particles in the preheating zone 11 is extended. This not only utilizes the low temperature of the preheating zone 11 to cool down the high-temperature carrier particles, but also utilizes the heat in the high-temperature carrier particles to heat the preheating zone 11, thus providing an auxiliary preheating effect for the carrier particles between the furnace body 1 and the outer wall of the conveying cylinder 34 in the preheating zone 11. When the carrier particles are conveyed to the left end of the inner spiral blade 22, due to the increase in pitch, the carrier particles will "collapse and scatter," thereby accelerating the discharge of residual heat in the carrier particles, which facilitates the collection of the finished product.

[0058] As one embodiment of the present invention, refer to Figure 5The outer spiral blade 21 has multiple stirring grooves 211 on the left side surface of a section in the high temperature zone 12. The depth of the stirring grooves 211 increases from the inside to the outside along the radial direction of the furnace body 1.

[0059] Under the aforementioned conditions, as the outer spiral blade 21 continues to rotate following the conveyor cylinder 34, the originally deeply buried carrier particles have the opportunity to be exposed to the surface through tumbling, directly contacting the high-temperature reaction gases and heat from the inner wall of the furnace body 1. Conversely, the surface carrier particles are also covered by newly slid-down carrier particles and enter the interior, effectively solving the problem of uneven reaction caused by the accumulation of carrier particles in the spiral gap. In this dynamic cycle, the carrier particles undergo violent relative motion and position exchange, making it impossible to form a stable "relatively static" state, further ensuring the uniformity of carrier particle deposition, and further ensuring the endurance performance of the lithium battery.

[0060] Example 2

[0061] Based on the first embodiment, this application also provides a method for preparing a silicon-oxygen anode material for a lithium-ion battery, applied to the preparation system for a silicon-oxygen anode material for a lithium-ion battery as described above; the preparation method includes:

[0062] S10: Inert gas at room temperature is conveyed into the furnace body, so that the inert gas at room temperature is heated by the high temperature zone. The heated inert gas, along with the heat, is sent into the interior of the bidirectional conveyor and finally discharged into the preheating zone inside the furnace body through the corresponding gas nozzle.

[0063] S20: Add carrier particles to the preheating zone inside the furnace body to preheat the carrier particles so as to remove oxygen and moisture from the preheating zone.

[0064] S30: Transports high-temperature reaction gas into the gas guide assembly, so that the high-temperature reaction gas entering the gas guide assembly enters the interior of the bidirectional conveyor under the diversion action, and is finally discharged into the high-temperature zone inside the furnace body through the corresponding gas nozzle.

[0065] S40: Start the drive assembly to make the bidirectional conveyor rotate to transport the carrier particles in the preheating zone to the high-temperature zone, so that the carrier particles can come into contact with the high-temperature reaction gas in the high-temperature zone and react.

[0066] For example, in step S10, room temperature inert gas can be supplied to the interior of the second inlet pipe 45, so that the room temperature inert gas will be heated by the high temperature zone 12 after entering the interior of the second outlet pipe 43 from the second inlet pipe 45. The heated inert gas carries heat and will enter the interior of the outer spiral blade 21 under the diversion effect of multiple branch pipes 431, and finally be discharged to the preheating zone 11 inside the furnace body 1 through the corresponding gas nozzle 41.

[0067] For example, in step S20, carrier particles can be added to the preheating zone 11 inside the furnace body 1 to preheat the carrier particles so as to remove oxygen and moisture from the preheating zone 11.

[0068] For example, in step S30, high-temperature reaction gas can be delivered into the inlet pipe 44 and room-temperature inert gas can be delivered into the inlet pipe 45. After the high-temperature reaction gas is discharged from the inlet pipe 44, it first fills the interior of the drive shaft 32 and then enters the outlet pipe 42. The high-temperature reaction gas entering the outlet pipe 42 enters the interior of the outer spiral blade 21 under the diversion action of multiple branch pipes 421, and finally is discharged to the high-temperature zone 12 inside the furnace body 1 through the corresponding gas nozzle 41.

[0069] For example, in step S40, the motor 31 can be started to drive the drive shaft 32 to rotate, so that when the drive shaft 32 rotates, it drives the conveying cylinder 34 to rotate synchronously, so that the outer spiral blade 21 rotates synchronously with the conveying cylinder 34, so as to transport the carrier particles in the preheating zone 11 to the high temperature zone 12, so that the carrier particles come into contact with the high temperature reaction gas in the high temperature zone 12 for reaction.

[0070] Preferably, the starting drive assembly causes the bidirectional conveyor to rotate, thereby conveying the carrier particles from the preheating zone to the high-temperature zone, allowing the carrier particles to contact and react with the high-temperature reaction gas in the high-temperature zone, and the subsequent steps include:

[0071] Driven by the drive component, the carrier particles gathered at the right end of the furnace body are guided into the drive component, thereby transporting the reacted carrier particles from the high temperature zone to the preheating zone. The heat attached to the carrier particles is used to assist in heating the preheating zone to ensure the preheating effect of the preheating zone on the carrier particles.

[0072] As the bidirectional conveyor continues to rotate, the agitator on the opposite side of the gas nozzle drives the carrier particles to continuously "climb-slide-climb again," achieving full contact and reaction between the carrier particles and the reactive gas.

[0073] For example, the carrier particles gathered at the right end of the furnace body 1 can be guided into the interior of the conveying cylinder 34 through the feed inlet 341 by the guide plate 35 following the rotation of the conveying cylinder 34. In this way, the reacted carrier particles are conveyed from the high temperature zone 12 to the preheating zone 11 inside the conveying cylinder 34. The heat attached to the carrier particles is used to assist in heating the preheating zone 11, so as to ensure the preheating effect of the preheating zone 11 on the carrier particles.

[0074] For example, since the nozzle 41 is disposed on the surface of the outer spiral blade 21, and the surface of the outer spiral blade 21 is provided with an agitation groove 211 on the side opposite to the nozzle 41, as the outer spiral blade 21 continues to rotate, the agitation groove 211 on the side opposite to the nozzle 41 drives the carrier particles to continuously perform a "climb-slide-climb" motion, thereby achieving full contact and reaction between the carrier particles and the reaction gas.

[0075] Example 3

[0076] Based on the first and second embodiments, the working principle of the preparation system and method for lithium-ion battery silicon-oxygen anode material provided in this application is as follows:

[0077] Before operation, high-temperature reaction gas is first introduced into the inlet pipe 44 and room-temperature inert gas is introduced into the inlet pipe 45. Then, carrier particles are added into the preheating zone 11 inside the furnace body 1. After the high-temperature reaction gas is discharged from the inlet pipe 44, it will first fill the interior of the drive shaft 32 and then enter the outlet pipe 42. The high-temperature reaction gas entering the outlet pipe 42 will enter the interior of the outer spiral blade 21 under the diversion effect of multiple branch pipes 421, and finally be discharged into the high-temperature zone 12 inside the furnace body 1 through the corresponding nozzle 41. The inert gas at room temperature is heated by the high-temperature zone 12 after entering the interior of the outlet pipe 43 from the inlet pipe 45. The heated inert gas, carrying heat, enters the interior of the outer spiral blade 21 under the diversion effect of multiple branch pipes 431, and is finally discharged into the preheating zone 11 inside the furnace body 1 through the corresponding gas nozzle 41. This achieves preheating treatment of the carrier particles, so as to remove oxygen and moisture from the preheating zone 11. This avoids the carrier particles from developing micro-cracks on the surface due to the sudden temperature difference when entering the high-temperature zone 12, effectively ensuring the integrity of the carrier particles.

[0078] When the motor 31 is started, the two gear rings 33 mesh with each other and are respectively connected to the motor 31 and the drive shaft 32. Therefore, the motor 31 can drive the drive shaft 32 to rotate when it is working. When the drive shaft 32 rotates, it drives the conveyor cylinder 34 to rotate synchronously through its connection with the conveyor cylinder 34. Since the outer spiral blade 21 set outside the conveyor cylinder 34 will rotate synchronously with the conveyor cylinder 34, the carrier particles in the preheating zone 11 will be continuously conveyed to the right by the outer spiral blade 21 to the high temperature zone 12, so that the carrier particles can come into contact with the high temperature reaction gas in the high temperature zone 12 for reaction.

[0079] After the carrier particles are conveyed to the right end of the furnace body 1 by the outer spiral blade 21, the feed inlet 341 and the fixed guide plate 35 on the conveying cylinder 34 guide the carrier particles gathered at the right end of the furnace body 1 into the interior of the conveying cylinder 34 as it rotates with the conveying cylinder 34. After entering the interior of the conveying cylinder 34, the carrier particles are conveyed from the high-temperature zone 12 to the preheating zone 11 by the inner spiral blade 22, which has the opposite spiral direction to the outer spiral blade 21. After the carrier particles are conveyed to the preheating zone 11 by the inner spiral blade 22, the heat attached to the carrier particles can assist in heating the preheating zone 11, ensuring the preheating effect of the preheating zone 11 on the carrier particles. This avoids the occurrence of micro-cracks on the surface of the carrier particles due to the sudden temperature difference after entering the high-temperature zone 12, further ensuring the endurance performance of the lithium battery.

[0080] Since the nozzle 41 is located on the surface of the outer spiral blade 21, and the surface of the outer spiral blade 21 opposite to the nozzle 41 is provided with a stirring groove 211, as the outer spiral blade 21 continues to rotate, the carrier particles will continuously perform the "climb-slide-climb" motion, which avoids the carrier particles in the spiral gap of the outer spiral blade 21 from being in a relatively static state, and achieves full contact between the carrier particles and the reaction gas, avoiding the situation of excessive or insufficient deposition of carrier particles at different positions, and further ensuring the battery life performance.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A preparation system for silicon-oxygen anode materials for lithium-ion batteries, comprising a horizontally arranged furnace body (1), wherein the furnace body (1) is provided with a preheating zone (11) and a high-temperature zone (12), characterized in that: It also includes a bidirectional conveyor (2), a drive assembly (3), and a gas guiding assembly (4). The bidirectional conveyor (2) is coaxially mounted on the furnace body (1). The drive assembly (3) is mounted on the furnace body (1) and connected to the bidirectional conveyor (2). When the drive assembly (3) is powered on, it drives the bidirectional conveyor (2) to rotate. When the bidirectional conveyor (2) rotates, it first transports the carrier particles from the preheating zone (11) to the high-temperature zone (12) for reaction, and then transports the reacted carrier particles from the high-temperature zone (12) back to the preheating zone (11) for cooling and finally discharges them into the furnace body (1). Externally, the gas guiding component (4) is installed on the furnace body (1). When the gas guiding component (4) is powered on, it delivers inert gas and high-temperature reaction gas into the furnace body (1) respectively. The inert gas enters the preheating zone (11) after being preheated in the high-temperature zone (12), and the high-temperature reaction gas remains in the high-temperature zone (12). The gas guiding component (4) includes a nozzle (41). The nozzle (41) is installed on the bidirectional conveyor (2). When the bidirectional conveyor (2) rotates, it drives the nozzle (41) to rotate synchronously and stirs the carrier particles in the gap of the bidirectional conveyor (2). The drive assembly (3) includes a motor (31), a drive shaft (32), a gear ring (33), and a conveying cylinder (34). The motor (31) is mounted on the furnace body (1), the drive shaft (32) is mounted on one end of the furnace body (1), and there are two gear rings (33) mounted on the motor (31) and the drive shaft (32) respectively. The two gear rings (33) mesh with each other. The conveying cylinder (34) is coaxially mounted inside the furnace body (1) and connected to the drive shaft (32). The bidirectional conveying component (2) includes an outer spiral blade (21) and an inner spiral blade (22). The outer spiral blade (21) is mounted outside the conveying cylinder (34), and the inner spiral blade (22) is mounted inside the conveying cylinder (34). The spiral directions of the outer spiral blade (21) and the inner spiral blade (22) are opposite. The air guiding assembly (4) also includes an air outlet pipe 1 (42), an air outlet pipe 2 (43), an air inlet pipe 1 (44), and an air inlet pipe 2 (45). The air outlet pipe 1 (42) and the air outlet pipe 2 (43) are both located on the inner spiral blade (22). The outer spiral blade (21) is hollow inside. The section of the air outlet pipe 1 (42) located in the high temperature zone (12) is provided with a connected branch pipe 1 (421). The section of the air outlet pipe 2 (43) located in the preheating zone (11) is provided with a connected branch pipe 2 (431). The branch pipe 1 (421) and the branch pipe 2 (431) both penetrate the conveying cylinder (34) and extend into the interior of the outer spiral blade (21). The drive assembly (3) also includes a guide plate (35), which is located at the right end of the outer spiral blade (21) and connected to the conveying cylinder (34). The conveying cylinder (34) has an inlet (341) close to the guide plate (35). The hollow area inside the outer spiral blade (21) is set as two non-connected sections. The air nozzle (41) located in the preheating zone (11) is located on the left side of the outer spiral blade (21), and the air nozzle (41) located in the high temperature zone (12) is located on the right side of the outer spiral blade (21).

2. The preparation system for a lithium-ion battery silicon-oxygen anode material according to claim 1, characterized in that: The internal space of the conveying cylinder (34) is greater than or equal to the space between the furnace body (1) and the conveying cylinder (34).

3. The preparation system for a lithium-ion battery silicon-oxygen anode material according to claim 1, characterized in that: The inner helical blade (22) is configured with a variable pitch.

4. A preparation system for a silicon-oxygen anode material for a lithium-ion battery according to any one of claims 1-3, characterized in that: The outer spiral blade (21) has multiple stirring grooves (211) on the left side surface of a section in the high temperature zone (12). The depth of the stirring grooves (211) increases from the inside to the outside along the radial direction of the furnace body (1).

5. A method for preparing a silicon-oxygen anode material for lithium-ion batteries, characterized in that, The method is applied to a preparation system for a lithium-ion battery silicon-oxygen anode material as described in any one of claims 1-4; the preparation method includes: S10: Inert gas at room temperature is conveyed into the interior of the furnace body, so that the inert gas at room temperature is heated by the high temperature zone. The heated inert gas, along with the heat, is sent into the interior of the bidirectional conveyor and finally discharged into the preheating zone inside the furnace body through the corresponding gas nozzle. S20: Add carrier particles to the preheating zone inside the furnace body to preheat the carrier particles so as to remove oxygen and moisture from the preheating zone. S30: Transports high-temperature reaction gas into the gas guide assembly, so that the high-temperature reaction gas entering the gas guide assembly enters the interior of the bidirectional conveyor under the diversion action, and is finally discharged into the high-temperature zone inside the furnace body through the corresponding gas nozzle. S40: Start the drive assembly to make the bidirectional conveyor rotate to transport the carrier particles in the preheating zone to the high-temperature zone, so that the carrier particles can come into contact with the high-temperature reaction gas in the high-temperature zone and react.

6. The method for preparing a silicon-oxygen anode material for a lithium-ion battery according to claim 5, characterized in that, The outer spiral blade has multiple agitation grooves on its left side surface in the high-temperature zone, and the depth of the grooves increases from the inside to the outside along the radial direction of the furnace body; the starting drive assembly causes the bidirectional conveyor to rotate to transport the carrier particles from the preheating zone to the high-temperature zone, so that the carrier particles can contact and react with the high-temperature reaction gas in the high-temperature zone, and the subsequent steps include: Driven by the drive component, the carrier particles gathered at the right end of the furnace body are guided into the drive component, thereby transporting the reacted carrier particles from the high temperature zone to the preheating zone. The heat attached to the carrier particles is used to assist in heating the preheating zone to ensure the preheating effect of the preheating zone on the carrier particles. As the bidirectional conveyor continues to rotate, the agitator on the opposite side of the gas nozzle drives the carrier particles to continuously "climb-slide-climb again," achieving full contact and reaction between the carrier particles and the reactant gas.

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