Pole piece heating equipment

Abstract

The utility model provides pole piece heating equipment, which is used for heating a winding core and comprises a winding needle, a heating device and a heating device, the first heating device is arranged on the winding needle and is used for heating the inner side of the winding core; the second heating device is used for heating the outer side of the winding core, the second heating device and the first heating device are arranged at intervals in the radial direction of the winding needle, the second heating device is arranged on the outer side of the winding needle, and the second heating device and the winding needle are arranged at intervals; the second heating device is used for heating the outer side of the winding core between the second heating device and the winding needle; the first heating device comprises a first infrared heating mechanism, the first infrared heating mechanism is arranged in the winding needle, and infrared rays emitted by the first infrared heating mechanism can penetrate through the winding needle and irradiate the inner side of the winding core. According to the pole piece heating equipment disclosed by the utility model, the wound pole piece can be heated more uniformly.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy technology field especially relates to a pole piece heating equipment. BACKGROUND

[0002] The winding process occupies a pivotal position in the production of lithium batteries, and its importance is self-evident. In this delicate process, the positive and negative electrodes and the separator of the lithium ion battery need to undergo precise winding operations to form a precise winding core structure. However, this winding core still needs to undergo a double process of preheating and hot pressing before it can finally be converted into a solid and reliable battery core component. However, in the current winding-preheating-hot pressing continuous operation process, we still face a series of severe challenges, which not only restrict the production efficiency, but also directly relate to the quality and safety of the battery.

[0003] Firstly, the time-consuming of the winding core reaching the required temperature for forming has become a key factor hindering the improvement of production efficiency. The thermal stability of the lithium battery separator, as a key component of the battery structure, is crucial. To ensure the stable operation of the battery in a high-temperature environment, the separator must have excellent heat resistance. However, this characteristic results in relatively weak heat conduction ability of the separator. Coupled with the complex winding core structure and numerous layers, the heat transfer within the winding core becomes particularly difficult. The uneven distribution of internal and external temperature not only affects the forming quality of the winding core, but also may lead to a decrease in battery performance. To solve this problem, the current process flow has to add a preheating link before hot pressing to gradually increase the winding core temperature. However, this measure undoubtedly prolongs the production cycle and increases the equipment investment and operating costs.

[0004] In addition, the lack or deficiency of existing battery winding machines in heating function further exacerbates the above-mentioned difficulties. Many traditional battery winding machines are not equipped with a heating system, resulting in ineffective preheating of the winding core during the winding process. This not only prolongs the time for subsequent hot pressing forming, but also may cause quality problems such as deformation and cracking of the winding core during hot pressing. Even though some advanced winding machines have heating functions, their heating methods are often single, making it difficult to ensure uniform distribution of internal temperature and overall heating effect of the battery core. During the heating process, the surface temperature of the battery core rises rapidly, while the internal temperature lags behind, forming a significant temperature gradient. This temperature decrease from the outside to the inside not only affects the forming quality of the battery core, but also may pose a potential risk to the safety of the battery. Therefore, the existing battery winding machines have deficiencies in heating uniformity, and there is an urgent need for a pole piece heating equipment that can achieve more uniform heating of the winding pole piece (winding core). SUMMARY

[0005] The utility model aims at at least solve one of prior art existing technical problems. For this, the utility model provides a pole piece heating equipment, can improve the heating evenness when heating to the winding core.

[0006] The pole piece heating equipment according to the embodiments of the utility model is used for heating the winding core, and includes a winding needle, the winding core is sleeved on the winding needle, a first heating device is arranged on the winding needle and heats the inner side of the winding core, a second heating device is used for heating the outer side of the winding core, the second heating device and the first heating device are arranged along the radial direction of the winding needle, the second heating device is arranged on the outer side of the winding needle, and the second heating device and the winding needle are arranged at intervals to enable the second heating device to heat the outer side of the winding core between the second heating device and the winding needle, and the first heating device includes a first infrared heating mechanism, the first infrared heating mechanism is arranged in the interior of the winding needle, and the infrared light emitted by the first infrared heating mechanism can pass through the winding needle and irradiate the inner side of the winding core.

[0007] The pole piece heating equipment according to the embodiments of the utility model has at least the following beneficial effects: while the first heating device heats the inner side of the winding core on the winding needle, the second heating device is used to heat the outer side of the winding core from the outside of the winding core, so that the heating of the winding core is more uniform inside and outside, and the problem of uneven heating caused by the too large temperature difference between the inside and the outside of the winding core is effectively solved.

[0008] According to some embodiments of the utility model, the first heating device includes a heating film, and the heating film is attached to the outer periphery of the winding needle.

[0009] According to some embodiments of the utility model, the winding needle is of transparent material.

[0010] According to some embodiments of the utility model, the pole piece heating equipment further includes a first temperature sensor, the first temperature sensor is arranged in the interior of the winding needle, and the first temperature sensor is used for detecting the temperature of the winding needle.

[0011] According to some embodiments of the utility model, the second heating device includes a second infrared heating mechanism, the second infrared heating mechanism faces the winding needle, and the infrared light of the second infrared heating mechanism is used for irradiating the outer side of the winding core.

[0012] According to some embodiments of the utility model, the second heating device includes a hot air heating mechanism, the hot air heating mechanism faces the winding needle, and the hot air heating mechanism is used for blowing hot air to the outer side of the winding core to heat the winding core.

[0013] According to some embodiments of the present application, the pole piece heating device further comprises a detection camera, the detection camera faces the winding core, the detection camera is used for collecting images of the winding core, the second infrared heating mechanism is arranged outside the shooting range of the detection camera, and the detection camera is arranged outside the irradiation range of the second infrared heating mechanism.

[0014] According to some embodiments of the present application, the pole piece heating device comprises two winding needles, the central axes of the two winding needles coincide, and the two winding needles are symmetrically arranged at two ends of the winding core.

[0015] According to some embodiments of the present application, the two winding needles abut against each other.

[0016] According to some embodiments of the present application, the pole piece heating device further comprises a second temperature sensor, the second temperature sensor is arranged at intervals with the winding core along the axial direction of the winding needle, and the second temperature sensor is used for detecting the temperature of the winding core.

[0017] Additional aspects and advantages of the present application will be given in part in the following description, will become apparent from the following description, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A pole piece heating device of the present application has a winding needle structure schematic view;

[0019] Figure 2 A pole piece heating device of the present application has two winding needle structure schematic view;

[0020] Figure 3 A pole piece heating device of the present application removes the winding core structure schematic view.

[0021] REFERENCE NUMERALS

[0022] 1, winding core; 2, winding needle; 3, first heating device; 31, first infrared heating mechanism; 32, heating film; 4, second heating device; 5, detection camera; 6, first temperature sensor. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the present application, and cannot be understood as limiting the present application.

[0024] In the description of the utility model, it is understood that the orientation description, such as the orientation or positional relationship of the indication such as upper and lower, is the orientation or positional relationship based on the drawing shown, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as the limitation of the utility model.

[0025] In the description of the utility model, more refers to two or more than two. In the description of the utility model, if the first and the second are described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0026] In the description of the utility model, unless otherwise explicitly limited, the words such as setting, installation and connection should be understood broadly, and the person skilled in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.

[0027] In the manufacturing process of the battery pole piece, the heating of the pole piece at least includes two parts, one part is to heat and dry the pole piece after the active material is coated on the current collector. Another part is the preheating of the battery before hot pressing.

[0028] After the active material is coated on the current collector, the subsequent heating and drying step becomes particularly critical. The main purpose of this step is to completely remove the solvent in the coating layer, ensuring that the active material can be firmly attached to the surface of the current collector, while forming a uniform and properly porous electrode film. This process is crucial for the overall performance and safety of the battery. First of all, the removal of solvent during the drying process is crucial. The coating layer usually contains a large amount of organic solvent, such as N-methyl pyrrolidone (NMP), which may cause the internal pressure of the battery to increase during use, even causing safety problems if not completely evaporated. Therefore, by precisely controlling the drying temperature and time, it can be ensured that the solvent is completely evaporated, thereby avoiding these problems. Secondly, the drying process plays a key role in improving the adhesion between the active material and the current collector. At the appropriate temperature, the active material can better combine with the surface of the current collector to form a firm bond. The enhancement of this bonding force ensures that the active material will not fall off due to mechanical stress during the charging and discharging cycle of the battery, thereby ensuring the long-term stability and reliability of the battery. In addition, the drying process also involves the formation of a pore structure that is conducive to the penetration of electrolyte and ion transmission. By controlling the drying conditions, the porosity of the electrode film can be optimized, allowing the electrolyte to fully penetrate into the electrode, while ensuring the rapid transmission of ions within the electrode. This optimized pore structure has a significant impact on improving the charging and discharging efficiency and power output of the battery. The drying process also plays an important role in controlling the film thickness and uniformity. Through precise drying processes, the thickness of the electrode film can be ensured to be uniform and consistent, avoiding local over-thickness or under-thickness. This uniformity is crucial for the consistency of the battery, as uneven electrode films can lead to inconsistent performance during use, affecting the overall performance of the battery pack. Finally, for some specific battery systems, the drying process is also accompanied by a heat treatment effect. At the appropriate temperature, the active material can undergo a crystallization process or form a more stable chemical structure. This heat treatment effect helps to improve the electrochemical performance of the battery, such as improving the cycle stability and capacity retention rate of the battery. In summary, heating and drying is an indispensable step in the manufacture of battery electrodes. It not only relates to the performance and safety of the battery, but also directly affects the life and reliability of the battery.

[0029] In the battery manufacturing process, heating and drying the electrode sheet is a crucial step. If the heating is uneven during this process, it will bring a series of negative effects. First, the inconsistency of the drying degree of the electrode sheet may cause different degrees of deformation after drying. This deformation not only affects the appearance of the battery, but also may damage the internal structure of the battery, thereby affecting its electrochemical performance. Secondly, due to uneven heating, uneven stress distribution may occur inside the electrode sheet, which may cause damage to the internal structure during the battery charging and discharging process, further affecting the cycle life and safety of the battery. In addition, local overheating may cause the material performance of some areas of the electrode sheet to degrade, or even burn out, which will directly reduce the capacity and performance of the battery. And the part that is not dry may become a source of moisture inside the battery, increasing the risk of internal short circuit of the battery, affecting the safety and reliability of the battery. Therefore, ensuring uniform heating of the electrode sheet during the heating and drying process is crucial for manufacturing batteries with stable performance, safety and reliability.

[0030] On the other hand, the positive and negative electrodes and the separator of the battery are wound together to form a complete roll core. But at this time the roll core is in a loose state, still needs to be treated by preheating-hot pressing process to form a dense state. Since the lithium battery separator needs to have certain thermal stability to ensure that it will not occur thermal runaway under high temperature conditions, its heat conduction ability is relatively poor, and because the roll core has many layers and is relatively thick as a whole, the temperature distribution gradient inside and outside the roll core is too large, which not only affects the forming quality of the roll core, but also reduces the production efficiency.

[0031] Referring to Figure 1 , Figure 2 and Figure 3The utility model discloses the pole piece heating equipment in first embodiment, is used for heating to the roll core 1, include: roll needle 2, first heating device 3 and second heating device 4, and the roll core 1 is set on roll needle 2, first heating device 3 sets up on roll needle 2 to and heats the inside of roll core 1, second heating device 4 is used for heating the outside of roll core 1, and second heating device 4 and first heating device 3 are along the radial interval of roll needle 2 and set up, and second heating device 4 sets up on the outside of roll needle 2, and second heating device 4 and roll needle 2 interval set up to make second heating device 4 heat the outside of roll core 1 between second heating device 4 and roll needle 2, first heating device 3 includes first infrared heating mechanism 31, and first infrared heating mechanism 31 sets up in the inside of roll needle 2, and the infrared light ray that first infrared heating mechanism 31 sends can pass through roll needle 2 and irradiate in the inside of roll core 1. In the manufacturing process of pole piece, will first coat active substance on the current collector, after coating, will heat pole piece and dry, in order to more conveniently heat and dry, will pole piece be wound on roll needle 2 and heat and dry, and pole piece will form cylindrical roll core 1 after winding on roll needle 2. The thickness of roll core 1 is larger at this time, and when heating roll core 1, it is easy to appear that the outside of roll core 1 has been dried, but the inside of roll core 1 has not been dried. Therefore set up two heating devices, are first heating device 3 and second heating device 4 respectively, wherein first heating device 3 sets up on roll needle 2, so that first heating device 3 is located in the inside of roll core 1 and heats roll core 1 from the inside of roll core 1. In addition, second heating device 4 is also set up, and second heating device 4 heats roll core 1 from the outside of roll core 1 simultaneously in the outside of roll core 1. Under the common action of first heating device 3 and second heating device 4, heat the electric core from the inside and the outside of roll core 1 simultaneously, make the heating of electric core more uniform, make the drying effect of electric core better.

[0032] Wherein first heating device 3 includes first infrared heating mechanism 31, wherein when first infrared heating mechanism 31 heats the inside of roll core 1, needs from the inside of roll needle 2 to irradiate the outside of roll needle 2 and irradiate to the inside of roll core 1. And if roll needle 2 blocks the infrared light ray that first infrared heating mechanism 31 emits at this time, then will greatly influence the heating effect of first infrared heating mechanism 31 to roll core 1. Therefore can set up roll needle 2 as grid, and the infrared light ray that first infrared heating mechanism 31 emits will irradiate from the hole of grid and heat the inside of roll core 1.

[0033] In another aspect, the winding needle 2 can also be made of transparent material. When the winding needle 2 is in a grid shape, the structure strength of the winding needle 2 is low, and the body of the grid blocks part of the light. The transparent winding needle 2 can make the infrared light emitted by the first infrared heating mechanism 31 emit from any position of the winding needle 2 without being blocked by the winding needle 2, which can make the heating effect of the first infrared heating mechanism 31 more uniform, and make the winding needle 2 smoother, thereby avoiding damage to the inside of the winding core 1.

[0034] According to some embodiments of the present application, the first heating device 3 includes a heating film 32 attached to the outer periphery of the winding needle 2. The first heating device 3 includes the heating film 32 and the first infrared heating mechanism 31, and the heating film 32 and the first infrared heating mechanism 31 heat the inside of the winding core 1 at the same time, which greatly improves the heating efficiency of the first heating device 3 and shortens the heating time of the winding core 1. Meanwhile, the first infrared heating mechanism 31 also makes the heating of the inside of the winding core 1 more uniform.

[0035] According to some embodiments of the present application, the pole piece heating equipment further includes a first temperature sensor 6 arranged inside the winding needle 2, and the first temperature sensor 6 is used for detecting the temperature of the winding needle 2. The inside of the winding core 1 is attached to the winding needle 2, so the temperature of the winding needle 2 is very close to the heating temperature of the winding core 1. By detecting the temperature of the winding needle 2, the heating temperature of the inside of the winding core 1 can be obtained, which avoids excessively high or low heating temperature. When the heating temperature is too high, the winding core 1 will be damaged, and when the heating temperature is too low, the heating efficiency of the winding core 1 will be greatly reduced. Therefore, by detecting the temperature of the winding needle 2 through the first temperature sensor 6, the heating temperature of the winding core 1 is detected, so that the heating of the inside of the winding core 1 reaches the optimal state.

[0036] According to some embodiments of the present application, the second heating device 4 includes a second infrared heating mechanism, and the second infrared heating mechanism is directed towards the winding needle 2. The infrared light of the second infrared heating mechanism is used for irradiating the outside of the winding core 1. The second infrared heating mechanism is arranged outside the winding core 1, and the outside structure of the winding core 1 changes a lot and is not flat. Therefore, the second infrared heating mechanism can heat the outside of the winding core 1 more uniformly.

[0037] According to some embodiments of the present application, the second heating device 4 includes a hot air heating mechanism, and the hot air heating mechanism is directed towards the winding needle 2. The hot air heating mechanism is used for blowing hot air to the outside of the winding core 1 to heat the winding core 1. The second heating device 4 includes the hot air heating mechanism and the second infrared heating mechanism, and the hot air heating mechanism and the second infrared heating mechanism heat the outside of the winding core 1 at the same time, which greatly improves the heating efficiency of the second heating device 4 and shortens the heating time of the winding core 1.

[0038] According to some embodiments of the present application, the pole piece heating device further comprises a detection camera 5, the detection camera 5 faces the winding core 1, the detection camera 5 is used for collecting images of the winding core 1, the second infrared heating mechanism is arranged outside the shooting range of the detection camera 5, and the detection camera 5 is arranged outside the irradiation range of the second infrared heating mechanism. The shape and temperature of the winding core 1 during heating can be detected by the detection camera 5, so that the heating of the winding core 1 can be better controlled.

[0039] According to some embodiments of the present application, the pole piece heating device comprises two winding needles 2, the central axes of the two winding needles 2 coincide, and the two winding needles 2 are symmetrically arranged at two ends of the winding core 1. The winding core 1 can be better fixed by the two winding needles 2, so that the winding core 1 is more stable during heating. Further, the two winding needles 2 abut each other. The stress inside the winding core 1 is more uniform.

[0040] According to some embodiments of the present application, the pole piece heating device further comprises a second temperature sensor, the second temperature sensor is arranged in the axial direction of the winding needle 2 and is spaced apart from the winding core 1, and the second temperature sensor is used for detecting the temperature of the winding core 1. Through the monitoring of the temperature of the winding core 1 by the second temperature sensor, not only the temperature of the winding core 1 can be monitored in real time, but also the difference between the heating efficiencies of the first heating device 3 and the second heating device 4 can be avoided. The heating efficiency of the first heating device 3 and the second heating device 4 can be adjusted by monitoring the temperature of the winding core 1 by the second temperature sensor, so that the heating of the winding core 1 is more uniform.

[0041] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. An electrode tab heating apparatus for heating a jellyroll, characterized by, The application relates to an electrode plate heating device. The electrode plate heating device comprises a roll core, a roll needle, a first heating device, and a second heating device. The roll core is sleeved on the roll needle. The first heating device is arranged on the roll needle and heats the inner side of the roll core. The second heating device is arranged on the outer side of the roll needle and is spaced apart from the roll needle to heat the outer side of the roll core between the second heating device and the roll needle. The first heating device comprises a first infrared heating mechanism arranged inside the roll needle.

2. The pole piece heating apparatus of claim 1, wherein The first infrared heating mechanism emits infrared light which can pass through the roll needle and irradiate the inner side of the roll core.

3. The pole piece heating apparatus according to claim 1 or 2, characterized by, The first heating device comprises a heating film attached to the outer periphery of the roll needle.

4. The pole piece heating apparatus of claim 1, wherein The roll needle is made of transparent material.

5. The pole piece heating apparatus of claim 1, wherein The electrode plate heating device further comprises a first temperature sensor arranged inside the roll needle.

6. The pole piece heating apparatus according to claim 1 or 5, characterized by The first temperature sensor is used for detecting the temperature of the roll needle.

7. The pole piece heating apparatus of claim 5, wherein The second heating device comprises a second infrared heating mechanism facing the roll needle.

8. The pole piece heating apparatus of claim 1, wherein The second infrared heating mechanism emits infrared light which is used for irradiating the outer side of the roll core.

9. A pole piece heating apparatus according to claim 8, wherein The second heating device comprises a hot air heating mechanism facing the roll needle.

10. The pole piece heating apparatus of claim 1, wherein The hot air heating mechanism is used for blowing hot air to the outer side of the roll core to heat the roll core. The electrode plate heating device further comprises a detection camera facing the roll core. The detection camera is used for collecting images of the roll core. The second infrared heating mechanism is arranged outside the shooting range of the detection camera, and the detection camera is arranged outside the irradiation range of the second infrared heating mechanism. The electrode plate heating device comprises two roll needles. The central axes of the two roll needles coincide, and the two roll needles are symmetrically arranged at the two ends of the roll core. The two roll needles abut against each other. The electrode plate heating device further comprises a second temperature sensor. The second temperature sensor is arranged in the axial direction of the roll needle and is spaced apart from the roll core. The second temperature sensor is used for detecting the temperature of the roll core.

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