A wet-process lithium battery diaphragm horizontal stretching shrinkage shaping device

Abstract

The present invention provides a wet-process lithium battery diaphragm transverse stretching shrinking shaping device. The wet-process lithium battery diaphragm transverse stretching shrinking shaping device comprises an inlet sprocket, a film clamp closing clamp, a film clamp opening clamp, an outlet sprocket, a chain, a clamp, a shrinkage adjustment system, a bellows, an air circulation fan, a heating system, and a cooling system. The present invention can change the transverse and longitudinal shrinkage rate of the diaphragm through the shrinkage adjustment system, reduce the thermal shrinkage rate of the diaphragm during use, avoid the occurrence of positive and negative electrode connection short circuit phenomenon, and improve the battery safety performance.

Description

Technical Field

[0001] The invention relates to the technical field of wet-process lithium battery diaphragm production, and in particular to a wet-process lithium battery diaphragm transverse stretching, shrinking and shaping device. Background Art

[0002] During the charge and discharge process of lithium-ion batteries, the diaphragm separates the positive and negative electrodes to prevent short circuits caused by contact between the two electrodes, absorbs sufficient electrolyte, provides sufficient electrolyte lithium ion channels, and has micropore self-closing protection functions. The lithium ion conductivity of the diaphragm is directly related to the overall performance of the lithium-ion battery. The performance of the diaphragm determines the battery's interface structure, electrolyte retention, and internal resistance, which in turn affects important characteristics of the battery, such as capacity, cycle performance, charge and discharge current density, and safety.

[0003] The existing wet-process diaphragm manufacturing method generally includes: batching casting → biaxial stretching → extraction → transverse stretching → winding and inspection. After extraction and drying, the oil film becomes a diaphragm with micropores, which is stretched transversely until it is rolled and inspected. After extraction and drying, the diaphragm undergoes a transverse stretching step under certain temperature conditions, which cannot completely release its internal stress. It is easy to cause the high-temperature thermal shrinkage rate to increase when installed in the battery, causing a short circuit between the positive and negative electrodes, reducing the safety of the battery.

[0004] In view of this, it is particularly important to design a wet-process lithium battery separator transverse stretching shrinkage shaping device, especially in the field of wet-process lithium battery separator production. Summary of the invention

[0005] The purpose of the present invention is to provide a wet-process lithium battery diaphragm transverse stretching shrinkage shaping device to solve the problem in the prior art that the diaphragm cannot completely release internal stress, resulting in a high-temperature thermal shrinkage rate of the diaphragm and causing a short circuit between the positive and negative electrodes.

[0006] In order to solve the above technical problems, a wet-process lithium battery diaphragm transverse pulling shrinkage shaping device is provided, which is characterized in that it includes an inlet sprocket, a film clamp closing clamp, a chain, a clamp, a bellows, an air circulation fan, a heating system, a cooling system, a shrinkage adjustment system, a track, a film clamp opener, an outlet sprocket, and a diaphragm. The inlet sprocket and the outlet sprocket are respectively placed at the two ends of the device to drive the chain to move. The chain is provided with a clamp and is installed on a track. A diaphragm is provided in the middle of the track. Bellows are placed on the upper and lower sides of the diaphragm. The film clamp closing clamp and the film clamp opener are respectively placed at the front and rear ends of the bellows. The air circulation fan is placed at the center of the tracks on both sides and is respectively connected to the heating system and the cooling system. The track is provided with a shrinkage adjustment system.

[0007] Preferably, the inlet sprocket and the outlet sprocket drive the chain to meet the transmission speed of 40-100m / min.

[0008] Preferably, the membrane clamp closer is a magnetic device and the membrane clamp opener is a magnetic and mechanical pre-opening device.

[0009] Preferably, the clamp pitch is 30-50 mm and is provided with an oil splash-proof cover.

[0010] More preferably, the bellows in the device are divided into preheating zone bellows, stretching zone bellows, heat setting zone bellows, shrinkage zone bellows, transition zone bellows and cooling zone bellows, wherein the preheating zone bellows are 4-8m long, the stretching zone bellows are 6-12m long, the heat setting zone bellows are 6-12m long, the shrinkage zone bellows are 6-12m long, the transition zone bellows are 2-4m long, and the cooling zone bellows are 4-8m long.

[0011] Furthermore, the heating system and the cooling system can provide a certain temperature for the bellows, wherein the temperatures of the bellows in the preheating stage, the transverse stretching stage, the heat setting stage, the transverse and longitudinal shrinkage stage, and the transition stage meet (80-160)℃±0.5℃, and the temperature of the bellows in the cooling stage meets (20-30)℃±1℃.

[0012] Preferably, the contraction adjustment system can adjust the transverse contraction amplitude of the diaphragm to ≤20% and the longitudinal contraction amplitude to ≤10% by adjusting the stretching angle and the retraction angle of the track direction changing path.

[0013] Preferably, during transverse stretching, the track stretching angle is ≤15°, and the retraction angle is ≤15°.

[0014] Furthermore, the hardness value of the rail meets 600-750HV.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] During the process of transverse stretching, shrinking and shaping by the device, the diaphragm will go through preheating, stretching, heat setting, transverse and longitudinal shrinkage, transition and cooling in sequence, which can completely release its internal residual stress, avoid the high-temperature thermal shrinkage rate during later use, and cause short circuit between the positive and negative electrodes, thereby improving battery safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a wet-process lithium battery separator transverse stretching shrinkage shaping device of the present invention;

[0018] Figure 2 It is a structural diagram of a wet-process lithium battery separator transverse stretching shrinkage shaping device of the present invention;

[0019] The numbers in the figure are: 1-inlet sprocket, 2-membrane clamp closer, 3-chain, 4-clamp, 5-bellows, 6-air circulation fan, 7-heating system, 8-cooling system, 9-shrinkage adjustment system, 10-track, 11-membrane clamp opener, 12-outlet sprocket, 13-diaphragm. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] like Figure 1 The device is a wet-process lithium battery diaphragm transverse stretching shrinkage shaping device, comprising an inlet sprocket 1, a film clamp closing clamp 2, a chain 3, a clamp 4, a bellows 5, an air circulation fan 6, a heating system 7, a cooling system 8, a shrinkage adjustment system 9, a track 10, a film clamp opener 11, and an outlet sprocket 12. The inlet sprocket 1 and the outlet sprocket 12 are respectively placed at the two ends of the device to drive the chain 3 to move. The chain 3 is provided with a clamp 4 and is installed on the track 10. A diaphragm 13 is provided in the middle of the track 10. Bellows 5 are placed on the upper and lower sides of the diaphragm 13. The film clamp closing clamp 2 and the film clamp opener 11 are respectively placed at the front and rear ends of the bellows 5. The air circulation fan 6 is placed at the center of the tracks 10 on both sides and is respectively connected to the heating system 7 and the cooling system 8. The track 10 is provided with a shrinkage adjustment system 9.

[0022] It should be noted that the inlet sprocket 1 and the outlet sprocket 12 drive the chain 3 to meet the transmission speed of 40-100m / min.

[0023] In the wet-process lithium battery diaphragm transverse stretching shrinkage shaping device, the film clamp closing device 2 is a magnetic device, and the film clamp opening device 11 is a magnetic and mechanical pre-opening device.

[0024] The device for horizontally stretching, shrinking and shaping a wet-process lithium battery diaphragm has four clamps with a pitch of 30-50 mm and is provided with an oil splash-proof cover.

[0025] The described wet-process lithium battery diaphragm transverse stretching shrinkage shaping device, in which the bellows 5 are divided into a preheating zone bellows, a stretching zone bellows, a heat setting zone bellows, a shrinking zone bellows, a transition zone bellows and a cooling zone bellows, wherein the length of the preheating zone bellows is 4-8m, the length of the stretching zone bellows is 6-12m, the length of the heat setting zone bellows is 6-12m, the length of the shrinking zone bellows is 6-12m, the length of the transition zone bellows is 2-4m, and the length of the cooling zone bellows is 4-8m.

[0026] A wet-process lithium battery diaphragm transverse stretching shrinkage shaping device, a heating system 7 and a cooling system 8 can provide a bellows 5 with a certain temperature, wherein the bellows in the preheating stage, the transverse stretching stage, the heat setting stage, the transverse and longitudinal shrinkage stage, and the transition stage meet the temperatures of (80-160)°C±0.5°C, and the bellows in the cooling stage meet the temperatures of (20-30)°C±1°C.

[0027] In the wet-process lithium battery diaphragm transverse stretching shrinkage shaping device, the shrinkage adjustment system 9 can adjust the diaphragm transverse shrinkage range ≤20% and the longitudinal shrinkage range ≤10% by adjusting the stretching angle and the retraction angle of the direction-changing path of the track 10.

[0028] The horizontal stretching shrinkage shaping device for wet-process lithium battery diaphragm has a stretching angle of ≤15° during horizontal stretching.

[0029] In the wet-process lithium battery diaphragm transverse stretching shrinkage shaping device, the hardness value of the track (10) meets 600-750HV.

[0030] Example 1

[0031] (1) The inlet sprocket and outlet sprocket drive the chain at a speed of 40 m / min

[0032] (2) Clip pitch 40mm

[0033] (3) The stretching angle and retraction angle of the track in the transverse stretching stage are set to 12°

[0034] (4) Set the horizontal shrinkage range to 15% and the vertical shrinkage range to 5%

[0035] (5) The bellows length in the preheating zone is 6m, the bellows length in the transverse stretching zone is 9m, the bellows length in the heat setting zone is 9m, the bellows length in the transverse and longitudinal shrinking zones is 9m, the bellows length in the transition zone is 3m, and the cooling stage time is 6m

[0036] (6) The bellows temperature in the preheating stage is set to 160℃±0.5℃, the bellows temperature in the transverse stretching stage is set to 160℃±0.5℃, the bellows temperature in the heat setting stage is set to 160℃±0.5℃, the bellows temperature in the transverse and longitudinal shrinking stage is set to 160℃±0.5℃, the bellows temperature in the transition stage is set to 160℃±0.5℃, and the bellows temperature in the cooling stage is set to 30℃±1℃

[0037] (7) The material hardness of the track is selected to be 600HV

[0038] Example 2

[0039] (1) The inlet sprocket and outlet sprocket drive the chain at a speed of 70 m / min

[0040] (2) Clip pitch 40mm

[0041] (3) The stretching angle and retraction angle of the track in the transverse stretching stage are set to 15°

[0042] (4) Set the horizontal shrinkage range to 20% and the vertical shrinkage range to 10%

[0043] (5) The bellows length in the preheating zone is 4m, the bellows length in the transverse stretching zone is 6m, the bellows length in the heat setting zone is 6m, the bellows length in the transverse and longitudinal shrinking zones is 6m, the bellows length in the transition zone is 2m, and the cooling stage time is 4m

[0044] (6) The bellows temperature in the preheating stage is set to 80℃±0.5℃, the bellows temperature in the transverse stretching stage is set to 80℃±0.5℃, the bellows temperature in the heat setting stage is set to 80℃±0.5℃, the bellows temperature in the transverse and longitudinal shrinking stage is set to 80℃±0.5℃, the bellows temperature in the transition stage is set to 80℃±0.5℃, and the bellows temperature in the cooling stage is set to 20℃±1℃

[0045] (7) The material hardness of the track is 700HV

[0046] Example 3

[0047] (1) The inlet sprocket and outlet sprocket drive the chain at a speed of 100 m / min

[0048] (2) Clip pitch 40mm

[0049] (3) During the lateral stretching stage, the stretching angle of the track is set to 10° and the retraction angle is set to 10°

[0050] (4) Set the horizontal shrinkage range to 15% and the vertical shrinkage range to 8%

[0051] (5) The bellows length in the preheating zone is 8m, the bellows length in the transverse stretching zone is 12m, the bellows length in the heat setting zone is 12m, the bellows length in the transverse and longitudinal shrinking zones is 12m, the bellows length in the transition zone is 4m, and the cooling stage time is 8m

[0052] (6) The bellows temperature in the preheating stage is set to 132℃±0.5℃, the bellows temperature in the transverse stretching stage is set to 135℃±0.5℃, the bellows temperature in the heat setting stage is set to 138℃±0.5℃, the bellows temperature in the transverse and longitudinal shrinkage stage is set to 134℃±0.5℃, the bellows temperature in the transition stage is set to 130℃±0.5℃, and the bellows temperature in the cooling stage is set to 22℃±1℃

[0053] (7) The material hardness of the track is selected as 750HV

[0054] Comparative Example 1

[0055] (1) The inlet sprocket and outlet sprocket drive the chain at a speed of 50 m / min

[0056] (2) Clip pitch 40mm

[0057] (3) The stretching angle and retraction angle of the track in the transverse stretching stage are set to 0°

[0058] (4) Set the horizontal shrinkage to 0% and the vertical shrinkage to 0%

[0059] (5) The bellows length in the preheating zone is 4m, the bellows length in the transverse stretching zone is 6m, the bellows length in the heat setting zone is 6m, the bellows length in the transverse and longitudinal shrinking zones is 6m, the bellows length in the transition zone is 2m, and the cooling stage time is 4m

[0060] (6) The bellows temperature in the preheating stage is set to 130℃±0.5℃, the bellows temperature in the stretching stage is set to 133℃±0.5℃, the bellows temperature in the heat setting stage is set to 135℃±0.5℃, the bellows temperature in the transverse and longitudinal shrinkage stage is set to 133℃±0.5℃, the bellows temperature in the transition stage is set to 130℃±0.5℃, and the bellows temperature in the cooling stage is set to 25℃±1℃

[0061] (7) The material hardness of the track is selected to be 600HV

[0062] Comparative Example 2

[0063] (1) The inlet sprocket and outlet sprocket drive the chain at a speed of 70 m / min

[0064] (2) Clip pitch 40mm

[0065] (3) The stretching angle and retraction angle of the track in the transverse stretching stage are set to 0°

[0066] (4) Set the horizontal shrinkage to 0% and the vertical shrinkage to 0%

[0067] (5) The bellows length in the preheating zone is 6m, the bellows length in the transverse stretching zone is 9m, the bellows length in the heat setting zone is 9m, the bellows length in the transverse and longitudinal shrinking zones is 9m, the bellows length in the transition zone is 3m, and the cooling stage time is 6m

[0068] (6) The bellows temperature in the preheating stage is set to 132℃±0.5℃, the bellows temperature in the stretching stage is set to 135℃±0.5℃, the bellows temperature in the heat setting stage is set to 138℃±0.5℃, the bellows temperature in the transverse and longitudinal shrinkage stage is set to 135℃±0.5℃, the bellows temperature in the transition stage is set to 130℃±0.5℃, and the bellows temperature in the cooling stage is set to 25℃±1℃

[0069] (7) The material hardness of the track is selected as 750HV

[0070] Table 1 Performance test results

[0071]

[0072] The above is an explanation of the transverse stretching and shrinkage shaping process after extraction of a wet-process lithium battery diaphragm of the present invention, which is used to help understand the present invention. However, the implementation mode of the present invention is not limited to the above-mentioned embodiments. Any changes, modifications, substitutions, combinations, and simplifications made without departing from the principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A wet-process lithium battery diaphragm horizontal stretching shrinkage shaping device, characterized in that: The invention comprises an inlet sprocket (1), a chain (3), a clamp (4), a bellows (5), an air circulation fan (6), a heating system (7), a cooling system (8), a track (10), and an outlet sprocket (12). It also comprises a contraction adjustment system (9), which is arranged on the track (10). It also comprises a film clamp closing clamp (2) arranged at the front end of the bellows (5) and a film clamp opening clamp (11) arranged at the rear end of the bellows (5); the inlet sprocket (1) and the outlet sprocket (12) are respectively placed at two ends of the device to drive the chain (3) to move, and the inlet sprocket (1) and the outlet sprocket (12) drive the chain (3) to meet the transmission speed of 40-100 m / min; the chain (3) is provided with a clamp (4) and is installed on the track (10), the pitch of the clamp (4) meets the requirements of 30-50 mm, and is provided with an oil splash-proof cover; two groups of chains (3), tracks (10), the inlet sprocket (1) and the outlet sprocket (12) are respectively arranged on both sides of the device; a diaphragm (13) is arranged in the middle of the two tracks (10); bellows (5) are placed on the upper and lower sides of the diaphragm (13), and the bellows (5) are divided into a preheating zone bellows, a stretching zone bellows, a heat setting zone bellows, a shrinking zone bellows, a transition zone bellows and a cooling zone bellows; the air circulation fan (6) is placed at the center of the tracks (10) on both sides and is respectively connected to the heating system (7) and the cooling system (8); the shrinkage adjustment system (9) can adjust the diaphragm's transverse shrinkage amplitude ≤20%, the longitudinal shrinkage amplitude ≤10% by adjusting the stretching angle and retraction angle of the direction-changing path of the track (10); when stretching transversely, the stretching angle of the track (10) is ≤15°, and the retraction angle is ≤15°; the membrane clamp closing device (2) adopts a magnetic device, and the membrane clamp opening device (11) is a magnetic and mechanical pre-opening device.

2. A wet-process lithium battery diaphragm transverse stretching shrinkage shaping device according to claim 1, characterized in that: The length of the bellows in the preheating zone is 4-8m, the length of the bellows in the stretching zone is 6-12m, the length of the bellows in the heat setting zone is 6-12m, the length of the bellows in the shrinking zone is 6-12m, the length of the bellows in the transition zone is 2-4m, and the length of the bellows in the cooling zone is 4-8m.

3. A wet-process lithium battery diaphragm transverse stretching shrinkage shaping device according to claim 2, characterized in that: The heating system (7) and the cooling system (8) provide the bellows (5) with a certain temperature, wherein the bellows temperature in the preheating stage, the transverse stretching stage, the heat setting stage, the transverse and longitudinal shrinking stage, and the transition stage meet 80-160°C ± 0.5°C, and the bellows temperature in the cooling stage meets 20-30°C ± 1°C.

4. The wet-process lithium battery separator transverse stretching shrinkage shaping device according to claim 1, characterized in that: The hardness value of the rail (10) meets 600-750HV.

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