Oven assembly for lithium battery separator preparation
Patent Information
- Application Number
- CN202521437715.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2026-09-11
- Estimated Expiration
- 2035-07-10
AI Technical Summary
[0004]隔膜透气均匀性主要受这两次拉伸影响，横向拉伸设备使用两侧链夹夹紧薄膜两端进行拉伸，这就导致拉伸应力先集中在薄膜中间位置，非晶区易运动的分子链段拉伸取向，由中间向两侧扩散，最终完成拉伸，形成扩孔；这样拉伸的结果就导致中间位置和两侧位置拉伸程度不一致，在保持拉伸温度不变的情况下，导致成孔大小差异，最终影响产品透气极差较大
[0018] The above-mentioned technical solution of this utility model has at least the following advantages:
Smart Images
Figure CN224743999U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of lithium battery separator preparation equipment, and more specifically, to an oven assembly for preparing lithium battery separators. Background Technology
[0002] The air permeability of lithium battery separators mainly affects the lithium-ion permeability and internal resistance of lithium batteries. Producing lithium battery separators with good air permeability uniformity is very beneficial to the stability of lithium battery production.
[0003] Currently, the wet biaxial stretching membrane equipment used in the production and preparation of lithium battery separators performs a first stretch (TD1) when the separator contains white oil (before extraction) and a second stretch (TD2) when the separator does not contain white oil (after extraction).
[0004] The uniformity of membrane air permeability is mainly affected by these two stretching processes. The transverse stretching equipment uses chain clamps on both sides to clamp the two ends of the film for stretching. This causes the tensile stress to be concentrated in the middle of the film first. The easily moving molecular chain segments in the amorphous region are stretched and oriented, and diffuse from the middle to both sides, eventually completing the stretching and forming pores. As a result of this stretching, the degree of stretching in the middle position and the two sides is inconsistent. When the stretching temperature is kept constant, it leads to differences in the size of the pores, which ultimately has a significant impact on the product's air permeability. Utility Model Content
[0005] (a) Technical problems to be solved
[0006] The technical problem to be solved by this invention is that the lithium battery separators produced by existing equipment have extremely poor air permeability.
[0007] (II) Technical Solution
[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0009] This utility model provides an oven assembly for preparing lithium battery separators, including a first track, a second track, a first chain clamp, a second chain clamp, and an oven. The first track has a preheating zone, a stretching zone, and a shaping zone connected to each other along its length. The second track is arranged opposite to the first track and has a preheating zone, a stretching zone, and a shaping zone corresponding to the first track along its length. The first chain clamp is slidably connected to the first track and is used to clamp one end of the lithium battery separator sheet. The second chain clamp is slidably connected to the second track and is used to clamp the other end of the lithium battery separator sheet. The oven covers the preheating zone, the stretching zone, and the shaping zone. The oven includes a hot air blower, a box body, an upper oven nozzle, and a lower oven nozzle, wherein the middle area of the upper oven nozzle and the lower oven nozzle is provided with a wind shield.
[0010] Preferably, the length of the wind shield is one-third of the total length of the upper oven nozzle, or the length of the wind shield is one-third of the total length of the lower oven nozzle.
[0011] Preferably, the windproof component is a stainless steel sheet or a heat-resistant tape.
[0012] Preferably, both the first track and the second track are circular tracks.
[0013] Preferably, the oven is provided with multiple baffles spaced apart along its length, which divide the oven into multiple heating zones.
[0014] Preferably, the preheating zone includes a first heating zone, a second heating zone, a third heating zone, and a fourth heating zone; the stretching zone includes a fifth heating zone, a sixth heating zone, a seventh heating zone, and an eighth heating zone; and the shaping zone includes a ninth heating zone, a tenth heating zone, an eleventh heating zone, a twelfth heating zone, a thirteenth heating zone, and a fourteenth heating zone.
[0015] Preferably, the middle region of the upper oven nozzles of the fifth heating zone, the seventh heating zone, the ninth heating zone, the eleventh heating zone, and the thirteenth heating zone is provided with a wind shield, and the middle region of the lower oven nozzles of the sixth heating zone, the eighth heating zone, the tenth heating zone, and the twelfth heating zone is provided with a wind shield.
[0016] Preferably, in the preheating zone, the distance between the first track and the second track is L1, and in the stretching zone, the distance between the first track and the second track is L2, wherein L2 > L1.
[0017] (III) Beneficial Effects
[0018] The above-mentioned technical solution of this utility model has at least the following advantages:
[0019] This invention incorporates a wind shield in the central region of the upper and lower oven nozzles. This wind shield prevents hot air from directly impacting the middle of the lithium-ion battery separator sheet, reducing the temperature at the center and minimizing the collapse of the large pores. This creates a temperature difference between the center and the sides of the separator, thus mitigating the significant air permeability issues caused by stretching. By reducing air permeability in the center while maintaining the same permeability on the sides, the overall air permeability of the lithium-ion battery separator is reduced. This results in less performance variation in the lithium-ion battery separator, significantly improving process stability. Furthermore, it minimizes the impact of air permeability variations on battery performance when supplying customers, thus reducing the risk of customer complaints. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of the oven assembly for preparing lithium battery separators provided in this embodiment of the utility model.
[0022] Figure 2 This is a schematic diagram of the structure of the upper oven nozzle and the lower oven nozzle provided in this embodiment of the utility model.
[0023] Figure 3 This is a schematic diagram of the structure of the upper oven nozzle provided in an embodiment of this utility model.
[0024] Figure 4 This is a structural schematic diagram of the windproof component provided in an embodiment of the present utility model.
[0025] The labels for the attached figures are as follows:
[0026] 10. Film surface; 1. First track; 2. Second track; 3. First chain clamp; 4. Second chain clamp; 5. Oven; 51. Upper oven nozzle; 52. Lower oven nozzle; 53. Wind shield; 54. Baffle; A. Preheating zone; B. Stretching zone; C. Shaping zone; 501. First heating zone; 502. Second heating zone; 503. Third heating zone; 504. Fourth heating zone; 505. Fifth heating zone; 506. Sixth heating zone; 507. Seventh heating zone; 508. Eighth heating zone; 509. Ninth heating zone; 510. Tenth heating zone; 511. Eleventh heating zone; 512. Twelfth heating zone; 513. Thirteenth heating zone; 514. Fourteenth heating zone. Detailed Implementation
[0027] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0028] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.
[0029] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or the number of technical features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this utility model is described in more detail below with reference to specific embodiments:
[0031] like Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, this utility model embodiment provides an oven assembly for preparing lithium battery separators, including a first track 1, a second track 2, a first chain clamp 3, a second chain clamp 4, and an oven 5; the first track 2 is provided with a preheating zone A, a stretching zone B, and a shaping zone C connected to each other along the length direction of the first track 2; the second track 1 is arranged opposite to the first track 2, and is provided with a preheating zone A, a stretching zone B, and a shaping zone C corresponding to the first track 1 along the length direction of the second track 2; the first chain clamp 3 is slidably connected to the first track 1, and is used to clamp one end of the lithium battery separator sheet; the second chain clamp 4 is slidably connected to the second track 2, and is used to clamp the other end of the lithium battery separator sheet; the oven 5 covers the preheating zone A, the stretching zone B, and the shaping zone C, and the oven 5 includes a hot air blower, a box body, an upper oven nozzle 51, and a lower oven nozzle 52, wherein the middle area of the upper oven nozzle 51 and the lower oven nozzle 52 is provided with a wind shield 53. Specifically, the first chain clamp 3 can slide along the length direction of the first slide rail 1, and the second chain clamp 4 can slide along the length direction of the second slide rail 2. The first chain clamp 3 holds one end of the lithium battery separator sheet, and the second chain clamp 4 holds the other end of the lithium battery separator sheet. The oven is used to heat the held lithium battery separator sheet. In the preheating zone, the oven heats the lithium battery separator sheet to a preset preheating temperature value so that the heated held lithium battery separator sheet has better plasticity. Then, the first chain clamp 3 moves along the first track 1, while the second chain clamp 4 moves along the second track 2. As the distance between the first track 1 and the second track 2 increases, the lithium battery separator sheet is stretched under the action of clamping force. In the stretching zone, the oven simultaneously heats the lithium battery separator sheet to a preset stretching temperature value. Finally, in the shaping zone, the lithium battery separator sheet is controlled at a preset shaping temperature. Figure 2As shown, the upper oven nozzle 51 and the lower oven nozzle 52 can heat the film surface 10 formed by stretching the lithium battery separator sheet.
[0032] As one of the optional embodiments of this example, the length of the wind shield 53 is one-third of the total length of the upper oven nozzle 51, or the length of the wind shield 53 is one-third of the total length of the lower oven nozzle 52.
[0033] As one optional implementation of this embodiment, the windproof component 53 is a stainless steel sheet or heat-resistant tape. Both stainless steel sheets and heat-resistant tape can achieve good heat insulation effects, thereby preventing hot air from the middle area from directly acting on the lithium battery separator sheet. Figure 3 and Figure 4 In the embodiment shown, the wind shield 53 is preferably a stainless steel sheet. The stainless steel sheet has hooks 531 at both ends. The hooks 531 pass through the air blowing holes on the upper oven nozzle 51 / lower oven nozzle 52, thereby hanging and fixing the stainless steel sheet on the upper oven nozzle 51 / lower oven nozzle 52.
[0034] In one optional implementation of this embodiment, both the first track 1 and the second track 2 are circular tracks. This facilitates the cyclic movement of the first chain clamp 3 along the first track 1 and the cyclic movement of the second chain clamp 4 along the second track 2.
[0035] In one optional implementation of this embodiment, a plurality of baffles 54 are spaced apart along the length of the oven 5, dividing the oven into multiple heating zones. The baffles 54 are used to separate adjacent heating zones, preventing the heat from two adjacent heating zones from affecting each other.
[0036] As one optional implementation of this embodiment, the preheating zone A includes a first heating zone 501, a second heating zone 502, a third heating zone 503, and a fourth heating zone 504; the stretching zone B includes a fifth heating zone 505, a sixth heating zone 506, a seventh heating zone 507, and an eighth heating zone 508; and the shaping zone C includes a ninth heating zone 509, a tenth heating zone 510, an eleventh heating zone 511, a twelfth heating zone 512, a thirteenth heating zone 513, and a fourteenth heating zone 514.
[0037] As one of the optional embodiments of this example, the middle region of the upper oven nozzle 51 of the fifth heating zone 505, the seventh heating zone 507, the ninth heating zone 509, the eleventh heating zone 511 and the thirteenth heating zone 513 is provided with a wind shield 53, and the middle region of the lower oven nozzle 52 of the sixth heating zone 506, the eighth heating zone 508, the tenth heating zone 510 and the twelfth heating zone 512 is provided with a wind shield 53.
[0038] As one of the optional implementations of this embodiment, in the preheating zone A, the distance between the first track 1 and the second track 2 is L1, and in the stretching zone B, the distance between the first track 1 and the second track 2 is L2, wherein L2 > L1.
[0039] The following are specific embodiments provided by this utility model:
[0040] The following examples are all used to prepare lithium battery separators with a thickness of 9 μm, an areal density of 5.3 g / cm³, and a porosity of 38%.
[0041] Control group: Neither the upper oven nozzle 51 nor the lower oven nozzle 52 is equipped with a wind shield 53;
[0042] Example 1: Wind shields 53 are provided in the middle area of the upper oven nozzle 51 and the middle area of the lower oven nozzle 52 of the fifth heating zone 505, the sixth heating zone 506, the seventh heating zone 507 and the eighth heating zone 508.
[0043] Example 2: In the fifth heating zone 505, the sixth heating zone 506, the seventh heating zone 507, the eighth heating zone 508, the ninth heating zone 509, the tenth heating zone 510, the eleventh heating zone 511, the twelfth heating zone 512, and the thirteenth heating zone 513, wind shields 53 are provided in the middle area of the upper oven nozzle 51 and the middle area of the lower oven nozzle 52.
[0044] Example 3: In the second heating zone 502, the third heating zone 503, the fourth heating zone 504, the fifth heating zone 505, the sixth heating zone 506, the seventh heating zone 507, the eighth heating zone 508, the ninth heating zone 509, the tenth heating zone 510, the eleventh heating zone 511, the twelfth heating zone 512, the thirteenth heating zone 513, and the fourteenth heating zone 514, wind shields 53 are provided in the middle area of the upper oven nozzle 51 and the middle area of the lower oven nozzle 52.
[0045] Example 4: A wind shield 53 is provided in the middle area of the upper oven nozzle 51 of the fifth heating zone 505, the seventh heating zone 507, the ninth heating zone 509, the eleventh heating zone 511 and the thirteenth heating zone 513, and a wind shield 53 is provided in the middle area of the lower oven nozzle 52 of the sixth heating zone 506, the eighth heating zone 508, the tenth heating zone 510 and the twelfth heating zone 512.
[0046] Fifteen test points were selected along the width direction of the lithium battery separators prepared in the control group and Examples 1-4 (taking this example as an example, the width of the lithium battery separator is 4500mm, the cutting width is 900*5, and three points are tested at each of the five cutting stations, for a total of 15 points). The air permeability value of the film at each test point was measured, and the results are summarized in Table 1. The air permeability range of the film (i.e., the difference between the maximum and minimum air permeability values at each test point of the same film) was calculated based on the data in Table 1. The air permeability range values are summarized in Table 2.
[0047] Table 1. Air permeability test data at test points in the control group and each embodiment.
[0048]
[0049] Table 2. Air permeability data for the control group and each embodiment.
[0050]
[0051] Based on the experimental results, we can conclude that:
[0052] Control group: Poor air permeability, reaching 49s / 100ml;
[0053] Examples 1-4: The extremely poor breathability has been somewhat improved;
[0054] Example 4: The best effect was achieved with extremely poor breathability, reaching 24s / 100ml.
[0055] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An oven assembly for preparing lithium battery separators, characterized in that, include: The first track has a preheating zone, a stretching zone, and a shaping zone that are interconnected along its length. The second track is arranged opposite to the first track, and along the length of the second track, it is provided with a preheating zone, a stretching zone and a shaping zone corresponding to the first track; The first chain clamp is slidably connected to the first track, and the first chain clamp is used to hold one end of the lithium battery separator sheet. The second chain clamp is slidably connected to the second track, and the second chain clamp is used to hold the other end of the lithium battery separator sheet. An oven covering the preheating zone, stretching zone, and shaping zone, the oven including a hot air blower, a box body, an upper oven nozzle, and a lower oven nozzle, wherein the middle area of the upper oven nozzle and the lower oven nozzle is provided with a wind shield.
2. The oven assembly for preparing lithium battery separators as described in claim 1, characterized in that, The length of the wind shield is one-third of the total length of the upper oven nozzle, or the length of the wind shield is one-third of the total length of the lower oven nozzle.
3. The oven assembly for preparing lithium battery separators as described in claim 1, characterized in that, The windproof component is a stainless steel sheet or a heat-resistant tape.
4. The oven assembly for preparing lithium battery separators as described in claim 1, characterized in that, Both the first track and the second track are circular tracks.
5. The oven assembly for preparing lithium battery separators as described in claim 1, characterized in that, The oven is provided with multiple baffles spaced along its length, which divide the oven into multiple heating zones.
6. The oven assembly for preparing lithium battery separators as described in claim 5, characterized in that, The preheating zone includes a first heating zone, a second heating zone, a third heating zone, and a fourth heating zone; the stretching zone includes a fifth heating zone, a sixth heating zone, a seventh heating zone, and an eighth heating zone; the shaping zone includes a ninth heating zone, a tenth heating zone, an eleventh heating zone, a twelfth heating zone, a thirteenth heating zone, and a fourteenth heating zone.
7. The oven assembly for preparing lithium battery separators as described in claim 6, characterized in that, The middle area of the nozzles in the upper ovens of the fifth, seventh, ninth, eleventh, and thirteenth heating zones is provided with a wind shield, and the middle area of the nozzles in the lower ovens of the sixth, eighth, tenth, and twelfth heating zones is provided with a wind shield.
8. The oven assembly for preparing lithium battery separators as described in claim 1, characterized in that, In the preheating zone, the distance between the first track and the second track is L1, and in the stretching zone, the distance between the first track and the second track is L2, wherein L2 > L1.