Battery cell insulation film heat shrinking device

Abstract

The utility model relates to battery technology field provides a kind of battery cell insulating film heat shrink device, comprising: positioning tool, is equipped with the positioning part for supporting and positioning pole group;Oven, for heating the pole group located on the positioning tool, make the insulating film heat shrink tightly on the circumferential side wall of the pole group;Conveying mechanism, the positioning tool is adapted to be set on the moving part of the conveying mechanism, the moving part is along its moving direction and is penetrated in the oven, for driving the pole group to pass through the oven.The battery cell insulating film heat shrink device can be used to heat the pole group wrapped with insulating film, so that the insulating film heat shrink tightly on the pole group, to avoid the insulating film to produce wrinkle and bulge, thereby prevent the insulating film from breaking and slipping during entering shell, improve the battery cell assembly yield, improve the safety performance of battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a heat shrinking device for battery cell insulating film. Background Technology

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage, leading to increasingly stringent requirements for their performance and safety. The assembly process for blade lithium batteries involves first covering the outside of the electrode assembly with an insulating film, then inserting the electrode assembly into the casing, and finally sealing the cover plate to the casing to encapsulate the electrode assembly within the casing, forming a battery cell. The battery cell achieves charging and discharging through positive and negative terminals led out from the positive and negative cover plates at both ends. The insulating film serves to prevent short circuits between the electrode assembly and the casing.

[0003] In the prior art, when the insulating film wraps the electrode assembly and is inserted into the housing, the insulating film at the end of the electrode assembly is prone to large wrinkles, which can cause the insulating film to be scratched. During the insertion process, the bulging area of ​​the insulating film is also easily scratched by the opening of the housing, and the insulating film is prone to slippage, resulting in an insufficient gap between the insulating film and the cover plate, which can easily cause explosion points when the cover plate is welded to the housing. Utility Model Content

[0004] This invention provides a heat-shrinking device for battery cell insulating film, which solves the problem in the prior art that the insulating film of lithium-ion power batteries is prone to damage and slippage when the electrode assembly is installed in the casing.

[0005] This utility model provides a heat shrinking device for battery cell insulating film, comprising: The positioning fixture is equipped with a positioning part for supporting and positioning the pole assembly; An oven is used to heat the electrode assembly located on the positioning fixture, so that the insulating film is heat-shrinkably wrapped around the peripheral wall of the electrode assembly; A conveying mechanism, wherein the positioning fixture is adapted to be disposed on the moving part of the conveying mechanism, the moving part passing through the oven along its moving direction, for driving the electrode assembly through the oven.

[0006] According to the present invention, a heat-shrinking device for battery cell insulating film is provided, wherein the positioning fixture includes: A support frame is adapted to be placed on the movable part; At least one claw assembly, the claw assembly including a plurality of claws spaced apart along a direction perpendicular to the moving direction, the claws being fixed to the support frame and having slots, the slots of the plurality of claws in each claw assembly forming a positioning part, the slots being adapted to engage with the pole group; Wherein, when the electrode group is positioned on the positioning part, the thickness direction of the electrode group is consistent with the moving direction; and the plurality of the claw assemblies are arranged at intervals along the moving direction.

[0007] According to the present invention, the dimensions of the claws in the arrangement direction of the plurality of claws are w2, 3mm≤w2≤100mm; and / or, the distance between two adjacent claws in the claw assembly is w3, w3≥5mm.

[0008] According to the present invention, a heat shrinking device for battery cell insulation film is provided, wherein the claw includes two opposing baffles, and the slot is formed between the two baffles; the baffle has an inner wall surface facing the slot, and the inner wall surface is provided with a guide surface connected to the slot opening of the slot, and the guide surface is inclined from the slot opening toward the other baffle.

[0009] According to the present invention, the guide surface has a dimension a in the width direction of the slot, where 2mm≤a≤20mm; and a dimension b in the depth direction of the slot, where 1≤b / a≤3.

[0010] According to the present invention, a heat shrinking device for battery cell insulating film is provided, wherein the thickness of the baffle is t2, and 3mm≤t2≤50mm.

[0011] According to the present invention, a heat shrinking device for insulating film of battery cell is provided, wherein the inner wall surface is further provided with a positioning surface connected between the guide surface and the bottom of the slot, the positioning surfaces of the two baffles are adapted to clamp the two sides of the electrode assembly, and the dimension of the positioning surface in the depth direction of the slot is d2, 3mm≤d2≤100mm.

[0012] According to the present invention, a heat shrinking device for battery cell insulating film is provided, wherein the distance between the two positioning surfaces that are close to each other between two adjacent claw assemblies is w4, and 5mm≤w4≤1000mm.

[0013] According to the present invention, a heat shrinking device for battery cell insulating film is provided, wherein the claw further includes a base plate, the base plate having a bottom surface and a top surface opposite to each other in its thickness direction, the bottom surface being connected to the support frame, and the two baffles being fixed to the top surface, the thickness of the base plate being t3, where 5mm≤t3≤200mm.

[0014] According to the present invention, a heat shrinking device for battery cell insulation film is provided, wherein the oven is provided with a fan and a heating component, and the heating component is arranged near the air inlet side or air outlet side of the fan.

[0015] The present invention provides a cell insulation film heat shrinking device, which can be used to heat the electrode assembly wrapped with insulation film, so that the insulation film is heat-shrinked and tightly wrapped to the electrode assembly. This can avoid wrinkles and bulges in the insulation film, thereby preventing damage and slippage of the insulation film during the casing process, improving the cell assembly yield and the battery safety performance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the heat shrinking device for battery cell insulating film provided by this utility model.

[0018] Figure 2 yes Figure 1 A schematic diagram of the heat-shrinkable device for the battery cell insulation film from another perspective.

[0019] Figure 3 This is a schematic diagram of the positioning fixture in the heat shrinking device for battery cell insulating film provided by this utility model.

[0020] Figure 4 yes Figure 3 A magnified view of point D, indicated by the middle circle.

[0021] Figure label: 21. Oven; 211. Heating channel; 22. Positioning fixture; 221. Support frame; 222. Claw; 222a. Baffle; 222b. Base plate; 2221. Slot; 2222. Guide surface; 2223. Positioning surface; 23. Moving part; 3. Insulating film; 4. Electrode assembly. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] In the description of the embodiments of this utility model, it should be noted that, unless otherwise expressly specified and limited, the terms "first" and "second" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0024] The following is combined with Figures 1-4 This invention describes a heat-shrinkable device for battery cell insulating film.

[0025] like Figure 1 As shown, the heat-shrinkable battery cell insulating film device provided in this embodiment includes a positioning fixture 22, an oven 21, and a conveying mechanism. The positioning fixture 22 is provided with a positioning part for supporting and positioning the electrode assembly 4. The oven 21 heats the electrode assembly 4 located on the positioning fixture 22, causing the insulating film 3 to be heat-shrink tightly wrapped around the peripheral sidewall of the electrode assembly 4. The positioning fixture 22 is adapted to be mounted on the moving part 23 of the conveying mechanism, which penetrates through the oven 21 along its moving direction, for driving the electrode assembly 4 through the oven 21.

[0026] During the production process, after the insulating film 3 is applied by the film-coating device, the electrode assembly 4 covered with the insulating film 3 is transferred to the positioning fixture 22. The positioning fixture 22 supports and positions the electrode assembly 4. Then, the positioning fixture 22 and the electrode assembly 4 are transferred to the oven 21 for heating, causing the insulating film 3 to shrink. After the insulating film 3 has been shrunk, the electrode assembly 4 is ready for the housing process.

[0027] The oven 21 is provided with heating channels 211 extending through both ends. The moving part 23 of the conveying mechanism passes through the heating channels 211 to drive the positioning fixture 22 and the electrode assembly 4 located thereon to pass through the oven 21 synchronously. During the passage through the oven 21, the electrode assembly 4 and the insulating film 3 are heated, causing the insulating film 3 to shrink and tightly wrap around the electrode assembly 4. The moving part 23 can be a conveyor belt or a conveyor roller, etc.

[0028] The heat shrinking device for the insulating film of the battery cell provided in this embodiment can be used to heat the electrode group 4 wrapped with the insulating film 3, so that the insulating film 3 is heat-shrinked and tightly wrapped with the electrode group 4. This can prevent the insulating film 3 from wrinkling and bulging, thereby preventing the insulating film 3 from being damaged and slipping during the casing process, improving the battery cell assembly yield and improving the battery safety performance.

[0029] Optionally, the oven 21 is equipped with a fan and a heating element, with the heating element positioned near the air inlet or outlet of the fan. Optionally, the heating element is a resistance wire or a heating lamp, etc. The fan blows the air heated by the heating element onto the electrode group 4, causing the insulating film 3 to be uniformly heated and rapidly contracted under the action of the hot airflow.

[0030] like Figure 1 and Figure 4 As shown, in some embodiments of this utility model, the positioning fixture 22 includes a support frame 221 and at least one claw assembly. The support frame 221 is adapted to be placed on the moving part 23. Optionally, the support frame 221 is a plate-shaped piece, allowing it to be placed stably on the moving part 23 of the conveying mechanism. The claw assembly includes a plurality of claws 222 spaced apart along the moving direction perpendicular to the moving part 23. The claws 222 are fixed to the support frame 221 and are provided with slots 2221. The slots 2221 of the plurality of claws 222 in each claw assembly form a positioning part. The slots 2221 are adapted to engage with the pole group 4. Wherein, when the pole group 4 is positioned in the positioning part, the thickness direction of the pole group 4 is consistent with the moving direction. When there are multiple claw assemblies, the multiple claw assemblies are spaced apart along the moving direction of the moving part 23.

[0031] Understandably, multiple jaws 222 of a jaw assembly engage with a pole group 4 via slots 2221 to support and position the pole group 4. Each jaw assembly has at least two jaws 222. By forming multi-point support for the pole group 4 through multiple jaws 222, the contact area between the positioning fixture 22 and the pole group 4 can be reduced, thus avoiding the impact of the positioning fixture 22 on the heat shrinkage effect of the pole group 4.

[0032] This claw assembly is suitable for supporting and positioning the rectangular pole group 4. The length dimension of the rectangular pole group 4 is greater than its width dimension, and its width dimension is greater than its thickness dimension. The pole lugs are located at the ends of the pole group 4 along its length.

[0033] In this embodiment, by arranging multiple claws 222 of the claw assembly along a direction perpendicular to the moving part 23, when positioning the electrode assembly 4, one end of the electrode assembly 4 in the width direction, i.e., one side in the length direction, is engaged with the engagement assembly. This avoids interference between the claws 222 and the electrode tabs, as well as the detachment of the insulating film 3. It also improves the stability of the electrode assembly 4 support and reduces the height of the oven 21. Furthermore, it aligns the thickness direction of the electrode assembly 4 with the moving direction of the moving part 23, allowing the electrode assembly 4 to enter the oven 21 along its thickness. Because the electrode assembly 4 is relatively thin, it enters the oven 21 along its thickness direction, so the moving part 23 does not need to move too fast. This allows the entire electrode assembly 4 to quickly enter the oven 21, which facilitates uniform shrinkage of the insulating film 3. Under the premise of meeting the thermal reaction time requirements, the volume of the oven 21 can be reduced, saving space. If the length or width direction of the electrode assembly 4 is aligned with the moving direction of the moving part 23, the portion that enters first will shrink first, and the portion that enters later will shrink later, resulting in uneven shrinkage and wrinkling of the insulating film 3, which will affect the subsequent insertion of the electrode assembly 4 into the shell.

[0034] like Figure 1 and Figure 3 As shown, when multiple claw assemblies are provided, the multiple claw assemblies are arranged at intervals along the moving direction of the moving part 23, so that the multiple electrode groups 4 are arranged along the moving direction of the moving part 23, and the moving part 23 drives the multiple electrode groups 4 to enter the oven 21 in sequence along the thickness direction.

[0035] Optionally, the claw 222 can be made of metal, such as aluminum, copper, or stainless steel, or of hard rubber that is heat-resistant, such as EPDM or fluororubber. Optionally, the support frame 221 and the claw 222 are integrally formed.

[0036] like Figure 2 As shown, in some embodiments of this utility model, the dimension of the claw 222 in the arrangement direction of multiple claws 222 is w2, where 3mm ≤ w2 ≤ 100mm. If w2 is too small, the claw 222 may easily damage the electrode group 4, causing a short circuit in the internal electrode sheet of the electrode group 4; if w2 is too large, it will increase the contact area between the claw 222 and the insulating film 3, affecting the thermal shrinkage effect at the contact position between the claw 222 and the insulating film 3, resulting in obvious wrinkling, and will also increase the volume of the claw 222, thereby additionally increasing the weight and material cost of the positioning fixture 22. The specific value of w2 can be determined according to the number of claws 222 and the size of the electrode group 4.

[0037] like Figure 2 As shown, in some embodiments of this utility model, the distance between two adjacent claws 222 in the claw assembly is w3, where w3 ≥ 5mm. If w3 is too small, that is, the distribution density of the claws 222 is too large, the insulating film 3 between two adjacent claws 222 is prone to wrinkling during heat shrinkage. The number of claws 222 is specifically determined according to the distance between the claws 222, with the goal of stably supporting the electrode group 4.

[0038] In some embodiments, 3mm≤w2≤100mm and w3≥5mm can effectively avoid the impact of the snap-fit ​​assembly on the thermal shrinkage of the insulating film 3.

[0039] like Figure 4 As shown, in some embodiments of this utility model, the claw 222 includes two opposing baffles 222a, and a slot 2221 is formed between the two baffles 222a. Each baffle 222a has an inner wall surface facing the slot 2221, and the inner wall surface is provided with a guide surface 2222 connected to the opening of the slot 2221. The guide surface 2222 is inclined from the opening towards the other baffle 222a. It can be understood that the guide surface 2222 is provided on the side of each baffle 222a that is close to the other, making the width of the opening of the slot 2221 greater than the width of the bottom. When the claw 222 and the electrode assembly 4 are engaged, the two guide surfaces 2222 guide the insertion of the electrode assembly 4, facilitating rapid engagement and positioning of the electrode assembly 4.

[0040] See Figure 4 In some embodiments of this utility model, the dimension of the guide surface 2222 in the width direction of the slot 2221 is 'a', where 2mm ≤ a ≤ 20mm. The dimension of the guide surface 2222 in the depth direction of the slot 2221 is 'b', where 1 ≤ b / a ≤ 3, i.e., 2mm ≤ b ≤ 60mm. If 'a' is too small, the guiding effect of the guide surface 2222 is not obvious; if 'a' is too large, the thickness of the baffle 222a will be too thick, increasing the weight and material cost of the positioning fixture 22. The ratio of dimension b to dimension a is between 1 and 3, facilitating the insertion and fixing of the pole assembly 4. If the ratio is too small, insertion is difficult; if the ratio is too large, the height of the claw 222 will be too high, also increasing the weight and material cost of the positioning fixture 22.

[0041] See Figure 4 In some embodiments of this utility model, the thickness of the baffle 222a is t2, where 3mm≤t2≤50mm. If t2 is too small, the strength of the chuck 222 will be insufficient and it will be easy to deform; if t2 is too large, it will increase the weight and material cost of the positioning fixture 22.

[0042] In some embodiments of this utility model, the inner wall surface is further provided with a positioning surface 2223 connecting the guide surface 2222 and the bottom of the slot 2221. The positioning surfaces 2223 of the two baffles 222a are suitable for clamping on both sides of the pole group 4. The dimension of the positioning surface 2223 in the depth direction of the slot 2221 is d2, where 3mm≤d2≤100mm.

[0043] Understandably, the claw 222 is positioned with the slot facing upwards, and the positioning surface 2223 is positioned vertically. The positioning surface 2223 connects the bottom of the slot 2221 and the guide surface 2222, while the guide surface 2222 is inclined away from the positioning surface 2223 and away from the slot 2221. The electrode assembly 4 is guided by the guide surface 2222 to the space between the two positioning surfaces 2223, where it is clamped and fixed to prevent it from tipping over.

[0044] The dimension of the positioning surface 2223 in the depth direction of the slot 2221 determines the clamping height of the claw 222 on the pole group 4. If d2 is too small, the pole group 4 will not be firmly fixed and will easily tip over; if d2 is too large, the contact area between the claw and the insulating film 3 will be too large, resulting in poor shrinkage effect of the insulating film 3 at the claw, obvious wrinkling, and additional increase in the weight and material cost of the positioning fixture 22.

[0045] See Figure 3 In some embodiments of this utility model, the distance between the two adjacent positioning surfaces 2223 of two adjacent claw assemblies is w4, where 5mm ≤ w4 ≤ 1000mm. This distance between the two adjacent positioning surfaces 2223 of two adjacent claw assemblies determines the distance between two adjacent pole groups 4. If w4 is too small, it will affect the uniform heating of the adjacent surfaces of the pole group 4, leading to wrinkling after shrinkage and unevenness of the insulating film 3. If w4 is too large, it wastes space and affects production efficiency.

[0046] like Figure 4 As shown, in some embodiments of this utility model, the claw 222 further includes a base plate 222b, which has a bottom surface and a top surface facing away from each other in its thickness direction. The bottom surface is connected to the support frame 221, and two baffles 222a are fixed to the top surface. The thickness of the base plate 222b is t3, where 5mm ≤ t3 ≤ 200mm.

[0047] The base plate 222b and two baffles 222a form a slot 2221, with the top surface of the base plate 222b forming the bottom of the slot 2221. The thickness t3 of the base plate 222b of the claw 222 determines the gap g3 between the bottom of the positioning pole group 4 and the support frame 221. (See [reference]) Figure 2 If t3 is too small, the gap between the electrode group 4 and the support frame 221 will be too small, affecting the uniform heating of the narrow surface at the bottom of the electrode group 4, causing the insulating film 3 to wrinkle after shrinkage and resulting in an uneven narrow surface. If t3 is too large, it will waste space and make the support frame 221 too bulky.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A heat-shrinking device for battery cell insulating film, characterized in that, include: The positioning fixture is equipped with a positioning part for supporting and positioning the pole assembly; An oven is used to heat the electrode assembly located on the positioning fixture, so that the insulating film is heat-shrinkably wrapped around the peripheral wall of the electrode assembly; A conveying mechanism, wherein the positioning fixture is adapted to be disposed on the moving part of the conveying mechanism, the moving part passing through the oven along its moving direction, for driving the electrode assembly through the oven.

2. The heat-shrinking device for battery cell insulating film according to claim 1, characterized in that, The positioning fixture includes: A support frame is adapted to be placed on the movable part; At least one claw assembly, the claw assembly including a plurality of claws spaced apart along a direction perpendicular to the moving direction, the claws being fixed to the support frame and having slots, the slots of the plurality of claws in each claw assembly forming a positioning part, the slots being adapted to engage with the pole group; Wherein, when the electrode group is positioned on the positioning part, the thickness direction of the electrode group is consistent with the moving direction; and the plurality of the claw assemblies are arranged at intervals along the moving direction.

3. The cell insulation film heat shrinking device according to claim 2, characterized in that, The dimensions of the jaws in the arrangement direction of the multiple jaws are w2, 3mm≤w2≤100mm; and / or, the distance between two adjacent jaws in the jaw assembly is w3, w3≥5mm.

4. The cell insulation film heat shrinking device according to claim 2, characterized in that, The claw includes two opposing baffles, and the slot is formed between the two baffles; the baffle has an inner wall surface facing the slot, and the inner wall surface is provided with a guide surface connected to the slot opening, and the guide surface is inclined from the slot opening toward the other baffle.

5. The cell insulation film heat shrinking device according to claim 4, characterized in that, The guide surface has a dimension 'a' in the width direction of the slot, where 2mm ≤ a ≤ 20mm; and a dimension 'b' in the depth direction of the slot, where 1 ≤ b / a ≤ 3.

6. The cell insulation film heat shrinking device according to claim 4, characterized in that, The thickness of the baffle is t2, where 3mm ≤ t2 ≤ 50mm.

7. The cell insulation film heat shrinking device according to claim 4, characterized in that, The inner wall surface is also provided with a positioning surface connecting the guide surface and the bottom of the slot. The positioning surfaces of the two baffles are adapted to clamp the two sides of the pole assembly. The dimension of the positioning surface in the depth direction of the slot is d2, 3mm≤d2≤100mm.

8. The cell insulation film heat shrinking device according to claim 7, characterized in that, The distance between the two positioning surfaces that are close to each other between two adjacent claw assemblies is w4, where 5mm ≤ w4 ≤ 1000mm.

9. The cell insulation film heat shrinking device according to claim 4, characterized in that, The claw also includes a base plate having a bottom surface and a top surface facing away from each other in its thickness direction. The bottom surface is connected to the support frame, and the two baffles are fixed to the top surface. The thickness of the base plate is t3, where 5mm ≤ t3 ≤ 200mm.

10. The cell insulation film heat shrinking device according to claim 1, characterized in that, The oven is equipped with a fan and a heating element, with the heating element located near the air inlet or outlet side of the fan.

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