A sleeve film device for cell assembly

Abstract

The application relates to the technical field of batteries and provides a sleeving device for assembling an electric core, which comprises a shaping mechanism for shaping a tubular insulating film so that the opening shape of the insulating film is matched with the cross section shape of the circumferential side wall of a pole group, and the shaped insulating film can move along the axial direction of the insulating film under the external pulling action; a guide tool which comprises an assembling part and a guide part, the assembling part has a first end and a second end opposite to each other, the first end is suitable for assembling with one end of the pole group, the second end is connected with the guide part, and the guide part is tapered in the direction away from the first end; the first end of the assembling part is provided with a slot, one end of the pole group can be inserted into the slot, and an avoiding groove is arranged in the slot and is suitable for accommodating the pole lug of the pole group; when the insulating film moves along the axial direction, the insulating film can be sleeved to the outside of the pole group under the guiding action of the guide part. The application can realize the rapid sleeving of the pole group and improves the sleeving efficiency.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a coating device for battery cell assembly. 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.

[0004] Related technologies use heat shrinking to tightly wrap the insulating film onto the peripheral wall of the electrode assembly, which can improve the problem of insulation film damage and slippage during casing. However, to ensure the uniformity of the insulation film after heat shrinking, a tubular insulating film is required. In production, the tubular insulating film needs to be sleeved onto the electrode assembly, but the opening of the insulating film is relatively small, resulting in low sleeve efficiency in actual production and greatly affecting the production efficiency of the battery cell. Summary of the Invention

[0005] This invention provides a film-coating device for battery cell assembly, which solves the problem of low efficiency in applying tubular insulating films to electrode groups in related technologies.

[0006] This invention provides a coating device for battery cell assembly, comprising:

[0007] A shaping mechanism is used to shape a tubular insulating film so that the opening shape of the insulating film matches the cross-sectional shape of the peripheral sidewall of the electrode assembly. The shaped insulating film can move along the axial direction of the insulating film under external tension.

[0008] The guiding fixture includes an assembly part and a guiding part. The assembly part has a first end and a second end facing away from each other. The first end is adapted to be assembled with one end of an electrode assembly, and the second end is connected to the guiding part. The guiding part is tapered in a direction away from the first end. The first end of the assembly part is provided with a slot, and one end of the electrode assembly can be inserted into the slot. The slot is provided with a clearance groove, which is adapted to receive the electrode tab of the electrode assembly.

[0009] When the insulating film moves along the axial direction, it can be sleeved onto the outside of the electrode assembly under the guidance of the guide portion.

[0010] According to the present invention, a cell assembly coating device is provided, wherein the shaping mechanism includes:

[0011] A fan is used to blow air into the insulating film, causing the insulating film to expand.

[0012] The pressure plate assembly includes a first pressure plate and a second pressure plate that are arranged opposite to each other and spaced apart, the first pressure plate and the second pressure plate being used to press against opposite sides of the expanded insulating film, respectively.

[0013] According to the present invention, a cell assembly coating device is provided, wherein the shaping mechanism further includes:

[0014] The suction cup assembly includes a first suction cup and a second suction cup that are arranged opposite to each other and spaced apart. The first suction cup and the second suction cup are used to adsorb onto opposite sides of the expanded insulating film, and the pressure plate assembly and the suction cup assembly are distributed sequentially along the moving direction of the insulating film.

[0015] According to the present invention, the assembly gap between the insulating film and the assembly part is g1, where 0.2mm≤g1≤10mm.

[0016] According to the present invention, the depth of the slot is d1, 5mm≤d1≤50mm; and / or the assembly gap between the slot and the electrode group is g2, 0.05mm≤g2≤3mm.

[0017] According to the present invention, a cell assembly sleeve device is provided, wherein the depth of the slot is d1, the assembly gap between the slot and the electrode group is g2, and the sleeve device satisfies at least one of the following two conditions: 5mm≤d1≤50mm and 0.05mm≤g2≤3mm.

[0018] According to the present invention, a cell assembly film device is provided, wherein the outer peripheral surface of the assembly part includes a plurality of planes for surrounding the electrode group, and the outer peripheral surface of the guide part includes a plurality of guide surfaces, wherein the plurality of guide surfaces are connected to the plurality of planes in a one-to-one correspondence, and the guide surfaces are inclined toward the guide part relative to the planes they are connected to.

[0019] According to the present invention, in a cell assembly cladding device, the inclination angle of the guide surface relative to the plane connected thereto is α, where 3°≤α≤80°;

[0020] According to the present invention, the dimension of the guide surface in the extension direction of the outer surface of the assembly part is w1, 3mm≤w1≤1000mm;

[0021] According to the present invention, a cell assembly film device is provided, wherein the outer peripheral wall of the electrode group includes a plurality of side surfaces surrounding the electrode group, and the plurality of planes are arranged parallel to the plurality of side surfaces in a one-to-one correspondence, and the height difference between the corresponding plane and the side surface in a direction perpendicular to the plane is h, wherein 0.5mm≤h≤20mm.

[0022] According to the present invention, a cell assembly sleeve device is provided, wherein the sleeve device satisfies at least one of the following two conditions: the roughness of the outer peripheral surface of the guide portion is less than Ra3.2 and at least the assembly portion of the guide tooling is a rubber part.

[0023] The present invention provides a sleeve device for battery cell assembly, which, by setting a shaping mechanism and a guiding fixture, provides a guide portion with a tapered structure at the end of the electrode assembly. During the sleeve operation, the shaping mechanism shapes the tubular insulating film, and the guiding fixture is assembled at the end of the electrode assembly. The insulating film, after being shaped by the shaping mechanism, can move axially along the insulating film under external tension, and then, guided by the guiding portion, is sleeved onto the outside of the electrode assembly, achieving rapid sleeve application and improving sleeve application efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention 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 invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the coating device for battery cell assembly provided by the present invention.

[0026] Figure 2 This is an exploded view of the guide tooling and electrode assembly in the cladding device for battery cell assembly provided by the present invention.

[0027] Figure 3 yes Figure 1 The cross-sectional view of the guide tooling and pole assembly structure at point AA.

[0028] Figure 4 yes Figure 1 A magnified view of point C, indicated by the middle circle.

[0029] Figure 5This is a schematic diagram of the guiding tooling in the casing device for battery cell assembly provided by the present invention.

[0030] Figure 6 yes Figure 1 The cross-sectional view of the guide tooling and pole assembly structure at BB.

[0031] Figure label:

[0032] 11. Shaping mechanism; 111. Pressure plate assembly; 111a. First pressure plate; 111b. Second pressure plate; 112. Suction cup assembly; 112a. First suction cup; 112b. Second suction cup; 12. Guide fixture; 121. Assembly part; 1211. Plane; 122. Guide part; 1221. Guide surface; 123. Slot; 1231. Slot wall; 124. Clearance slot; 3. Insulating film; 4. Electrode group; 41. Electrode ear; 42. Side side; X. Length direction of electrode group; Y. Width direction of electrode group; Z. Thickness direction of electrode group. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly 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 the present invention 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.

[0035] The following is combined Figures 1-6 The present invention describes a coating device for battery cell assembly.

[0036] like Figure 1As shown, the sleeve device for battery cell assembly provided in this embodiment of the invention includes a shaping mechanism 11 and a guiding fixture 12. The shaping mechanism 11 is used to shape the tubular insulating film 3 so that the opening shape of the insulating film 3 matches the cross-sectional shape of the peripheral sidewall of the electrode group 4. The shaped insulating film 3 can move axially along the insulating film 3 under external tension. The guiding fixture 12 includes an assembly part 121 and a guiding part 122. The assembly part 121 has a first end and a second end facing away from each other. The first end is adapted to be assembled with one end of the electrode group 4, and the second end is connected to the guiding part 122. The guiding part 122 is tapered away from the first end of the assembly part 121. When the insulating film 3 moves axially, it can be sleeved onto the outside of the electrode group 4 under the guidance of the guiding part 122.

[0037] The shaped insulating film 3 can move axially under external tension. This can be understood as the shaping mechanism 11 adjusting the shape of the tubular insulating film 3 radially without interfering with its axial movement. In actual production, the insulating film 3 can be pulled from the shaping mechanism 11 onto the electrode assembly 4 by machine or manually to complete the film application. The shaping mechanism 11 can be vertically positioned, with the electrode assembly 4 placed below it, and the insulating film 3 pulled downwards for film application. After film application, the electrode assembly 4 with the insulating film 3 is transferred to a heat-shrinking device for heat shrinking.

[0038] See Figure 2 The assembly part 121 is used for assembly and connection with one end of the electrode group 4 along its length. When the two are assembled and connected, the assembly part 121 and the guide part 122 are distributed along the length direction of the electrode group 4. In actual film application operation, the length direction of the electrode group 4 is usually aligned with the moving direction of the insulating film 3, which is beneficial for smooth film application.

[0039] The guide portion 122 tapers away from the assembly portion 121, meaning its cross-section gradually decreases in the direction away from the assembly portion 121. During the film-coating operation, the guide fixture 12 is first assembled to one end of the electrode assembly 4 via the assembly portion 121, and then the end of the electrode assembly 4 with the guide fixture 12 is oriented towards the forming mechanism 11. Under external tension, the insulating film 3 moves axially toward the electrode assembly 4, sequentially covering the guide portion 122, the assembly portion 121, and the electrode assembly 4. The tapered guide portion 122 allows the guide fixture 12 to slide smoothly into the insulating film 3, thereby enabling the insulating film 3 to be smoothly fitted onto the outside of the electrode assembly 4, achieving efficient film coating.

[0040] The sleeve device for battery cell assembly provided in this embodiment of the invention includes a shaping mechanism 11 and a guiding fixture 12. The guiding fixture 12 is used to assemble with the end of the electrode assembly 4, giving the end of the electrode assembly 4 a tapered guiding portion 122. During the sleeve operation, the shaping mechanism 11 shapes the tubular insulating film 3, and the guiding fixture 12 is assembled at the end of the electrode assembly 4. The insulating film 3, after being shaped by the shaping mechanism 11, can move axially along the insulating film 3 under external pulling force, and then be sleeved onto the outside of the electrode assembly 4 under the guidance of the guiding portion 122, thus achieving rapid sleeve application and improving sleeve application efficiency.

[0041] Optionally, see Figure 1 The shaping mechanism 11 includes a fan (not shown) and a pressure plate assembly 111. The fan blows air into the insulating film 3, causing the insulating film 3 to expand. The pressure plate assembly 111 includes a first pressure plate 111a and a second pressure plate 111b that are opposite to each other and spaced apart. The first pressure plate 111a and the second pressure plate 111b are adapted to press against opposite sides of the expanded insulating film 3, respectively.

[0042] Specifically, a shaping channel is formed between the first pressure plate 111a and the second pressure plate 111b, allowing the insulating film 3 to move axially. During the film application operation, the electrode assembly 4 is located on the exit side of this shaping channel. The shaping channel can be arranged vertically. The expanded insulating film 3 moves from top to bottom under external traction and is shaped as it passes through the first pressure plate 111a and the second pressure plate 111b. During the removal process, it is simultaneously applied onto the electrode assembly 4. The number of pressure plate assemblies 111 can be one or more, and multiple pressure plate assemblies 111 are spaced apart along the moving direction of the insulating film 3. The specific number is determined according to the length of the insulating film 3 and the length of the pressure plate.

[0043] Optionally, the first pressure plate 111a and the second pressure plate 111b can move closer to each other and further apart. During the film application operation, the first pressure plate 111a and the second pressure plate 111b are first moved further apart so that the expanded insulating film 3 can move between the first pressure plate 111a and the second pressure plate 111b. Then, the first pressure plate 111a and the second pressure plate 111b are brought closer to each other to a set distance to shape the insulating film 3.

[0044] It should be noted that this embodiment is not limited to shaping the insulating film 3 by means of a fan and a pressure plate assembly 111. For example, the shaping mechanism 11 includes two support plates arranged opposite each other, which can extend into the interior of the insulating film 3, and the insulating film 3 is shaped by the two support plates moving away from each other.

[0045] Furthermore, the shaping mechanism 11 also includes a suction cup assembly 112. The suction cup assembly 112 includes a first suction cup 112a and a second suction cup 112b that are arranged opposite to each other and spaced apart. The first suction cup 112a and the second suction cup 112b are used to adhere to opposite sides of the expanded insulating film 3, respectively. The pressure plate assembly 111 and the suction cup assembly 112 are distributed sequentially along the moving direction of the insulating film 3.

[0046] Understandably, during the film application operation, the insulating film 3 removed from the pressure plate assembly 111 passes through the suction cup assembly 112, between the first suction cup 112a and the second suction cup 112b, before being fitted onto the electrode assembly 4. By having the first suction cup 112a and the second suction cup 112b hold the opposite sides of the insulating film 3, the opening shape of the insulating film 3 can be kept stable, making it easier to fit onto the electrode assembly 4.

[0047] The first suction cup 112a and the second suction cup 112b can move closer to each other and further apart. During the film application operation, the first suction cup 112a and the second suction cup 112b are first moved further apart so that the insulating film 3 removed from the pressure plate assembly 111 can move smoothly between the first suction cup 112a and the second suction cup 112b. Then, the first suction cup 112a and the second suction cup 112b are brought closer to each other to a set distance to fix the opening shape of the insulating film 3.

[0048] See Figure 4 In some embodiments of the present invention, the assembly gap between the insulating film 3 and the assembly part 121 is g1, where g1 ≥ 0.2 mm. If g1 is too small, it is easy to cause difficulty in fitting the guide fixture 12. Taking the cross-section of the electrode group 4 as a rectangle as an example, the inner width of the rectangular opening of the shaped insulating film 3 is M1, and the inner length is L1; the width of the assembly part 121 is M2, and the length is L2, where M1-M2 ≥ 0.4 mm, and L1-L2 ≥ 0.4 mm.

[0049] Furthermore, g1 ≤ 10mm. If g1 is too large, it indicates that the perimeter of the insulating film 3 is too long, which can easily lead to poor uniformity of the thickness of the insulating film 3 after heat shrinking, and the wrapping is not tight, making it easy to slip when inserted into the shell. Optionally, the value of g1 can be 0.4mm, 0.8mm, 1.2mm, 2mm, 5mm or 8mm, etc.

[0050] See Figure 4 In some embodiments of the present invention, the first end of the assembly part 121 is provided with a slot 123, and one end of the pole group 4 can be inserted into the slot 123. The assembly part 121 and the pole group 4 can be conveniently assembled through plug-in cooperation.

[0051] Furthermore, the depth of slot 123 is d1, where 5mm ≤ d1 ≤ 50mm. If the insertion depth is too shallow, the connection will be weak, and the guide fixture 12 may easily fall off during operation; if the insertion depth is too deep, it will increase the volume and weight of the guide fixture 12, increasing material costs and causing inconvenience during operation. Optionally, d1 can be 5mm, 10mm, 20mm, 40mm, or 50mm, etc.

[0052] In some embodiments of the present invention, the assembly gap between the slot 123 and the pole group 4 is g2, where 0.05mm ≤ g2 ≤ 3mm. If g2 is too small, it is easy to cause difficulty in insertion; if g2 is too large, it is easy to cause insecure insertion, and the guide fixture 12 is easy to slip off the pole group 4. Taking the cross-section of the pole group 4 as a rectangle as an example, the dimension of the slot 123 in the thickness direction of the pole group 4 is M3, and the dimension of the slot 123 in the width direction of the pole group 4 is L3; the thickness of the pole group 4 is M4, and the width of the pole group 4 is L4, where 0.1mm ≤ M3 - M4 ≤ 6mm, and 0.1mm ≤ L3 - L4 ≤ 6mm.

[0053] In some embodiments of the present invention, 5mm≤d1≤50mm and 0.05mm≤g2≤3mm can ensure reliable and convenient connection between the guide fixture 12 and the pole group 4 without increasing the volume and weight of the guide fixture 12.

[0054] like Figures 3-6 As shown, in some embodiments of the present invention, the slot 123 is provided with a relief groove 124, which is adapted to accommodate the tab 41 of the electrode assembly 4. Specifically, the electrode assembly 4 includes a body and a tab 41. The body has an end face at one end in the length direction of the electrode assembly 4, and the tab 41 protrudes from the end face. The slot 123 is used to insert into the body of the electrode assembly 4, and the relief groove 124 in the slot 123 can accommodate the tab 41 to prevent the guide tool 12 from damaging the tab 41.

[0055] The clearance groove 124 is recessed at least at the bottom of the slot 123. When the assembly part 121 is assembled with the pole assembly 4, the bottom of the slot 123 limits the insertion depth of the pole assembly 4, thus defining a cavity between the end face of the body and the bottom of the clearance groove 124 that can accommodate the tab 41. The width direction of the tab 41 is consistent with the width direction of the pole assembly 4. Generally, the width of the tab 41 is smaller than the width of the pole assembly 4. Therefore, the size of the clearance groove 124 is smaller than the size of the slot 123 in the width direction of the pole assembly 4.

[0056] Furthermore, in the thickness direction of pole group 4, the dimension of the clearance groove 124 is larger than the dimension of the slot 123. See also Figure 5 and Figure 6The slot 123 has two groove walls 1231 that are arranged opposite each other in the thickness direction of the pole group 4. The clearance groove 124 is recessed in the bottom of the slot 123 and the two groove walls 1231. This increases the clearance space of the clearance groove 124 in the thickness direction of the pole group 4, so as to avoid the pole tab 41 from scraping against the assembly part 121 during the assembly process of the guide fixture 12 and the pole group 4.

[0057] See Figure 2 and Figure 4 In some embodiments of the present invention, the outer peripheral surface of the assembly portion 121 includes a plurality of planes 1211 for surrounding the pole group 4, and the outer peripheral surface of the guide portion 122 includes a plurality of guide surfaces 1221. The plurality of guide surfaces 1221 are connected to the plurality of planes 1211 in a one-to-one correspondence, and the guide surfaces 1221 are inclined toward the guide portion 122 relative to the planes 1211 they are connected to.

[0058] After the assembly part 121 is assembled with the electrode group 4, multiple planes 1211 of the assembly part 121 surround the outer side of the electrode group 4, allowing the insulating film 3 to slide to the outer side of the electrode group 4 through the outer peripheral surface of the assembly part 121. Optionally, the outer peripheral surface of the assembly part 121 is configured to conform to the peripheral sidewall of the electrode group 4, and the peripheral sidewall of the electrode group 4 includes multiple side surfaces 42 surrounding the electrode group 4. The multiple planes 1211 of the assembly part 121 are arranged parallel to the multiple side surfaces 42 of the electrode group 4 in a one-to-one correspondence. Each guide surface 1221 of the guide part 122 is inclined towards the guide part 122 relative to the plane 1211 connected to it, causing the guide part 122 to gradually taper away from the assembly part 121.

[0059] For example, the outer wall of the rectangular pole group 4 includes four side surfaces 42 surrounding the pole group 4. The outer peripheral surface of the mounting part 121 includes four planes 1211 surrounding the pole group 4, and these four planes 1211 are arranged parallel to each of the four side surfaces 42 of the pole group 4. The outer peripheral surface of the guide part 122 includes four guide surfaces 1221, and these four guide surfaces 1221 are connected to the four planes 1211 in a corresponding manner.

[0060] It should be noted that the guide surface 1221 is not limited to the inclined surface described in the above embodiments. For example, the guide surface 1221 can also be an arc-shaped surface that protrudes in a direction away from the guide portion 122.

[0061] See Figure 4 In some embodiments of the present invention, the tilt angle of the guide surface 1221 relative to the plane 1211 connected thereto is α, where 3° ≤ α ≤ 80°. If the tilt angle is too small, it is not convenient for the guide fixture 12 to be quickly fitted into the insulating film 3; if the tilt angle is too large, the insulating film 3 is prone to hitting the wall, which is not conducive to the smooth sliding of the insulating film 3 towards the pole group 4. Optionally, α can be 10°, 40°, 45° or 70°, etc.

[0062] See Figure 4 In some embodiments of the present invention, the dimension of the guide surface 1221 in the extension direction of the outer surface of the assembly part 121 is w1, where 3mm ≤ w1 ≤ 1000mm. Wherein, when the assembly part 121 is assembled and connected to one end of the electrode group 4 in the length direction, the extension direction of the outer surface of the assembly part 121 is the length direction of the electrode group 4. If the dimension of the guide surface 1221 in this direction is too small, the guiding area will be too small, failing to effectively guide the deformation of the insulating film 3 nozzle and its sliding towards the electrode group 4; if the dimension of the guide surface 1221 in this direction is too large, it will additionally increase the volume and weight of the guiding fixture 12, increasing material costs and causing inconvenience in operation. Optionally, w1 can be 100mm, 300mm, 500mm, or 800mm, etc.

[0063] See Figure 4 In some embodiments of the present invention, the outer peripheral wall of the electrode assembly 4 includes a plurality of side surfaces 42 surrounding the electrode assembly 4. A plurality of planes 1211 of the assembly part 121 are arranged parallel to the plurality of side surfaces 42 of the electrode assembly 4 in a one-to-one correspondence. The height difference between the corresponding plane 1211 and the side surface 42 in the direction perpendicular to the plane 1211 is h, where 0.5mm ≤ h ≤ 20mm. If h is too small, the outer peripheral wall of the electrode assembly 4 will not be smooth enough, making it easy for the insulating film 3 to be stuck when sliding outside the electrode assembly 4, resulting in difficulty in fitting it in. If h is too large, it means that the perimeter of the insulating film 3 is also too large, easily causing poor uniformity of the thickness of the heat-shrinked insulating film 3, and the wrapping will not be tight, making it easy to slip when inserted into the shell. Optionally, h can be 1mm, 5mm, 10mm, or 15mm, etc.

[0064] Furthermore, the roughness of the outer peripheral surface of the guide part 122 is less than Ra3.2. If the roughness is too large, it will easily lead to coating failure or poor coating under production line cycle time, causing equipment alarms.

[0065] Optionally, at least the assembly part 121 of the guide fixture 12 may be a rubber part. For example, the assembly part 121 may be made of soft rubber materials such as fluororubber or EPDM. The rubber assembly part 121 can flexibly contact the electrode assembly 4, preventing scratches during assembly of the electrode assembly 4. The guide part 122 may also be a rubber part, and the guide part 122 and the assembly part 121 may be integrally molded. Alternatively, the guide part 122 may be a hard plastic part, which makes it easier to obtain a smoother guide surface 1221.

[0066] The value ranges of α, g1, and h defined in the above embodiments were tested through the following experimental procedure, and the experimental data shown in Table 1 were obtained. Experimental procedure: Using guide fixtures 12 corresponding to different values ​​of α, g1, and h, multiple electrode groups 4 were subjected to a film-fitting operation. The insulating film 3 was moved axially by a traction mechanism for film fitting. A force sensor was installed in the traction mechanism to detect the traction force during film fitting. If the detected traction force was greater than 50N, it indicated that the insulating film 3 was difficult to fit, and the equipment alarmed. After film fitting, the insulating film 3 was heat-shrinked, and the thickness uniformity of the heat-shrinked insulating film 3 was measured. The heat-shrinked electrode group 4 was then inserted into the housing to test the difficulty of insertion.

[0067] Table 1: Sheathing operation tests of guide fixtures for different α, g1, and h values

[0068]

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and these 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 the present invention.

Claims

1. A casing film device for an electric cell assembly, characterized by comprising: include: A shaping mechanism is used to shape a tubular insulating film so that the opening shape of the insulating film matches the cross-sectional shape of the peripheral sidewall of the electrode assembly. The shaped insulating film can move axially under external tension. The shaping mechanism includes a fan, a pressure plate assembly, and a suction cup assembly. The fan blows air into the insulating film, causing it to expand. The pressure plate assembly includes a first pressure plate and a second pressure plate that are positioned opposite each other and spaced apart. The first pressure plate and the second pressure plate are respectively pressed onto opposite sides of the expanded insulating film. The suction cup assembly includes a first suction cup and a second suction cup that are positioned opposite each other and spaced apart. The first suction cup and the second suction cup are respectively adsorbed onto opposite sides of the expanded insulating film. The pressure plate assembly and the suction cup assembly are distributed sequentially along the direction of movement of the insulating film. A guiding fixture includes an assembly part and a guiding part. The assembly part has a first end and a second end facing away from each other. The first end is adapted to be assembled with one end of an electrode assembly, and the second end is connected to the guiding part. The guiding part is tapered in a direction away from the first end. The first end of the assembly part is provided with a slot, into which one end of the electrode assembly can be inserted. The slot is provided with a clearance groove adapted to receive the electrode tabs of the electrode assembly. The outer peripheral surface of the assembly part includes a plurality of planes for surrounding the electrode assembly. The outer peripheral surface of the guiding part includes a plurality of guiding surfaces, which are connected one-to-one with the plurality of planes. The guiding surfaces are inclined toward the guiding part relative to the planes they are connected to. When the insulating film moves along the axial direction, it can be sleeved onto the outside of the electrode assembly under the guidance of the guide portion.

2. The envelope apparatus for electric cell assembly of claim 1, wherein, The assembly gap between the insulating film and the assembly part is g1, where 0.2mm≤g1≤10mm.

3. The envelope apparatus for electric cell assembly of claim 1, wherein, The depth of the slot is d1, the assembly gap between the slot and the pole group is g2, and the diaphragm device satisfies at least one of the following two conditions: 5mm≤d1≤50mm and 0.05mm≤g2≤3mm.

4. The jacketing apparatus for electric cell assembly of claim 1, wherein, The angle of inclination of the guide surface relative to the plane connected to it is α, where 3°≤α≤80°.

5. The jacketing apparatus for electric cell assembly of claim 1, wherein, The dimension of the guide surface in the extension direction of the outer surface of the assembly part is w1, where 3mm≤w1≤1000mm.

6. The envelope apparatus for electric cell assembly of claim 1, wherein, The outer peripheral wall of the electrode group includes multiple side surfaces surrounding the electrode group. The multiple planes are arranged parallel to the multiple side surfaces in a one-to-one correspondence. The height difference between the corresponding plane and the side surface in the direction perpendicular to the plane is h, where 0.5mm≤h≤20mm.

7. The envelope apparatus for electric cell assembly of claim 1, wherein, The film-coating device satisfies at least one of the following conditions: the roughness of the outer peripheral surface of the guide portion is less than Ra3.2, and at least the assembly portion of the guide tooling is a rubber part.

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