A heat sealing apparatus
By designing a heat-sealing device with stepped end caps and limiting components, the problem of controlling the cell encapsulation thickness was solved, ensuring sealing effect and insulation performance, and reducing maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WANXIANG 123 CO LTD
- Filing Date
- 2025-07-31
- Publication Date
- 2026-08-04
AI Technical Summary
Existing cell packaging equipment cannot effectively control the packaging thickness, resulting in low packaging strength or uneven packaging, which can easily lead to problems such as leakage and poor insulation, especially at the tabs where control is difficult.
A heat sealing device is used, with the end cap designed in a stepped shape, including a stepped structure and a limiting member. The top and bottom of the step form the first and second heat sealing zones, respectively. The limiting member is used to limit the sealing width at the tab and to prevent the aluminum-plastic film from overheating and melting through a non-thermal conductive component, thus ensuring the sealing effect.
This achieves a reliable seal at the tabs, preventing the formation of adhesive particles and cracks, improving the insulation performance of the battery cell, and reducing maintenance costs.
Smart Images
Figure CN224588634U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat sealing equipment, and in particular to a heat sealing device. Background Technology
[0002] Battery cells are widely used and indispensable in modern life and production. They power various devices and systems, driving technological innovation and the development of sustainable energy. A typical battery cell consists of the cell itself for energy storage and an aluminum-plastic film that protects and encapsulates the cell. Between the aluminum-plastic films lies a PP layer (polypropylene polymer), located on the inner layer of the aluminum-plastic film closest to the cell. This PP layer prevents direct contact between the electrolyte and the aluminum layer of the aluminum-plastic film. It also melts at high temperatures and has adhesive properties. The two aluminum-plastic films are melted and bonded together under a heat-sealing head, thus achieving the encapsulation of the battery cell.
[0003] The current packaging method for soft-pack battery cells involves placing the bare cell between two layers of aluminum-plastic film with recessed positioning. After aligning the aluminum-plastic film, a heating head is used to simultaneously apply pressure and heat the film from both top and bottom. The PP layer of the aluminum-plastic film melts and bonds together under the heat of the heating head. After the heating head is removed, the PP layer cools and solidifies, thus completing the cell packaging. The heating head is a flat and smooth metal structure, and the thickness of the aluminum-plastic film after sealing is uniform.
[0004] However, the main problem with this packaging method lies in controlling the packaging thickness. If the packaging thickness is too thick, the bonding between the PP layers is insufficient, resulting in low packaging strength and an inability to guarantee that the cell will not leak throughout its entire lifespan. If the packaging thickness is too thin, severe extrusion of the PP layer will form small droplet-like adhesive particles at the sealing edge. Under external force, these particles are prone to cracking, allowing the electrolyte to directly contact the aluminum layer through the cracks, leading to poor insulation of the cell. Especially at the top seal, the bonding between the PP layer of the aluminum-plastic film and the tab adhesive, as well as the filling of pores, are more complex and difficult to control, making leakage or insulation problems more likely. Therefore, improving existing packaging equipment to enable simpler control of packaging thickness is an urgent problem to be solved. Utility Model Content
[0005] The purpose of this invention is to solve the problem that traditional battery cell packaging equipment cannot control the thickness of the battery cell packaging area, and therefore provides a battery cell packaging equipment.
[0006] A battery cell packaging device adopts the following technical solution:
[0007] A heat-sealing device, used for heating an aluminum-plastic film wrapped around a battery cell tab to achieve heat sealing at the tab, characterized in that: it includes at least a pair of oppositely arranged end caps, the sides of the end caps that are close to each other are provided with steps, the steps form a first surface at the top of the step and a second surface on the step, at least one of the first surfaces is provided with limiting members at both ends, the limiting members and the first surface constitute a first heat-sealing area for heat sealing the tab, and the second surfaces together constitute a second heat-sealing area.
[0008] By adopting the above technical solution, the first and second sides form a stepped first sealing area and a second sealing area at the electrode tab. The second heat-sealing area provides a space for the molten PP layer in the first heat-sealing area, which ensures the sealing effect while avoiding the formation of small droplet-like glue particles at the edge of the sealing area of the electrode tab. These particles would crack under external force, causing the electrolyte to come into direct contact with the aluminum layer through the crack, resulting in poor insulation of the battery cell.
[0009] Furthermore, the limiting component is a pad, and the height of the pad is less than the sum of the electrode tab and twice the thickness of the aluminum-plastic film.
[0010] Preferably, the pad is detachably connected to the first surface.
[0011] Furthermore, the pad includes a non-thermal conductive component.
[0012] The use of non-thermal conductive components in the pad ensures that the aluminum-plastic film on the side of the electrode tab will not melt due to heat during the heat sealing process, causing the PP layer on the inner side of the aluminum-plastic film to overflow to the side.
[0013] Furthermore, the sum of the widths of the first and second surfaces is less than the thickness of the end cap.
[0014] Preferably, the width of the first surface is not less than one-quarter of the thickness of the end cap.
[0015] Furthermore, the width of the second surface is smaller than the width of the first surface.
[0016] The width of the first side is at least one-quarter of the head thickness. By ensuring the width of the sealing area at the tab, the sealing effect after heat sealing is reliable.
[0017] Furthermore, the first surface and the second surface have a height difference, which is 2% to 25% of the electrode tab and twice the thickness of the aluminum-plastic film.
[0018] During the heat sealing process, the inner sides of the aluminum-plastic film on the second side come into contact with each other. The aluminum-plastic film in the heat sealing area of the sealing head undergoes a large deformation during the heat sealing process and will be squeezed out to both sides. After the aluminum-plastic film on the second side is heated by the second side, the PP is sealed inside the second sealing area to prevent small droplets from forming at the edge of the first sealing area after the PP cools down.
[0019] Furthermore, the end cap includes at least a heat-conducting element.
[0020] Furthermore, the end cap is provided with several heating blocks on its side.
[0021] Furthermore, a connecting block is provided on the side of the end caps that are separated from each other.
[0022] In summary, this application has at least the following beneficial effects:
[0023] 1. The first sealing area corresponds to the first sealing area at the battery cell tab, ensuring the width of the first sealing area to guarantee its sealing effect; the second surface forms the second heat-sealing area, which corresponds to the second sealing area, and there is a height difference of 2% to 25% between the tab and the first surface, which is twice the thickness of the aluminum-plastic film. This ensures that the aluminum-plastic film of the second sealing area, after being heated by the second heat-sealing area, can accommodate the molten PP generated during the heat-sealing process of the first sealing area and can bond with each other to isolate the battery cell from the PP. At the same time, it protects the solidified PP to prevent the first sealing area from cracking under external force, which would cause the electrolyte to come into direct contact with the aluminum layer through the crack, resulting in poor insulation of the battery cell.
[0024] 2. The limiting component limits the minimum thickness of the heat seal, ensuring that the tabs will not be damaged due to excessive pressure during the heat sealing process. The detachable design allows it to be used not only for tab heat sealing, but also for heat sealing processes such as edge sealing that do not require a minimum height limit. It also facilitates later maintenance. If damage or deformation occurs, it can be directly replaced, effectively reducing maintenance costs. Attached Figure Description
[0025] Figure 1 This is a side view of the heat sealing equipment of this application;
[0026] Figure 2 This is a front view structural diagram of the heat sealing equipment of this application;
[0027] Figure 3 This is a schematic diagram of the heat sealing process.
[0028] Figure label:
[0029] 1. End cap; 10. Step; 11. First surface; 12. Second surface; 13. Limiting element; 14. First heat-sealing zone; 15. Second heat-sealing zone; 2. Battery cell; 20. Aluminum-plastic film; 21. First sealing zone; 22. Second sealing zone; 3. Heating block; 4. Connecting block. Detailed Implementation
[0030] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0031] Example 1
[0032] refer to Figure 1 , 2 A heat sealing device for heat sealing at least the tabs of a battery cell 2 includes at least two oppositely arranged end caps 1. The first side of the end caps 1 that is close to each other is provided with a step 10. The top of the step 10 is a first surface 11 and the bottom is a second surface 12. The sum of the widths of the first surface 11 and the second surface 12 is less than the thickness of the end cap 1, and the width of the second surface 12 is less than the width of the first surface 11.
[0033] It should be noted that the width of the first surface 11 is not less than one-quarter of the thickness of the end cap 1 in order to ensure a reliable seal for the heat-sealed object during the heat-sealing process.
[0034] The first surface 11 has detachable pads at both ends.
[0035] It should be noted that the end cap 1 includes at least a heat-conducting component, and the limiting component 13 includes a non-heat-conducting component. In this embodiment, the limiting component 13 is a pad.
[0036] Combination Figure 2 And refer to Figure 3 The battery cell 2 includes a tab (not shown in the figure). The outer side of the battery cell 2 is covered with an aluminum-plastic film 20, which completely covers the tab. The thickness of the pad is less than the sum of the thickness of the tab and the two layers of aluminum-plastic film 20, but greater than the thickness of the tab.
[0037] Refer again Figure 2 The pad and the first surface 11 form the first heat-sealing area 14, combined with Figure 3 The width of the electrode tab is smaller than the width of the heat-sealing area, and the part of the electrode tab located in the heat-sealing area is the first sealing area 21.
[0038] Refer again Figure 1 The second surface 12 and the first surface 11 have a tab and a height difference of 2% to 25% of the thickness of twice the aluminum-plastic film 20, combined with Figure 3 The opposite second surface 12 forms the second heat-sealing area 15 corresponding to the second sealing area 22.
[0039] refer to Figure 3 The end cap 1 has several heating blocks 3 on its side and a connecting block 4 on the opposite side of the end cap 1.
[0040] The working process of the heat sealing equipment proposed in this embodiment will now be described with reference to the accompanying drawings.
[0041] Reference Appendix Figure 3 Place the tab side of cell 2 close to end cap 1 and insert the tab between end cap 1, then combine. Figure 2Place the tabs between the limiting members 13 and adjust the tab installation position (i.e., the length of the tabs extending into the end cap 1). After completing the above steps, heat and press the end cap 1 with the heating block 3 until the end cap 1 and the limiting member 13 are pressed together. At this time, the first heat sealing area 14 and the second heat sealing area 15 heat seal the tabs and finally form the first sealing area 21 and the second sealing area 22. After the heat sealing is completed, open the end cap 1, remove the battery cell 2 and let it cool naturally.
[0042] Example 2
[0043] Based on Example 1, a new implementation method is now proposed.
[0044] A heat sealing device is used for sealing the sides of electrical equipment. The limiting members 13 are removed from both ends of the first surface 11, and the rest of the implementation is the same as in Example 1.
Claims
1. A heat-sealing device, used for heating at least the aluminum-plastic film (20) wrapping the tabs of a battery cell (2) to achieve heat sealing at the tabs, characterized in that: It includes at least one pair of opposing end caps (1), with a step (10) correspondingly provided on the side of the end caps (1) that are close to each other. The step (10) forms a first surface (11) on the top of the step (10) and a second surface (12) on the step (10). At least one of the first surfaces (11) has a limiting member (13) at both ends. The limiting member (13) and the first surface (11) constitute a first heat-sealing area (14) for heat-sealing the electrode tab, and the second surface (12) constitutes a second heat-sealing area (15).
2. A heat sealing apparatus as claimed in claim 1, wherein The limiting member (13) is a pad, and the height of the pad is less than the sum of the electrode tab and twice the thickness of the aluminum-plastic film (20).
3. A heat sealing apparatus as claimed in claim 2, wherein The pad includes a non-thermal conductive component.
4. A heat sealing apparatus as claimed in claim 1, wherein The sum of the widths of the first surface (11) and the second surface (12) is less than the thickness of the end cap (1).
5. A heat sealing apparatus as claimed in claim 4, wherein The width of the first surface (11) is not less than one-quarter of the thickness of the end cap (1).
6. A heat sealing apparatus as claimed in claim 5, wherein The width of the second face (12) is smaller than the width of the first face (11).
7. A heat sealing apparatus as defined in claim 1, wherein The first surface (11) and the second surface (12) have a height difference, which is 2% to 25% of the thickness of the tab and twice the thickness of the aluminum-plastic film (20).
8. A heat sealing apparatus as defined in claim 1, wherein The end cap (1) includes at least a heat-conducting element.
9. A heat sealing apparatus as defined in claim 1, wherein The end cap (1) is provided with several heating blocks (3) on its side.
10. A heat sealing apparatus as defined in claim 1, wherein A connecting block (4) is provided on the side of the end caps (1) that are separated from each other.