Sealing head for secondary liquid injection sealing of soft package battery and heat sealing device for secondary liquid injection sealing

Abstract

The utility model provides an end socket for secondary liquid injection sealing of a soft package battery and a heat sealing device for secondary liquid injection sealing, and relates to the technical field of soft package battery processing. An end socket for secondary liquid injection sealing of a soft package battery comprises an upper base, an upper end socket, a lower base and a lower end socket, the upper end socket and the lower end socket both comprise heat sealing surfaces, and heat sealing holes are formed in the heat sealing surfaces of the upper end socket and the lower end socket; the upper sealing head is connected to the upper base and protrudes out of the upper base, and the lower sealing head is connected to the lower base and protrudes out of the lower base; the upper base and the lower base are both provided with heating rods, and the heating rods are used for heating the upper sealing head and / or the lower sealing head. By adopting the sealing head, the high polymer material in the aluminum plastic film in the area near the liquid injection hole is directionally transferred to the liquid injection hole in a hot pressing manner, and the liquid injection hole is sealed, so that the sealing performance of the battery is ensured, the corrosion risk and the falling risk of the additional aluminum plastic film are reduced, the process is simple, and industrial production is convenient to realize.

Description

Technical Field

[0001] This utility model relates to the field of pouch battery processing technology, and in particular to a sealing head for secondary liquid injection sealing of pouch batteries and a heat sealing device for secondary liquid injection sealing. Background Technology

[0002] During the charge-discharge cycle of a pouch battery, lithium ions repeatedly migrate between the positive and negative electrodes, constantly inserting and extracting into the electrode materials. This process causes changes in the lattice structure of the active material particles in the positive and negative electrodes. At the same time, in the presence of the electrolyte, reactions occur continuously, leading to the continuous consumption of the electrolyte. As the amount of electrolyte decreases, lithium ion migration is hindered, preventing some active material particles from undergoing lithium ion insertion and extraction, resulting in battery capacity decay.

[0003] At this stage, adding new electrolyte can be done manually to prevent further capacity degradation and improve battery cycle life. However, sealing the aluminum-plastic film back to its original state after adding electrolyte is quite challenging. Poor sealing can cause external moisture to enter the battery, react with the electrolyte to produce gas, and lead to safety accidents such as bulging and leakage. Patent CN111710893A uses a hollow heart-shaped end cap, which can encapsulate non-square soft-pack batteries. Patent CN115064791A uses two aluminum-plastic films to cover both sides of the injection hole, and then uses a conventional straight end cap for heat sealing.

[0004] The irregularly shaped end cap in the existing technology CN111710893A is not a closed shape and can only be used for the overall packaging of soft-pack cells, not for packaging scenarios with electrolyte injection holes. CN115064791A uses an external aluminum-plastic film on both sides of the hole, but the alignment of the external aluminum-plastic film with the secondary electrolyte injection port cannot be guaranteed during the heat sealing process; in addition, the sealing performance of the external aluminum-plastic film is poor, and there is a risk of detachment and leakage during the later use of the battery; at the same time, because conventional end caps are used for packaging, the adhesive extruded from the PP layer due to heat and pressure during the packaging process cannot be discharged normally, and is all pressed inside the aluminum-plastic film, posing a significant risk of corrosion and leakage to the battery. Utility Model Content

[0005] In view of the shortcomings of the current technical solutions, in order to solve the problem that there is no end cap specifically for heat sealing the secondary liquid injection port of soft-pack batteries in the existing technology; and to solve the problem that the secondary liquid injection port of soft-pack batteries cannot be sealed simply and effectively in the existing technology, and that the outer aluminum-plastic film of the secondary liquid injection port is easy to fall off after sealing, which poses a risk of leakage, this utility model provides an end cap for sealing the secondary liquid injection port of soft-pack batteries and a heat sealing device for sealing the secondary liquid injection port.

[0006] In a first aspect, this application provides a sealing head for secondary liquid injection sealing of a pouch battery:

[0007] A sealing head for secondary liquid injection sealing of a soft-pack battery includes an upper sealing head, an upper base, a lower sealing head, and a lower base. Both the upper sealing head and the lower sealing head include a heat-sealing surface with a heat-sealing hole. The upper sealing head is connected to and protrudes from the upper base, and the lower sealing head is connected to and protrudes from the lower base.

[0008] Furthermore, both the upper and lower bases are equipped with heating rods, which are used to heat the upper or lower end cap.

[0009] Furthermore, the area of ​​the heat-sealed cover is larger than the area of ​​the heat-sealed secondary injection port.

[0010] Furthermore, the size of the heat-sealing hole is smaller than or equal to the size of the secondary liquid injection port of the pouch battery.

[0011] Furthermore, the size of the heat-sealing hole is 2-20mm.

[0012] Furthermore, the outer contour shape of the heat sealing surface includes one of the following: circle, ellipse, triangle, and polygon; the shape of the heat sealing hole includes one of the following: circle, ellipse, triangle, and polygon.

[0013] Furthermore, the upper end cap and the lower end cap have the same shape.

[0014] Secondly, this application provides a heat-sealing device for secondary liquid injection sealing:

[0015] A heat-sealing device for secondary liquid injection sealing includes the sealing head for secondary liquid injection sealing of soft-pack batteries as described in this application.

[0016] A heat sealing device for secondary liquid injection sealing includes a frame, a battery positioning fixture, a sealing head for secondary liquid injection sealing of soft-pack batteries, and a driving device. The battery positioning fixture, upper base, and lower base are mounted on the frame, and the upper sealing head and lower sealing head are disposed on both sides of the battery positioning fixture.

[0017] The battery positioning fixture has a tab groove, a main body aluminum-plastic film groove, and a heat-sealing perforation; the tab groove is used to position the tabs of the soft-pack battery, and the main body aluminum-plastic film groove is used to position the main body aluminum-plastic film of the battery.

[0018] When the soft-pack battery is placed on the battery positioning fixture and is in the positioning state, the secondary liquid injection port on one side of the soft-pack battery is located at the heat-sealing perforation and is opposite to the lower sealing head;

[0019] The two output terminals of the drive device are respectively connected to the upper base and the lower base.

[0020] Furthermore, when the heat-sealing device heat-seales the secondary liquid injection port of the soft-pack battery, the center of the heat-sealing hole of the upper end cap, the center of the heat-sealing hole of the lower end cap, and the center of the secondary liquid injection port of the soft-pack battery are on a straight line.

[0021] Beneficial effects:

[0022] This utility model, by using the end cap of this application, transfers the polymer material in the aluminum-plastic film near the injection hole to the injection hole through hot pressing, and seals the injection hole. By using the battery's own aluminum-plastic film for encapsulation, the battery's sealing performance can be well guaranteed, while reducing the risk of corrosion and the risk of the external aluminum-plastic film falling off. The process is simple, easy to operate, and convenient for industrial production. Attached Figure Description

[0023] Figure 1 This is a front view of a pouch cell after electrolyte has been added;

[0024] Figure 2 This is a slanted view of a pouch cell after electrolyte has been added.

[0025] Figure 3 A schematic diagram of the structure of the sealing head used for secondary liquid injection sealing of soft-pack batteries;

[0026] Figure 4 , two Schematic diagram of the heat sealing device for secondary liquid injection sealing;

[0027] Figure 5 A partial structural diagram of a heat-sealing device for sealing a soft-pack battery after secondary electrolyte injection;

[0028] Figure 6 A schematic diagram of the structure of the battery positioning fixture for placing soft-pack batteries;

[0029] Figure 7 A schematic diagram of the battery positioning fixture.

[0030] Figure label:

[0031] 1. Soft-pack battery; 2. Secondary liquid filling and sealing head; 3. Frame; 4. Battery positioning fixture; 5. Drive unit; 11. Tab; 12. Main aluminum-plastic film; 13. Liquid filling hole; 14. Top seal; 21. Upper base; 22. Upper head; 23. Lower base; 24. Lower head; 25. Heat sealing surface; 26. Heat sealing hole; 27. Heating rod; 41. Tab groove; 42. Main aluminum-plastic film groove; 43. Heat sealing perforation. Detailed Implementation

[0032] To make this practical technical solution clearer, the following is combined with... Figures 1 to 7 The present invention will be further described in detail with reference to specific embodiments.

[0033] In the description of this utility model, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] In this utility model, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] like Figures 3 to 7 As shown, a heat sealing device for secondary liquid injection sealing includes a frame 3, a battery positioning fixture 4, a soft-pack battery 1, a sealing head 2 for secondary liquid injection sealing, and a driving device 5; the battery positioning fixture 4, the upper base 21, the lower base 23, and the driving device 5 are mounted on the frame 3; according to this embodiment, preferably, the driving device 5 is a cylinder.

[0036] like Figure 1 and Figure 2 As shown, the electrolyte is added through the injection hole 13 on the aluminum-plastic film of the battery. Generally, the injection hole is located between the top seal 14 and the middle 12 of the main aluminum-plastic film, that is, the unsealed area inside the top seal. There are injection holes 13 on both sides of the soft pack battery 1. New electrolyte is added into the soft pack battery 1 through the injection hole 13, and then it is sealed.

[0037] like Figure 3As shown, the sealing head 2 for secondary liquid injection sealing of the soft-pack battery 1 includes an upper base 21, an upper sealing head 22, a lower base 23, and a lower sealing head 24. Both the upper sealing head 22 and the lower sealing head 24 include a heat-sealing surface 25, and heat-sealing holes 26 are opened on the heat-sealing surface 25 of the upper sealing head 22 and the lower sealing head 24. The upper sealing head 22 is connected to the upper base 21 and protrudes from the upper base 21, and the lower sealing head 24 is connected to the lower base 23 and protrudes from the lower base 23. Both the upper base 21 and the lower base 23 are provided with heating rods 27, which are used to heat the upper sealing head 22 or the lower sealing head 24. The two output ends of the driving device 5 are respectively connected to the upper base 21 and the lower base 23, causing the upper base 21 and the lower base 23 to move away from or towards the battery positioning fixture 4, thereby enabling the upper sealing head 22 and the lower sealing head 24 to seal the secondary liquid injection of the soft-pack battery 1.

[0038] According to this embodiment, preferably, the upper end cap 22 and the lower end cap 24 are annular, and the outer contour of the heat sealing surface 25 and the shape of the heat sealing hole 26 of the upper end cap 22 and the lower end cap 24 are circular. The size of the heat sealing hole 26 is 15mm, which is equal to the size of the secondary liquid injection port of the soft-pack battery 1.

[0039] like Figures 4 to 7 As shown, the battery positioning fixture 4 has a tab groove 41, a main body aluminum-plastic film groove 42 and a heat sealing perforation 43; the tab groove 41 is used to position the tab 11 of the soft pack battery 1, and the main body aluminum-plastic film groove 42 is used to position the main body aluminum-plastic film 12 of the battery.

[0040] When the soft-pack battery 1 is placed on the battery positioning fixture 4 and is in a positioning state, the secondary liquid injection port on one side of the soft-pack battery 1 is located at the heat sealing perforation 43 and is opposite to the lower end cap 24. When the heat sealing device heat seals the heat sealing secondary liquid injection port of the soft-pack battery 1, the center of the heat sealing hole 26 of the upper end cap 22, the center of the heat sealing hole 26 of the lower end cap 24 and the center of the secondary liquid injection port of the soft-pack battery 1 are on a straight line.

[0041] The process of heat-sealing the injection hole 13 of the soft-pack battery 1 using the secondary liquid injection sealing heat-sealing device in this application is as follows:

[0042] Preheat the upper end cap 22 and lower end cap 24 to 190±5℃; then place the soft-pack battery 1 on the battery positioning fixture 4, with the tab 11 located in the tab groove 41 and the battery body aluminum-plastic film 12 placed in the body aluminum-plastic film groove 42; at this time, the center of the injection hole 13 is aligned with the center of the heat sealing hole 26 of the upper end cap 22 and the lower end cap 24, and the center of the heat sealing hole 26 of the lower end cap 24 is on a straight line with the center of the secondary injection port of the soft-pack battery 1. The size of the heat sealing hole 26 is... Both the upper and lower end caps 22 and 24 are circular in shape and the same size as the injection hole 13. Under the drive of the cylinder of the drive device 5, the upper end cap 22 and the lower end cap 24 press together to the middle of the injection hole 13. The heat-sealing surface 25 of the upper end cap 22 and the lower end cap 24 abut against the aluminum-plastic film around the injection holes 13 on both sides of the soft pack battery 1. The end cap pressure is controlled at 0.1-0.5 MPa for 3-5 seconds. Then the upper end cap 22 and the lower end cap 24 return to their original positions. The soft pack battery 1 is then removed, and the encapsulation process ends.

[0043] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A closure head for soft-pack battery secondary injection sealing, characterized by, The soft package battery secondary injection sealing head (2) comprises an upper base (21), an upper head (22), a lower base (23), and a lower head (24), the upper head (22) and the lower head (24) each comprise a heat sealing surface (25), and the heat sealing surface (25) of the upper head (22) and the lower head (24) is provided with a heat sealing hole (26); the upper head (22) is connected to the upper base (21) and protrudes from the upper base (21), and the lower head (24) is connected to the lower base (23) and protrudes from the lower base (23). The upper base (21) and the lower base (23) are each provided with a heating rod (27) for heating the upper head (22) and / or the lower head (24).

2. The soft-pack battery secondary injection sealing head according to claim 1, characterized by, The area of the heat sealing surface (25) is greater than the area of the secondary injection port of the soft package battery (1).

3. The soft-pack battery secondary injection sealing head according to claim 2, characterized by The size of the heat sealing hole (26) is less than or equal to the size of the secondary injection port of the soft package battery (1).

4. The soft-pack battery secondary injection sealing head according to claim 3, characterized by The size of the heat sealing hole (26) is 2-20 mm.

5. The soft-pack battery secondary injection sealing head according to claim 1, characterized by, The outer contour shape of the heat sealing surface (25) comprises one of an ellipse and a polygon, and the shape of the heat sealing hole (26) comprises one of an ellipse and a polygon.

6. The soft-pack battery secondary injection sealing head according to claim 1, characterized by The upper head (22) and the lower head (24) are of the same shape.

7. A heat sealing device for secondary liquid injection sealing, characterized by comprising: The soft package battery secondary injection sealing head (2) comprises an upper base (21), an upper head (22), a lower base (23), and a lower head (24), the upper head (22) and the lower head (24) each comprise a heat sealing surface (25), and the heat sealing surface (25) of the upper head (22) and the lower head (24) is provided with a heat sealing hole (26); the upper head (22) is connected to the upper base (21) and protrudes from the upper base (21), and the lower head (24) is connected to the lower base (23) and protrudes from the lower base (23).

8. The heat sealing apparatus for secondary liquid injection sealing according to claim 7, wherein The upper base (21) and the lower base (23) are each provided with a heating rod (27) for heating the upper head (22) and / or the lower head (24). The area of the heat sealing surface (25) is greater than the area of the secondary injection port of the soft package battery (1). The size of the heat sealing hole (26) is less than or equal to the size of the secondary injection port of the soft package battery (1). The size of the heat sealing hole (26) is 2-20 mm.

9. The heat sealing apparatus for secondary liquid injection sealing according to claim 8, wherein The outer contour shape of the heat sealing surface (25) comprises one of an ellipse and a polygon, and the shape of the heat sealing hole (26) comprises one of an ellipse and a polygon. The upper head (22) and the lower head (24) are of the same shape. The soft package battery secondary injection sealing head (2) comprises an upper base (21), an upper head (22), a lower base (23), and a lower head (24), the upper head (22) and the lower head (24) each comprise a heat sealing surface (25), and the heat sealing surface (25) of the upper head (22) and the lower head (24) is provided with a heat sealing hole (26); the upper head (22) is connected to the upper base (21) and protrudes from the upper base (21), and the lower head (24) is connected to the lower base (23) and protrudes from the lower base (23). The upper base (21) and the lower base (23) are each provided with a heating rod (27) for heating the upper head (22) and / or the lower head (24). The area of the heat sealing surface (25) is greater than the area of the secondary injection port of the soft package battery (1). The size of the heat sealing hole (26) is less than or equal to the size of the secondary injection port of the soft package battery (1). The size of the heat sealing hole (26) is 2-20 mm. The outer contour shape of the heat sealing surface (25) comprises one of an ellipse and a polygon, and the shape of the heat sealing hole (26) comprises one of an ellipse and a polygon. The upper head (22) and the lower head (24) are of the same shape. The soft package battery secondary injection sealing head (2) comprises an upper base (21), an upper head (22), a lower base (23), and a lower head (24), the upper head (22) and the lower head (24) each comprise a heat sealing surface (25), and the heat sealing surface (25) of the upper head (22) and the lower head (24) is provided with a heat sealing hole (26); the upper head (22) is connected to the upper base (21) and protrudes from the upper base (21), and the lower head (24) is connected to the lower base (23) and protrudes from the lower base (23). The upper base (21) and the lower base (23) are each provided with a heating rod (27) for heating the upper head (22) and / or the lower head (24). The area of the heat sealing surface (25) is greater than the area of the secondary injection port of the soft package battery (1). The size of the heat sealing hole (26) is less than or equal to the size of the secondary injection port of the soft package battery (1). The size of the heat sealing hole (26) is 2-20 mm. The outer contour shape of the heat sealing surface (25) comprises one of an ellipse and a polygon, and the shape of the heat sealing hole (26) comprises one of an ellipse and a polygon. The upper head (22) and the lower head (24) are of the same shape.

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