Edge sealing structure for soft package battery

Abstract

The utility model discloses an edge sealing structure for a soft package battery, which comprises a lower heat sealing mould, an upper heat sealing mould and a battery body, the upper heat sealing mould is arranged above the lower heat sealing mould, a top plate is arranged on the lower side of the upper heat sealing mould, a pole lug is fixed on the battery body, an aluminum plastic film is wrapped on the outer side of the battery body, and the aluminum plastic film is arranged on the outer side of the battery body. The aluminum-plastic film and the tab are positioned between the lower heat-sealing mold and the upper heat-sealing mold, and sleeves are vertically fixed on the side edge of the lower heat-sealing mold in a bilateral symmetry manner. According to the edge sealing structure for the soft package battery, under the condition that the overall length of the aluminum plastic film is not changed, the horizontal length of the heat sealing edge can be effectively shortened by changing the heat sealing interface of the aluminum plastic film into a wave shape, and the protruding sharp corner of the complete edge can be shrunk towards the tab side in the horizontal direction on the premise that the heat sealing strength meets the requirement; a convex angle structure brought by three sealing edges of the soft package battery is improved, a receding structure newly added during structural design is reduced, the cold plate receding design of a thermal management scheme is reduced, and the available space of 2mm in the height direction of a system can be increased.

Description

Technical Field

[0001] The utility model relates to the technical field of soft-pack batteries, in particular to an edge sealing structure for soft-pack batteries. Background Art

[0002] Traditional soft-pack battery edge sealing solutions include three-edge sealing and four-edge sealing, which correspond to different process solutions and thermal management solutions respectively, and have a direct impact on the system energy density. The method of improving energy density is called the goal that the new energy industry is constantly pursuing. There is still little technical research specifically on improving energy density by optimizing the soft-pack battery packaging method. The existing packaging methods on the market are mainly three-edge sealing and four-edge sealing. Four-edge sealing poses greater challenges to thermal management design. The convex corners formed by three-edge sealing have different degrees of influence on the structural design and system energy density. The superiority of the energy density of the soft-pack battery cell cannot be normally exerted. Therefore, in response to the above problems, a sealing structure for soft-pack batteries is designed to better meet the actual use needs. Utility Model Content

[0003] The purpose of the utility model is to provide an edge sealing structure for soft-pack batteries to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a sealing structure for a soft-pack battery, comprising a lower heat-sealing mold, an upper heat-sealing mold and a battery body, wherein an upper heat-sealing mold is arranged above the lower heat-sealing mold, a top plate is arranged on the lower side of the upper heat-sealing mold, a pole ear is fixed on the battery body, an outer side of the battery body is wrapped with an aluminum-plastic film, and the aluminum-plastic film and the pole ear are located between the lower heat-sealing mold and the upper heat-sealing mold.

[0005] Preferably, sleeves are vertically fixed to the sides of the lower heat-sealing mold in a left-right symmetrical manner, and four sleeves are provided. Through the action of the sleeves, basic guarantee can be provided for the matching and guiding of the lower heat-sealing mold and the upper heat-sealing mold.

[0006] Preferably, guide pillars are vertically fixed symmetrically on the sides of the upper heat sealing mold, and there is a one-to-one correspondence between the guide pillars and the sleeves, and the guide pillars and the sleeves are slidingly connected. Through the sliding guiding effect between the guide pillars and the sleeves, the stable assembly of the lower heat sealing mold and the upper heat sealing mold can be ensured.

[0007] Preferably, both the lower heat-sealing mold and the upper heat-sealing mold are provided with corrugations, and the corrugations on the lower heat-sealing mold cooperate with the corrugations on the upper heat-sealing mold. Through the action of the corrugations, the aluminum-plastic film on both sides of the tab can be folded inwardly into a special shape, thereby ensuring the stability of the aluminum-plastic film bonding after edge sealing.

[0008] Preferably, vertical rods are fixed symmetrically and vertically on the upper surface of the top plate, and a circular plate is fixed on the vertical rods, and the circular plate is slidably connected to the upper heat sealing mold, and the top plate and the upper heat sealing mold are nested. The top plate can realize automatic ejection, which is convenient for product export after edge sealing, thereby facilitating material removal, and the sliding effect between the circular plate and the upper heat sealing mold can ensure the stability of the top plate movement.

[0009] Preferably, one end of a spring is fixed to the upper end surface of the circular plate, and the other end of the spring is fixed in the upper heat sealing mold. Through the action of the spring, a basic force can be provided for the automatic reset of the circular plate and the top plate to ensure the normal operation of the edge sealing.

[0010] Compared with the prior art, the beneficial effects of the utility model are as follows: the edge sealing structure for soft-pack batteries, while keeping the overall length of the aluminum-plastic film unchanged, changes the heat-sealing interface of the aluminum-plastic film into a wavy shape, which can effectively shorten the horizontal length of the heat-sealed edge; on the premise that the heat-sealing strength meets the requirements, the protruding sharp corners of the complete edge can be horizontally shrunk toward the pole ear side, thereby improving the convex angle structure caused by the three-edge sealing of the soft-pack battery, reducing the newly added air avoidance structure during structural design, reducing the cold plate air avoidance design of the thermal management solution, and increasing the available space by 2 mm in the system height direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the three-dimensional structure of the lower heat-sealing mold and the battery body of the utility model;

[0012] Figure 2 This is a schematic diagram of the three-dimensional structure of the lower heat-sealing mold and the upper heat-sealing mold of the utility model;

[0013] Figure 3 It is a schematic diagram of the partial cross-section of the three-dimensional structure of the upper heat-sealing mold of the utility model;

[0014] Figure 4 It is a schematic diagram of the three-dimensional structure of the battery body of the utility model.

[0015] In the figure: 1. lower heat sealing mold; 101. sleeve; 2. upper heat sealing mold; 201. guide pillar; 3. wave pattern; 4. top plate; 401. vertical rod; 402. round plate; 5. spring; 6. battery body; 7. pole ear; 8. aluminum-plastic film. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] See also Figure 1-Figure 4 The utility model provides a technical solution: a sealing edge structure for a soft-pack battery, comprising a lower heat-sealing mold 1, an upper heat-sealing mold 2 and a battery body 6, wherein the upper heat-sealing mold 2 is arranged above the lower heat-sealing mold 1, a top plate 4 is arranged at the lower side of the upper heat-sealing mold 2, a pole ear 7 is fixed on the battery body 6, an aluminum-plastic film 8 is wrapped around the outer side of the battery body 6, and the aluminum-plastic film 8 and the pole ear 7 are located between the lower heat-sealing mold 1 and the upper heat-sealing mold 2.

[0018] A sleeve 101 is also symmetrically and vertically fixed on the side of the lower heat-sealing mold 1, and four sleeves 101 are provided; a guide column 201 is also symmetrically and vertically fixed on the side of the upper heat-sealing mold 2, and there is a one-to-one correspondence between the guide column 201 and the sleeve 101, and the guide column 201 and the sleeve 101 are slidably connected; the lower heat-sealing mold 1 and the upper heat-sealing mold 2 are both provided with a corrugated pattern 3, and the corrugated pattern 3 on the lower heat-sealing mold 1 cooperates with the corrugated pattern 3 on the upper heat-sealing mold 2;

[0019] When sealing the edge of soft pack batteries, Figure 1-Figure 4As shown, firstly, the lower heat sealing mold 1 and the upper heat sealing mold 2 are installed on the heat press, and then the aluminum-plastic film 8 and the pole ear 7 that need to be heat-pressed and sealed are matched with the mold. At this time, the pole ear 7 is located at the middle horizontal position of the lower heat sealing mold 1, and the aluminum-plastic film 8 is located at the wavy lines 3 on both sides of the lower heat sealing mold 1. The device is powered by an external power supply, and the heat press is started to drive the upper heat sealing mold 2 to move downward. With the sliding guide effect between the guide column 201 and the sleeve 101, the wavy lines 3 on the lower heat sealing mold 1 and the wavy lines 3 on the upper heat sealing mold 2 can be matched to achieve the heat pressing effect of the aluminum-plastic film 8, wherein the heat sealing temperature is 180℃<T<220℃, and the heat sealing pressure is 120kgf<N1<200 kgf, heat sealing time 4s<t1<6s, at this time, the aluminum-plastic film 8 is hot-pressed into a wavy structure, and in the hot pressing process, changing the heat sealing interface of the aluminum-plastic film to a wavy shape can effectively shorten the horizontal length of the heat-sealed edge. Under the premise that the heat sealing strength meets the requirements, the protruding sharp corners of the complete edge can be horizontally contracted toward the side of the pole ear 7 to improve the state of the protruding sharp corners. The semicircular structures are tangentially connected to keep the end without sharp corners (the angle with the edge of the mold is greater than 90°), the chamfer radius of the mold contact position is ≥1mm (to prevent burrs and gaps), and the length is the yield strength in accordance with national standards (200MPa to 300 MPa), the structure is convenient for quick replacement and repair; the second part: the straight position is consistent with the existing heat sealing structure, the flatness adopts GB / T3880.2-2006 (generally required to be less than 30 microns), and the chamfer radius of both sides is ≥1mm (to prevent burrs and gaps); the third part: the chamfer radius of the connection between the straight part and the curved part is 2mm; the overall thickness is 8~10mm, and the structural strength should ensure that when the heat sealing pressure is 200±70kgf, the stroke difference is <0.2mm, and the corresponding position of the heat sealing is completely closed to ensure the heat sealing effect. After the heat sealing is completed, Figure 4 As shown;

[0020] A vertical rod 401 is fixed symmetrically and vertically on the upper end surface of the top plate 4, and a circular plate 402 is fixed on the vertical rod 401, and the circular plate 402 is slidably connected to the upper heat-sealing mold 2, and the top plate 4 and the upper heat-sealing mold 2 are nested; one end of a spring 5 is fixed on the upper end surface of the circular plate 402, and the other end of the spring 5 is fixed in the upper heat-sealing mold 2;

[0021] During the thermocompression packaging process, Figure 1-Figure 3As shown, when the upper heat-sealing mold 2 moves downward under the action of the hot press, when the top plate 4 contacts the pole ear 7, the top plate 4 is forced to slide upward, and the sliding between the circular plate 402 and the upper heat-sealing mold 2 can ensure the stability of the movement of the top plate 4 until the top plate 4 is nested into the upper heat-sealing mold 2. At this time, the lower end surface of the top plate 4 is flush with the lower end surface of the upper heat-sealing mold 2, and the spring 5 is in a contracted state, thereby ensuring the normal hot-pressing packaging. After the hot-pressing packaging is completed, when the upper heat-sealing mold 2 moves up and separates from the lower heat-sealing mold 1, the top plate 4 can be reset under the action of the spring 5, thereby realizing the ejection effect on the pole ear 7, avoiding the problem of inconvenience in demoulding caused by the adhesion of the aluminum-plastic film 8 to the upper heat-sealing mold 2 after hot-pressing packaging. This is the working principle of the edge sealing structure for soft-pack batteries.

[0022] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sealing structure for a soft-pack battery, comprising a lower heat-sealing mold (1), an upper heat-sealing mold (2) and a battery body (6), characterized in that: An upper heat-sealing mould (2) is arranged above the lower heat-sealing mould (1), a top plate (4) is arranged at the lower side of the upper heat-sealing mould (2), a pole lug (7) is fixed on the battery body (6), an outer side of the battery body (6) is wrapped with an aluminum-plastic film (8), and the aluminum-plastic film (8) and the pole lug (7) are located between the lower heat-sealing mould (1) and the upper heat-sealing mould (2).

2. The edge sealing structure for a soft pack battery according to claim 1, characterized in that: A sleeve (101) is also vertically fixed to the side of the lower heat-sealing mould (1) in a left-right symmetrical manner, and four sleeves (101) are provided.

3. The edge sealing structure for a soft pack battery according to claim 1, characterized in that: A guide post (201) is also fixed vertically and symmetrically on the side of the upper heat-sealing mould (2), and there is a one-to-one correspondence between the guide post (201) and the sleeve (101), and the guide post (201) and the sleeve (101) are slidably connected.

4. The edge sealing structure for a soft pack battery according to claim 1, characterized in that: The lower heat-sealing mould (1) and the upper heat-sealing mould (2) are both provided with wave patterns (3), and the wave patterns (3) on the lower heat-sealing mould (1) cooperate with the wave patterns (3) on the upper heat-sealing mould (2).

5. The edge sealing structure for a soft pack battery according to claim 1, characterized in that: A vertical rod (401) is vertically fixed to the upper end surface of the top plate (4) in a symmetrical manner, and a circular plate (402) is fixed on the vertical rod (401). The circular plate (402) is slidably connected to the upper heat-sealing mold (2), and the top plate (4) and the upper heat-sealing mold (2) are nested.

6. The edge sealing structure for a soft pack battery according to claim 5, characterized in that: One end of a spring (5) is fixed to the upper end surface of the circular plate (402), and the other end of the spring (5) is fixed in the upper heat-sealing mould (2).

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