Puncture device used in the secondary sealing process of pouch lithium batteries

Abstract

This utility model relates to the field of battery manufacturing technology, and in particular to a piercing device for the secondary sealing process of soft-pack lithium batteries. The device includes: a lifting mechanism capable of vertical lifting; a piercing assembly mounted on the lifting mechanism and driven by the lifting mechanism to perform vertical lifting movements; the piercing assembly includes a handle and a piercing execution part disposed at the working end of the handle; the piercing execution part includes at least two piercing heads that are separated from each other, for simultaneously piercing at least two drainage holes in the air bag of the soft-pack battery.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery manufacturing technology, and in particular to a puncture device for the secondary sealing process of soft-pack lithium batteries. Background Technology

[0002] In the manufacturing process of pouch lithium batteries, the second sealing (i.e., the second encapsulation) is a critical step. In this step, the air pocket of the battery needs to be punctured to effectively extract the gas and excess electrolyte from inside the battery in a vacuum environment, thereby ensuring the battery's performance and safety.

[0003] Currently, the industry commonly uses a conventional single-headed piercing tool to perform the aforementioned piercing operation. However, in actual production, this technical solution has a significant drawback: because only a single drain hole is provided, during vacuum pumping, if there is a large amount of electrolyte in a certain area inside the battery, the liquid will be concentrated and discharged at high speed from that single hole. In the complex sealed vacuum chamber, this concentrated jet of electrolyte is prone to splashing and backflow, and can contaminate and corrode the main body of the battery cell, resulting in poor cell appearance and even affecting its internal performance.

[0004] This problem directly leads to increased production costs. To solve it, manufacturers typically need to manually screen and remove corroded cells, which not only increases labor costs but also results in material waste. Summary of the Invention

[0005] One of the objectives of this utility model is to provide a puncture device for the secondary sealing process of soft-pack lithium batteries, which can effectively avoid the backflow corrosion problem caused by the concentrated discharge of electrolyte from a single hole, thereby improving the product appearance yield and reducing production costs.

[0006] In a first aspect, the present invention provides a piercing device for the secondary sealing process of a soft-pack lithium battery, comprising: The lifting mechanism allows for vertical lifting. The bayonet assembly is mounted on the lifting mechanism and is driven by the lifting mechanism to perform vertical lifting movements. The bayonet assembly includes a handle and a piercing actuator disposed at the working end of the handle. The puncture actuator includes at least two separate piercing heads for simultaneously piercing at least two drainage holes in the air bag of the pouch battery.

[0007] Optionally, the number of the at least two bayonet heads is two or three.

[0008] Optionally, at least two of the bayonet heads may penetrate in different directions.

[0009] Optionally, at least two of the bayonet heads have different piercing directions, including, At least two of the bayonet heads form a predetermined angle between their central axes, and / or, The piercing ends of at least two of the bayonet heads have a height difference in position on a plane perpendicular to the lifting direction.

[0010] Optionally, when the different piercing directions result in the formation of a preset angle, the preset angle ranges from 10° to 90°.

[0011] Optionally, all of the bayonet heads have the same piercing direction.

[0012] Optionally, each of the bayonet heads is conical or pyramidal. As can be seen from the above, the piercing device of this embodiment, by setting multiple drainage holes, fundamentally changes the electrolyte drainage dynamics. It decomposes the concentrated, high-speed jet of the traditional single-hole method into multiple dispersed, low-speed liquid streams, greatly reducing the risk of electrolyte splashing, backflow, and corrosion of the battery cell due to concentrated spraying, and significantly improving the product appearance yield. Applying the piercing device of this embodiment creates multiple holes in the pouch battery, providing more channels for gas and liquid drainage, helping to shorten the vacuuming time, and potentially making the electrolyte drainage more uniform in different areas of the battery, thereby improving the consistency of battery performance. This device can directly replace the existing single-head piercing mechanism without requiring major modifications to the overall structure of the secondary sealing equipment, has low implementation costs, and is easy to quickly promote on existing production lines. Attached Figure Description

[0013] The accompanying drawings, which are provided to further illustrate the present invention and form part of this application, do not constitute an undue limitation of the present invention.

[0014] Figure 1 A schematic diagram of a piercing device provided in an embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of a piercing device descending to pierce during an embodiment of the present invention.

[0015] Figure label: 1: Lifting mechanism; 2: Knife handle; 3: Bayonet head. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0017] Examples of embodiments of the present invention are shown in the accompanying drawings in a detailed description below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0018] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., 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 according to the specific circumstances.

[0021] See Figure 1 , 2 .

[0022] The piercing device for the secondary sealing process of soft-pack lithium batteries of the present invention mainly consists of two core parts: a lifting mechanism 1 and a piercing assembly.

[0023] The lifting mechanism 1 can be implemented using conventional linear drive devices such as cylinders, electric push rods, or servo motor-driven linear modules. The bayonet assembly is fixedly mounted to the output end of the lifting mechanism 1 via a connecting plate, and is driven by it to perform precise vertical lifting movements. The bayonet assembly includes a handle 2 and a piercing actuator, the piercing actuator integrating at least two separate bayonet heads 3. These bayonet heads 3 are preferably fixed to the working end of the handle 2 in a specific layout.

[0024] Its working principle is as follows: after the air bag of the pouch battery is positioned at the piercing station, the control system instructs the lifting mechanism 1 to push the piercing assembly downward. Multiple piercing heads 3 on the piercing actuator simultaneously contact and pierce the air bag, instantly forming at least two drainage holes. Subsequently, the lifting mechanism 1 rises back, making room for subsequent vacuuming and sealing processes.

[0025] As can be seen from the above, the piercing device of this embodiment, by setting multiple drainage holes, fundamentally changes the electrolyte drainage dynamics. It decomposes the concentrated, high-speed jet of the traditional single-hole method into multiple dispersed, low-speed liquid streams, greatly reducing the risk of electrolyte splashing, backflow, and corrosion of the battery cell due to concentrated spraying, and significantly improving the product appearance yield. Applying the piercing device of this embodiment creates multiple holes in the pouch battery, providing more channels for gas and liquid drainage, helping to shorten the vacuuming time, and potentially making the electrolyte drainage more uniform in different areas of the battery, thereby improving the consistency of battery performance. This device can directly replace the existing single-head piercing mechanism without requiring major modifications to the overall structure of the secondary sealing equipment, has low implementation costs, and is easy to quickly promote on existing production lines.

[0026] As a further illustration of the invention, the number of bayonet heads 3 can be two or three (e.g., but not limited to a symmetrical arrangement). The two or three bayonet heads 3 achieve an optimal balance between effective diversion and ensuring structural compactness. Too few bayonet heads result in insufficient diversion; too many may lead to structural complexity, increased cost, and the close proximity of multiple holes could weaken the structural strength of the airbag.

[0027] As an illustration of this embodiment, the different piercing directions of any two bayonet heads 3 can be achieved in the following ways: Option A: A predetermined angle α is formed between the central axes of at least two bayonet heads 3. This angle α is preferably controlled within the range of 10° to 90°. For example, in the double bayonet head option, the two bayonet heads 3 are arranged in a "V" shape; Option B: The piercing ends of at least two bayonet heads 3 have a height difference on a plane perpendicular to the lifting direction, so that the tips of the two (or more) bayonet heads 3 are staggered in the vertical direction, with one higher and one lower.

[0028] Even though the two bayonet heads 3 penetrate in a parallel direction (i.e., their central axes are parallel), due to the height difference (ΔZ) between their tips, they will pierce holes sequentially at different thickness levels of the air bag. This is equivalent to creating a three-dimensional, deep drainage channel on the "side" of the air bag, rather than two holes on a vertical plane. This structure can also effectively disrupt and disperse the concentrated discharge of electrolyte, achieving a diversion effect. It is another efficient and easy-to-manufacture method, distinct from the "angled" scheme.

[0029] Option C: A hybrid option combining options A and B can also be adopted.

[0030] As can be seen above, Scheme A uses directional differences to create different trajectories for the discharged liquid flow; Scheme B uses height differences to create a three-dimensional drainage channel along the thickness of the air bag. Both schemes can prevent the liquid flow from converging prematurely within a limited space, significantly reducing the risk of liquid flow interference and backflow corrosion. Technicians can select or combine different directional differentiation schemes according to actual working conditions to achieve the best diversion effect.

[0031] It should be noted that, but not limited to, all bayonet heads 3 can be designed with the same piercing direction, i.e., the central axes of each bayonet head 3 are parallel to each other. This parallel layout simplifies the structure, facilitates manufacturing, and helps reduce production costs. All bayonet heads 3 penetrate at the same angle and depth, ensuring consistent hole morphology, making it suitable for scenarios with specific requirements for uniform drainage.

[0032] As an illustration of this embodiment, each bayonet head 3 can be specifically implemented as either a cone or a pyramid. The pyramid shape can be further categorized as a triangular pyramid, a square pyramid, etc. A cone shape results in low puncture resistance, minimal damage to the airbag material, and smooth edges on the formed hole. A pyramid shape, due to its sharp lateral edges, provides stronger puncture capability, is suitable for thicker or more resilient airbag materials, and the formed hole is less prone to clogging.

[0033] In summary, the piercing device of this embodiment, used in the secondary sealing process of soft-pack lithium batteries, solves the industry problem of electrolyte backflow corrosion through the basic concept of multi-head piercing.

[0034] The above embodiments do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments should be included within the scope of protection of this technical solution.

Claims

1. A puncture device for the secondary sealing process of soft-pack lithium batteries, characterized in that, include: The lifting mechanism allows for vertical lifting. The bayonet assembly is mounted on the lifting mechanism and is driven by the lifting mechanism to perform vertical lifting movements. The bayonet assembly includes a handle and a piercing actuator disposed at the working end of the handle. The puncture actuator includes at least two separate piercing heads for simultaneously piercing at least two drainage holes in the air bag of the pouch battery.

2. The puncture device for the secondary sealing process of a soft-pack lithium battery according to claim 1, characterized in that, The number of the at least two bayonet heads is two or three.

3. A puncture device for the secondary sealing process of a soft-pack lithium battery according to claim 1 or 2, characterized in that, At least two of the bayonet heads have different piercing directions.

4. A puncture device for the secondary sealing process of a soft-pack lithium battery according to claim 3, characterized in that, At least two of the bayonet heads have different piercing directions, including, At least two of the bayonet heads form a predetermined angle between their central axes, and / or, The piercing ends of at least two of the bayonet heads have a height difference in position on a plane perpendicular to the lifting direction.

5. A puncture device for the secondary sealing process of a soft-pack lithium battery according to claim 4, characterized in that, When the different puncture directions result in the formation of a preset angle, the preset angle ranges from 10° to 90°.

6. A puncture device for the secondary sealing process of a soft-pack lithium battery according to claim 1 or 2, characterized in that, All of the bayonet heads have the same piercing direction.

7. A puncture device for the secondary sealing process of a soft-pack lithium battery according to claim 1 or 2, characterized in that, Each of the bayonet heads is conical or pyramidal in shape.

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