Battery cell pressure resistance testing device

Abstract

This utility model discloses a cell withstand voltage testing device, relating to the field of battery technology. The cell withstand voltage testing device, used for testing the withstand voltage of pouch cell packaging, includes: a base plate; a clamping plate, disposed above the base plate, with a through hole on the clamping plate, and the pouch cell disposed between the base plate and the clamping plate; and an air pipe connector, disposed on the pouch cell and communicating with the inner space of the aluminum-plastic film of the pouch cell, the air pipe connector passing through the through hole. When in use, the cell withstand voltage testing device restricts the deformation freedom of the upper sealing area of ​​the pouch cell and inflates the pouch cell through the air pipe connector. By using auxiliary structures such as edge-folding adhesive tape and width-limiting blocks, this device can separately limit the deformation freedom of the cell in the width or length direction, thereby guiding the internal air pressure to preferentially act on the target sealing area, achieving zoned, independent, and precise withstand voltage strength testing of the three key packaging parts: side seal, secondary seal, and tab seal, facilitating targeted optimization of packaging process parameters.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically relating to a battery cell withstand voltage testing device. Background Technology

[0002] Pouch lithium-ion batteries are widely used in electric vehicles, energy storage systems, and consumer electronics due to their high energy density, light weight, and customizable shape. Pouch cells are typically encapsulated using an aluminum-plastic film, with sealing areas including side seals, secondary seals, and tab seals. The sealing quality and pressure resistance of these areas directly affect the cell's safety, reliability, and cycle life during use. Insufficient sealing strength can lead to cracking during charging and discharging due to internal gas generation or external mechanical stress, causing serious safety accidents such as leakage, fire, or even explosion. Therefore, accurate and reliable testing of the pressure resistance of each sealing area of ​​a pouch cell is crucial for evaluating the rationality of the cell design, verifying the stability of the packaging process, and improving product quality control.

[0003] Currently, industry testing of the packaging strength of pouch cells mainly relies on testing with dummy cells or empty aluminum-plastic bags, which cannot accurately reflect the packaging strength of real cells. Furthermore, existing testing methods typically only perform overall withstand voltage testing on the entire cell, failing to provide independent, directional strength assessments of different sealing areas such as side seals, secondary seals, and tab seals.

[0004] In summary, there is an urgent need for a safe, reliable, and zoned packaging withstand voltage test device for finished soft-pack battery cells, so as to truly reflect the actual strength performance of each sealing area and provide effective technical support for cell design verification, process stability monitoring, and failure analysis. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a battery cell withstand voltage testing device.

[0006] The objective of this utility model can be achieved through the following technical solution: a battery cell withstand voltage testing device for testing the withstand voltage of pouch battery cells, comprising:

[0007] Base plate;

[0008] A clamping plate is disposed above the base plate, and the clamping plate is provided with through holes. The soft-pack battery cell is disposed between the base plate and the clamping plate.

[0009] An air tube connector is disposed on the soft-pack battery cell and is in communication with the inner space of the aluminum-plastic film of the soft-pack battery cell. The air tube connector passes through the through hole.

[0010] When the battery cell withstand voltage testing device is used, it restricts the degree of freedom of deformation of the upper part of the sealed area of ​​the soft-pack battery cell and inflates the soft-pack battery cell through the air pipe connector.

[0011] As a further improvement of this utility model, it also includes a flange nut, which is disposed on the aluminum-plastic film of the soft-pack battery cell, and the air pipe connector is screwed to the flange nut.

[0012] As a further improvement of this utility model, it also includes a thickness limiting bolt, which is inserted into the base plate and the clamping plate to adjust the distance between the clamping plate and the base plate.

[0013] As a further improvement of this utility model, it also includes a set screw, which is disposed on the side of the clamping plate, and the movement direction of the set screw is perpendicular to the movement direction of the thickness limiting bolt.

[0014] As a further improvement of this utility model, it also includes a locking bolt, and the sides of the base plate and the clamping plate are provided with receiving grooves, and the locking bolt is disposed in the receiving grooves.

[0015] As a further improvement of this utility model, it also includes a washer and a locking nut, wherein the washer and the locking nut are disposed above the clamping plate and sequentially sleeved on the locking bolt, and the locking nut abuts against the clamping plate through the washer.

[0016] As a further improvement of this utility model, a fixing block is provided at the bottom of the base plate, and one end of the locking bolt is rotatably connected to the fixing block.

[0017] As a further improvement of this utility model, it also includes edge-folding adhesive tape, which is pasted on at least one of the side seal and the second seal of the soft-pack battery cell and connected to the base plate.

[0018] As a further improvement of this utility model, it also includes a width limiting block, which is disposed at at least one of the side seal and the second seal of the soft-pack battery cell, and the width limiting block abuts against the soft-pack battery cell.

[0019] As a further improvement of this utility model, it also includes foam, which is attached to the tabs of the soft-pack battery cell and connected to the base plate.

[0020] Based on the above technical solution, this utility model can produce at least the following technical effects:

[0021] 1. This device performs withstand voltage tests directly on finished soft-pack battery cells, avoiding the test deviations caused by traditional methods that rely on empty aluminum-plastic bags or fake battery cells. It can truly reflect the withstand voltage performance of the side seal, secondary seal, and tab seal of the actual battery cell in a complete structural state, significantly improving the engineering reference value and process guidance significance of the test results.

[0022] 2. By using auxiliary structures such as edge-folding tape, width-limiting blocks, and foam, combined with the limiting adjustment mechanism of the clamping plate and the base plate, this device can limit the deformation freedom of the battery cell in the width or length direction, thereby guiding the internal air pressure to act preferentially on the target sealing area, realizing the partitioned, independent, and precise withstand pressure strength test of the three key packaging parts: side seal, second seal, and tab seal, which facilitates targeted optimization of packaging process parameters;

[0023] 3. The device adopts a modular design, including components such as adjustable thickness limiting bolts, locking bolts, set screws and width limiting blocks, which can flexibly adjust the clamping gap and limiting width to adapt to soft-pack battery cells of different thicknesses and widths. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. 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 one embodiment of a battery cell withstand voltage testing device.

[0026] Figure 2 This is a schematic diagram of a pouch cell.

[0027] Figure 3 This is a schematic diagram of the flange nut, air pipe connector, and folded adhesive tape.

[0028] Figure 4 This is a schematic diagram of another embodiment of the battery cell withstand voltage testing device.

[0029] In the diagram, 100 is the base plate; 110 is the locking bolt; 120 is the locking nut; 121 is the washer; 130 is the fixing block; 200 is the clamping plate; 210 is the through hole; 220 is the thickness limiting bolt; 230 is the set screw; 240 is the width limiting block; 250 is the receiving groove; 300 is the soft-pack battery cell; 310 is the flange nut; 320 is the air pipe connector; 330 is the folded edge adhesive tape; 340 is the foam; 350 is the side seal; 360 is the second seal; and 370 is the electrode tab seal. Detailed Implementation

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indication will also change accordingly. Furthermore, in this utility model, descriptions involving "first," "second," "a," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly defined. In this utility model, unless otherwise explicitly specified and defined, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to the specific circumstances. Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope claimed by this utility model.

[0031] The following are specific embodiments of this utility model, in conjunction with the accompanying drawings. Figure 1-4 The technical solution of this utility model will be further described below, but this utility model is not limited to the following embodiments.

[0032] This utility model provides a battery cell withstand voltage testing device for testing the withstand voltage strength of the packaging structure of finished soft-pack battery cell 300. It is particularly suitable for independent and directional strength assessment of key sealing areas such as side seal 350, secondary seal 360 and tab seal 370.

[0033] The battery cell withstand voltage testing device includes components such as a base plate 100, a clamping plate 200, an air pipe connector 320, a flange nut 310, a thickness limiting bolt 220, a set screw 230, a locking bolt 110, a gasket 121, a locking nut 120, a fixing block 130, an edge-folding adhesive tape 330, a width-limiting block 240, and foam 340.

[0034] Before testing, the finished soft-pack battery cell 300 to be tested is first subjected to safety pretreatment: the battery cell is over-discharged through an external circuit to reduce its voltage to near zero volts in order to eliminate residual electrical energy and ensure that no safety accidents will be caused by internal short circuits or electric arcs during subsequent inflation tests.

[0035] Subsequently, a test area (usually located in the middle of the cell) is selected and marked on the surface of the aluminum-plastic film of the battery cell. Adhesive is applied to the surface of the flange nut 310 that contacts the aluminum-plastic film, and the flange nut 310 is firmly bonded to the marked location. The adhesive can be UV glue, polyolefin hot melt adhesive, acrylic double-sided tape, etc., without specific limitations. When using UV glue, the flange nut 310 must be made of transparent material to allow for UV curing. After the adhesive has cured, the gas pipe connector 320 is threaded onto the flange nut 310. Next, a fine needle is used to pierce the aluminum-plastic film downwards from the center of the gas pipe connector 320, connecting the gas pipe connector 320 to the internal cavity of the battery cell, forming a gas passage. This structure ensures that gas can be stably injected into the battery cell during inflation, while preventing premature rupture of the aluminum-plastic film due to localized stress concentration, thus achieving sealed inflation of the finished battery cell.

[0036] The processed battery cell is placed on the base plate 100. The base plate 100 is a rigid flat plate structure used to support the battery cell and provide a limiting reference. The clamping plate 200 is located directly above the base plate 100 and has a through hole 210. The through hole 210 is aligned with the air pipe connector 320, so that the air pipe connector 320 can extend upward through the through hole 210 for easy connection to an external air source pipeline.

[0037] To adjust the gap between the clamping plate 200 and the base plate 100, the device is equipped with multiple thickness-limiting bolts 220, which are vertically inserted between the base plate 100 and the clamping plate 200. By rotating the thickness-limiting bolts 220, the gap between the clamping plate 200 and the base plate 100 can be precisely controlled, thereby accommodating soft-pack battery cells 300 of different thicknesses. After adjustment, the gap is tightened by set screws 230 located on the side of the clamping plate 200. The axis of the set screws 230 is perpendicular to the thickness-limiting bolts 220, and their ends abut against the side of the thickness-limiting bolts 220 to prevent loosening due to vibration or pressure fluctuations during testing, ensuring a stable clamping gap.

[0038] Furthermore, the base plate 100 and the clamping plate 200 have receiving grooves 250 on their sides, and the locking bolt 110 passes through these grooves. The lower end of the locking bolt 110 is rotatably connected to the fixing block 130 located at the bottom of the base plate 100, and the upper end is sequentially fitted with a washer 121 and a locking nut 120. When the locking nut 120 is tightened, it applies a downward clamping force to the clamping plate 200 through the washer 121, causing the clamping plate 200 and the base plate 100 to clamp the battery cell together, preventing it from shifting or warping during inflation.

[0039] Depending on the testing objective, this device can be flexibly configured with auxiliary structures to achieve directional testing of specific sealed areas:

[0040] (I) Implementation Method of 370 Pressure Resistance Test for Electrode Seals

[0041] First, U-shaped folding tape 330 is applied to the folded edge of the battery cell to firmly fix the folded edge to the base plate 100, restricting its free deformation during inflation. In other embodiments, any type of tape can be used instead of folding tape 330, or the entire folded edge can be encapsulated and fixed with glue. Then, two width-limiting blocks 240 are installed on the base plate 100, and their positions are adjusted so that the gap between the two blocks matches the width of the battery cell, thereby limiting and clamping the battery cell in the width direction. At this point, the battery cell is constrained in the width direction, and only the area of ​​the tab seal 370 has the potential to break.

[0042] Connect the air tube to air tube connector 320 and slowly introduce compressed air. As the internal air pressure increases, the cell expands, but because other areas are effectively confined, stress concentrates at the tab seal 370, eventually causing it to rupture. By recording the air pressure value at the moment of rupture, the true withstand pressure strength of the tab seal 370 can be obtained.

[0043] (II) Implementation Method for Side Seal 350 and Second Seal 360 Withstand Pressure Test

[0044] Unlike the tab withstand voltage test, the width limiting block 240 is not installed here, allowing the battery cell to remain free in the width direction. At the same time, foam 340 is attached to the tab area of ​​the battery cell. The foam 340 is of moderate thickness, and its edge protrudes from the battery cell body at least to ensure that when the clamping plate 200 is pressed down, the foam 340 effectively buffers and compresses the tab seal 370 area, significantly reducing the tendency of this area to break.

[0045] Because the pouch cell 300 is typically elongated, its width-direction sealing edges (i.e., side seals 350 and secondary seals 360) bear greater tension under internal pressure. With the tab seal 370 protected by foam 340 and the folded edges not secured by adhesive tape, internal air pressure will preferentially cause the side seal 350 or secondary seal 360 to rupture. This method allows for accurate acquisition of the withstand voltage data for the side seal 350 or secondary seal 360.

[0046] It is worth noting that the folded edge adhesive tape 330 can be selectively pasted on either or both of the side seal 350 and the second seal 360, and the width limiting block 240 can also be adjusted in position or quantity according to testing requirements. The thickness and pasting area of ​​the foam 340 can also be adapted according to the size of the battery cell, demonstrating the good versatility and adjustability of this device.

[0047] In summary, this invention successfully achieved independent withstand voltage testing of the three key sealing areas of the finished 300-cell soft-pack battery through a structured clamping and limiting design and a zoned constraint strategy. This not only solves the testing distortion problem caused by the reliance on simulated samples in traditional methods, but also significantly improves the accuracy and operability of packaging process verification. The device is simple in structure, highly safe, and has good repeatability, making it widely applicable in battery R&D, process verification, and production line quality control, demonstrating significant practical value and promising prospects for widespread adoption.

[0048] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A cell withstand voltage testing device for testing the withstand voltage of pouch cells (300) packaging, characterized in that, include: Base plate (100); A clamping plate (200) is disposed above the base plate (100), and a through hole (210) is provided on the clamping plate (200). The soft-pack battery cell (300) is disposed between the base plate (100) and the clamping plate (200). An air pipe connector (320) is disposed on the soft-pack battery cell (300) and is in communication with the inner space of the aluminum-plastic film of the soft-pack battery cell (300). The air pipe connector (320) passes through the through hole (210). When the battery cell withstand voltage test device is used, it restricts the degree of freedom of deformation of the upper part of the sealed area of ​​the soft-pack battery cell (300) and inflates the soft-pack battery cell (300) through the air pipe connector (320).

2. The cell withstand voltage testing device according to claim 1, characterized in that, It also includes a flange nut (310), which is disposed on the aluminum-plastic film of the soft-pack battery cell (300), and the air pipe connector (320) is screwed to the flange nut (310).

3. The cell withstand voltage testing device according to claim 1, characterized in that, It also includes a thickness limiting bolt (220), which is inserted into the base plate (100) and the clamping plate (200) to adjust the distance between the clamping plate (200) and the base plate (100).

4. The cell withstand voltage testing device according to claim 3, characterized in that, It also includes a set screw (230), which is disposed on the side of the clamp (200), and the movement direction of the set screw (230) is perpendicular to the movement direction of the thickness limiting bolt (220).

5. The cell withstand voltage testing device according to claim 1, characterized in that, It also includes a locking bolt (110), and the sides of the base plate (100) and the clamping plate (200) are provided with receiving grooves (250), and the locking bolt (110) is disposed in the receiving grooves (250).

6. The cell withstand voltage testing device according to claim 5, characterized in that, It also includes a washer (121) and a locking nut (120), the washer (121) and the locking nut (120) are disposed above the clamping plate (200) and are sequentially sleeved on the locking bolt (110), and the locking nut (120) abuts against the clamping plate (200) through the washer (121).

7. The cell withstand voltage testing device according to claim 5, characterized in that, A fixing block (130) is provided at the bottom of the base plate (100), and one end of the locking bolt (110) is rotatably connected to the fixing block (130).

8. The cell withstand voltage testing device according to claim 1, characterized in that, It also includes edge-folding adhesive tape (330), which is attached to at least one of the side seal (350) and the second seal (360) of the soft-pack battery cell (300) and connected to the base plate (100).

9. The cell withstand voltage testing device according to claim 1, characterized in that, It also includes a width limiting block (240), which is disposed at at least one of the side seal (350) and the second seal (360) of the soft-pack battery cell (300), and the width limiting block (240) abuts against the soft-pack battery cell (300).

10. A cell withstand voltage testing device according to claim 1, characterized in that, It also includes foam (340), which is attached to the tab of the soft-pack battery cell (300) and connected to the base plate (100).

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