Explosion-proof membrane structure of power battery

Abstract

The embodiment of the utility model provides an explosion-proof membrane structure of a power battery, which comprises a first base material layer, an explosion layer and a sealing layer, a plurality of pressure relief areas are arranged in the explosion layer, strength ribs are arranged among the pressure relief areas, a connecting strip is arranged between the pressure relief areas and the strength ribs, pre-nicks are arranged in the pressure relief areas, and the sealing layer is arranged on the first base material layer. The pressure relief structure has the advantages that the blasting layer is arranged between the first base material layer and the sealing layer, the pressure relief area is divided into the six areas through the pre-nicks preset on the blasting layer, the six blasting areas are formed, the shape of cracks is determined, during pressure relief, the multiple openings are used for exhausting air, and the pressure relief effect is good. In addition, the strength ribs are arranged between the pressure relief areas, so that the edges of the pressure relief areas can be firmer, and the situation that the pressure is lower than the designed pressure due to premature fracture caused by external force or material fatigue is avoided.

Description

Technical Field

[0001] This utility model relates to the field of power batteries, and more particularly to an explosion-proof membrane structure for power batteries. Background Technology

[0002] Typical explosion-proof structures for power batteries utilize explosion-proof membranes to cover and connect to the pressure relief holes of the battery cover. When the internal pressure of the power battery rises abnormally, the explosion-proof membrane plays a role in venting and relieving pressure. It releases high-temperature and high-pressure gases to the outside of the power battery through the pressure relief area, reducing the internal pressure and providing a certain degree of protection to prevent the casing from exploding.

[0003] The shape of the crack in the central area of ​​the existing explosion-proof membrane is unpredictable when it bursts, the burst opening may not be sufficient, the venting effect is not stable enough, and it affects the rapid release of internal pressure. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an explosion-proof membrane structure for power batteries, which solves the technical problems of unpredictable crack shape in the central area of ​​the film when the existing explosion-proof membrane bursts, insufficient burst opening, unstable venting effect, and impaired rapid release of internal pressure.

[0006] (II) Technical Solution

[0007] The purpose of this utility model is to provide an explosion-proof film structure for a power battery, which includes a first substrate layer, an explosion-proof layer, and a sealing layer. Flame-retardant acrylic adhesive is provided between the first substrate layer and the explosion-proof layer, and between the explosion-proof layer and the sealing layer. A release film is bonded to the lower end face of the sealing layer through flame-retardant acrylic adhesive. Several pressure relief zones are provided in the explosion-proof layer. Strength ribs are provided between the pressure relief zones. A connecting strip is provided between the pressure relief zones and the strength ribs. Pre-marks are provided in the pressure relief zones. The pressure relief zones are divided into six areas by the pre-marks, and each area is separated by the pre-marks.

[0008] Preferably, the first substrate layer and the sealing layer are polymer films, the material of which is one of polypropylene, polyethylene terephthalate, polyethylene, and biaxially oriented polypropylene.

[0009] Preferably, the bursting layer is a PET film.

[0010] Preferably, the width of the pressure relief zone is B1, and the width of the strength rib is B2. B1 and B2 satisfy the following relationships: 2mm≤B1≤10mm, 1mm≤B2≤5mm, and B1:B2 satisfies the relationship 1≤B1:B2≤10.

[0011] Preferably, the pressure relief zone has a symmetrical structure, with the regions at both ends of the pressure relief zone being equilateral trapezoidal in shape, and the regions on both sides of the pressure relief zone being four right trapezoidal shapes that are opposite to each other in pairs.

[0012] Preferably, the thickness of the first substrate layer is 0.05 mm to 0.08 mm.

[0013] (III) Beneficial Effects

[0014] By setting a bursting layer between the first substrate layer and the sealing layer, the pressure relief area is divided into six regions by pre-marked grooves on the bursting layer, forming six bursting zones. This determines the shape of the cracks. During pressure relief, multiple openings release gas, enhancing the venting effect and allowing the internal pressure of the power battery to be released quickly. In addition, setting strength ribs between the pressure relief areas makes the edges of the pressure relief areas more robust, preventing premature rupture due to external forces or material fatigue, which would lead to pressure relief below the design pressure. Attached Figure Description

[0015] The accompanying drawings are provided to further understand the technical solution of this utility model and constitute a part of the specification. They are used together with the embodiments of this utility model to explain the technical solution of this utility model, and do not constitute a limitation on the technical solution of this utility model.

[0016] Figure 1 This is a schematic diagram of the explosion-proof membrane structure of a power battery;

[0017] Figure 2 This is a diagram of the burst layer structure of the explosion-proof membrane structure of a power battery;

[0018] Figure 3 This is a diagram of the burst layer structure of the explosion-proof membrane structure of a power battery;

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. First substrate layer; 2. Bursting layer; 21. Strength rib; 22. Pressure relief zone; 221. Pre-score; 222. Connecting strip; 3. Sealing layer; 4. Release film; 5. Flame-retardant acrylic adhesive. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0022] The following is in conjunction with the appendix Figures 1 to 3To further describe, this utility model discloses an explosion-proof film structure for a power battery, including a first substrate layer 1, a burst layer 2, and a sealing layer 3. Flame-retardant acrylic adhesive 5 is provided between the first substrate layer 1 and the burst layer 2, and between the burst layer 2 and the sealing layer 3. A release film 4 is bonded to the lower end face of the sealing layer 3 through the flame-retardant acrylic adhesive 5. The burst layer 2 is provided with a plurality of pressure relief zones 22. Strength ribs 21 are provided between the pressure relief zones 22. A connecting strip 222 is provided between the pressure relief zones 22 and the strength ribs 21. Pre-scores 221 are provided in the pressure relief zones 22. The pressure relief zones 22 are divided into six regions by the pre-scores 221, and each region is separated by the pre-scores 221.

[0023] In a preferred embodiment, the first substrate layer 1 and the sealing layer 3 are polymer films, the material of which is one of polypropylene, polyethylene terephthalate, polyethylene, and biaxially oriented polypropylene.

[0024] In a preferred embodiment, the bursting layer 2 is a PET film.

[0025] In a preferred embodiment, the width of the pressure relief zone 22 is B1, and the width of the strength rib 21 is B2. B1 and B2 satisfy the following relationships: 2mm≤B1≤10mm, 1mm≤B2≤5mm, and B1:B2 satisfies the relationship 1≤B1:B2≤10.

[0026] In a preferred embodiment, the pressure relief zone 22 has a symmetrical structure, with the regions at both ends of the pressure relief zone 22 being equilateral trapezoidal in shape, and the regions on both sides of the pressure relief zone 22 being four opposing right-angled trapezoidal shapes.

[0027] In a preferred embodiment, the thickness of the first substrate layer 1 is 0.05 mm to 0.08 mm.

[0028] Based on the tests conducted in the above embodiments, the following parameters can be obtained:

[0029] project Technical parameters 180-degree peel force ≥1.2 Initial tack (ball size) ≥2# Room temperature holding capacity (1 inch) ≥48H Long-term temperature resistance (°C) 80 Short-term temperature resistance (°C) 120 Insulation resistance (MΩ) ＞500

[0030] In summary, by setting a bursting layer between the first substrate layer and the sealing layer, and using the pre-marked grooves on the bursting layer to divide the pressure relief area into six regions, forming six bursting zones, the crack shape is determined. During pressure relief, multiple openings release gas, enhancing the venting effect and allowing the internal pressure of the power battery to be released quickly. In addition, setting strength ribs between the pressure relief areas can make the edges of the pressure relief areas more robust, preventing premature rupture due to external forces or material fatigue, thus avoiding pressure relief below the design pressure.

[0031] Although embodiments of the present invention have been shown above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications and variations to the above embodiments, but such modifications are all included within the broad scope of the foregoing disclosure, drawings and claims.

Claims

1. An explosion-proof membrane structure of a power battery, comprising a first substrate layer, an explosion layer and a sealing layer, wherein a fire-retardant acrylic glue is arranged between the first substrate layer and the explosion layer, and between the explosion layer and the sealing layer, and a release film is adhered to the lower end surface of the sealing layer through the fire-retardant acrylic glue, characterized in that: The blasting layer is provided with several pressure relief zones, and strength ribs are provided between the pressure relief zones. A connecting strip is provided between the pressure relief zone and the strength ribs. The pressure relief zone is provided with pre-marks, and the pressure relief zone is divided into six areas by the pre-marks, and each area is separated by the pre-marks.

2. The explosion-proof membrane structure of a power battery according to claim 1, characterized in that: The first substrate layer and sealing layer are polymer films, and their materials are one of polypropylene, polyethylene terephthalate, polyethylene, and biaxially oriented polypropylene.

3. The explosion-proof membrane structure of a power battery according to claim 1, characterized in that: The bursting layer is a PET film.

4. The explosion-proof membrane structure of the power battery according to claim 1, characterized in that: The width of the pressure relief zone is B1, and the width of the strength rib is B2. B1 and B2 satisfy the following relationships: 2mm≤B1≤10mm, 1mm≤B2≤5mm, and B1:B2 satisfies the relationship 1≤B1:B2≤10.

5. The explosion-proof membrane structure of a power battery according to claim 1, characterized in that: The pressure relief zone has a symmetrical structure. The areas at both ends of the pressure relief zone are equilateral trapezoidal in shape, and the areas on both sides of the pressure relief zone are four right trapezoidal shapes that are opposite each other in pairs. 6.The explosion-proof membrane structure of a power battery according to claim 1, characterized in that: The thickness of the first substrate layer is 0.05 mm to 0.08 mm.

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