Pressure relief structure, battery and battery module

Abstract

The utility model relates to the technical field of batteries, and discloses a pressure relief structure, a battery and a battery module, the pressure relief structure comprises a fixing part, a connecting part and a puncturing part, when the pressure relief structure of the structure is used, the pressure relief structure is installed in a packaging film of a battery, the fixing part is fixedly connected to the packaging film, and when the battery swells, the packaging film expands outwards, the packaging film pulls the connecting part outwards, and the connecting part moves relative to the puncture part, so that the puncture part is exposed out of the second straight body section, the spine part is in contact with and punctures the bulged packaging film, and pressure relief is achieved; and the safety performance of the battery can be effectively improved. The hardness of the puncture part is larger than that of the connecting part, the puncture part is prevented from moving in the process that the packaging film pulls the connecting part, the puncture part is stably kept in the packaging film, the puncture part can puncture the packaging film easily, meanwhile, the hardness of the puncture part is large, the puncture part can puncture the packaging film quickly and effectively, and pressure can be released quickly and effectively when the battery swells.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a pressure relief structure, a battery and a battery module. Background Art

[0002] Soft-pack batteries have advantages such as high specific energy, small size and light weight, so the application market of soft-pack batteries is relatively large. A soft-pack battery mainly includes pole ears, a pole group and a packaging film. The packaging film encapsulates the pole group and the pole ears and is sealed by hot pressing. When the existing soft-pack battery bulges, there is a lack of safety protection measures, resulting in low safety performance of the soft-pack battery. Summary of the Utility Model

[0003] In view of this, the utility model provides a pressure relief structure, a battery and a battery module to solve the problem of low safety of the existing battery when bulging.

[0004] In the first aspect, the utility model provides a pressure relief structure, including:

[0005] A fixing part, adapted to be connected to the packaging film of the battery;

[0006] A connecting part, including a first straight section, a bending section and a second straight section. The two ends of the bending section connect the first straight section and the second straight section, and the other end of the first straight section connects the fixing part;

[0007] A puncturing part, arranged on the second straight section. One end of the puncturing part far from the bending section is connected to the second straight section, and a pointed part is arranged at one end of the puncturing part facing the bending section; the hardness of the puncturing part is greater than that of the connecting part;

[0008] The pressure relief structure is adapted to be arranged in the packaging film of the battery. When the battery bulges, the packaging film pulls the connecting part, so that the puncturing part is exposed outside the second straight section, and the pointed part pierces the packaging film.

[0009] Beneficial effects: When the pressure relief structure of this structure is in use, it is installed in the packaging film of the battery, and the fixing part is fixedly connected to the packaging film. When the battery bulges, the packaging film expands outwards. As Figure 2 shown, the packaging film pulls the connecting part outwards, and the connecting part moves relative to the puncturing part, so that the puncturing part is exposed outside the second straight section, and the pointed part contacts and pierces the bulged packaging film to realize pressure relief, which can effectively improve the safety performance of the battery. The hardness of the puncturing part is greater than that of the connecting part, which can prevent the puncturing part from moving during the process of the packaging film pulling the connecting part. The puncturing part is stably kept in the packaging film, which is beneficial to its piercing the packaging film. At the same time, the puncturing part has a relatively high hardness, which is beneficial to its quickly and effectively piercing the packaging film, and can quickly and effectively relieve pressure when the battery bulges.

[0010] In an alternative embodiment, the connecting portion is strip-shaped, and one end in the length direction of the connecting portion is bent to form the bent section.

[0011] Advantageous effects: The connecting portion is strip-shaped, which facilitates the connecting portion to move along with the encapsulation film when the encapsulation film is pulled outward during battery swelling, so that the puncturing portion is exposed.

[0012] In an alternative embodiment, the extending direction of the second straight section is parallel to the extending direction of the first straight section, and the length of the second straight section is less than the length of the first straight section.

[0013] Advantageous effects: The length of the second straight section is less than or equal to the length of the first straight section. When the encapsulation film pulls the connecting portion, the connecting portion only needs to move a small distance outward to expose the puncturing portion out of the second straight section, so that the spike portion can puncture the encapsulation film in time to release pressure.

[0014] In an alternative embodiment, the puncturing portion is strip-shaped.

[0015] Advantageous effects: When the encapsulation film pulls the puncturing portion, the strip-shaped puncturing portion is more likely to be exposed out of the connecting portion. At the same time, the puncturing portion being strip-shaped is more conducive to puncturing the encapsulation film.

[0016] In an alternative embodiment, the puncturing portion further includes a connecting portion, both ends of the connecting portion are respectively connected to the second straight section and the spike portion, the connecting portion is rectangular, and the spike portion is triangular.

[0017] Advantageous effects: One end of the connecting portion facing the fixing portion is connected to the second straight section, which can ensure the connection length and connection strength between the puncturing portion and the second straight section, thereby effectively preventing the puncturing portion from detaching from the second straight section when the encapsulation film pulls the connecting portion.

[0018] In an alternative embodiment, the connecting portion is connected to at least one of the spike portions.

[0019] In an alternative embodiment, the puncturing portion is integrally formed on the second straight section, intermittent holes are provided on the second straight section, and the puncturing portion is arranged in the intermittent holes.

[0020] Advantageous effects: The intermittent holes disconnect the side wall of the puncturing portion from the side wall of the second straight section, so that when the connecting portion is pulled, the puncturing portion can be separated from the second straight section. The puncturing portion and the second straight section are integrally formed, that is, the puncturing portion and the connecting portion are integrally formed, which is convenient for the forming and manufacturing of the pressure relief mechanism.

[0021] In a second aspect, the present utility model further provides a battery, including:

[0022] An encapsulation film;

[0023] The electrode group is disposed inside the encapsulation film;

[0024] For the pressure relief structure described in any one of the above, the fixing portion is connected to the encapsulation film. The battery includes a pressure relief structure and has the same technical effect as the pressure relief structure, which will not be elaborated here.

[0025] In an alternative embodiment, along the thickness direction of the battery, the second straight section and the first straight section are respectively located outside two large faces of the electrode group, and the bent section is wrapped outside the end face of the electrode group.

[0026] Beneficial effects: When the encapsulation film bulges and pulls the connection portion, a force can be better applied to the second straight section in a direction away from the puncture portion, so that the puncture portion can be quickly and effectively exposed outside the second straight section.

[0027] In a third aspect, the present invention further provides a battery module including the above battery. The battery module includes a battery and has the same technical effect as the battery, which will not be elaborated here. Description of the Drawings

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 Schematic diagram of a pressure relief structure in a normal state according to an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of a pressure relief structure in a bulged state according to an embodiment of the present invention;

[0031] Figure 3 Schematic diagram of another pressure relief structure in a normal state according to an embodiment of the present invention;

[0032] Figure 4 Schematic diagram of a battery according to an embodiment of the present invention;

[0033] Figure 5 Schematic diagram of the battery in a bulged state;

[0034] Figure 6 Schematic diagram of a battery with double-sided electrode tabs;

[0035] Figure 7 Schematic diagram of a battery with single-sided electrode tabs.

[0036] Description of the Reference Numerals:

[0037] 1. Pressure relief structure; 11. Fixed part; 12. Connecting part; 121. First straight section; 122. Bending section; 123. Second straight section; 1231. Intermittent hole; 13. Puncture part; 131. Spike part; 132. Connecting part; 2. Packaging film; 3. Pole group; 4. Packaging line; 5. Internal pole ear; 6. External pole ear; 7. Welding area; 8. Pole ear glue. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0039] Existing batteries lack safety protection measures when bulging occurs, resulting in low safety performance of the batteries.

[0040] Combine the following Figures 1 to 7 , describing an embodiment of the utility model.

[0041] According to an embodiment of the present utility model, on one hand, a pressure relief structure 1 is provided, comprising a fixing portion 11 , a connecting portion 12 and a puncture portion 13 .

[0042] Among them, the fixing part 11 is suitable for connecting with the packaging film 2 of the battery; the connecting part 12 includes a first straight section 121, a bent section 122 and a second straight section 123, the two ends of the bent section 122 are connected to the first straight section 121 and the second straight section 123, and the other end of the first straight section 121 is connected to the fixing part 11; the puncture part 13 is arranged on the second straight section 123, the end of the puncture part 13 away from the bent section 122 is connected to the second straight section 123, and the end of the puncture part 13 facing the bent section 122 is provided with a spike part 131; the hardness of the puncture part 13 is greater than the hardness of the connecting part 12; the pressure relief structure 1 is suitable for being arranged in the packaging film 2 of the battery, when the battery is bulging, the packaging film 2 pulls the connecting part 12 so that the puncture part 13 is exposed to the second straight section 123, and the spike part 131 punctures the packaging film 2.

[0043] When the pressure relief structure 1 of this structure is used, it is installed in the packaging film 2 of the battery, and the fixing part 11 is fixedly connected to the packaging film 2. When the battery bulges, the packaging film 2 expands outwards. Figure 2As shown, the encapsulation film 2 pulls the connecting portion 12 outward, and the connecting portion 12 moves relative to the puncturing portion 13 so that the puncturing portion 13 is exposed outside the second straight section 123, and the spike portion 131 contacts and pierces the bulged encapsulation film 2 to achieve pressure relief, which can effectively improve the safety performance of the battery. The hardness of the puncturing portion 13 is greater than that of the connecting portion 12 to prevent the puncturing portion 13 from moving during the process of the encapsulation film 2 pulling the connecting portion 12. The puncturing portion 13 is stably maintained inside the encapsulation film 2, which is beneficial for it to pierce the encapsulation film 2. At the same time, the puncturing portion 13 has a greater hardness, which is beneficial for it to quickly and effectively pierce the encapsulation film 2, and can quickly and effectively relieve pressure when the battery bulges.

[0044] As Figures 1 to 3 shown, in one embodiment, the connecting portion 12 is strip-shaped, and one end in the length direction of the connecting portion 12 is bent to form a bent section 122. The connecting portion 12 being strip-shaped facilitates the connecting portion 12 to move with the encapsulation film 2 when the encapsulation film 2 pulls the connecting portion 12 outward during battery bulging, so that the puncturing portion 13 is exposed.

[0045] As Figures 1 to 3 shown, in some embodiments, the extending direction of the second straight section 123 is parallel to the extending direction of the first straight section 121, and the length of the second straight section 123 is less than the length of the first straight section 121. Since the length of the second straight section 123 is less than the length of the first straight section 121, when the encapsulation film 2 pulls the first straight section, the first straight section 121 only needs to be moved outward by a small distance to expose the puncturing portion 13 outside the second straight section 123, so that the spike portion 131 can timely pierce the encapsulation film 2 to relieve pressure.

[0046] In other embodiments, the length of the second straight section 123 may also be the same as the length of the first straight section 121; the extending direction of the second straight section 123 is also inclined to the extending direction of the first straight section 121.

[0047] As Figures 1 to 3 shown, in some embodiments, the puncturing portion 13 is also strip-shaped. When the encapsulation film 2 pulls the puncturing portion 13, the strip-shaped puncturing portion 13 is more likely to be exposed outside the second straight section 123. At the same time, the puncturing portion 13 being strip-shaped is more beneficial for it to pierce the encapsulation film 2.

[0048] As Figure 1 shown, the extending direction of the long side of the puncturing portion 13 is the same as the extending direction of the long side of the second straight section 123. When the encapsulation film 2 pulls the puncturing portion 13, the puncturing portion 13 remains stationary, and the first straight section 121 and the second straight section 123 move away from the puncturing portion 13.

[0049] Optionally, in some embodiments, the puncturing portion 13 further includes a connecting portion 132. Two ends of the connecting portion 132 are respectively connected to the second straight section 123 and the spike portion 131. The connecting portion 132 is rectangular, and the spike portion 131 is triangular. One end of the connecting portion 132 facing the fixing portion 11 is connected to the second straight section 123, which can ensure the connection length and connection strength between the puncturing portion 13 and the second straight section 123, so as to effectively avoid the puncturing portion 13 detaching from the second straight section 123 when the encapsulation film 2 pulls the connecting portion 12.

[0050] As Figure 1 shown, the connecting portion 132 is kept at a certain distance from the end of the second straight section 123 on the side away from the first straight section 121, which can ensure the fixing strength between the puncturing portion 13 and the second straight section 123 and avoid the puncturing portion 13 from breaking when the connecting portion 12 is pulled.

[0051] As Figure 1 shown, the spike portion 131 is arranged towards the bent side of the second straight section 123, and the connecting portion 132 is arranged on the side opposite to the bent side of the second straight section 123. The apex angle of the spike portion 131 is a small acute angle, which effectively ensures the sharpness of the spike portion 131 and ensures that it can quickly and effectively pierce the encapsulation film 2.

[0052] Optionally, in some embodiments, the connecting portion 132 is connected to at least one spike portion 131 to ensure the piercing effect of the spike portion 131.

[0053] For example, in some embodiments, as Figure 1 and Figure 2 shown, the connecting portion 132 is connected to one spike portion 131.

[0054] In other embodiments, as Figure 3 shown, the connecting portion 132 is connected to two spike portions 131, which can increase the number of piercing points and improve the pressure relief effect.

[0055] In other embodiments, the connecting portion 132 may also be connected to more than three spike portions 131.

[0056] Optionally, in some embodiments, the connecting portion 132 and the spike portion 131 are integrally formed.

[0057] In other embodiments, the puncturing portion 13 may also be conical or needle-shaped. One end of the puncturing portion 13 is connected to the second straight section 123. In the normal state, the puncturing portion 13 is located inside the second straight section 123. When the battery bulges, the encapsulation film 2 pulls the connecting portion 12 to expose the puncturing portion 13 outside the second straight section 123.

[0058] As Figure 1 and Figure 3As shown, the puncturing part 13 is integrally formed on the second straight section 123. The second straight section 123 is provided with intermittent holes 1231, and the puncturing part 13 is arranged in the intermittent holes 1231. The intermittent holes 1231 disconnect the side wall of the puncturing part 13 from the side wall of the second straight section 123, so that when the connecting part 12 is pulled, the puncturing part 13 can be separated from the second straight section 123. The puncturing part 13 and the second straight section 123 are integrally formed, that is, the puncturing part 13 and the connecting part 12 are integrally formed, which is convenient for forming the pressure relief mechanism.

[0059] In some embodiments, the connecting part 12 and the fixing part 11 are also integrally formed to ensure the connection strength between the connecting part 12 and the fixing part 11, and to prevent the connecting part 12 and the fixing part 11 from disconnecting when the encapsulation film 2 is pulled.

[0060] The fixing part 11, the connecting part 12 and the puncturing part 13 are integrally formed, with good structural integrity, and the pressure relief structure 1 can be made quickly and conveniently.

[0061] The fixing part 11, the connecting part 12 and the puncturing part 13 are all in the shape of thin plates, so as to pull the connecting part 12 and expose the piercing member outside the second straight section 123.

[0062] Optionally, in some embodiments, the material of the pressure relief structure 1 includes plastic, which has a certain degree of flexibility, facilitating the deformation of the connecting part 12 as the encapsulation film 2 is pulled. At the same time, the pressure relief structure 1 made of plastic material is arranged inside the encapsulation film 2 of the battery and has no interference with the battery, which can ensure the safety performance of the battery.

[0063] In some embodiments, the puncturing part 13 can be cured to make the hardness of the puncturing part 13 greater than that of the connecting part 12.

[0064] According to an embodiment of the present invention, on the other hand, a battery is also provided, which includes an encapsulation film 2, a battery cell group 3 and the above-mentioned pressure relief structure 1. Among them, the battery cell group 3 is arranged inside the encapsulation film 2; the fixing part 11 of the pressure relief structure 1 is connected to the encapsulation film 2.

[0065] When the battery with this structure bulges, the encapsulation film 2 expands outwards, and the encapsulation film 2 pulls the connecting part 12 outwards, so that the puncturing part 13 is exposed outside the second straight section 123, and the spiky part 131 contacts and pierces the bulged encapsulation film 2 to achieve pressure relief, which can effectively improve the safety performance of the battery.

[0066] Optionally, in some embodiments, the fixing part 11 can be adhesively fixed on the encapsulation film 2, and the fixing part 11 is fixed conveniently and reliably.

[0067] In other embodiments, the fixing part 11 can also be heat-melted and fixed on the encapsulation film 2 to firmly fix one side of the pressure relief mechanism on the encapsulation film 2, ensuring that the encapsulation film 2 effectively pulls the connecting part 12 through the fixing part 11.

[0068] The two sides with larger battery area are its large sides. The pressure relief structure 1 is located inside the encapsulation film 2. As Figure 4 shown, in some embodiments, along the thickness direction of the battery, the second straight section 123 and the first straight section 121 are respectively located outside the two large sides of the electrode group 3, and the bent section 122 is wrapped outside the end face of the electrode group 3. That is, the fixing part 11 and the second straight section 123 are respectively located on both sides of the electrode group 3 in the thickness direction, and the first straight section 121 and the second straight section 123 of the connecting part 12 are arranged on both sides of the electrode group 3 in the thickness direction. When the encapsulation film 2 bulges and pulls the connecting part 12, a force can be better applied to the second straight section 123 in the direction away from the puncturing part 13, so that the puncturing part 13 can quickly and effectively expose the second straight section 123.

[0069] As Figure 4 shown, the encapsulation film 2 is encapsulated outside the electrode group 3, and an encapsulation line 4 is formed after hot pressing and encapsulating the four sides of the encapsulation film 2.

[0070] The battery further includes an internal tab 5 and an external tab 6. The internal tab 5 is electrically connected to the electrode group 3, and the external tab 6 is electrically connected to the internal tab 5.

[0071] Optionally, the internal tab 5 and the external tab 6 are connected by welding. As Figure 4 shown, a welding area 7 is formed at the welding position of the internal tab 5 and the external tab 6.

[0072] The internal tab 5 includes an internal positive tab and an internal negative tab, and the external tab 6 includes an external positive tab and an external negative tab. The internal positive tab is welded to the external positive tab, and the internal negative tab is welded to the external negative tab.

[0073] As Figure 4 shown, an ear glue 8 is provided at the connection between the external tab 6 and the encapsulation film 2.

[0074] Optionally, as Figure 6 shown, in some embodiments, the battery has tabs on different sides, and the positive tab and the negative tab are respectively located at both ends of the battery in the length direction.

[0075] In other embodiments, as Figure 7 shown, the battery has tabs on the same side, and the positive tab and the negative tab are located at the same end of the battery in the length direction.

[0076] As Figure 6 and Figure 7 shown, after the encapsulation film 2 is hot-pressed and encapsulated, its two sides are bent to form folded edges, and the folded edges are attached to the side of the battery to reduce the floor space of the battery and improve the energy density and volume packing efficiency of the module when the batteries are grouped.

[0077] Optionally, in some embodiments, the battery includes a soft-pack battery.

[0078] According to an embodiment of the present utility model, on the other hand, a battery module is further provided, including the above-mentioned battery.

[0079] In the battery module with this structure, when the battery inside bulges, the encapsulation film 2 expands outwards, and the encapsulation film 2 pulls the connecting portion 12 outwards, so that the puncturing portion 13 is exposed outside the second straight section 123, and the spike portion 131 contacts and punctures the bulged encapsulation film 2 to achieve pressure relief, which can effectively improve the safety performance of the battery and the battery module.

[0080] Although the embodiments of the present utility model have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A pressure relief structure, characterized in that, Comprising: A fixing part, adapted to be connected to the packaging film of the battery; A connecting part, including a first straight section, a bending section and a second straight section, the two ends of the bending section connect the first straight section and the second straight section, and the other end of the first straight section connects the fixing part; A puncturing part, provided on the second straight section, one end of the puncturing part away from the bending section is connected to the second straight section, and a spike part is provided at one end of the puncturing part facing the bending section; the hardness of the puncturing part is greater than that of the connecting part; A pressure relief structure, adapted to be arranged inside the packaging film of the battery. When the battery bulges, the packaging film pulls the connecting part, so that the puncturing part is exposed outside the second straight section, and the spike part pierces the packaging film.

2. The pressure relief structure according to claim 1, wherein The connecting part is strip-shaped, and one end in the length direction of the connecting part is bent to form the bending section.

3. The pressure relief structure according to claim 2, characterized in that The extending direction of the second straight section is parallel to the extending direction of the first straight section, and the length of the second straight section is less than or equal to the length of the first straight section.

4. The pressure relief structure according to claim 1 or 2, characterized in that The puncturing part is strip-shaped.

5. The pressure relief structure according to claim 4, characterized in that, The puncturing part further includes a connecting part, the two ends of the connecting part are respectively connected to the second straight section and the spike part, the connecting part is rectangular, and the spike part is triangular.

6. The pressure relief structure according to claim 5, wherein, The connecting part is connected to at least one spike part.

7. The pressure relief structure according to claim 1 or 2, characterized in that, The puncturing part is integrally formed on the second straight section, and intermittent holes are provided on the second straight section, and the puncturing part is arranged in the intermittent holes.

8. A battery, characterized in that, Comprising: A packaging film; An electrode group, arranged inside the packaging film; The pressure relief structure according to any one of claims 1 to 7, wherein the fixing part is connected to the packaging film.

9. The battery according to claim 8, characterized in that, Along the thickness direction of the battery, the second straight section and the first straight section are respectively located outside the two large surfaces of the electrode group, and the bending section is wrapped outside the end face of the electrode group.

10. A battery module, characterized in that, A battery comprising claim 8 or 9.

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