Sealing element, battery cap and battery

Abstract

The utility model provides a sealing element, a battery cap and a battery, the sealing element is used for insulating and sealing a gap between the cap of the battery and a shell, the sealing element comprises a body, and the body comprises a first sub-body located between the shell and the cap; wherein the melting point of at least part of the first sub-body is greater than the temperature in the enclosure space of the shell when the battery is in the maximum discharge state. In the embodiment of the invention, the melting point of at least part of the first sub-body is higher than the temperature in the enclosure space of the shell when the battery is in the maximum discharge state, that is, the first sub-body does not melt or partially melt when the battery is in the maximum discharge state; namely, the first sub-body can still separate the cap and the shell of the battery when the battery is in the maximum discharge state, so that the problem of short circuit of the battery caused by contact between the shell and the cap is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a sealing component, a battery cap and a battery. Background Art

[0002] In the related technology, a sealing ring is used to seal between the battery steel shell and the cap. During the high-power discharge process of the battery, the internal temperature of the battery will be too high, which will cause part of the sealing ring between the battery steel shell and the cap to melt. On this basis, part of the battery steel shell and the cap will be in direct contact, resulting in the risk of short circuit in the battery. Utility Model Content

[0003] The embodiments of the utility model provide a seal, a battery cap and a battery, which can improve the technical problem that when the battery is discharged at a high power, the internal temperature is too high, which causes a partial melting of the seal ring between the battery steel shell and the cap, thereby causing a short circuit in the battery.

[0004] In a first aspect, an embodiment of the utility model provides a sealing member for insulating and sealing a gap between a cap and a shell of a battery, comprising a body, wherein the body comprises a first sub-body located between the shell and the cap;

[0005] Wherein, at least part of the melting point of the first sub-body is greater than the temperature in the space enclosed by the shell when the battery is in a maximum discharge state.

[0006] In one embodiment, the surface temperature of the shell when the shell is in the maximum discharge state is defined as A; wherein A satisfies: 120° C.≤A≤140° C.;

[0007] The material of the first sub-body includes at least one of soluble polytetrafluoroethylene and polyphenylene sulfide.

[0008] In one embodiment, the first sub-body has a first state when the shell surface temperature is lower than the A value interval, and a second state when the shell surface temperature is within the A value interval;

[0009] Define that the thickness of the first sub-body between the shell and the cap when the first sub-body is in the first state is D1, and the thickness of the first sub-body between the shell and the cap when the first sub-body is in the second state is D2;

[0010] Wherein, D1 and D2 satisfy: D2≥0.8D1.

[0011] In one embodiment, the main body further includes a second sub-body connected to the first sub-body, and the material of the second sub-body is the same as or different from that of the first sub-body.

[0012] In one embodiment, the material of the second sub-body includes at least one of soluble polytetrafluoroethylene, polyphenylene sulfide, and polybutylene terephthalate.

[0013] In one embodiment, the material of the second sub-body is polybutylene terephthalate;

[0014] The roughness of the first sub-body is greater than the roughness of the second sub-body.

[0015] In one embodiment, the cap further includes a first side of the shell facing the shell in the axial direction of the shell, and the melting point of at least a portion of the first sub-body between the first side and the shell is greater than the temperature in the shell enclosure space when the battery is in a maximum discharge state.

[0016] In one embodiment, the body is in a hollow ring shape.

[0017] In a second aspect, an embodiment of the present invention provides a battery cap, wherein the battery cap comprises the sealing member as described above.

[0018] In a third aspect, an embodiment of the utility model provides a battery, wherein the battery comprises the battery cap as described above.

[0019] Beneficial effects of the embodiments of the utility model:

[0020] In the embodiments of the present application, by providing at least a portion of the melting point of the first sub-body to be greater than the temperature in the space enclosed by the shell when the battery is in the maximum discharge state, that is, the first sub-body will not melt or will partially melt when the battery is in the maximum discharge state, that is, the first sub-body can still separate the cap and the shell of the battery when the battery is in the maximum discharge state, thereby avoiding the problem of short circuit of the battery due to contact between the shell and the cap. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is an assembly diagram of a sealing ring made of PBT in the related art;

[0023] Figure 2 yes Figure 1 Schematic diagram of the structure of the battery melting when the surface temperature is in the A value range;

[0024] Figure 3 It is a schematic diagram of the structure of the sealing member provided in an embodiment of the present application when the battery surface temperature is in the A value range;

[0025] Figure 4 is a schematic structural diagram of a seal provided in an embodiment of the present application;

[0026] Figure 5 is a cross-sectional schematic diagram of a battery cap provided in an embodiment of the present application;

[0027] Figure 6 It is a cross-sectional schematic diagram of a battery provided in an embodiment of the present application.

[0028] Reference numerals:

[0029] 100. sealing member; 1. main body; 11. first sub-body; 12. second sub-body; 2. cover cap; 2A. first side; 3. shell. DETAILED DESCRIPTION

[0030] 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, rather than all of the embodiments. Based on the embodiments in 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. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0031] In the related technology, a sealing ring is used to seal between the battery steel shell and the cap. During the high-power discharge process of the battery, the internal temperature of the battery will be too high, which will cause part of the sealing ring between the battery steel shell and the cap to melt. On this basis, part of the battery steel shell and the cap will be in direct contact, resulting in the risk of short circuit in the battery.

[0032] In view of this, the utility model provides a seal, a battery cap and a battery. Figures 1 to 6 This is an embodiment of the present utility model.

[0033] See also Figures 3 to 6The seal 100 is used for insulating and sealing the gap between the cap 2 and the shell 3 of the battery. The seal 100 includes a main body 1, and the main body 1 includes a first sub-body 11 located between the shell 3 and the cap 2; wherein, at least part of the melting point of the first sub-body 11 is greater than the temperature in the space enclosed by the shell 3 when the battery is in the maximum discharge state.

[0034] In the embodiments of the present application, by setting the melting point of at least part of the first sub-body 11 to be greater than the temperature in the space enclosed by the shell 3 when the battery is in the maximum discharge state, that is, the first sub-body 11 will not melt or will partially melt when the battery is in the maximum discharge state, that is, the first sub-body 11 can still separate the cap 2 and the shell 3 of the battery when the battery is in the maximum discharge state, thereby avoiding the problem of short circuit of the battery caused by contact between the shell 3 and the cap 2.

[0035] It should be supplemented that, in actual use of the battery, the heat generated inside the battery shell 3 and near the battery end is the greatest, and the above content stipulates that the melting point of at least part of the first sub-body 11 is greater than the temperature of the space enclosed by the shell 3 when the battery is in the maximum discharge state, and the temperature of the space enclosed by the shell 3 also includes the space range of the battery end area enclosed by the shell 3. Therefore, it is necessary to avoid the sealing member 100 between the shell 3 and the cap 2 from melting to cause direct contact between the battery shell 3 and the cap 2, that is, it is necessary to improve the heat resistance of the sealing member 100 between the battery shell 3 and the cap 2. Therefore, the first sub-body 11 having a melting point greater than the temperature of the space enclosed by the shell 3 when the battery is in the maximum discharge state is provided.

[0036] In some embodiments of the present application, the cap 2 further includes a first side 2A facing the shell 3 in the axial direction of the shell 3, and the melting point of at least a portion of the first sub-body 11 between the first side 2A and the shell 3 is greater than the temperature in the space enclosed by the shell 3 when the battery is in the maximum discharge state. That is, in this embodiment, since a portion of the first sub-body 11 between the first side 2A and the shell 3 is easily melted when the battery is in the maximum discharge state, it is necessary to ensure that the first sub-body 11 between the first side 2A and the shell 3 will not melt or partially melt when the battery is in the maximum discharge state, so as to avoid the contact between the shell 3 and the cap 2 and cause the battery to short-circuit.

[0037] It should be noted that in the related art, the sealing ring provided between the battery steel shell and the cap is made of polybutylene terephthalate; in some embodiments of the present application, when the battery is in the maximum discharge state, the surface temperature of the shell 3 is detected, and the surface temperature of the shell 3 is measured to be A; wherein A satisfies: 120℃≤A≤140℃. Please refer to Figure 1 to Figure 2 , that is, when the surface temperature of the shell 3 is within this range, the battery sealing ring made of polybutylene terephthalate in the related art melts at the position of the shell 3 and the cap 2 of the corresponding battery, please refer to Figure 3 The melting point of the first sub-body 11 described in the embodiment of the present application is greater than the temperature in the space enclosed by the shell 3 when the battery is in the maximum discharge state, that is, the melting point of at least part of the first sub-body 11 is greater than the melting point of polybutylene terephthalate, and thus the battery will not melt or only partially melt when it is in the maximum discharge state, so as to avoid the problem of short circuit of the battery caused by direct contact between the shell 3 and the cap.

[0038] The material of the first sub-body 11 includes at least one of soluble polytetrafluoroethylene and polyphenylene sulfide. That is, in one embodiment, the material of the first sub-body 11 is soluble polytetrafluoroethylene (Polyfluoroalkoxy, PFA); in another embodiment, the material of the first sub-body 11 is polyphenylene sulfide (Polyphenylene sulfide, PPS); in another embodiment, the material of the first sub-body 11 can also be a mixture of soluble polytetrafluoroethylene (Polyfluoroalkoxy, PFA) and polyphenylene sulfide (Polyphenylene sulfide, PPS). In this way, when the battery is discharged at high power, the first sub-body 11 located between the battery shell 3 and the cap will not melt or partially melt, so as to avoid contact between the battery steel shell and the cap, thereby causing a short circuit in the battery.

[0039] It should be added that the melting point of soluble polytetrafluoroethylene (PFA) is between 290°C and 312°C, the melting point of polyphenylene sulfide (PPS) is between 280°C and 290°C, and the melting point of polybutylece terephthalate (PBT) is between 220°C and 230°C. That is, the melting points of soluble polytetrafluoroethylene and polyphenylene sulfide are higher than that of polybutylece terephthalate, thereby avoiding the risk of the first sub-body 11 melting when the battery is discharged at high power.

[0040] In addition, since the temperature of the enclosed space inside the shell 3 is positively correlated with the surface temperature of the shell 3, that is, when the temperature of the enclosed space inside the shell 3 rises, the surface temperature of the shell 3 also rises. In order to facilitate the experimenter to conduct experimental detection, in the embodiment of the present application, the surface temperature of the shell 3 is indirectly detected to reflect the temperature change of the enclosed space inside the shell 3, and the state of the sealing ring located between the cap 2 and the shell 3 is detected. Among them, a temperature detection device is used to detect the surface temperature of the battery. Specifically, the temperature detection device includes a temperature sensing line.

[0041] It can be understood that when the battery is in the maximum discharge state, the surface temperature of the shell 3 is measured to be between 120°C and 140°C, and the internal enclosure temperature of the shell 3 is between 220°C and 280°C, that is, when the battery is in the maximum discharge state, the internal enclosure temperature of the shell 3 is higher than the melting point of polybutylene terephthalate, which may cause the sealing ring made of polybutylene terephthalate in the related art to melt, while the internal enclosure temperature of the shell 3 is lower than the melting point of soluble polytetrafluoroethylene and polyphenylene sulfide, that is, in the present application, the first sub-body 11 made of at least one of soluble polytetrafluoroethylene and polyphenylene sulfide will not melt.

[0042] In some embodiments of the present application, the first sub-body 11 has a first state when the surface temperature of the shell 3 is lower than the A value interval, and a second state when the surface temperature of the shell 3 is in the A value interval; it is defined that the thickness of the first sub-body 11 between the shell 3 and the cap when it is in the first state is D1, and the thickness of the first sub-body 11 between the shell 3 and the cap when it is in the second state is D2; wherein, D1 and D2 satisfy: D2≥0.8D1. That is, when the first sub-body 11 uses at least one of the above-mentioned soluble polytetrafluoroethylene and polyphenylene sulfide as its main component material, when the material of the first sub-body 11 is all one of the soluble polytetrafluoroethylene and polyphenylene sulfide, the first sub-body 11 will not melt, that is, D2 equals D1, and when the material of the first sub-body 11 is partially one of the soluble polytetrafluoroethylene and polyphenylene sulfide, the first sub-body 11 is partially melted, ensuring that the thickness of the first sub-body 11 after melting is still greater than 80% of the original thickness, thereby retaining a sufficient safety distance between the battery shell 3 and the cap 2.

[0043] See also Figure 5, the body 1 further includes a second sub-body 12 connected to the first sub-body 11, and the material of the second sub-body 12 is the same as or different from the material of the first sub-body 11. Wherein, when the battery is in a high-power discharge state, that is, a high-temperature state, the first sub-body 11 will not melt to the point where the battery shell 3 and the cap 2 are in direct contact, and the materials of other parts of the body 1 are not limited in this embodiment. Therefore, as can be seen from the above content, the body 1 further includes a second sub-body 12, and the first sub-body 11 can be connected to the second sub-body 12, that is, the first sub-body 11 and the second sub-body 12 are integrated. The material of the second sub-body 12 is not limited, and the melting point of the second sub-body 12 can be higher than the melting point of the first sub-body 11, or the melting point of the second sub-body 12 can be the same as the melting point of the first sub-body 11, or the melting point of the second sub-body 12 can be lower than the melting point of the first sub-body 11.

[0044] Specifically, in one embodiment of the present application, the material of the second sub-body 12 includes at least one of soluble polytetrafluoroethylene, polyphenylene sulfide, and polybutylene terephthalate. That is, under the premise that the material of the first sub-body 11 is at least one of soluble polytetrafluoroethylene and polyphenylene sulfide, the material of the second sub-body 12 can be at least one of soluble polytetrafluoroethylene, polyphenylene sulfide, and polybutylene terephthalate, or a mixture of at least two of them.

[0045] In one embodiment of the present application, when the material of the second sub-body 12 is polybutylene terephthalate, the roughness of the first sub-body 11 is greater than the roughness of the second sub-body 12. Wherein, when the body 1 is installed in the shell 3 of the battery, glue needs to be coated on the surface of the body 1. When the material of the first sub-body 11 is at least one of soluble polytetrafluoroethylene and polyphenylene sulfide, the glue has non-adhesiveness due to the same material as the first sub-body 11, resulting in the glue not being easy to adhere to the first sub-body 11. Therefore, the surface of the first sub-body 11 needs to be processed to enhance the roughness of the surface of the first sub-body 11, thereby improving the adsorption force of the surface of the first sub-body 11 on the glue. It can be understood that, on this basis, the roughness of the first sub-body 11 is greater than the roughness of the second sub-body 12, so as to facilitate the glue to adhere to the surface of the body 1.

[0046] In addition, in one embodiment of the present application, the body 1 is configured in a hollow ring shape, and the body 1 is configured in this way to facilitate installation into the battery housing 3. The body 1 has an inner cavity that can be used for installing components such as the cap 2 and explosion-proof disks.

[0047] The utility model further proposes a battery cap, which includes a seal 100. The seal 100 is as described above. Since the battery cap adopts all the technical solutions of all the above embodiments, it at least has the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0048] The utility model further proposes a battery, which includes a battery cap. The battery cap is as described above. Since the battery adopts all the technical solutions of all the above embodiments, it at least has the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0049] Among them, a 21700-type cylindrical battery is used as one of the specific embodiments of this application for explanation. The seal 100 is installed in a 21700-type cylindrical battery (the following content is briefly described by battery), and the seal 100 is set at the end position of the battery shell 3, wherein the cap 2 is located in the enclosed area of ​​the seal 100. When the battery is assembled, the end of the battery shell 3 is bent, so that part of the seal 100 is located between the cap 2 and the shell 3, and this part is the first sub-body 11 mentioned above. The other part of the seal 100 is located between the explosion-proof plate and other parts and the shell 3, and this part is the second sub-body 12 mentioned above. The material of the first sub-body 11 includes one of soluble polytetrafluoroethylene and polyphenylene sulfide. Therefore, when the internal temperature of the battery is too high, the first sub-body 11 made of soluble polytetrafluoroethylene and polyphenylene sulfide will not melt or partially melt, so as to avoid direct contact between the shell 3 and the cap 2 to cause a short circuit in the battery. The environment in which the second sub-body 12 is located does not have the high temperature resistance requirement of the first sub-body 11, so the material of the second sub-body 12 can be the same as that of the first sub-body 11, or different from that of the first sub-body 11, that is, the material of the second sub-body 12 is at least one of soluble polytetrafluoroethylene, polyphenylene sulfide, and polybutylene terephthalate.

[0050] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A seal for insulating and sealing the gap between a cap and a shell of a battery, characterized in that: It comprises a body, wherein the body comprises a first sub-body located between the shell and the cap; Wherein, at least part of the melting point of the first sub-body is greater than the temperature in the space enclosed by the shell when the battery is in a maximum discharge state.

2. The seal according to claim 1, characterized in that The surface temperature of the shell when the shell is in the maximum discharge state is defined as A; wherein A satisfies: 120°C≤A≤140°C; The material of the first sub-body includes at least one of soluble polytetrafluoroethylene and polyphenylene sulfide.

3. The seal according to claim 2, characterized in that The first sub-body has a first state when the shell surface temperature is lower than the A value interval, and a second state when the shell surface temperature is within the A value interval; Define that the thickness of the first sub-body between the shell and the cap when the first sub-body is in the first state is D1, and the thickness of the first sub-body between the shell and the cap when the first sub-body is in the second state is D2; Wherein, D1 and D2 satisfy: D2≥0.8D1.

4. The seal according to claim 2, characterized in that The main body further includes a second sub-body connected to the first sub-body, and the material of the second sub-body is the same as or different from that of the first sub-body.

5. The seal according to claim 4, characterized in that The material of the second sub-body includes at least one of soluble polytetrafluoroethylene, polyphenylene sulfide, and polybutylene terephthalate.

6. The seal according to claim 4, characterized in that The material of the second sub-body is polybutylene terephthalate; The roughness of the first sub-body is greater than the roughness of the second sub-body.

7. The seal according to any one of claims 1 to 6, characterized in that: The cap also includes a first side facing the shell in the axial direction of the shell, and the melting point of at least a portion of the first sub-body between the first side and the shell is greater than the temperature of the shell enclosure space when the battery is in a maximum discharge state.

8. The seal according to any one of claims 1 to 6, characterized in that: The body is in a hollow ring shape.

9. A battery cap, characterized in that: Comprising a seal as claimed in any one of claims 1 to 8.

10. A battery, characterized in that: Comprising the battery cap as claimed in claim 9.

Images