Cover plate assembly and single battery

Abstract

The utility model discloses a cover plate assembly and a single battery, and belongs to the technical field of batteries, the cover plate assembly comprises a cover plate, and the cover plate is provided with an explosion-proof hole; the insulating part is connected with the cover plate, the insulating part faces the explosion-proof hole, and the insulating part is provided with a containing groove facing the cover plate; the supporting piece is arranged in the containing groove and connected with the cover plate and the insulating piece, and the melting point of the supporting piece is larger than that of the insulating piece. When the battery is in thermal runaway, the supporting piece is higher in high-temperature resistance compared with the insulating piece and can be effectively supported between the cover plate and the electrode assembly, the electrode assembly is prevented from moving towards the cover plate and blocking the anti-explosion hole, high-temperature gas generated by the thermal runaway of the battery can be smoothly discharged from the anti-explosion hole, and the safety of the battery is improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a cover plate assembly and a single cell. Background Art

[0002] At present, after the electrode assembly is placed in the battery shell, the shell is sealed by a top cover. An explosion-proof structure needs to be arranged on the top cover to release pressure in time when thermal runaway occurs in the battery. At the same time, an insulating part needs to be set between the top cover and the electrode assembly in the shell to separate the top cover and the electrode assembly.

[0003] However, when the battery experiences thermal runaway, parts inside the shell, such as insulating parts, are easily melted and disappear due to the heat, and the electrode assembly is easy to move inside the shell, move to the top cover and block the explosion-proof structure, which can easily cause the battery to catch fire or even explode. Utility Model Content

[0004] Purpose of the utility model: An embodiment of the present application provides a cover plate assembly, aiming to solve the above-mentioned technical problems; another purpose of an embodiment of the present application is to provide a single cell battery.

[0005] Technical solution: A cover plate assembly described in an embodiment of the present application includes:

[0006] A cover plate, wherein the cover plate is provided with an explosion-proof hole;

[0007] An insulating member, the insulating member is connected to the cover plate, the insulating member faces the explosion-proof hole, and the insulating member has a receiving groove facing the cover plate;

[0008] A support member is disposed in the accommodating groove, the support member is respectively connected to the cover plate and the insulating member, and the melting point of the support member is greater than the melting point of the insulating member.

[0009] In some embodiments, the insulating member is provided with a first exhaust hole, and the first exhaust hole is connected to the explosion-proof hole.

[0010] In some embodiments, the support member includes a support plate and a plurality of branches, the plurality of branches are connected to a side of the support plate facing the cover plate, the support plate is connected to the insulating member, and the plurality of branches are spaced apart from each other and respectively connected to the cover plate.

[0011] In some embodiments, the orthographic projection of the support member on the cover plate is located outside the explosion-proof hole.

[0012] In some embodiments, the support plate is provided with a second exhaust hole, and the second exhaust hole is connected to the explosion-proof hole and the first exhaust hole.

[0013] In some embodiments, the second exhaust hole is directly opposite to the explosion-proof hole, and an opening area of ​​the second exhaust hole is greater than or equal to an opening area of ​​the explosion-proof hole.

[0014] In some embodiments, the support plate is provided with a third exhaust hole, the third exhaust hole is connected to the first exhaust hole, and the third exhaust hole is spaced apart from the second exhaust hole.

[0015] In some embodiments, the second exhaust hole and the third exhaust hole are both located between two adjacent branches, and an exhaust channel is formed between the adjacent branches, and the exhaust channel connects the second exhaust hole and the third exhaust hole.

[0016] In some embodiments, the insulating member includes a main body and a covering member, the main body is formed with the accommodating groove, and the covering member is connected to the main body and covers the outer side of the supporting member.

[0017] Correspondingly, a single cell battery described in an embodiment of the present application includes the above-mentioned cover plate assembly, and also includes a shell and an electrode assembly, the shell has a accommodating cavity and an opening connected to the accommodating cavity, the electrode assembly and the insulating member are arranged in the accommodating cavity, the cover plate is covered on the opening, and the insulating member is located between the cover plate and the electrode assembly.

[0018] Beneficial effect: The cover plate assembly of the embodiment of the present application includes a cover plate, an insulating member and a support member connected to each other, wherein the cover plate is provided with an explosion-proof hole, the insulating member faces the explosion-proof hole, and the insulating member is provided with a receiving groove facing the cover plate, the support member is arranged in the receiving groove, the support member is respectively connected to the cover plate and the insulating member, and the melting point of the support member is greater than the melting point of the insulating member. The receiving groove forms a positioning for the support member, reducing the increase in the overall thickness of the cover plate assembly caused by the support member. When the battery has thermal runaway, the insulating member melts at high temperature and gradually loses its supporting effect on the electrode assembly inside the battery. The support member is more resistant to high temperature than the insulating member, and can effectively maintain support between the cover plate and the electrode assembly, preventing the electrode assembly from moving toward the cover plate and blocking the explosion-proof hole, which is conducive to the smooth discharge of high-temperature gas generated by thermal runaway of the battery from the explosion-proof hole, thereby improving the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the exploded structure of the cover plate assembly, the shell, and the electrode assembly provided in Example 1 of the present application;

[0021] Figure 2 is a schematic diagram of the exploded structure of the cover plate assembly provided in Example 1 of the present application;

[0022] Figure 3 is a schematic structural diagram of a support member provided in Example 1 of the present application;

[0023] Figure 4 is a schematic diagram of the exploded structure of the cover plate assembly provided in Example 2 of the present application;

[0024] Figure 5 It is a structural schematic diagram of the front view explosion-proof valve of the cover plate assembly provided in Example 2 of the present application;

[0025] Figure 6 is along Figure 5 Schematic diagram of the cross-sectional structure along the AA line;

[0026] Figure 7 is a schematic structural diagram of a support member provided in Example 2 of the present application;

[0027] Figure 8 is a schematic structural diagram of a front view of a receiving groove of a cover plate assembly provided in Example 3 of the present application;

[0028] Fig. 9 is along Figure 8 Schematic diagram of the cross-sectional structure along the middle BB line;

[0029] Figure numerals: 1, cover plate assembly; 10, cover plate; 100, explosion-proof hole; 101, explosion-proof valve; 102, pole; 11, insulating member; 110, accommodating groove; 111, structural groove; 112, first exhaust hole; 113, body; 114, covering member; 12, supporting member; 120, support plate; 121, branch; 1210, supporting sheet; 1211, support foot; 122, second exhaust hole; 123, third exhaust hole; 124, exhaust channel; 2, shell; 20, accommodating chamber; 21, opening; 22, side plate; 3, electrode assembly; 30, pole ear; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0031] In the description of the present application, it should be understood that the terms "thickness", "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined.

[0032] The applicant noted that in order to improve the energy density of the battery, the internal space utilization rate of the single cell is getting higher and higher, the wall thickness of the battery shell is getting thinner and thinner, and the structure inside the battery for fixing the electrode assembly is also getting thinner and thinner. There is usually a lower plastic structure for insulating support between the battery top cover structure and the internal electrode assembly. When the battery has thermal runaway, the structure for insulating and supporting the electrode assembly has a relatively low melting point and is easy to melt and disappear first. At this time, the thermal runaway of the electrode assembly has not ended and it is easy to move inside the battery. If the electrode assembly moves to the explosion-proof structure of the top cover, it is easy to cause the pressure relief channel to be blocked, which can easily cause the battery to catch fire and explode.

[0033] In view of this, combined with Figures 1 to 9 , an embodiment of the present application provides a cover plate assembly, aiming to overcome at least one of the above-mentioned technical problems.

[0034] In the following embodiments, a first direction X, a second direction Y and a third direction Z that intersect each other are introduced, wherein the first direction X is parallel to the thickness direction of the cover assembly 1, the second direction Y is parallel to the length direction of the cover assembly 1, and the third direction Z is parallel to the width direction of the cover assembly 1.

[0035] Embodiment 1:

[0036] Reference Figures 1 to 3 The cover plate assembly 1 includes a cover plate 10, an insulating member 11 and a support member 12, the cover plate 10 and the support member 12 are arranged in sequence in the first direction X, wherein the cover plate 10 is provided with an explosion-proof hole 100, the explosion-proof hole 100 penetrates the cover plate 10 in the first direction X, the insulating member 11 is connected to the cover plate 10 and is opposite to the explosion-proof hole 100 in the first direction X, the insulating member 11 is provided with a receiving groove 110 toward the cover plate 10, the support member 12 is arranged in the receiving groove 110 and is respectively connected to the cover plate 10 and the insulating member 11, and the melting point of the support member 12 is greater than the melting point of the insulating member 11.

[0037] The accommodating groove 110 forms a positioning for the support member 12, reducing the increase in the overall thickness of the cover plate assembly 1 caused by the support member 12. When the battery has thermal runaway, the insulating member 11 melts at high temperature and gradually loses its supporting effect on the electrode assembly 3 inside the battery. The design melting point of the support member 12 is higher than that of the insulating member 11, so the support member 12 is more resistant to high temperatures than the insulating member 11, and can effectively maintain support between the cover plate 10 and the electrode assembly 3, preventing the electrode assembly 3 from moving toward the cover plate 10 and blocking the explosion-proof hole 100, which is conducive to the smooth discharge of high-temperature gas generated by thermal runaway of the battery from the explosion-proof hole 100, thereby improving the safety of the battery.

[0038] It should be noted that the insulating member 11 can be made of plastic material such as polymers such as polypropylene. The insulating member 11 begins to melt at around 160°C, and the internal problem of thermal runaway of the battery can reach above 400°C. Therefore, the support member 12 can be made of a material with a melting point higher than 400°C, such as aluminum alloy material. The support member 12 made of aluminum alloy material has a melting point greater than 600°C and can better maintain support between the electrode assembly 3 and the cover plate 10 under the high temperature of thermal runaway of the battery.

[0039] In addition, the receiving groove 110 structure can be used to locate the position of the support member 12. In some embodiments, the support member 12 can be welded and fixed to the cover plate 10 in advance, and the receiving groove 110 forms an avoidance for the support member 12. In the first direction X, the size of the support member 12 is designed to be smaller than the size of the insulating member 11, so the addition of the support member 12 will not increase the size of the overall cover plate assembly 1 in the first direction X, which is beneficial to avoid affecting the overall size of the battery.

[0040] In some embodiments, reference Figure 2 The insulating member 11 can be manufactured by integral molding. During the molding process, the insulating member 11 can form a receiving groove 110 and a structural groove 111. The structural groove 111 can reduce the material usage of the overall insulating member 11 on the one hand, and reduce the overall quality of the insulating member 11 on the other hand. The number of structural grooves 111 can be flexibly adjusted according to the actual size of the insulating member 11 and the structural requirements. In this embodiment, two structural grooves 111 are formed as an example. The two structural grooves 111 and the receiving groove 110 are sequentially spaced in the second direction Y. The structural groove 111 faces the explosion-proof hole 100 in the first direction X. The insulating member 11 is provided with a first exhaust hole 112, which is located in the structural groove 111 and is interconnected with the explosion-proof hole 100.

[0041] In some embodiments, reference Figures 1 to 3The orthographic projection of the support member 12 on the cover plate 10 is at least partially located outside the explosion-proof hole 100. In this embodiment, taking the formation position of the accommodating groove 110 and the position of the explosion-proof hole 100 as an example, the corresponding support member 12 is not opposite to the explosion-proof hole 100 in the first direction X, so as to avoid the support member 12 from forming an obstruction to the exhaust passage of the explosion-proof hole 100, and at the same time avoid the installation structure of the support member 12 from affecting the installation of structures such as the explosion-proof valve 101 at the explosion-proof hole 100.

[0042] In addition, in some embodiments, the accommodating groove 110 may also be partially opposite to the explosion-proof hole 100. At this time, although part of the support member 12 is opposite to the explosion-proof hole 100 in the first direction X, it can still ensure that the explosion-proof hole 100 can release pressure smoothly.

[0043] In some embodiments, reference Figure 2 and Figure 3 The support member 12 includes a support plate 120 and a plurality of branches 121. The plurality of branches 121 are connected to the side of the support plate 120 facing the cover plate 10. The support plate 120 is connected to the insulating member 11. The plurality of branches 121 are spaced apart from each other and are respectively connected to the cover plate 10. In this embodiment, two branches 121 are taken as an example. The two branches 121 are spaced apart in the second direction Y. The branches 121 include a support sheet 1210 connected to the support plate 120 and a support leg 1211 at one end of the support sheet 1210 away from the support plate 120. In this embodiment, each support leg 1211 is divided into two parts in the third direction Z. The support leg 1211 can be used as a welding leg for the support member 12 to weld the cover plate 10 as a whole. Multi-point welding is formed by the plurality of support legs 1211 to improve the stability of the support member 12 connecting the cover plate 10. As a flat structure, the support plate 120 needs to be directly attached to the electrode assembly 3 when the battery is thermally runaway, which is conducive to maintaining the stability of the supporting electrode assembly 3.

[0044] Correspondingly, the present embodiment also provides a single cell battery, comprising the above-mentioned cover plate assembly 1, and also comprising a shell 2 and an electrode assembly 3, the shell 2 having a accommodating cavity 20, and an opening 21 connected to the accommodating cavity 20 is opened at one end of the shell 2 in the first direction X, the electrode assembly 3 having a pole ear 30 at one end in the first direction X, the electrode assembly 3 and the insulating member 11 are arranged in the accommodating cavity 20, and the pole ear 30 faces the cover plate 10, and a pole column 102 is arranged on the cover plate 10 relative to the pole ear 30, when the cover plate 10 is covered on the opening 21, the pole ear 30 can pass through the insulating member 11 and be electrically connected to the pole column 102, and the insulating member 11 is located between the cover plate 10 and the electrode assembly 3, and at the same time, the support member 12 is arranged between the cover plate 10 and the electrode assembly 3 to form a preset support structure.

[0045] In addition, if Figure 1 As shown, a side plate 22 is further provided in the shell 2 on one side of the electrode assembly 3 in the second direction Y. The side plate 22 and the insulating member 11 are both fixedly connected to the shell 2 as fixing structures of the electrode assembly 3 .

[0046] It can be understood that the single cell has all the technical features and corresponding beneficial effects of the above-mentioned cover plate assembly 1, which will not be elaborated here.

[0047] Embodiment 2:

[0048] Reference Figures 4 to 7 The difference between this embodiment and embodiment 1 is that the support member 12 as a whole can be opposite to the explosion-proof hole 100 in the first direction X, and the support plate 120 is provided with a second exhaust hole 122, the second exhaust hole 122 penetrates the support plate 120 in the first direction X, and the second exhaust hole 122 connects the explosion-proof hole 100 and the first exhaust hole 112.

[0049] It can be understood that, correspondingly, in this embodiment, the receiving groove 110 on the insulating member 11 is opposite to the explosion-proof hole 100 in the first direction X, and the explosion-proof hole 100 is located in the opening 21 of the receiving groove 110 .

[0050] Further, in some embodiments, referring to Figures 4 to 6 , the second exhaust hole 122 is directly opposite to the explosion-proof hole 100, and the opening area of ​​the second exhaust hole 122 is greater than or equal to the opening area of ​​the explosion-proof hole 100. On this basis, the support member 12 completely avoids hindering the exhaust of the explosion-proof hole 100 through the second exhaust hole 122, that is, the battery pressure relief exhaust efficiency is determined by the explosion-proof hole 100 and the explosion-proof valve 101 installed at the explosion-proof hole 100.

[0051] Further, in some embodiments, referring to Figures 4 to 7 , the support plate 120 is provided with a third exhaust hole 123, the third exhaust hole 123 is connected to the first exhaust hole 112, and the third exhaust hole 123 and the second exhaust hole 122 are spaced apart from each other in the second direction Y. In this embodiment, taking a plurality of third exhaust holes 123 as an example, under the premise of ensuring that the contact area between the support plate 120 and the insulating member 11 is sufficient, more third exhaust holes 123 are provided to further reduce the influence of the support member 12 as a whole on the thermal runaway pressure relief and exhaust of the battery, and further reduce the structural quality of the support member 12 on the other hand. Correspondingly, it can be understood that the coverage of the first exhaust hole 112 can be appropriately increased here to adapt to the number of more third exhaust holes 123.

[0052] In addition, in some embodiments, reference Figures 4 to 7In this embodiment, a single support member 12 also includes two branches 121 as an example, the second exhaust hole 122 and the third exhaust hole 123 are both located between two adjacent branches 121, and an exhaust channel 124 is formed between the adjacent branches 121, and the exhaust channel 124 connects the second exhaust hole 122 and the third exhaust hole 123. The exhaust channel 124 facilitates the exhaust passage connecting the second exhaust hole 122 and the third exhaust hole 123, and at the same time, the pressure relief gas is smoothly discharged to the explosion-proof hole 100 in the second direction Y.

[0053] Embodiment 3:

[0054] Reference Figure 8 and Fig. 9 The difference between this embodiment and the second embodiment is that the insulating member 11 includes a body 113 and a covering member 114, the body 113 is formed with a receiving groove 110, and the covering member 114 is connected to the body 113 and covers the outside of the support member 12. In this embodiment, the insulating member 11 as a whole can be injection molded by a plastic material, that is, the body 113 and the covering member 114 are actually integrally molded, and before the injection molding, the support member 12 as a whole can be molded and injection molded inside the insulating member 11 by encapsulating, thereby forming a structure in which the insulating member 11 covers the support member 12.

[0055] It should be noted that the insulating member 11 covers the supporting member 12 while retaining the structure of the second exhaust hole 122, the second exhaust hole 122 and the third exhaust hole 123, that is, it ensures that the supporting member 12 is buried in the insulating member 11 without hindering the normal pressure relief and exhaust of the explosion-proof hole 100.

[0056] The above is a detailed introduction to a cover plate assembly and a single cell provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate, wherein the cover plate is provided with an explosion-proof hole; An insulating member, the insulating member is connected to the cover plate, the insulating member faces the explosion-proof hole, and the insulating member has a receiving groove facing the cover plate; A support member is disposed in the accommodating groove, the support member is respectively connected to the cover plate and the insulating member, and the melting point of the support member is greater than the melting point of the insulating member.

2. The cover plate assembly according to claim 1, characterized in that: The insulating member is provided with a first exhaust hole, and the first exhaust hole is connected to the explosion-proof hole.

3. The cover plate assembly according to claim 2, characterized in that: The support member includes a support plate and a plurality of branches, wherein the plurality of branches are connected to a side of the support plate facing the cover plate, the support plate is connected to the insulating member, and the plurality of branches are spaced apart from each other and respectively connected to the cover plate.

4. The cover plate assembly according to claim 1, characterized in that: The orthographic projection of the support member on the cover plate is located outside the explosion-proof hole.

5. The cover plate assembly according to claim 3, characterized in that: The support plate is provided with a second exhaust hole, and the second exhaust hole is connected with the explosion-proof hole and the first exhaust hole.

6. The cover plate assembly according to claim 5, characterized in that: The second exhaust hole is directly opposite to the explosion-proof hole, and an opening area of ​​the second exhaust hole is greater than or equal to an opening area of ​​the explosion-proof hole.

7. The cover plate assembly according to claim 5 or 6, characterized in that: The support plate is provided with a third exhaust hole, the third exhaust hole is connected to the first exhaust hole, and the third exhaust hole is spaced apart from the second exhaust hole.

8. The cover plate assembly according to claim 7, characterized in that: The second exhaust hole and the third exhaust hole are both located between two adjacent branches, and an exhaust channel is formed between the adjacent branches, and the exhaust channel connects the second exhaust hole and the third exhaust hole.

9. The cover plate assembly according to claim 1, characterized in that: The insulating member includes a body and a covering member, wherein the body is formed with the accommodating groove, and the covering member is connected to the body and covers the outer side of the supporting member.

10. A single cell battery, characterized in that: include: The cover plate assembly as described in any one of claims 1 to 9 further includes a shell and an electrode assembly, the shell having a accommodating cavity and an opening connected to the accommodating cavity, the electrode assembly and the insulating member are arranged in the accommodating cavity, the cover plate is covered on the opening, and the insulating member is located between the cover plate and the electrode assembly.

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