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 has a first direction, the cover plate assembly comprises a cover plate, and the cover plate is provided with a pressure relief hole in the first direction; the insulating part is connected with the cover plate in the first direction, and the insulating part is provided with a placement groove facing the cover plate; the supporting piece is arranged in the placement groove, and the melting point of the supporting piece is larger than that of the insulating piece; and the buckling piece is connected with the insulating piece, and the supporting piece is clamped by the buckling piece and the insulating piece so as to fix the supporting piece in the first direction. When thermal runaway of the battery occurs, the supporting piece can be effectively kept between the cover plate and the electrode assembly, the electrode assembly is prevented from moving towards the cover plate and blocking the pressure relief hole, high-temperature gas generated by thermal runaway of the battery can be smoothly discharged from the pressure relief 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, in addition to the electrode assembly, various insulating fixing structures need to be set up in the battery shell to stabilize and fix the electrode assembly, and the shell needs to be encapsulated through the top cover. Among them, an explosion-proof structure needs to be arranged on the top cover to release pressure in time when the battery has thermal runaway. When the battery has thermal runaway, various insulating fixing structures in the shell are easily melted and disappeared due to heat. At this time, the electrode assembly is easy to move to the top cover under the action of high temperature and high pressure gas and block the explosion-proof structure, which will cause the battery to catch fire or even explode. Utility Model Content

[0003] 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.

[0004] Technical solution: A cover plate assembly according to an embodiment of the present application, the cover plate assembly has a first direction, and the cover plate assembly includes:

[0005] A cover plate, wherein the cover plate is provided with a pressure relief hole in the first direction;

[0006] an insulating member, the insulating member being connected to the cover plate in the first direction, and the insulating member being provided with a placement groove toward the cover plate;

[0007] A support member, the support member is arranged in the placement groove, and the melting point of the support member is greater than the melting point of the insulating member;

[0008] A buckle member is connected to the insulating member, and the buckle member and the insulating member clamp the supporting member to fix the supporting member in the first direction.

[0009] In some embodiments, the placement groove has a peripheral wall surrounding the support member and a bottom wall connected to the support member, and the peripheral wall is connected to the bottom wall;

[0010] The buckle is connected to the peripheral wall, the support is provided with a buckle groove toward the buckle for the buckle to be engaged, and the buckle and the bottom wall clamp the support.

[0011] In some embodiments, there are multiple snap fasteners, and the multiple snap fasteners are arranged around the peripheral wall.

[0012] In some embodiments, the insulating member is provided with a first hole in the first direction, and the first hole is connected to the pressure relief hole.

[0013] In some embodiments, an orthographic projection of the support member on the cover plate is at least partially located outside the pressure relief hole.

[0014] In some embodiments, the support member is provided with a second hole, the second hole penetrates the support member in the first direction, the insulating member is provided with a third hole, the third hole penetrates the insulating member in the first direction, and the second hole connects the third hole and the pressure relief hole.

[0015] In some embodiments, the orthographic projection area of ​​the support member on the cover plate is S1 mm 2 , the opening area of ​​the second hole is S2 mm 2 , satisfying 0.7225≥S2 / S1≥0.5625.

[0016] In some embodiments, the insulating member is provided with a through hole in the first direction for the pole ear to pass through, and the through hole is located on one side of the placement groove in the second direction. The peripheral wall is provided with a through groove, and the through groove penetrates the peripheral wall in the second direction to connect the through hole and the pressure relief hole, and the first direction and the second direction intersect.

[0017] In some embodiments, a dimension of the support member in the first direction is less than or equal to a depth of the seating groove in the first direction.

[0018] 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.

[0019] 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.

[0020] Beneficial effects: The cover assembly of the embodiment of the present application includes a cover, an insulating member, a support member and a snap member, wherein the cover is provided with a pressure relief hole in the first direction, the insulating member is connected to the cover in the first direction, the insulating member is provided with a placement groove toward the cover, the support member is provided in the placement groove, the melting point of the support member is greater than the melting point of the insulating member; the snap member is connected to the insulating member, and the snap member and the insulating member clamp the support member to fix the support member in the first direction. The placement groove cooperates with the snap member to form a positioning for the support member, thereby improving the installation convenience of the support member, and the placement groove also reduces the increase in the overall thickness of the cover assembly by the support member. When the battery has thermal runaway, the insulating member melts under high temperature and gradually loses its supporting effect on the electrode assembly inside the battery. Compared with the insulating member, the support member is more resistant to high temperature and can effectively maintain the support between the cover and the electrode assembly, thereby preventing the electrode assembly from moving toward the cover and blocking the pressure relief hole, which is conducive to the smooth discharge of high-temperature gas generated by thermal runaway of the battery from the pressure relief hole, thereby improving the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] 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;

[0023] Figure 2 It is a schematic diagram of the exploded structure of the insulating member and the supporting member provided in Example 1 of the present application;

[0024] Figure 3 It is a schematic diagram of the structure of the insulating member and the supporting member provided in Example 2 of the present application;

[0025] Figure 4 It is a schematic diagram of the exploded structure of the insulating member and the supporting member provided in Example 2 of the present application;

[0026] Figure 5 is a partial cross-sectional view of an insulating member and a supporting member provided in Example 2 of the present application;

[0027] Figure 6 is a schematic structural diagram of a support member provided in Example 2 of the present application;

[0028] 1. The cover plate assembly; 10. The cover plate; 100. The pressure relief hole; 101. The pressure relief valve; 102. The pole; 11. The insulating member; 110. The placement groove; 1100. The peripheral wall; 1101. The bottom wall; 111. The exhaust groove; 112. The first hole; 113. The third hole; 114. The through hole; 115. The through groove; 12. The supporting member; 120. The snap groove; 121. The second hole; 122. The first connecting part; 123. The structural groove; 124. The second connecting part; 13. The snap member; 2. The shell; 20. The accommodating cavity; 21. The opening; 22. The side plate; 3. The electrode assembly; 30. The pole ear; 4. The bottom cover member; X. The first direction; Y. The second direction; Z. The third direction. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] The applicant noted that in addition to the electrode assembly, various insulating fixing structures are required in the battery shell to stably fix the electrode assembly. Most of the insulating fixing structures are made of plastic materials such as polypropylene, which have a melting point of about 160°C. When the battery has thermal runaway, the internal temperature of the battery can reach above 400°C. The various insulating fixing structures in the shell are easily melted and disappear due to heat. At this time, the electrode assembly is easily moved to the battery pressure relief structure under the action of high-temperature and high-pressure gas and block the pressure relief structure, thereby causing the battery to catch fire or even explode.

[0032] In view of this, combined with Figures 1 to 6, an embodiment of the present application provides a cover plate assembly, aiming to overcome at least one of the above-mentioned technical problems.

[0033] 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.

[0034] Embodiment 1:

[0035] Reference Figure 1 and Figure 2 The cover plate assembly 1 includes a cover plate 10 and an insulating member 11 connected to the cover plate 10 in a first direction X, wherein the cover plate 10 is provided with a pressure relief hole 100 in the first direction X, the insulating member 11 is provided with a placement groove 110 facing the cover plate 10, a support member 12 is provided in the placement groove 110, and the melting point of the support member 12 is greater than the melting point of the insulating member 11. At the same time, the insulating member 11 is connected with a snap member 13, and the snap member 13 and the insulating member 11 relatively clamp the support member 12 in the first direction X to fix the support member 12 in the placement groove 110.

[0036] The placement groove 110 cooperates with the snap fastener 13 to form a positioning for the support member 12, thereby improving the installation convenience of the support member 12. The placement groove 110 also reduces 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 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 pressure relief hole 100, which is conducive to the smooth discharge of high-temperature gas generated by thermal runaway of the battery from the pressure relief hole 100, thereby improving the safety of the battery.

[0037] 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 about 160°C. In this embodiment, the support member 12 is designed to be a block structure. The support member 12 can be embedded in the mounting groove 110. The support member 12 can be made of a material with a melting point higher than 400°C, such as ceramic material. The support member 12 made of ceramic material can have a melting point greater than 2000°C, and can better maintain support between the electrode assembly 3 and the cover plate 10 under high temperature of thermal runaway of the battery.

[0038] In some embodiments, reference Figure 2The placement groove 110 has a peripheral wall 1100 surrounding the support member 12 and a bottom wall 1101 connected to the support member 12, and the peripheral wall 1100 is connected to the bottom wall 1101, and the buckle 13 is connected to the peripheral wall 1100. The support member 12 is provided with a buckle groove 120 for the buckle 13 to be engaged, and the buckle 13 and the bottom wall 1101 clamp the support member 12.

[0039] Further, in some embodiments, referring to Figure 2 There are multiple fasteners 13, and the multiple fasteners 13 are arranged around the peripheral wall 1100.

[0040] Specifically, in this embodiment, two snap fasteners 13 are used as an example, and the number of snap fastener grooves 120 corresponds to the number of snap fasteners 13. In this embodiment, the snap fasteners 13 are arranged on opposite sides of the peripheral wall 1100 in the second direction Y, and the corresponding two snap fastener grooves 120 are respectively located on opposite sides of the support member 12 in the second direction Y, so that the cross section of the support member 12 formed perpendicular to the third direction Z is a convex shape. In other embodiments, the number of snap fasteners 13 can also be flexibly increased or decreased as needed. For example, when the snap fastener grooves 120 are arranged around the support member 12, more snap fasteners 13 can be arranged around the support member 12 on the peripheral wall 1100.

[0041] In some embodiments, reference Figure 1 and Figure 2 The insulating member 11 can be manufactured by integral molding. During the molding process, the insulating member 11 can form a placement groove 110 and an exhaust groove 111. The exhaust groove 111 can reduce the material usage of the entire insulating member 11 and reduce the overall quality of the insulating member 11. The number of exhaust grooves 111 can be flexibly adjusted according to the actual size and structural requirements of the insulating member 11. In this embodiment, two exhaust grooves 111 are formed as an example. The two exhaust grooves 111 and the placement groove 110 are sequentially spaced in the second direction Y. The exhaust groove 111 faces the pressure relief hole 100 in the first direction X. The insulating member 11 is provided with a first hole 112 in the first direction X. The first hole 112 is located in the exhaust groove 111 and is interconnected with the pressure relief hole 100.

[0042] In this embodiment, each exhaust groove 111 is provided with a plurality of first holes 112, and the plurality of first holes 112 are evenly distributed in the exhaust groove 111. When thermal runaway occurs in the battery, the high-temperature and high-pressure gas generated inside the battery can be discharged from the first hole 112 toward the pressure relief hole 100. The plurality of first holes 112 are beneficial for ensuring that the insulating member 11 and the electrode assembly 3 have sufficient contact area while ensuring that the first hole 112 can provide sufficient pressure relief and exhaust efficiency.

[0043] In some embodiments, reference Figure 1, the orthographic projection of the support member 12 on the cover plate 10 is at least partially located outside the pressure relief hole 100. In this embodiment, taking the formation position of the placement groove 110 and the position of the pressure relief hole 100 as an example, the corresponding support member 12 is not opposite to the pressure relief 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 pressure relief 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 pressure relief valve 101 at the pressure relief hole 100.

[0044] In addition, in some embodiments, when the opening area of ​​the pressure relief hole 100 is designed to be larger, the placement groove 110 may also be partially opposite to the pressure relief hole 100. At this time, although part of the support member 12 is opposite to the pressure relief hole 100 in the first direction X, it can still ensure that the pressure relief hole 100 can release pressure smoothly.

[0045] In some embodiments, reference Figure 1 and Figure 2 The insulating member 11 is provided with a through hole 114 in the first direction X for the tab 30 to pass through. In the actual assembly process, the through hole 114 is used for the tab 30 of the electrode assembly 3 to pass through so as to be electrically connected to the pole 102 on the cover plate 10. In this embodiment, the through hole 114 is located on one side of the placement groove 110 in the second direction Y, and the peripheral wall 1100 is provided with a through groove 115, which penetrates the peripheral wall 1100 in the second direction Y, thereby connecting the through hole 114 and the first hole 112.

[0046] Specifically, in the present embodiment, a plurality of through grooves 115 are provided, and two are provided on opposite sides of the peripheral wall 1100 in the second direction Y. The provision of the through grooves 115 can reduce the obstruction of the peripheral wall 1100 to the through hole 114 and the first hole 112 in the second direction Y, thereby facilitating the flow of gas in the through hole 114 and the exhaust groove 111. When thermal runaway occurs in the battery, high-temperature and high-pressure gas can also be ejected from the through hole 114. At this time, the high-temperature and high-pressure gas can pass through the through grooves 115 and be introduced into the exhaust groove 111, so that it can be smoothly discharged from the pressure relief hole 100, which is beneficial to improving the auxiliary exhaust effect of the insulating member 11.

[0047] In addition, in some embodiments, reference Figure 1 and Figure 2 , the dimension of the support member 12 in the first direction X is less than or equal to the depth of the placement groove 110 in the first direction X. In this embodiment, taking the case where the dimension of the support member 12 in the first direction X is equal to the depth of the placement groove 110 in the first direction X as an example, after the support member 12 is embedded in the placement groove 110, the end of the support member 12 facing the cover plate 10 can be flush with the end of the insulating member 11 facing the cover plate 10, so the addition of the support member 12 will not increase the dimension of the overall cover plate assembly 1 in the first direction X, which is beneficial to avoid affecting the overall size of the battery.

[0048] Similarly, in other embodiments, if the size of the support member 12 in the first direction X is smaller than the depth of the mounting groove 110 in the first direction X, it can also avoid affecting the overall size of the battery.

[0049] 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 of 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 through hole 114 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 the support member 12 is arranged between the cover plate 10 and the electrode assembly 3 to form a preset support structure.

[0050] 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 .

[0051] In addition, in this embodiment, referring to Figure 1 The shell 2 is further provided with a bottom cover 4 at the other end in the first direction X. The structure of the bottom cover 4 is similar to that of the cover plate 10. In this embodiment, it is only used to seal the shell 2 and lead out the electrode. In other embodiments, if the bottom cover 4 is also provided with a pressure relief structure, a support member 12 can also be added between the bottom cover 4 and the electrode assembly 3, so as to ensure that the pressure relief structure at the bottom cover 4 is not blocked by the electrode assembly 3 when thermal runaway occurs in the battery.

[0052] 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.

[0053] Embodiment 2:

[0054] In some embodiments, reference Figures 3 to 6 The support member 12 is provided with a second hole 121. In this embodiment, the second hole 121 is arranged at the center of the top surface of the support member 12, and the second hole 121 penetrates the support member 12 in the first direction X. The insulating member 11 is provided with a third hole 113. The third hole 113 penetrates the insulating member 11 in the first direction X. The second hole 121 connects the third hole 113 and the pressure relief hole 100.

[0055] Specifically, refer to Figure 4 and Figure 5In this embodiment, the third hole 113 is disposed on the bottom wall 1101 , and two third holes 113 are provided in this embodiment, and the two third holes 113 are spaced apart in the second direction Y.

[0056] Reference Figure 6 In this embodiment, the support member 12 actually includes two first connection parts 122 and two second connection parts 124. The two first connection parts 122 are arranged at intervals in the second direction Y, and the two second connection parts 124 are arranged at intervals in the third direction Z. The two first connection parts 122 and the two second connection parts 124 are connected and surround the second hole 121. Among them, the buckle groove 120 is provided on the top surface of the first connection part 122, and the bottom surface of the first connection part 122 and the top surface and bottom surface of the second connection part 124 are provided with a structural groove 123. The structural groove 123 is conducive to reducing the mass of the overall support member 12. At the same time, the structural groove 123 on the bottom surface of the first connection part 122 forms a channel connecting the third hole 113 and the second hole 121, which is conducive to ensuring the exhaust effect formed by the third hole 113 toward the second hole 121.

[0057] In some embodiments, in order to ensure that the support member 12 has sufficient support surface to support the electrode assembly 3 after the battery thermal runaway, the positive projection area of ​​the support member 12 on the cover plate 10 is S1 mm 2 , the opening area of ​​the second hole 121 is S2 mm 2 , satisfying 0.7225≥S2 / S1≥0.5625. In this embodiment, S1 mm 2 The length and width of the support member 12 in the second direction Y are the product of the length and width in the third direction Z. The length and width of the support member 12 can be directly measured by a ruler. The cross section of the second hole 121 perpendicular to the first direction X can be approximately a square hole, i.e. S2mm 2 It is the product of the length of the second hole 121 in the second direction Y and the width in the third direction Z. The length and width of the second hole 121 can also be directly measured by a ruler. On the one hand, it is to avoid that the second hole 121 is too large, which causes the overall support member 12 to have too low support strength and is difficult to stably support between the electrode assembly 3 and the cover plate 10. On the other hand, it is to avoid that the second hole 121 is too small, which causes the second hole 121 to have a poor exhaust effect.

[0058] 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: The cover plate assembly has a first direction, and the cover plate assembly includes: A cover plate, wherein the cover plate is provided with a pressure relief hole in the first direction; an insulating member, the insulating member being connected to the cover plate in the first direction, and the insulating member being provided with a placement groove toward the cover plate; A support member, the support member is arranged in the placement groove, and the melting point of the support member is greater than the melting point of the insulating member; A buckle member is connected to the insulating member, and the buckle member and the insulating member clamp the supporting member to fix the supporting member in the first direction.

2. The cover plate assembly according to claim 1, characterized in that: The placement groove has a peripheral wall surrounding the support member and a bottom wall connected to the support member, and the peripheral wall is connected to the bottom wall; The buckle is connected to the peripheral wall, the support is provided with a buckle groove toward the buckle for the buckle to be engaged, and the buckle and the bottom wall clamp the support.

3. The cover plate assembly according to claim 2, characterized in that: There are a plurality of the buckles, and the buckles are arranged around the peripheral wall.

4. The cover plate assembly according to claim 1, characterized in that: The insulating member is provided with a first hole in the first direction, and the first hole is connected to the pressure relief hole.

5. The cover plate assembly according to claim 1, characterized in that: The orthographic projection of the support member on the cover plate is at least partially located outside the pressure relief hole.

6. The cover plate assembly according to claim 4, characterized in that: The support member is provided with a second hole, which penetrates the support member in the first direction; the insulating member is provided with a third hole, which penetrates the insulating member in the first direction; and the second hole connects the third hole and the pressure relief hole.

7. The cover plate assembly according to claim 6, characterized in that: The orthographic projection area of ​​the support member on the cover plate is S1 mm 2 , the opening area of ​​the second hole is S2 mm 2 , satisfying 0.7225≥S2 / S1≥0.5625.

8. The cover plate assembly according to claim 2, characterized in that: The insulating member is provided with a through hole in the first direction for the pole ear to pass through, and the through hole is located on one side of the placement groove in the second direction. The peripheral wall is provided with a through groove, and the through groove penetrates the peripheral wall in the second direction to connect the through hole and the pressure relief hole, and the first direction and the second direction intersect.

9. The cover plate assembly according to claim 1, characterized in that: The dimension of the supporting member in the first direction is smaller than or equal to the depth of the seating groove in the first direction.

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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