A cover plate assembly and a single cell

Abstract

The present application discloses a cover plate assembly and a single cell, belonging to the technical field of batteries. The cover plate assembly has a first direction. The cover plate assembly includes a cover plate, and the cover plate is provided with an explosion-proof hole in the first direction; an insulating member, the insulating member is connected to the cover plate in the first direction, and the insulating member is provided with a receiving groove facing the cover plate; a support member, the support member is disposed in the receiving groove, and the melting point of the support member is greater than the melting point of the insulating member; a limiting member, the limiting member is disposed in the receiving groove and connected to the insulating member, and the limiting member abuts against the support member in a direction perpendicular to the first direction so as to fix the support member in the receiving groove. When the battery of the present application undergoes thermal runaway, the support member can effectively maintain the support between the cover plate and the electrode assembly, preventing the electrode assembly from moving towards the cover plate and blocking the explosion-proof hole, which is beneficial to the smooth discharge of the high-temperature gas generated by the thermal runaway of the battery through the explosion-proof hole, improving the safety of the battery.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a cover plate assembly and a single cell battery. Background Art

[0002] Currently, in addition to the electrode assembly, various insulating and fixing structures need to be provided in the battery housing to stably fix the electrode assembly, and the housing also needs to be encapsulated by a top cover. Among them, an explosion-proof structure needs to be arranged on the top cover to release pressure in time when the battery undergoes thermal runaway. When the battery undergoes thermal runaway, various insulating and fixing structures in the housing are prone to heat melting and disappearing. At this time, the electrode assembly is likely to move to the top cover under the action of high-temperature and high-pressure gas and block the explosion-proof structure, thereby causing the battery to catch fire or even explode. Summary of the Invention

[0003] Object of the Invention: The embodiments of this application provide a cover plate assembly, aiming to solve the above technical problems; another object of the embodiments of this application is to provide a single cell battery.

[0004] Technical Solution: A cover plate assembly described in the embodiments of this application, the cover plate assembly has a first direction, and the cover plate assembly includes:

[0005] A cover plate, the cover plate is provided with an explosion-proof hole in the first direction;

[0006] An insulating member, the insulating member is connected to the cover plate in the first direction, and the insulating member is provided with a receiving groove facing the cover plate;

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

[0008] A limiting member, the limiting member is arranged in the receiving groove and connected to the insulating member, and the limiting member abuts against the support member in a direction perpendicular to the first direction, so that the support member is fixed in the receiving groove.

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

[0010] A plurality of the limiting members are provided, and the plurality of limiting members are connected to the peripheral wall.

[0011] In some embodiments, the plurality of limiting members are arranged around the peripheral wall;

[0012] And / or, the plurality of limiting members are arranged at intervals in the first direction.

[0013] In some embodiments, the limiting member has a corresponding first end and a second end in the first direction, the second end faces the bottom wall, and a first chamfer is provided on a side of the first end facing away from the peripheral wall.

[0014] In some embodiments, the support member has a third end and a fourth end in the first direction, the fourth end faces the bottom wall, and a second chamfer is formed around an edge of the fourth end.

[0015] In some embodiments, an orthographic projection of the support member on the cover plate is at least partially located outside the explosion-proof hole.

[0016] In some embodiments, the insulating member is provided with an exhaust hole in the first direction, and the exhaust hole is connected to the explosion-proof hole.

[0017] In some embodiments, the matching clearance between the support member and the peripheral wall is a mm, satisfying: 0.2 mm ≥ a ≥ 0.1 mm;

[0018] And / or, the dimension of the limiting member in a direction perpendicular to the peripheral wall is b mm, satisfying: 0.5 mm ≥ b ≥ 0.2 mm.

[0019] In some embodiments, a dimension of the support member in the first direction is less than or equal to a depth of the receiving groove in the first direction.

[0020] 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.

[0021] Beneficial effect: The cover plate assembly of the embodiment of the present application includes a cover plate, an insulating member, a support member and a limit member, wherein the cover plate is provided with an explosion-proof hole in a first direction, the insulating member is connected to the cover plate in the first direction, the insulating member is provided with a receiving groove toward the cover plate, the support member is arranged in the receiving groove, the melting point of the support member is greater than the melting point of the insulating member, the limit member is arranged in the receiving groove and connected to the insulating member, the limit member abuts the support member in a direction perpendicular to the first direction to fix the support member in the receiving groove; the receiving groove cooperates with the limit to form an abutment positioning for the support member, thereby improving the installation convenience of the support member, and the receiving groove also reduces 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 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 end cover and the electrode assembly, thereby preventing the electrode assembly from moving toward the end cover and blocking the pressure relief hole, which is conducive to the high-temperature gas generated by the thermal runaway of the battery to be discharged smoothly from the explosion-proof hole, thereby improving the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 It is a schematic diagram of the exploded structure of the cover plate assembly, the shell, and the electrode assembly of Example 1 of the present application;

[0024] Figure 2 This is a schematic diagram of the structure of the insulating member and the supporting member of Example 1 of the present application;

[0025] Figure 3 It is a schematic diagram of the exploded structure of the insulating member and the supporting member of Example 1 of the present application;

[0026] Figure 4 is a schematic structural diagram of a front view of an opening of a receiving groove on an insulating member of Embodiment 1 of the present application;

[0027] Figure 5 yes Figure 4 Schematic diagram of the cross-sectional structure along line AA;

[0028] Figure 6 yes Figure 5 A magnified view of the structure of part B;

[0029] Figure 7 is a schematic structural diagram of a side of the insulating member of Embodiment 1 of the present application that is away from the opening of the accommodation groove;

[0030] Figure 8It is an exploded structural schematic diagram of the insulating part and the supporting part in Embodiment 2 of the present application;

[0031] Figure 9 It is a structural schematic diagram of the front view of the receiving groove opening on the insulating part in Embodiment 2 of the present application;

[0032] Figure 10 It is Figure 9 The sectional structural schematic diagram along the C-C line in

[0033] Figure 11 It is Figure 10 The enlarged structural diagram of part D in

[0034] Reference numerals: 1. Cover plate assembly; 10. Cover plate; 100. Explosion-proof hole; 101. Explosion-proof valve; 102. Terminal post; 11. Insulating part; 110. Receiving groove; 1100. Peripheral wall; 1101. Bottom wall; 111. Structural groove; 112. Exhaust hole; 113. Through hole; 12. Supporting part; 120. Third end; 121. Fourth end; 122. Second chamfer; 13. Limiting part; 130. First end; 131. Second end; 132. First chamfer; 2. Shell; 20. Accommodating cavity; 21. Opening; 22. Side plate; 3. Electrode assembly; 30. Tab; 4. Bottom cover part; X. First direction; Y. Second direction; Z. Third direction. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "thickness", "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is 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 should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more, and at least one means it can be one, two or more, unless otherwise specifically defined.

[0037] The applicant has noticed that in addition to the electrode assembly inside the battery case, various insulating and fixing structures need to be provided to stably fix the electrode assembly. Most of the insulating and fixing structures are made of plastic materials such as polypropylene materials, etc., and their melting points are basically around 160°C. When the battery undergoes thermal runaway, the internal temperature of the battery can reach above 400°C. Various insulating and fixing structures inside the case are prone to heat melting and disappearing. At this time, the electrode assembly is prone to move 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.

[0038] In view of this, in combination with Figures 1 to 11 , the embodiment of the present application provides a cover plate assembly, aiming to overcome at least one of the above technical problems.

[0039] In the following embodiments, the first direction X, the second direction Y, and the third direction Z that intersect pairwise are introduced, where the first direction X is parallel to the thickness direction of the cover plate assembly 1, the second direction Y is parallel to the length direction of the cover plate assembly 1, and the third direction Z is parallel to the width direction of the cover plate assembly 1.

[0040] Embodiment 1:

[0041] Referring to 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 the first direction X. Among them, the cover plate 10 is provided with an explosion-proof hole 100 in the first direction X, the insulating member 11 is provided with a receiving groove 110 facing the cover plate 10, a support member 12 is provided in the receiving groove 110, the melting point of the support member 12 is greater than the melting point of the insulating member 11. At the same time, a limiting member 13 is also provided in the receiving groove 110. The limiting member 13 is connected to the insulating member 11, and the limiting member 13 abuts against the support member 12 in a direction perpendicular to the first direction X, so that the support member 12 is fixed in the receiving groove 110.

[0042] The cooperation of the receiving groove 110 and the limit forms the abutment and positioning of the support member 12, improving the installation convenience of the support member 12. The receiving groove 110 also reduces the increase in the overall thickness dimension of the cover plate assembly 1 caused by the support member 12. When the battery undergoes thermal runaway, the insulating member 11 melts at a high temperature and gradually loses its supporting effect on the internal electrode assembly 3 of the battery. The support member 12 is more heat-resistant than the insulating member 11 and can effectively maintain the support between the end cover and the electrode assembly 3, preventing the electrode assembly 3 from moving towards the end cover member and blocking the pressure relief hole, which is beneficial to the smooth discharge of the high-temperature gas generated by the battery thermal runaway through the explosion-proof hole 100 and improves the safety of the battery.

[0043] 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 receiving 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.

[0044] In some embodiments, reference Figure 2 and Figure 3 The receiving groove 110 has a peripheral wall 1100 surrounding the support member 12 and a bottom wall 1101 connected to the support member 12, the peripheral wall 1100 is connected to the bottom wall 1101, and a plurality of stoppers 13 are provided, and the plurality of stoppers 13 are connected to the peripheral wall 1100. It should be noted that in this embodiment, the stoppers 13 are of a long strip structure extending perpendicular to the first direction X, and the support member 12 is interference-fitted with the plurality of stoppers 13 during the process of being placed in the receiving groove 110, that is, the support member 12 is stably embedded in the receiving groove 110 to achieve fixation by overcoming the interference resistance of the plurality of stoppers 13 perpendicular to the first direction X.

[0045] Further, in some embodiments, referring to Figure 3 , multiple limit members 13 are arranged around the peripheral wall 1100. In this embodiment, the peripheral wall 1100 has four surfaces connected to each other. In order to optimize the arrangement structure of the multiple limit members 13 and the abutment effect against the support member 12, the multiple limit members 13 can be evenly distributed on the four surfaces of the peripheral wall 1100.

[0046] In addition, in order to expand the range of action of the stopper 13 abutting the support member 12, multiple stoppers 13 are arranged at intervals along the first direction X, that is, multiple stoppers 13 are arranged on the four surfaces of the peripheral wall 1100 along the first direction X, ensuring that multiple abutment ends are provided for each side of the support member 12 facing the peripheral wall 1100, thereby improving the effect of positioning the support member 12. Specifically, in this embodiment, two stoppers 13 are provided on each surface of the peripheral wall 1100. In other embodiments, the number of stoppers 13 can be flexibly increased or decreased according to the sizes of the insulating member 11 and the support member 12.

[0047] In addition, in some embodiments, reference Figures 2 to 6 The stopper 13 has a first end 130 and a second end 131 corresponding to each other in the first direction X, the second end 131 faces the bottom wall 1101, and a first chamfer 132 is provided on the side of the first end 130 away from the peripheral wall 1100. When the support member 12 is introduced into the receiving groove 110, the first chamfer 132 is conducive to reducing the obstruction of the stopper 13 to the support member 12.

[0048] Further, seeFigure 6 The support member 12 has a third end 120 and a fourth end 121 in the first direction X. The fourth end 121 faces the bottom wall 1101, and a second chamfer 122 is circumferentially formed at the edge of the fourth end 121. The second chamfer 122 is used to cooperate with the first chamfer 132 to guide the overall support member 12 into the receiving groove 110, further reducing the obstruction of the limiting member 13 to the support member 12 and reducing the installation difficulty of the support member 12.

[0049] In some embodiments, referring to Figures 1 to 3 the insulating member 11 and the plurality of limiting members 13 can be integrally formed. During the forming 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 and reduce the overall mass of the insulating member 11. The number of the structural grooves 111 can be flexibly adjusted according to the actual size and structural requirements of the insulating member 11. In this embodiment, taking the example that two structural grooves 111 are formed, 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, and the insulating member 11 is provided with an exhaust hole 112 in the first direction X. The exhaust hole 112 is located in the structural groove 111 and communicates with the explosion-proof hole 100.

[0050] Referring to Figure 1 and Figure 7 in this embodiment, a plurality of exhaust holes 112 are provided in each structural groove 111, and the plurality of exhaust holes 112 are evenly distributed in the structural groove 111. When the battery undergoes thermal runaway, the high-temperature and high-pressure gas generated inside the battery can be led out from the exhaust hole 112 towards the explosion-proof hole 100. The plurality of exhaust holes 112 are beneficial to ensuring that while the insulating member 11 has sufficient contact area with the electrode assembly 3, the exhaust hole 112 can provide sufficient exhaust efficiency.

[0051] In some embodiments, referring to Figures 1 to 3 the 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 example that the formation position of the receiving groove 110 is misaligned with the position of the explosion-proof hole 100, the corresponding support member 12 is not opposite to the explosion-proof hole 100 in the first direction X, avoiding the support member 12 from obstructing the exhaust passage of the explosion-proof hole 100 and avoiding 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.

[0052] In addition, in other embodiments, when the opening area of the explosion-proof hole 100 is designed to be relatively large, the receiving groove 110 can 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, the explosion-proof hole 100 can still be ensured to relieve pressure smoothly.

[0053] In some embodiments, referring toFigure 6 The fitting clearance between the support member 12 and the surrounding wall 1100 is a mm, satisfying: 0.2mm≥a≥0.1mm, a can be any one of 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm or a range value consisting of any two of them.

[0054] Correspondingly, the dimension of the limit member 13 in the direction perpendicular to the surrounding wall 1100 is b mm, satisfying: 0.5mm≥b≥0.2mm, b can be 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm, and 5mm, any one of which or any two of which are in the range.

[0055] In some embodiments, reference Figure 5 , the size of the support member 12 in the first direction X is less than or equal to the depth of the receiving groove 110 in the first direction X. In this embodiment, the size of the support member 12 in the first direction X is less than the depth of the receiving groove 110 in the first direction X. Therefore, the addition of the support member 12 will not increase the size of the entire cover plate assembly 1 in the first direction X, which is beneficial to avoid affecting the overall size of the battery.

[0056] In addition, in some embodiments, reference Figure 2 and Figure 3 The insulating member 11 is provided with a through hole 113 in the first direction X for the tab 30 to pass through. In the actual assembly process, the through hole 113 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 113 is located on the side of the accommodating groove 110 away from the structural groove 111 in the second direction Y.

[0057] Correspondingly, this embodiment also provides a single cell.

[0058] Reference Figure 1, The single cell includes the above-mentioned cover plate assembly 1, and also includes a housing 2 and an electrode assembly 3. The housing 2 has a receiving cavity 20, and an opening 21 communicating with the receiving cavity 20 is provided at one end of the housing 2 in the first direction X. One end of the electrode assembly 3 in the first direction X has a tab 30. The electrode assembly 3 and the insulating member 11 are disposed in the receiving cavity 20, and the tab 30 faces the end cover member. A terminal 102 is provided on the cover plate 10 opposite to the tab 30. When the cover plate 10 covers the opening 21, the tab 30 can pass through the through hole 113 and be electrically connected to the terminal 102, and the insulating member 11 is located between the cover plate 10 and the electrode assembly 3. At the same time, a support member 12 is disposed between the cover plate 10 and the electrode assembly 3 to form a preset support structure.

[0059] In addition, as Figure 1 shown, a side plate 22 is further provided inside the housing 2 on one side of the electrode assembly 3 in the second direction Y. Both the side plate 22 and the insulating member 11 are fixedly connected to the housing 2 as fixing structures of the electrode assembly 3.

[0060] In addition, in this embodiment, referring to Figure 1 , a bottom cover member 4 is further provided at the other end of the housing 2 in the first direction X. The structure of the bottom cover member 4 is similar to that of the cover plate 10. In this embodiment, it is only used for sealing the housing 2 and leading out the electrodes. In other embodiments, if the bottom cover member 4 is also provided with a pressure relief structure, a support member 12 can also be added between the bottom cover member 4 and the electrode assembly 3, so as to ensure that the pressure relief structure at the bottom cover member 4 is not blocked by the electrode assembly 3 when the battery undergoes thermal runaway.

[0061] Embodiment 2:

[0062] Referring to Figures 8 to 11 , the difference between this embodiment and Embodiment 1 is that in this embodiment, the limiting member 13 adopts a long strip structure extending in the first direction X, and the dimension of each limiting member 13 perpendicular to the first direction X is larger than the dimension of the limiting member 13 in the first direction X in Embodiment 1.

[0063] Similarly, in order to expand the acting range of the limiting member 13 against the support member 12, a plurality of limiting members 13 can be evenly distributed on the four surfaces of the peripheral wall 1100 in this embodiment. Two limiting members 13 are provided on each surface of the peripheral wall 1100 in this embodiment, and the two limiting members 13 are spaced apart in a direction perpendicular to the first direction X. As Figure 10 and Figure 11 shown, the first end 130 of the limiting member 13 extends to the opening 21 end of the receiving groove 110, and the second end 131 extends to the bottom wall 1101. Ensure that a plurality of abutting acting ends are provided for each side of the support member 12 facing the peripheral wall 1100, so as to improve the effect of positioning the support member 12. In addition, in other embodiments, the number of the limiting members 13 can be flexibly increased or decreased according to the sizes of the insulating member 11 and the support member 12.

[0064] The above has introduced in detail a cover plate assembly and a single cell provided by the embodiments of the present application, and specific examples have been used to illustrate the principle and implementation manner 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; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions 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 an explosion-proof hole in the first direction; An insulating member, the insulating member is connected to the cover plate in the first direction, the insulating member is provided with a receiving groove toward the cover plate, the insulating member is provided with a through hole for the tab to pass through in the first direction, the through hole and the receiving groove are arranged in the second direction, the insulating member is provided with an exhaust hole in the first direction, and the exhaust hole is connected to the explosion-proof hole; A support member, the support member is arranged in the receiving groove, the melting point of the support member is greater than the melting point of the insulating member, and the orthographic projection of the support member on the cover plate is at least partially located outside the explosion-proof hole; a limiting member, the limiting member being disposed in the containing groove and connected to the insulating member, the limiting member abutting against the supporting member in a direction perpendicular to the first direction so that the supporting member is fixed to the containing groove; The accommodating groove has a peripheral wall surrounding the supporting member and a bottom wall connected to the supporting member, and the peripheral wall is connected to the bottom wall; a plurality of the limiting members are provided, and the plurality of the limiting members are connected to the peripheral wall; A plurality of the limiting members are arranged around the peripheral wall; and / or a plurality of the limiting members are arranged at intervals along the first direction; The stopper has a first end and a second end corresponding to each other in the first direction, the second end faces the bottom wall, and a first chamfer is provided on a side of the first end away from the peripheral wall; the support member has a third end and a fourth end in the first direction, the fourth end faces the bottom wall, and a second chamfer is provided on the circumferential edge of the fourth end; The matching clearance between the support member and the peripheral wall is a mm, satisfying: 0.2mm≥a≥0.1mm; and / or the size of the limit member in a direction perpendicular to the peripheral wall is b mm, satisfying: 0.5mm≥b≥0.2mm.

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

3. A single cell, characterized in that, include: The cover plate assembly as described in claim 1 or 2 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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