Battery cell cover plate assembly and square battery

Abstract

The utility model provides a kind of electric core cover plate assembly and square battery, it is related to battery technical field, electric core cover plate assembly includes light aluminum plate, explosion-proof valve, pole assembly and lower plastic;Light aluminum plate includes light aluminum plate body and first boss, mounting hole is equipped on light aluminum plate body, first boss is protruded in light aluminum plate body top surface, first boss is equipped with air hole and profiling groove, profiling groove is located at the outer edge of air hole, profiling groove bottom surface is equipped with first exhaust groove and second exhaust groove, first exhaust groove is located at the outer edge of profiling groove, second exhaust groove is communicated first exhaust groove and air hole;Explosion-proof valve is installed in profiling groove, and it is attached profiling groove bottom surface;Pole assembly is installed in mounting hole;Lower plastic is sealedly connected with light aluminum plate.After explosion-proof valve and light aluminum plate body are welded, if there is welding pinhole, it will leak through first exhaust groove, second exhaust groove and air hole when carrying out airtightness detection, so as to detect welding pinhole, prevent false seal, improve the accuracy of airtightness detection result.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cell cover assembly and a square battery. Background Technology

[0002] The current lithium battery market is experiencing increasing demand, with increasingly stringent requirements for battery reliability and zero tolerance for leakage. The explosion-proof valve on the cell cover is laser-welded to the aluminum sheet of the cover, serving to release gas and prevent the casing from exploding when the cell is overcharged or short-circuited.

[0003] In the existing technology, the explosion-proof valve is installed by stamping a contoured groove into the aluminum plate of the cover plate, placing the explosion-proof valve in it, and fixing it after laser welding. After welding, the contact surface between the two may produce a false seal, making it difficult for gas to pass through. When there are welding pinholes, they are difficult to detect. After the battery cell expands, the gap between the contact surface between the two opens again, causing leakage. Utility Model Content

[0004] In view of this, the present invention proposes a cell cover plate assembly and a square battery to solve the technical problem mentioned in the background art that the explosion-proof valve and the aluminum plate may produce a false seal after welding, and the gap between the two contact surfaces will open again after the cell expands, causing leakage.

[0005] The technical solution of this utility model is implemented as follows: In a first aspect, this utility model provides a battery cell cover assembly, including a plain aluminum plate, an explosion-proof valve, an electrode assembly, and a lower plastic layer, wherein: The aluminum plate includes an aluminum plate body and a first boss. The aluminum plate body is provided with mounting holes. The first boss protrudes from the top surface of the aluminum plate body. The first boss is provided with a vent hole and a contour groove. The contour groove is located at the outer edge of the vent hole. The bottom surface of the contour groove is provided with a first exhaust groove and a second exhaust groove. The first exhaust groove is located at the outer edge of the contour groove. The second exhaust groove connects the first exhaust groove and the vent hole. The explosion-proof valve is installed in the contour groove and fits the bottom surface of the contour groove; The pole assembly is installed in the mounting hole; The lower plastic is sealed to the aluminum plate.

[0006] Based on the above technical solutions, preferably, the width of the first exhaust groove is ≥1.5mm.

[0007] Based on the above technical solutions, preferably, the width of the second exhaust groove is ≥1mm.

[0008] Based on the above technical solutions, preferably, the electrode assembly includes a welding piece, a positive electrode, a negative electrode, a first sealing ring, and a second sealing ring. The welding piece is welded to the aluminum plate body and its two ends are respectively connected to the inner wall of the mounting hole to divide the mounting hole into a positive electrode hole and a negative electrode hole. The positive electrode is installed in the positive electrode hole, the negative electrode hole is installed in the negative electrode hole, the first sealing ring is located between the positive electrode and the welding piece, and the second sealing ring is located between the negative electrode and the welding piece.

[0009] Based on the above technical solutions, preferably, it also includes an upper plastic, wherein the aluminum plate body has a protrusion along the edge of the mounting hole, the protrusion forms an annular gap with the outer wall of the positive electrode post and the negative electrode post, the upper plastic is installed in the annular gap, and the upper plastic is provided with a separator strip, the separator strip being located between the positive electrode post and the negative electrode post.

[0010] Based on the above technical solutions, preferably, the protrusion is provided with a notch.

[0011] Based on the above technical solutions, preferably, the mounting hole is located in the middle of the aluminum plate body.

[0012] Based on the above technical solutions, preferably, a protective patch is also included, which is installed in the vent hole and located on the top surface of the first boss.

[0013] Based on the above technical solutions, preferably, the aluminum plate further includes a second boss, which protrudes from the top surface of the aluminum plate body. The second boss and the first boss are located on both sides of the mounting hole, and the second boss is provided with a liquid injection hole.

[0014] Secondly, this utility model provides a square battery, including a bottom shell, a battery cell, and a battery cell cover assembly as described in the first aspect, wherein the battery cell is installed in the bottom shell, and the aluminum plate body is connected to the bottom shell.

[0015] The cell cover assembly and square battery of this utility model have the following advantages over the prior art: (1) A first exhaust groove and a second exhaust groove are provided on the bottom surface of the contour groove. The first exhaust groove is located on the outer edge of the contour groove, and the second exhaust groove connects the first exhaust groove and the vent hole. After the explosion-proof valve is welded to the aluminum plate body, when the air tightness test is performed, if there is a welding pinhole, it will leak air through the first exhaust groove, the second exhaust groove and the vent hole, thereby detecting the welding pinhole, preventing false sealing, and improving the accuracy of the air tightness test result. (2) By setting the width of the first exhaust groove to ≥1.5mm, the effectiveness of exhaust is ensured and the accuracy of airtightness detection is improved; (3) By setting the width of the second exhaust groove to ≥1mm, the effectiveness of exhaust is ensured and the accuracy of airtightness detection is improved; (4) The mounting hole is divided into a positive electrode hole and a negative electrode hole by the welding piece. The positive electrode post and the negative electrode hole are respectively installed in the positive electrode hole and the negative electrode hole. The first sealing ring is located between the positive electrode post and the welding piece, and the second sealing ring is located between the negative electrode post and the welding piece. While achieving sealing, insulation is also provided between the positive electrode post and the aluminum plate body, and between the negative electrode post and the aluminum plate body, thereby improving reliability and stability. (5) The aluminum plate body has a protrusion along the edge of the mounting hole. The protrusion forms an annular gap with the outer wall of the positive and negative terminals. The upper plastic is installed in the annular gap to fill the annular gap and prevent small conductive objects from falling into the annular gap and triggering a short circuit. The upper plastic is provided with a separator strip. The separator strip is located between the positive and negative terminals to separate the positive and negative terminals, prevent short circuits, and improve safety. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a front view of the battery cell cover assembly of this utility model; Figure 2 This is an exploded view of the battery cell cover assembly of this utility model. Figure 3 This is a perspective view of the aluminum plate of this utility model from a first-view perspective; Figure 4 This is a perspective view of the aluminum plate of this utility model from a second angle. Figure 5 For the present utility model Figure 4 Enlarged view of part A in the middle; Figure 6 This is a schematic diagram of the first protrusion of this utility model; Figure 7 This is a schematic diagram of the structure of the welding piece and the aluminum plate body after welding. Figure 8 This is a schematic diagram of the pole assembly of this utility model; Figure 9 This is a schematic diagram of the lower plastic structure of this utility model; Figure 10 This is a schematic diagram of the square battery of this utility model.

[0018] Explanation of reference numerals in the attached diagram: 1-Aluminum plate, 2-Explosion-proof valve, 3-Pole post assembly, 4-Lower plastic, 5-Upper plastic, 6-Protective patch; 100 - Bottom shell; 11-Bright aluminum plate body, 111-Mounting hole, 1111-Positive electrode hole, 1112-Negative electrode hole, 112-Protrusion, 1121-Notch, 12-First boss, 121-Ventilation hole, 122-Shaped groove, 123-First exhaust groove, 124-Second exhaust groove, 13-Second boss, 131-Injection hole; 31-Welding piece, 32-Positive electrode post, 33-Negative electrode post, 34-First sealing ring, 35-Second sealing ring; 41-Lower plastic body, 411-Positive electrode connection hole, 412-Negative electrode connection hole, 42-First sealing block, 421-Receiving groove, 43-Second sealing block, 431-Liquid permeation hole; 51-Separator bar. Detailed Implementation

[0019] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of the embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0020] Reference Figures 1-9 As shown, in a first aspect embodiment of the present invention, a battery cell cover assembly is provided, comprising an aluminum plate 1, an explosion-proof valve 2, an electrode assembly 3, and a lower plastic 4, wherein: The aluminum plate 1 includes an aluminum plate body 11 and a first boss 12. The aluminum plate body 11 has mounting holes 111. The first boss 12 protrudes from the top surface of the aluminum plate body 11. The first boss 12 has ventilation holes 121 and contoured grooves 122. The contoured grooves 122 are formed on the surface of the first boss 12 near the aluminum plate body 11. The contoured grooves 122 are located at the outer edge of the ventilation holes 121. The bottom surface of the contoured grooves 122 has a first exhaust groove 123 and a second exhaust groove 12. 4. The first exhaust groove 123 is located on the outer edge of the contour groove 122, and the second exhaust groove 124 connects the first exhaust groove 123 and the vent hole 121; the explosion-proof valve 2 is installed in the contour groove 122 and fits against the bottom surface of the contour groove 122, so that after the explosion-proof valve 2 is installed in the contour groove 122, the first exhaust groove 123 and the second exhaust groove 124 can connect the fitting surface with the vent hole 121, so that if there is a welding pinhole, it can be detected immediately to avoid false sealing; The pole assembly 3 is installed in the mounting hole 111; The lower plastic 4 is sealed to the aluminum plate 1.

[0021] It should be noted that in this embodiment, the first exhaust groove 123 is an oblong groove, and the second exhaust groove 124 is an inclined elongated groove, and multiple second exhaust grooves 124 are provided. Of course, the shape and distribution of the first exhaust groove 123 and the second exhaust groove 124 can be other shapes, and are not limited to the scheme shown in the above figure.

[0022] The battery cell cover assembly proposed in this embodiment has a first exhaust groove 123 and a second exhaust groove 124 on the bottom surface of the contour groove 122. The first exhaust groove 123 is located at the outer edge of the contour groove 122, and the second exhaust groove 124 connects the first exhaust groove 123 and the vent hole 121. After the explosion-proof valve 2 is welded to the aluminum plate body 11, during the air tightness test, if there is a welding pinhole, it will leak air through the first exhaust groove 123, the second exhaust groove 124 and the vent hole 121, thereby detecting the welding pinhole, preventing false sealing, and improving the accuracy of the air tightness test results.

[0023] In some embodiments, the width of the first exhaust groove 123 is ≥1.5mm. This parameter setting ensures the effectiveness of exhaust and improves the accuracy of airtightness detection.

[0024] In some embodiments, the width of the second exhaust groove 124 is ≥1mm. This parameter setting ensures the effectiveness of exhaust and improves the accuracy of airtightness testing.

[0025] In some embodiments, the electrode assembly 3 includes a welding piece 31, a positive electrode 32, a negative electrode 33, a first sealing ring 34, and a second sealing ring 35. The welding piece 31 is welded to the aluminum plate body 11 and its two ends are respectively connected to the inner wall of the mounting hole 111. The welding piece 31 is located in the middle of the mounting hole 111 to divide the mounting hole 111 into a positive electrode hole 1111 and a negative electrode hole 1112. The positive electrode 32 is installed in the positive electrode hole 1111, and the negative electrode hole 1112 is installed in the negative electrode hole 1112. The first sealing ring 34 is located between the positive electrode 32 and the welding piece 31, and the second sealing ring 35 is located between the negative electrode 33 and the welding piece 31. The mounting hole 111 is divided into a positive electrode hole 1111 and a negative electrode hole 1112 by the welding piece 31. The positive electrode post 32 and the negative electrode hole 1112 are respectively installed in the positive electrode hole 1111 and the negative electrode hole 1112. The first sealing ring 34 and the second seal achieve sealing while insulating the positive electrode post 32 from the aluminum plate body 11 and the negative electrode post 33 from the aluminum plate body 11, thereby improving reliability and stability.

[0026] In some embodiments, the cell cover assembly further includes an upper plastic 5. The aluminum plate body 11 has a protrusion 112 along the edge of the mounting hole 111. The protrusion 112 forms an annular gap with the outer walls of the positive terminal 32 and the negative terminal 33. The upper plastic 5 is installed in the annular gap, and the upper plastic 5 has a separator strip 51 located between the positive terminal 32 and the negative terminal 33. By installing the upper plastic 5 in the annular gap, the annular gap is filled, preventing small conductive objects from falling into the annular gap and triggering a short circuit hazard. The separator strip 51 located between the positive terminal 32 and the negative terminal 33 separates the positive terminal 32 and the negative terminal 33, preventing short circuits and improving safety.

[0027] In some embodiments, the protrusion 112 is provided with a notch 1121. The protrusion 112 is provided with a notch 1121 symmetrically on both sides along the width direction of the mounting hole 111, which facilitates the placement and removal of the plastic 5, making installation and disassembly easier and improving convenience.

[0028] In some embodiments, the mounting hole 111 is located in the middle of the aluminum plate body 11. By positioning the mounting hole 111, the positive electrode post 32 and the negative electrode post 33 are located in the middle of the aluminum plate body 11. Compared to the traditional scheme where the positive electrode post 32 and the negative electrode post 33 are located on opposite sides of the aluminum plate body 11, this scheme allows for better utilization of the space on both sides, resulting in a more compact structure and improved energy density.

[0029] In some embodiments, the cell cover assembly further includes a protective patch 6, which is installed in the vent hole 121 and located on the top surface of the first boss 12. The protective patch 6 protects the explosion-proof valve 2, preventing accidental opening and improving reliability and stability.

[0030] In some embodiments, the aluminum plate 1 further includes a second boss 13, which protrudes from the top surface of the aluminum plate body 11. The second boss 13 and the first boss 12 are located on both sides of the mounting hole 111, and the second boss 13 is provided with a liquid injection hole 131. By providing the liquid injection hole 131 on the second boss 13, the liquid injection operation of the battery cell will not affect the explosion-proof valve 2, thereby improving reliability and stability.

[0031] In some embodiments, the lower plastic 4 includes a lower plastic body 41, a first sealing block 42 and a second sealing block 43. The first sealing block 42 cooperates with the first boss 12 and is provided with a receiving groove 421 for accommodating the explosion-proof valve 2. The second sealing block 43 cooperates with the second boss 13 and is provided with a liquid permeation hole 431 corresponding to and connected to the liquid injection hole 131. The lower plastic body 41 is provided with a positive electrode connection hole 411 and a negative electrode connection hole 412. The positive electrode connection hole 411 corresponds to the positive electrode hole 1111 and the negative electrode connection hole 412 corresponds to the negative electrode hole 1112.

[0032] The working principle of the battery cell cover assembly is as follows: after the explosion-proof valve 2 is welded to the aluminum plate body 11, during the air tightness test, if there is a welding pinhole, it will leak air through the first exhaust groove 123, the second exhaust groove 124 and the vent hole 121, thereby detecting the welding pinhole, preventing false sealing, and improving the accuracy of the air tightness test results.

[0033] Based on the same concept, the second aspect of the present invention, combined with... Figure 10 As shown, a square battery is proposed, including a bottom shell 100, a battery cell, and a battery cell cover assembly as described in the first aspect. The battery cell is installed in the bottom shell 100, and the aluminum plate body 11 is connected to the bottom shell 100. The positive electrode tab of the battery cell is connected to the positive terminal 32, and the negative electrode tab is connected to the negative terminal 33.

[0034] The square battery proposed in this embodiment can more comprehensively detect false seals in the welding between the explosion-proof valve 2 and the aluminum plate body 11, thereby improving the accuracy of the airtightness test results.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A cell cover assembly, characterized in that, Includes a bare aluminum plate (1), an explosion-proof valve (2), an electrode assembly (3), and a lower plastic sheet (4), wherein: The aluminum plate (1) includes an aluminum plate body (11) and a first boss (12). The aluminum plate body (11) is provided with mounting holes (111). The first boss (12) protrudes from the top surface of the aluminum plate body (11). The first boss (12) is provided with a vent hole (121) and a contour groove (122). The contour groove (122) is located at the outer edge of the vent hole (121). The bottom surface of the contour groove (122) is provided with a first exhaust groove (123) and a second exhaust groove (124). The first exhaust groove (123) is located at the outer edge of the contour groove (122). The second exhaust groove (124) connects the first exhaust groove (123) and the vent hole (121). The explosion-proof valve (2) is installed in the contour groove (122) and fits the bottom surface of the contour groove (122); The pole assembly (3) is installed in the mounting hole (111); The lower plastic (4) is sealed to the aluminum plate (1).

2. The cell cover assembly as described in claim 1, characterized in that, The width of the first exhaust groove (123) is ≥1.5mm.

3. The cell cover assembly as described in claim 1, characterized in that, The width of the second exhaust groove (124) is ≥1mm.

4. The cell cover assembly as described in claim 1, characterized in that, The electrode assembly (3) includes a welding piece (31), a positive electrode post (32), a negative electrode post (33), a first sealing ring (34), and a second sealing ring (35). The welding piece (31) is welded to the aluminum plate body (11) and its two ends are respectively connected to the inner wall of the mounting hole (111) to divide the mounting hole (111) into a positive electrode hole (1111) and a negative electrode hole (1112). The positive electrode post (32) is installed in the positive electrode hole (1111), and the negative electrode hole (1112) is installed in the negative electrode hole (1112). The first sealing ring (34) is located between the positive electrode post (32) and the welding piece (31), and the second sealing ring (35) is located between the negative electrode post (33) and the welding piece (31).

5. The cell cover assembly as described in claim 4, characterized in that, It also includes an upper plastic (5), the light aluminum plate body (11) is provided with a protrusion (112) along the edge of the mounting hole (111), the protrusion (112) forms an annular gap with the outer wall of the positive electrode post (32) and the negative electrode post (33), the upper plastic (5) is installed in the annular gap, and the upper plastic (5) is provided with a separator (51), the separator (51) is located between the positive electrode post (32) and the negative electrode post (33).

6. The cell cover assembly as described in claim 5, characterized in that, The protrusion (112) has a notch (1121).

7. The cell cover assembly as described in claim 1, characterized in that, The mounting hole (111) is located in the middle of the aluminum plate body (11).

8. The cell cover assembly as described in claim 1, characterized in that, It also includes a protective patch (6), which is installed in the vent hole (121) and located on the top surface of the first boss (12).

9. The cell cover assembly as described in claim 1, characterized in that, The light aluminum plate (1) also includes a second boss (13), which protrudes from the top surface of the light aluminum plate body (11). The second boss (13) and the first boss (12) are located on both sides of the mounting hole (111). The second boss (13) is provided with a liquid injection hole (131).

10. A square battery, characterized in that, It includes a bottom shell (100), a battery cell, and a battery cell cover assembly as described in any one of claims 1-9, wherein the battery cell is installed in the bottom shell (100), and the aluminum plate body (11) is connected to the bottom shell (100).

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