Battery cell cover plate assembly and battery cell assembly

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell cover plate assembly and a battery cell assembly, the battery cell cover plate assembly comprises a connecting sheet, the connecting sheet comprises a pole connecting part and a tab connecting part which are connected in sequence, the top surface of the tab connecting part forms a connecting surface used for being connected with a tab, and the top surface of the pole connecting part is provided with a vertically extending through hole; the polar column is provided with a connecting column which is arranged in the through hole in a penetrating manner; according to the utility model, after the pole post and the connecting piece are welded and connected, the welding part of the pole post and the connecting piece is in non-single plane connection, and the welding connection area is larger, so that the reliability of the pole post and the connecting piece after being welded can be effectively improved, and in addition, as the connecting surface connected with the pole lug is positioned at the top of the pole lug connecting part, after the pole lug is connected with the pole lug connecting part, the reliability is improved. Compared with the prior art, not only is the structure more compact and the occupied space smaller, but also one side of the pole connecting part tends to tilt upwards when the pole lug connecting part is pulled down by the pole lug, so that the pole and the pole connecting part can be matched more tightly, and the risk of separation is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell cover plate assembly and a battery cell assembly. Background Art

[0002] With the rapid development of new energy technologies, power batteries, due to their excellent characteristics, have been increasingly widely used in various electric tools and new energy vehicles. The safety during the use of power batteries is one of the indicators that cannot be ignored. Power batteries not only need to have a high capacity but also should have good reliability in use. As an important part of power batteries, the cover plate assembly plays a role in guiding current and sealing the power batteries.

[0003] Currently, the two poles of existing power batteries are mainly connected to the corresponding pole posts through connecting pieces. The connecting piece has a planar connecting surface, and the pole post is correspondingly provided with a mating surface. The mating surface of the pole post and the connecting surface of the connecting piece are welded. Although the structure of the power battery applied to this assembly connection method is relatively simple, during long-term use, the connection position between the pole post and the connecting piece is prone to break and separate under vibration or bumpy conditions, and then a short-circuit phenomenon occurs, resulting in poor reliability in the use of power batteries. Summary of the Utility Model

[0004] In view of this, the utility model provides a battery cell cover plate assembly and a battery cell assembly to solve the problem of poor reliability of the connection method between the pole post and the connecting piece in existing power batteries.

[0005] In a first aspect, the utility model provides a battery cell cover plate assembly, including: a connecting piece, including a pole post connecting portion and an ear connecting portion connected in sequence. The top surface of the ear connecting portion forms a connecting surface for connecting with the ear. The top surface of the pole post connecting portion forms a first mating surface, and a vertically extending through hole is provided on the first mating surface; a pole post, the bottom of which forms a second mating surface that mates with the first mating surface. The position of the pole post at the second mating surface has a connecting post for passing through the through hole of the connecting piece, and the pole post is welded to the through hole of the connecting piece through the connecting post; a cover plate, located above the connecting piece and having an assembly hole for the pole post to pass through.

[0006] Beneficial effect: a through hole is arranged on the first mating surface and a connecting column is arranged on the second mating surface; after the pole and the connecting piece are welded together, the welding position of the two is not a single plane connection and the welding connection area is large, which can effectively improve the stability and reliability of the pole and the connecting piece after welding. At the same time, the weld between the through hole and the connecting column can also improve the current passing capacity at this position. In addition, since the connection surface connected to the pole ear is located at the top of the pole ear connecting part, after the pole ears and the pole ear connecting parts are connected, not only is the structure more compact and occupies less space, but when the pole ear pulls down the pole ear connecting part, one side of the pole column connecting part will tend to curl up, so that the pole column and the pole column connecting part can be more closely matched, reducing the risk of separation, and effectively solving the problem of poor reliability of the connection method between the pole column and the connecting piece in the existing power battery.

[0007] In an optional embodiment, the top of the pole connecting part has an upwardly protruding boss, and the bottom of the pole connecting part forms a groove upwardly corresponding to the position of the boss, the top surface of the boss forms a first mating surface, the through hole is located on the boss and connected to the groove, and the top surface of the groove is recessed upward around the position of the through hole to form a welding groove.

[0008] Beneficial effect: The pole-to-pole connection is achieved through penetration welding at the position of the welding groove, which further improves the connection strength and can also accommodate the welding points generated there, improves the flatness of the top surface of the groove, and prevents the welding points from protruding downward and interfering with other components.

[0009] In an optional embodiment, the welding groove is an annular groove, the through hole is a circular hole, the welding groove is arranged close to the side wall of the groove, and the distance from the inner side wall of the welding groove to the inner wall of the through hole along the radial direction is greater than or equal to 1.2 mm.

[0010] Beneficial effect: A welding groove of this size can prevent the welding at the welding groove and the welding molten width at the through-hole position from overlapping each other, and can reduce the risk of pore welding slag, etc.

[0011] In an optional embodiment, it further includes a first insulating member arranged between the connecting plate and the cover plate, the welding groove is an annular groove, the boss is a truncated cone, and the distance from the outer wall of the welding groove to the side wall of the boss along the radial direction is greater than or equal to 0.8 mm.

[0012] Beneficial effect: This form of specification and size can not only meet the connection strength requirements, but also improve the safety and reliability of welding at the welding groove. When welding the wall, heat is transferred to melt other surrounding components.

[0013] In an optional embodiment, the depth of the welding groove is greater than or equal to 0.2 mm.

[0014] Beneficial effects: It can prevent the solder joints at the welding groove from protruding downward beyond the top surface of the groove 1013, improving the flatness of this local position.

[0015] In an optional implementation, a through groove is formed at one end of the tab connection part far from the pole connection part along the direction close to the pole connection part, and connection surfaces are respectively formed on the top surfaces of the tab connection part on both sides of the through groove.

[0016] Beneficial effects: The tab connection part in this form is lighter in weight, enabling one tab connection part to be connected to two tabs simultaneously, with a simple and reliable structural form.

[0017] In an optional implementation, the cover plate includes a main body plate and an assembly plate. The main body plate is assembled and connected to the pole. A welding hole is formed in the main body plate corresponding to the tab connection part, and the assembly plate matches the shape of the welding hole and is assembled in the welding hole.

[0018] Beneficial effects: After the cell cover plate assembly is installed, the tabs and the tab connection part can be directly welded through the welding hole, effectively simplifying the assembly steps and improving production efficiency.

[0019] In an optional implementation, the number of connection pieces and poles is both two and they are respectively arranged corresponding to the positive and negative electrodes of the cell. The cover plate has welding holes for the tab connection part corresponding to each connection piece.

[0020] Beneficial effects: The area of the welding holes formed in the cover plate in this form is small, facilitating the assembly and connection of the tabs while having higher structural strength and being less likely to deform.

[0021] In a second aspect, the present utility model further provides a cell assembly, which includes: the above-mentioned cell cover plate assembly, a cell, with tabs provided at the top. The tabs include a connection section and a bent section. The connection section is located on one side of the tab connection part of the cell cover plate assembly, and the bent section is connected to the top of the connection section and extends along the top surface of the tab connection part. The tab is welded to the tab connection part.

[0022] In an optional implementation, two tabs are respectively provided at the positive and negative electrodes of the cell. The two tabs of the same pole are oppositely arranged on both sides of the corresponding tab connection part, and the bent sections of the two tabs are welded to the same tab connection part. Description of the Drawings

[0023] In order to more clearly illustrate the specific implementation manners of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific implementation manners or the prior art. Obviously, the following drawings are some implementation manners of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 A three-dimensional schematic diagram of a cell cover assembly without an installation assembly plate according to an embodiment of the present invention;

[0025] Figure 2 is Figure 1 A cross-sectional view of the cell cover assembly shown after installing the assembly plate;

[0026] Figure 3 is Figure 2 An enlarged schematic view of part A of the cell cover assembly shown;

[0027] Figure 4 is Figure 1 A three-dimensional schematic diagram of the connecting piece of the cell cover assembly shown;

[0028] Figure 5 is Figure 1 A three-dimensional schematic diagram of the pole column of the cell cover assembly shown;

[0029] Figure 6 A three-dimensional schematic diagram of a cell assembly according to an embodiment of the present invention

[0030] Figure 7 is Figure 6 A three-dimensional schematic diagram of the cell assembly shown without the housing installed;

[0031] Figure 8 is Figure 7 A three-dimensional schematic diagram of the cell assembly shown with the tab not welded.

[0032] Explanation of reference numerals:

[0033] 1. Connecting piece; 101. Pole column connecting part; 1011. First mating surface; 1012. Boss; 1013. Groove; 1014. Welding groove; 102. Tab connecting part; 1021. Connecting surface; 1022. Through groove; 103. Through hole;

[0034] 2. Pole column; 201. Second mating surface; 202. Connecting column;

[0035] 3. Cover plate; 301. Main body plate; 3011. Welding hole; 302. Assembly plate; 3021. Sealing plate; 3022. Insulating plate;

[0036] 4. First insulating member; 5. Second insulating member; 6. Cell; 601. Tab; 7. Housing. Detailed implementation manners

[0037] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0038] Combine the following Figures 1 to 8 , describing an embodiment of the utility model.

[0039] According to an embodiment of the utility model, on the one hand, a battery cell cover plate assembly is provided, comprising: a connecting plate 1, a pole 2 and a cover plate 3, the connecting plate 1 comprising a pole connecting portion 101 and a pole lug connecting portion 102 connected in sequence, the top surface of the pole lug connecting portion 102 forming a connecting surface 1021 for connecting to the pole lug 601, the top surface of the pole connecting portion 101 forming a first mating surface 1011, the first mating surface 1011 being provided with a vertically extending through hole 103; a second mating surface 201 mating with the first mating surface 1011 is formed at the bottom of the pole 2, the pole 2 is located at the position of the second mating surface 201 and has a connecting column 202 for penetrating into the through hole 103, the pole 2 is welded to the through hole 103 of the connecting plate 1 through the connecting column 202, and the cover plate 3 is located on the upper side of the connecting plate 1 and has an assembly hole for the pole 2 to penetrate.

[0040] By using the battery cell cover plate assembly of the present embodiment, a through hole 103 is provided on the first mating surface 1011 and a connecting column 202 is provided on the second mating surface 201. After the pole 2 is welded to the connecting piece 1, the welding position of the two is not a single plane connection and the welding connection area is large, which can effectively improve the stability and reliability of the pole 2 and the connecting piece 1 after welding. At the same time, the weld between the through hole 103 and the connecting column 202 can also improve the current passing capacity at this position. In addition, since the connecting surface 1021 connected to the pole ear 601 is located at the top of the pole ear connecting part 102, after the pole ear 601 is connected to the pole ear connecting part 102, not only is the structure more compact and the space occupied smaller, but when the pole ear 601 pulls down the pole ear connecting part 102, one side of the pole column connecting part 101 will tend to curl up, so that the pole 2 and the pole column connecting part 101 can be more closely matched, reducing the risk of separation, and effectively solving the problem of poor reliability of the connection method between the pole and the connecting piece in the existing power battery.

[0041] It should be noted that top refers to Figure 3 The arrow in the middle points to the "up" side, and the bottom refers to Figure 3 The arrow in the middle points to the "down" side, and upward means the side that faces Figure 3The "up" direction indicated by the arrow, and pulling down means towards Figure 3 the "down" direction indicated by the arrow in the figure for pulling.

[0042] In the related art, the connecting piece 1 and the tab 601 of the battery cell 6 are usually arranged vertically. The bottom surface of the connecting piece 1 is connected to the tab 601. In order to improve the connection reliability between the two, the tab 601 usually needs to be bent and welded and fixed to the bottom surface of the connecting piece 1 through the outer wall. In this connection method, the tab 601 needs to occupy a relatively large space, resulting in a cavity at the top of the battery cell assembly. In addition, the tab 601 will push up the connecting piece 1, causing the pole connection part 101 of the connecting piece 1 to have a tendency to move downward under the action of the lever principle, and further causing the pole connection part 101 of the connecting piece 1 to be easily separated from the pole 2, resulting in poor structural stability at the top of the battery cell assembly. However, the battery cell cover assembly in this embodiment can reliably solve the defects existing in the above structural form.

[0043] In a possible implementation manner, the top of the pole connection part 101 has a convex platform 1012 protruding upward, and a groove 1013 is formed upward at the position corresponding to the convex platform 1012 at the bottom of the pole connection part 101. The top surface of the convex platform 1012 forms a first mating surface 1011. The through hole 103 is located in the convex platform 1012 and communicates with the groove 1013. The top surface of the groove 1013 is recessed upward around the position of the through hole 103 to form a welding groove 1014. The pole 2 and the pole connection part 101 are connected by penetration welding at the position of the welding groove 1014. While further improving the connection strength, the welding groove 1014 can also accommodate the solder joints generated at this place, improving the flatness of the top surface of the groove 1013 and preventing the solder joints from protruding downward and interfering with other components.

[0044] Among them, the specific shapes of the first mating surface 1011 and the second mating surface 201 are not limited and can be circular, square, etc., as long as they are convenient for manufacturing. In addition, the specific specifications and dimensions of the convex platform 1012 and the groove 1013 are not strictly limited and can be flexibly selected and adjusted according to the specifications and dimensions of the battery cell assembly.

[0045] In a possible implementation manner, the welding groove 1014 is an annular groove, the through hole 103 is a round hole, the welding groove 1014 is arranged close to the side wall of the groove 1013, and the distance from the inner side wall of the welding groove 1014 to the inner wall of the through hole 103 along the radial direction is greater than or equal to 1.2 mm. After welding in the welding groove 1014 of this form, the stress uniformity is better and the connection is more stable and reliable, which can avoid the stress concentration phenomenon generated at local positions. In addition, for the welding groove 1014 of this size, it can prevent the welding at the welding groove 1014 from overlapping with the welding penetration width at the position of the through hole 103, and can reduce the risk of gas holes, welding slag, etc.

[0046] Specifically, as Figure 3 shown, the dimension represented by W is the distance from the inner wall of the welding groove 1014 along the radial direction to the inner wall of the through hole 103.

[0047] Furthermore, the distance from the inner wall of the welding groove 1014 along the radial direction to the inner wall of the through hole 103 is greater than or equal to 1.2 mm, which can also improve the safety and reliability during welding at the position of the welding groove 1014, and prevent heat transfer during welding from melting other surrounding components.

[0048] In a possible implementation manner, the battery cell cover plate assembly further includes a first insulating member 4 disposed between the connecting piece 1 and the cover plate 3. The welding groove 1014 is an annular groove, and the boss 1012 is a frustum. The distance from the outer wall of the welding groove 1014 along the radial direction to the side wall of the boss 1012 is greater than or equal to 0.8 mm. Such a specification size can, while meeting the connection strength requirements, also improve the safety and reliability during welding at the position of the welding groove 1014, and prevent heat transfer during welding from melting other surrounding components.

[0049] Specifically, as Figure 3 shown, the dimension represented by L is the distance from the outer wall of the welding groove 1014 along the radial direction to the side wall of the boss 1012.

[0050] Furthermore, the battery cell cover plate assembly further includes a second insulating member 5 disposed between the assembly hole and the pole post 2. The pole post 2 includes a first post section, a second post section, and a third post section from top to bottom. The diameters of the first post section, the second post section, and the third post section decrease in sequence. The third post section is the connecting post 202. The first post section and the second post section form a stepped surface. The first post section forms a limiting rib for positioning and cooperating with the cover plate 3. The bottom surface of the first post section cooperates with the top surface of the cover plate 3 through the second insulating member 5, and the side wall of the second post section cooperates with the inner wall of the assembly hole through the second insulating member 5.

[0051] Wherein, the pole post connecting portion 101 is disposed higher than the pole ear connecting portion 102, and at least one stepped surface is formed at the connection of the pole post connecting portion 101 and the pole ear connecting portion 102. The shape of the first insulating member 4 corresponds to and matches the shape of the stepped surface.

[0052] In a possible implementation manner, the depth of the welding groove 1014 is greater than or equal to 0.2 mm, which can prevent the solder joint at this position from protruding downward from the top surface of the groove 1013 and improve the flatness of this local position.

[0053] In a possible implementation, one end of the tab connection portion 102 away from the pole connection portion 101 forms a through groove 1022 along the direction close to the pole connection portion 101. Connection surfaces 1021 are respectively formed on the top surfaces of the tab connection portion 102 on both sides of the through groove 1022. The tab connection portion 102 in this form is lighter in weight, enabling one tab connection portion 102 to be connected to two tabs 601 simultaneously, and the structural form is simple and reliable.

[0054] It can be understood that as an alternative implementation, the tab connection portion 102 can also be an integral structure without the through groove 1022 provided thereon.

[0055] In a possible implementation, the cover plate 3 includes a main body plate 301 and an assembly plate 302. The main body plate 301 is assembled and connected to the pole 2. A welding hole 3011 corresponding to the tab connection portion 102 is provided on the main body plate 301. The assembly plate 302 is matched with the shape of the welding hole 3011 and is assembled in the welding hole 3011. After the battery cell cover plate assembly is installed, the tabs 601 and the tab connection portion 102 can be directly welded through the welding hole 3011, which can effectively simplify the assembly steps and improve the production efficiency.

[0056] Specifically, the assembly plate 302 includes a sealing plate 3021 and an insulating plate 3022 connected in sequence from top to bottom. The sealing plate 3021 is used for assembling and connecting with the cover plate 3, and the insulating plate 3022 can effectively improve the insulation reliability between the sealing plate 3021 and the internal components.

[0057] In a possible implementation, the number of both the connection pieces 1 and the poles 2 is two and they are respectively arranged corresponding to the positive and negative electrodes of the battery cell 6. The cover plate 3 has welding holes 3011 corresponding to the tab connection portions 102 of each connection piece 1. The area of the welding holes 3011 provided on the cover plate 3 in this form is small, which is convenient for the assembly and connection of the tabs 601 and has higher structural strength and is not easily deformed.

[0058] It can be understood that as an alternative implementation, there can also be only one welding hole 3011, and one welding hole 3011 covers the areas corresponding to two tab connection portions 102 at the same time.

[0059] Specifically, as Figure 2As shown, the specific structure and material of the terminal 2 of the positive electrode and the terminal 2 of the negative electrode are not limited, and can be selected according to the actual structure of the terminal 2 of the positive electrode and the terminal 2 of the negative electrode. According to an embodiment of the present invention, on the other hand, a battery cell assembly is provided, which includes: the above-mentioned battery cell cover assembly and the battery cell 6. A tab 601 is provided on the top of the battery cell 6. The tab 601 includes a connecting section and a bent section. The connecting section is located on one side of the tab connecting portion 102 of the battery cell cover assembly. The bent section is connected to the top of the connecting section and extends along the top surface of the tab connecting portion 102. The tab 601 is welded to the tab connecting portion 102.

[0060] Specifically, the tab 601 and the tab connecting portion 102 are welded by welding processes such as laser welding or ultrasonic welding to achieve electrical connection.

[0061] In a possible implementation manner, two tabs 601 are respectively provided on the positive electrode and the negative electrode of the battery cell 6. The two tabs 601 of the same pole are oppositely arranged on both sides of the corresponding tab connecting portion 102, and the bent sections of the two tabs 601 are welded to the same tab connecting portion 102.

[0062] In a possible implementation manner, the battery cell assembly further includes a housing 7. The housing 7 has a receiving groove with an upward opening. The battery cell 6 is disposed in the receiving groove, and the battery cell cover assembly is disposed on the top of the housing 7 to block the opening.

[0063] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cover assembly, characterized in that: include: A connecting piece, comprising a pole connecting portion and a pole lug connecting portion connected in sequence, wherein the top surface of the pole lug connecting portion forms a connecting surface for connecting with the pole lug, and the top surface of the pole connecting portion forms a first mating surface, wherein a vertically extending through hole is provided on the first mating surface; A pole, a second mating surface mating with the first mating surface is formed at the bottom of the pole, a connecting column for passing through the through hole is provided at the position of the pole located at the second mating surface, and the pole is welded and connected to the through hole of the connecting piece through the connecting column; The cover plate is located on the upper side of the connecting piece and has an assembly hole for the pole to pass through.

2. The battery cover assembly according to claim 1, characterized in that: The top of the pole connecting part has an upwardly protruding boss, and the bottom of the pole connecting part forms a groove upwardly corresponding to the position of the boss, the top surface of the boss forms the first mating surface, the through hole is located on the boss and connected to the groove, and the top surface of the groove is concave upward around the position of the through hole to form a welding groove.

3. The battery cover assembly according to claim 2, characterized in that: The welding groove is an annular groove, the through hole is a circular hole, the welding groove is arranged close to the side wall of the groove, and the distance from the inner side wall of the welding groove to the inner wall of the through hole along the radial direction is greater than or equal to 1.2 mm.

4. The battery cover assembly according to claim 2, characterized in that: It also includes a first insulating member arranged between the connecting plate and the cover plate, the welding groove is an annular groove, the boss is a truncated cone, and the distance from the outer wall of the welding groove to the side wall of the boss along the radial direction is greater than or equal to 0.8 mm.

5. The battery cover assembly according to claim 2, characterized in that: The depth of the welding groove is greater than or equal to 0.2 mm.

6. The battery cell cover plate assembly according to any one of claims 1 to 5, characterized in that: An end of the pole lug connection portion away from the pole post connection portion forms a through slot along a direction close to the pole post connection portion, and top surfaces of the pole lug connection portion located on both sides of the through slot form connection surfaces respectively.

7. The battery cell cover plate assembly according to any one of claims 1 to 5, characterized in that: The cover plate includes a main body plate and an assembly plate. The main body plate is assembled and connected to the pole. The main body plate is provided with a welding hole corresponding to the pole ear connection portion. The assembly plate matches the shape of the welding hole and is assembled in the welding hole.

8. The battery cover assembly according to claim 7, characterized in that: The number of the connecting sheets and the poles are both two and they are respectively arranged corresponding to the positive electrode and the negative electrode of the battery cell, and the cover plate has the welding hole at the pole ear connection part corresponding to each connecting sheet.

9. A battery cell assembly, characterized in that: include: The battery cell cover assembly according to any one of claims 1 to 8; A battery cell is provided with a pole lug on the top, the pole lug includes a connecting section and a bending section, the connecting section is located on one side of the pole lug connecting portion of the battery cell cover assembly, the bending section is connected to the top of the connecting section and extends along the top surface of the pole lug connecting portion, and the pole lug is welded to the pole lug connecting portion.

10. The battery core assembly according to claim 9, characterized in that: The positive electrode and the negative electrode of the battery cell are respectively provided with two pole tabs, the two pole tabs of the same pole are relatively arranged on both sides of the corresponding pole tab connection part, and the bending sections of the two pole tabs are welded to the same pole tab connection part.

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