Top cover assembly with simple structure and square battery monomer

Abstract

The utility model discloses a top cover assembly with a simple structure and a square battery monomer, the top cover assembly comprises a top cover, a lower plastic plate, pole columns, a connecting sheet, a sealing ring and a plastic part, the top cover is provided with a thinning area surrounding each pole column through hole, and bulges are arranged at the joints of the thinning areas and the outer edges of the pole column through holes; the sealing ring is sleeved on the bulge; the pole is placed at the pole through hole and is in contact with the upper end surface of the sealing ring; and a lug boss is arranged on the side wall of the pole. The lower plastic plate is provided with a convex ring; the convex circular ring extends into the pole through hole to form an insulation structure with the sealing ring; the convex welding part of the connecting sheet penetrates through the pole abdicating hole and then is welded with the welding part on the lower end surface of the pole; plastic parts are arranged among the sealing ring, the side wall of the pole and the top cover, the end part of the reinforcing welding sheet is welded in the thinning area, and the reinforcing welding sheet is not in contact with the pole. Stable connection of the pole and the top cover is achieved through pouring of the reinforcing welding piece and the injection molding material, the material consumption of the positive pole and the negative pole is reduced, the machining difficulty of the top cover assembly is lowered, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the structure of a square lithium secondary battery, and particularly relates to a top cover assembly with a simple structure and a square battery cell. Background Art

[0002] The existing top cover of a square lithium-ion battery generally consists of an aluminum top cover, positive and negative electrode posts, a sealing ring, an upper plastic, a lower plastic plate, rivets, etc. Among them, the aluminum top cover serves as the main body of the top cover. The electrode posts are assembled into the electrode post holes of the aluminum top cover, and then the electrode posts are fixedly connected to the aluminum top cover by riveting or injection molding. Its process is relatively complex, and the material cost and processing cost are relatively high. Moreover, it is easy to have a situation of poor sealing during sealing. Summary of the Utility Model

[0003] The utility model provides a top cover assembly with a simple structure and a square battery cell to solve the deficiencies described in the above prior art.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A top cover assembly with a simple structure includes a top cover, a lower plastic plate, electrode posts, connecting pieces, a sealing ring, and a plastic part. There are two electrode post through holes, a liquid injection hole, and an explosion-proof component on the top cover; the lower plastic plate is located on the lower end face of the top cover and is provided with electrode post relief holes, liquid injection relief holes, and explosion-proof relief holes; the top cover is provided with a thinning area around each electrode post through hole, and a protrusion is provided at the junction of the thinning area and the outer edge of the electrode post through hole; the sealing ring is provided with a groove corresponding to the protrusion, and the sealing ring is sleeved on the protrusion through the groove. The electrode post is placed at the electrode post through hole, and the lower end face of the electrode post contacts the upper end face of the sealing ring; and a protrusion part is provided on the side wall of the electrode post, and the protrusion part extends beyond the outer edge of the sealing ring.

[0006] A protruding ring is provided at the position of each electrode post relief hole on the lower plastic plate, and the through hole of the protruding ring is the electrode post relief hole; the protruding ring extends into the electrode post through hole to jointly form an insulating structure with the sealing ring. The connecting piece is located below the lower plastic plate, and the protruding welding part of the connecting piece passes through the electrode post relief hole and is welded to the welding part of the lower end face of the electrode post.

[0007] A plastic part is provided between the sealing ring, the side wall of the electrode post, and the top cover. A strengthening welding piece is provided in the plastic part. One end of the strengthening welding piece is welded to the thinning area, and the strengthening welding piece does not contact the electrode post. Setting a protrusion in the thinning area to engage with the groove of the sealing ring can better fix the sealing ring to avoid dislocation, and change the connection method between the electrode post and the top cover. Using the strengthening welding piece to enhance the connection strength between the electrode post and the top cover, and the plastic part is formed by filling the material into the gaps between the strengthening welding piece, the top cover, the sealing ring, and the electrode post and wrapping the strengthening welding piece, so the connection is more stable. The use of electrode post materials can be minimized, reducing costs and not affecting subsequent tab welding.

[0008] As a preferred embodiment of the present utility model, a part of the sealing ring extends into the pole post through-hole and contacts the end of the raised ring.

[0009] As a preferred embodiment of the present utility model, the strengthening welding piece is provided with a first bending part, at least a part of the first bending part is located above the raised part and the orientation of the first bending part is different from that of the raised part. Both the raised part and the first bending part are for better connecting the pole post and the top cover.

[0010] As a preferred embodiment of the present utility model, the strengthening welding piece is provided with a second bending part, the bottom surface of the second bending part is welded to the bottom wall of the thinning area; a part of the side surface of the second bending part is welded to the side wall of the thinning area.

[0011] The present utility model also provides a square battery cell, which includes an electrode assembly, the above-mentioned top cover assembly with a simple structure and a housing; the tab of the electrode assembly is welded to the corresponding connecting piece, the electrode assembly is placed in the inner cavity of the housing, and the edge of the top cover of the top cover assembly with a simple structure is hermetically welded to the opening of the housing; after injecting electrolyte through the liquid injection hole, it is sealed. The lower plastic plate is used to fix the position of the electrode assembly to prevent the electrode assembly from contacting the metal components of the top cover and avoid the risk of short circuit.

[0012] Beneficial effects:

[0013] The present utility model uses the method of strengthening welding pieces and injection molding materials to achieve stable connection between the pole post and the top cover, reduce the material consumption of the positive and negative pole posts, and reduce costs; moreover, it also reduces the processing difficulty of the top cover assembly, improves production efficiency, and further improves the production efficiency of the battery cell formed by it and reduces production costs. Description of the drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is an exploded view of the structure of the top cover assembly with a simple structure of the present utility model.

[0016] Figure 2 It is a cross-sectional view of the top cover assembly with a simple structure of the present utility model.

[0017] Figure 3 It is Figure 2 A partial enlarged view of part A in

[0018] Figure 4 It is an exploded view of the square battery cell of the present utility model. Detailed implementation mode

[0019] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0020] Embodiment:

[0021] A simple structure top cover assembly, as Figure 1 shown, includes a top cover 1, a lower plastic plate 2, a pole column 3, a connecting piece 4, a sealing ring 5 and a plastic part 6.

[0022] There are two pole column through holes 11, a liquid injection hole and an explosion-proof component on the top cover 1; the explosion-proof component includes an explosion-proof valve and an explosion-proof valve through hole. The explosion-proof valve is welded to the lower part of the explosion-proof valve through hole of the upper top cover, and the protection piece is pasted on the upper part of the explosion-proof valve through hole of the top cover. The explosion-proof valve is provided with an explosion-proof scoring line. When the internal pressure of the battery cell increases to the threshold value, the explosion-proof scoring line cracks to relieve pressure, avoiding damage to the shell. The explosion-proof valve is formed by stamping high-tensile aluminum material, and the protection piece is formed by punching a PET film and applying acrylic glue.

[0023] The adopted top cover is formed by stamping industrial pure aluminum or aluminum alloy. The thickness of the aluminum cover plate is 1-5 mm, the length is 150-250 mm, and the width is 40-140 mm.

[0024] The two pole column through holes are respectively a positive pole column through hole and a negative pole column through hole;

[0025] The lower plastic plate 2 is located on the lower end surface of the top cover 1 and is provided with a pole column relief hole, a liquid injection relief hole and an explosion-proof relief hole; the lower plastic plate is injection-molded from PP material.

[0026] The top cover 1 is provided with a thinning area 12 around each pole column through hole, and the thickness of the thinning area is 1 / 2 of the thickness of the top cover; a protrusion 13 is provided at the junction of the thinning area 12 and the outer edge of the pole column through hole 11; the height of the protrusion is 0.1-0.8 mm.

[0027] The pole columns and the connecting pieces are in one-to-one correspondence. When the pole column is a positive pole column, the connecting piece is a positive connecting piece. The positive pole column is formed by stamping industrial pure aluminum or aluminum alloy. The lower surface of the negative pole column is made of copper alloy, and the upper surface is made of aluminum or aluminum alloy. The positive connecting piece is made of aluminum or aluminum alloy material with a thickness of 0.2-2 mm, and the negative connecting piece is made of copper or copper alloy material with a thickness of 0.1-1.5 mm.

[0028] This embodiment takes the negative pole as an example to show a new connection method between the top cover and the pole column, asFigure 2 and 3 As shown,

[0029] The sealing ring 5 is provided with a groove corresponding to the protrusion 13 , and the sealing ring 5 is sleeved on the protrusion 13 through the groove, and the sealing ring 5 extends into the pole through hole 11 and contacts the end of the protrusion ring.

[0030] The pole 3 is placed at the pole through hole and the lower end surface of the pole contacts the upper end surface of the sealing ring 5; and a protrusion 31 is provided on the side wall of the pole 3, and the protrusion 31 exceeds the outer edge of the sealing ring;

[0031] A reinforcing welding sheet 7 is welded at each thinning area, and the reinforcing welding sheet does not contact the pole; and the reinforcing welding sheet 7 is provided with a first bending portion 71, and the first bending portion 71 is located above the raised portion 31 and the direction of the first bending portion 71 is different from the direction of the raised portion 31. The raised portion and the first bending portion are both for better connecting the pole and the top cover.

[0032] The reinforcing welding sheet 7 is provided with a second bending portion 72 , the bottom surface of the second bending portion 72 is welded to the bottom wall of the thinning area; and part of the side surface of the second bending portion 72 is welded to the side wall of the thinning area.

[0033] The gaps between the reinforcing welding sheet, the top cover, the sealing ring and the pole are filled with injection molding material, wherein the injection molding material is formed by insert injection molding of PPS material; the injection molding material completely wraps the reinforcing welding sheet to form a plastic part.

[0034] The lower plastic plate 2 is provided with a raised ring at the position of each pole clearance hole 21, and the through hole of the raised ring is the pole clearance hole 21; the raised ring extends into the pole through hole 11 and contacts the end of the sealing ring 5 located in the pole through hole, and together constitutes an insulating structure; the connecting plate 4 is located below the lower plastic plate 2 and the raised welding portion 41 of the connecting plate 4 passes through the pole clearance hole 21 and is welded to the welding portion of the lower end surface of the pole 3.

[0035] The present invention also provides a square battery cell, such as Figure 4 As shown, it includes an electrode assembly 8, an integrated top cover assembly and a shell 9; the electrode lugs of the electrode assembly are welded to the corresponding connecting pieces, and the electrode assembly is placed in the inner cavity of the shell, and the top cover edge of the simple structure top cover assembly is sealed and welded to the shell mouth; the injection hole is sealed after the electrolyte is injected. The lower plastic plate is used to fix the position of the electrode assembly to prevent the electrode assembly from contacting the metal assembly of the top cover to avoid the risk of short circuit.

[0036] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0037] As mentioned above, the above is only a preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution and the inventive concept of the present utility model, making equivalent replacements or changes, should be covered by the protection scope of the present utility model.

Claims

1. A top cover assembly with a simple structure, comprising a top cover (1), a lower plastic plate (2), a pole (3), a connecting plate (4), a sealing ring (5) and a plastic part (6), wherein the top cover (1) is provided with two pole through holes (11), a liquid injection hole and an explosion-proof assembly; the lower plastic plate (2) is located at the lower end surface of the top cover (1) and is provided with a pole clearance hole, a liquid injection clearance hole and an explosion-proof clearance hole; the characteristics are: The top cover (1) is provided with a thinning area (12) around each pole through hole, and a protrusion (13) is provided at the junction of the thinning area (12) and the outer edge of the pole through hole (11); the sealing ring (5) is provided with a groove corresponding to the protrusion (13), the sealing ring (5) is sleeved on the protrusion (13) through the groove, the pole (3) is placed at the pole through hole and the lower end surface of the pole contacts the upper end surface of the sealing ring (5); and the side wall of the pole (3) is provided with a protrusion (31), and the protrusion (31) exceeds the outer edge of the sealing ring; The lower plastic plate (2) is provided with a raised circular ring at the position of each pole clearance hole (21), and the through hole of the raised circular ring is the pole clearance hole (21); the raised circular ring extends into the pole through hole (11) and together with the sealing ring (5) forms an insulating structure; the connecting piece (4) is located below the lower plastic plate (2) and the raised welding portion (41) of the connecting piece (4) passes through the pole clearance hole (21) and is welded to the welding portion of the lower end surface of the pole (3); A plastic part (6) is provided between the sealing ring, the side wall of the pole and the top cover, and a reinforcing welding sheet (7) is provided in the plastic part (6). One end of the reinforcing welding sheet (7) is welded to the thinning area (12), and the reinforcing welding sheet does not contact the pole.

2. The simplified structure top cover assembly according to claim 1, characterized in that: The sealing ring (5) partially extends into the pole through hole (11) and contacts the end of the raised circular ring.

3. The simple structure top cover assembly according to claim 1 or 2, characterized in that: The reinforcing welding sheet (7) is provided with a first bent portion (71), the first bent portion (71) being at least partially located above the raised portion (31), and the orientation of the first bent portion (71) being different from the orientation of the raised portion (31).

4. The simplified structure top cover assembly according to claim 3, characterized in that: The reinforcing welding sheet (7) is provided with a second bending portion (72), the bottom surface of the second bending portion (72) is welded to the bottom wall of the thinning zone; and part of the side surface of the second bending portion (72) is welded to the side wall of the thinning zone.

5. A square battery cell, characterized in that: It comprises an electrode assembly, a simple structure top cover assembly as described in any one of claims 1 to 4, and a shell; the pole ears of the electrode assembly are welded to the corresponding connecting pieces, and the electrode assembly is placed in the inner cavity of the shell, and the top cover edge of the simple structure top cover assembly is sealed and welded to the shell mouth; the injection hole is sealed after the electrolyte is injected.

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