Cover plate structure and battery cell

Abstract

The utility model relates to the technical field of batteries, and discloses a cover plate structure and a battery cell, the cover plate structure comprises: a cover plate body, which is provided with two spaced welding through holes, each welding through hole is suitable for corresponding to a partial area on a connecting sheet and a group of tabs, and the thickness of the cover plate body is T0; the two poles are arranged on the cover plate body and penetrate through the cover plate body; each sealing plate is arranged in the corresponding welding through hole in a covering mode so as to seal the corresponding welding through hole, a clamping groove is formed in the lower side of each sealing plate, the thickness of each sealing plate is T1, and T1 / T0 is larger than or equal to 0.6 and smaller than or equal to 1; and each insulating part is arranged on the lower side of the corresponding sealing plate, each insulating part is provided with a buckle corresponding to the corresponding clamping groove, and the buckles are matched with the clamping grooves in a clamped mode. The welding through holes are convenient for welding equipment to weld the tabs and the connecting pieces, poor welding is avoided, the sealing plate covers the welding through holes to ensure the sealing performance, the insulating part is clamped and matched with the sealing plate, and the reliability is high.

Description

Technical Field

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

[0002] A connecting piece is typically installed between the electrode group and the cover plate of a battery cell. One side of the connecting piece is welded to the electrode tab on the electrode group, and the other side is welded to the electrode post on the cover plate, thereby achieving an electrical connection between the electrode group and the electrode post. During the assembly of the battery cell, the connecting piece must first be welded to the electrode group, and then the electrode post must be welded to the connecting piece. During the welding process of the connecting piece and the electrode post, due to the presence of the cover plate, the welding head of the welding equipment is usually located outside the battery cell, and laser penetration welding must be used from above the electrode post. As a result, poor welding such as cold welds can easily occur, affecting the quality of the battery cell. Utility Model Content

[0003] In view of this, the present invention provides a cover plate structure and a battery cell to solve the problem of poor welding that is easily generated during the assembly process of the battery cell.

[0004] In the first aspect, the utility model provides a cover plate structure, including: a cover plate body, which is provided with two spaced-apart welding through holes, each of the welding through holes is suitable for corresponding to a partial area on a connecting plate and a group of pole ears, and the thickness of the cover plate body is T0; two poles, the poles are arranged on the cover plate body and pass through the cover plate body; two sealing plates, each of the sealing plates is covered in one of the welding through holes to seal the welding through holes, and a card groove is constructed on the lower side of the sealing plate, and the thickness of the sealing plate is T1, wherein 0.6≤T1 / T0≤1; two insulating parts, each insulating part is arranged on the lower side of one of the sealing plates, and a buckle corresponding to the card groove is provided on the insulating part, and the buckle is engaged with the card groove.

[0005] Beneficial effect: by opening two welding through holes on the cover body, it is convenient for the welding equipment to pass through the welding through holes to weld the pole ears and connecting pieces inside the battery cell after the cover structure is covered on the open end of the shell. The operation is convenient and it is easy to observe the welding conditions of the pole ears and connecting pieces, avoiding welding problems such as cold welding, thereby ensuring the welding quality and improving the qualified rate of the battery cell. At the same time, by setting a sealing plate in each welding through hole for sealing, the sealing after the battery cell is assembled is guaranteed, and the ratio of the thickness T1 of the sealing plate to the thickness T0 of the cover body is within the range of 0.6 to 1, thereby ensuring the structural strength of the sealing plate and avoiding the problem of the overall strength of the cover structure being deteriorated due to the opening of the welding through holes. An insulating part is connected to the lower side of each sealing plate to ensure the insulation between the sealing plate and the pole group and connecting piece inside the battery cell, and by setting the insulating part and the sealing plate to be snap-fitted, the insulating part and the sealing plate are convenient to assemble, and the snap-fit connection form has good stability and high reliability, thereby ensuring the stability of the cover structure performance.

[0006] In an optional embodiment, the slot includes a first slot section and a second slot section, the first slot section is connected to the lower end of the second slot section, and the projection area of the first slot section on the lower surface of the sealing plate is smaller than the projection area of the second slot section on the lower surface of the sealing plate; the buckle includes two clamping parts, and the two clamping parts are spaced apart along the first direction to form a clearance space between the two clamping parts, each of the clamping parts includes a connecting section and a hook, one end of the connecting section is connected to the insulating part body of the insulating part and the other end is connected to the hook, each hook extends in a direction away from the other hook, the connecting sections of the two clamping parts cooperate with the first slot section together, and the hooks of the two clamping parts cooperate with the second slot section together.

[0007] Beneficial effect: By setting the cross-sectional area of the first groove section to be smaller than the cross-sectional area of the second groove section, and at the same time setting the buckle to include two spaced-apart clamping parts, and the hooks on the two clamping parts extending in opposite directions, when the buckle is inserted into the slot, the inner wall of the first groove section squeezes the hook, and the connecting section is slightly elastically deformed. The two hooks approach each other to facilitate the hook to pass through the first groove section. When the hook enters the second groove section, the connecting section rebounds, and the hook is supported in the second groove section. The first groove section limits the hook from moving downward, thereby realizing the connection between the buckle and the slot, and the stability of the clamping structure after assembly is better.

[0008] In an optional embodiment, the ratio between the groove depth t1 of the first groove section and the thickness T1 of the sealing plate is: 0.1≤t1 / T1≤0.55, the ratio between the groove depth t2 of the second groove section and the thickness T1 of the sealing plate is: 0.2≤t2 / T1≤0.8, and (t1+t2) / T1≤0.9.

[0009] Beneficial effect: By limiting the ratio of the groove depth t1 of the first groove section to the thickness T1 of the sealing plate to be in the range of 0.1 to 0.55, and the ratio of the groove depth t2 of the second groove section to the thickness T1 of the sealing plate to be in the range of 0.2 to 0.8, the strength of the fit between the clip and the groove is ensured, thereby ensuring that the sealing plate and the insulating part are tightly fitted. At the same time, by limiting the ratio of the total groove depth t1+t2 of the groove to the thickness T1 of the sealing plate to (t1+t2) / T1 less than or equal to 0.9, it is avoided that the total groove depth of the groove is too large, which leads to too low structural strength of the sealing plate, thereby further ensuring the reliability of the sealing plate and improving the reliability of the cover plate structure.

[0010] In an optional embodiment, the thickness T1 of the sealing plate ranges from 1.5 mm to 2.0 mm; the groove depth t1 of the first groove section ranges from 0.2 mm to 0.8 mm; and the groove depth t2 of the second groove section ranges from 0.4 mm to 1 mm.

[0011] Beneficial effect: By limiting the groove depth t1 of the first groove section to be within the range of 0.2mm to 0.8mm, and the groove depth t2 of the second groove section to be within the range of 0.4mm to 1mm, the strength of the fit between the clip and the slot is guaranteed, thereby ensuring a tight fit between the sealing plate and the insulating part. At the same time, by limiting the thickness T1 of the sealing plate to be within the range of 1.5mm to 2.0mm, the strength of the sealing plate itself is guaranteed, and sufficient space is provided for the setting of the slot, further ensuring the stability of the snap fit with the insulating part.

[0012] In an optional embodiment, the inner wall of the first slot segment is inclined, and the area of the open end of the first slot segment is smaller than the cross-sectional area of the end thereof connected to the second slot segment; the connecting segment is inclined and its inclination angle is the same as the inclination angle of the inner wall of the first slot segment.

[0013] Beneficial effect: The inclined inner wall on the first groove section provides a guide for the buckle to enter the slot, making it easier for the buckle to enter the slot. After the buckle enters the slot, the inclined inner wall on the first groove section fits with the inclined connecting section on the buckle. The opening area of the slot is smaller than the cross-sectional area of the slot section inside the slot, which prevents the buckle from falling out and further improves the stability after assembly.

[0014] In an optional embodiment, the angle θ between the inner wall of the first groove section and the up-down direction is in the range of 10°≤θ≤80°; and / or, the distance W1 between the sides of the two clamping parts that are close to each other along the first direction is in the range of 1mm~5mm; and / or, the distance W2 between the sides of the roots of the two clamping parts that are away from each other along the first direction is in the range of 2mm~7.5mm.

[0015] Beneficial effect: By setting the angle θ between the inner wall of the first groove section and the up-down direction to be within the range of 10° to 80°, the stability and reliability of the snap-fitting between the slot and the buckle are ensured. By setting the distance W1 between the sides of the two snap-fitting parts that are close to each other to be within the range of 1mm to 5mm, the elasticity of the buckle can be ensured, so that the buckle can smoothly enter the slot, and the reliability of the snap-fitting between the buckle and the slot can be ensured. By setting the distance W2 between the sides of the roots of the two snap-fitting parts that are far away from each other to be within the range of 2mm to 7.5mm, the buckle can be easily formed, the processing difficulty can be reduced, and the yield rate can be improved. The stable fit between the buckle and the slot can also be ensured, thereby improving the safety of the battery cell.

[0016] In an optional embodiment, the maximum dimension W3 of the root of the connecting section along the first direction has a value range of 0.35mm≤W3≤1.2mm; and / or the dimension W4 of the lower surface of the hook along the first direction has a value range of W4≥0.5mm.

[0017] Beneficial Effects: By limiting the dimension W3 of the root of the connecting section along the first direction to a value within the range of 0.35mm to 1.2mm, it is possible to avoid both the problem of insufficient strength due to an undersized root of the connecting section and the reduced elasticity of the snap-fit portion due to an oversized root of the connecting section. This ensures that the root of the snap-fit has sufficient strength to protect the snap-fit from damage during assembly and disassembly, while also ensuring that the snap-fit has sufficient elastic deformation capacity to smoothly enter the slot, thereby ensuring the snap-fit effect. By limiting the dimension W4 of the hook along the first direction to be greater than or equal to 0.5mm, it is ensured that the hook will not easily fall out of the second slot section, ensuring the snap-fit effect, achieving a stable connection between the insulating member and the sealing plate, and ensuring the assembly strength of the sealing plate and the insulating member.

[0018] In an optional embodiment, the circumferential edge of the open end of the slot is set as a first guide surface, and the side edge of the hook away from the insulating body and away from the clearance space is constructed as a second guide surface, and the second guide surface cooperates with the first guide surface to provide guidance for the buckle to be installed in the slot.

[0019] Beneficial effect: The first guide surface and the second guide surface provide guidance for the buckle to move into the slot, ensuring that the buckle can be smoothly installed in the slot, facilitating the buckle to be assembled in place, and helping to improve assembly efficiency.

[0020] In an optional embodiment, the distance L1 between the two welding through holes is ≥5 mm; and / or, in the width direction of the cover body, the size of the cover body is L0, and the distance from the edge of the welding through hole to the edge of the cover body is L2, wherein L2 is ≥5 mm and 2×L2>0.2×L0.

[0021] Beneficial Effects: By setting the distance L1 between the two welding holes to be greater than or equal to 5mm, the structural strength of the cover plate body is ensured while preventing mutual interference between the heat-affected zones of the two welding holes when welding the sealing plate at the welding holes, thereby improving the welding yield. By setting the distance L2 from the edge of the welding hole to the edge of the cover plate body and the width L0 of the cover plate body to meet the relationship L2 ≥ 5mm and 2×L2>0.2×L0, the sufficient strength of the cover plate body can be ensured, thereby improving the reliability of the cover plate structure.

[0022] In a second aspect, the present invention further provides a battery cell, comprising: a housing having an open end; a pole group disposed within the housing, the pole group having two sets of pole tabs; the aforementioned cover plate structure, wherein the two welding through-holes on the cover plate structure correspond one-to-one with the two sets of pole tabs; and two connecting tabs, wherein the two connecting tabs correspond one-to-one with the two sets of pole tabs, each connecting tab being connected between a set of pole tabs and a pole post. Because the battery cell includes the cover plate structure, it has the same effects as the cover plate structure and will not be further described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a structural schematic diagram of a cover plate structure without a sealing plate and an insulating member installed in an embodiment of the present utility model;

[0025] Figure 2 for Figure 1 A top view of the cover structure shown;

[0026] Figure 3 for Figure 2 Cross-sectional view in the AA direction;

[0027] Figure 4 This is a schematic structural diagram of a sealing plate and an insulating member assembled according to an embodiment of the present invention;

[0028] Figure 5for Figure 4 A cross-sectional view of the middle sealing plate and the insulating member after assembly;

[0029] Figure 6 for Figure 5 A partial enlarged schematic diagram of B in the middle;

[0030] Figure 7 This is a structural schematic diagram of a sealing plate according to an embodiment of the present utility model;

[0031] Figure 8 for Figure 7 A cross-sectional view of the sealing plate is shown;

[0032] Figure 9 for Figure 8 A partial enlarged schematic diagram of center C;

[0033] Figure 10 This is a schematic structural diagram of an insulating member according to an embodiment of the present utility model;

[0034] Figure 11 for Figure 10 A cross-sectional view of the insulating member shown;

[0035] Figure 12 for Figure 11 A partial enlarged schematic diagram of D in the middle;

[0036] Figure 13 This is a schematic structural diagram of a battery cell according to an embodiment of the present utility model;

[0037] Figure 14 for Figure 13 A top view of the battery cell shown;

[0038] Figure 15 for Figure 13 Cross-sectional view in the AA direction;

[0039] Figure 16 for Figure 15 A partial enlarged schematic diagram of E in the middle;

[0040] Figure 17 This is a schematic structural diagram of a battery cell according to an embodiment of the utility model when the sealing plate is not welded and the tab is not welded to the connector;

[0041] Figure 18 for Figure 17 A top view of a battery cell with no sealing plate welded and no tabs welded to connectors;

[0042] Figure 19 for Figure 18 Cross-sectional view in the AA direction;

[0043] Figure 20 for Figure 17The position relationship diagram of the internal electrode group and the connecting piece of the battery cell without welding the sealing plate and the tabs;

[0044] Figure 21 This is a schematic structural diagram of a battery cell according to an embodiment of the present utility model when the tabs are welded to the connectors and the sealing plate is not welded;

[0045] Figure 22 for Figure 21 A top view of a battery cell in which the tabs are welded to the connectors and the sealing plate is not welded;

[0046] Figure 23 for Figure 22 Cross-sectional view in the AA direction;

[0047] Figure 24 for Figure 21 The diagram shows the positional relationship between the electrode group and the connecting piece inside the battery cell, where the electrode tabs are welded to the connectors but the sealing plate is not welded.

[0048] Description of reference numerals:

[0049] 1. Shell; 2. Pole group; 201. Pole ear; 202. Pole group body; 3. Cover plate body; 301. Welding through hole; 302. Filling hole; 4. Pole; 5. Connecting piece; 6. Sealing plate; 610. Slot; 611. First slot section; 612. Second slot section; 613. First guide surface; 7. Insulator; 710. Buckle; 701. Snap-fit portion; 702. Clearance; 711. Connecting section; 712. Hook; 713. Second guide surface; 720. Insulator body; 8. Sealing ring; 901. First plastic part; 902. Second plastic part. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0051] The following combination Figures 1 to 24 , describing the embodiments of the present utility model.

[0052] According to an embodiment of the present invention, on the one hand, a cover structure is provided, including: a cover body 3, two poles 4, two sealing plates 6 and two insulating members 7. The cover body 3 is provided with two spaced-apart welding through-holes 301, each welding through-hole 301 being suitable for corresponding to a partial area on a connecting plate 5 and a group of pole ears 201, and the thickness of the cover body 3 is T0; the pole 4 is provided on the cover body 3 and passes through the cover body 3; each sealing plate 6 is covered in a welding through-hole 301 to seal the welding through-hole 301, and a card groove 610 is constructed on the lower side of the sealing plate 6, and the thickness of the sealing plate 6 is T1, wherein 0.6≤T1 / T0≤1; each insulating member 7 is provided on the lower side of a sealing plate 6, and a snap 710 corresponding to the card groove 610 is provided on the insulating member 7, and the snap 710 is snap-fitted with the card groove 610. Among them, a group of pole ears refers to a positive pole ear group or a negative pole ear group; the thickness of the cover body 3 refers to the thickness of the cover body 3 along the Figures 15 and 16 The arrow in the middle indicates the "up and down" direction; the lower side refers to Figures 15 and 16 The side in the direction of "down" indicated by the middle arrow.

[0053] It should be noted that the electrode group 2 consists of a electrode group body 202 and a pole ear 201, the pole ear 201 is connected to one end of the electrode group body 202 facing the cover body 3, the pole ear 201 includes a positive pole ear and a negative pole ear, the number of electrode groups 2 in the battery cell is one or more, all positive pole ears together constitute a positive pole ear group, and all negative pole ears together constitute a negative pole ear group; the number of connecting plates 5 is two, and the two poles 4 are spaced apart on the cover body 3, one of the two poles 4 is a positive pole and the other is a negative pole, the positive pole ear group is connected to the positive pole through a connecting plate 5, and the negative pole ear group is connected to the negative pole through another connecting plate 5.

[0054] The cover plate structure of this embodiment is applied, by opening two welding through holes 301 on the cover plate body 3, so that after the cover plate structure is covered on the open end of the shell 1, the welding equipment passes through the welding through holes 301 to weld the pole ear 201 and the connecting piece 5 inside the battery cell. The operation is convenient and it is easy to observe the welding condition of the pole ear 201 and the connecting piece 5, thereby avoiding welding problems such as cold welding, thereby ensuring the welding quality and improving the qualified rate of the battery cell. At the same time, a sealing plate 6 is set in each welding through hole 301 for sealing, thereby ensuring the sealing of the battery cell after assembly is completed, and The ratio of the thickness T1 of the sealing plate 6 to the thickness T0 of the cover plate body 3 is within the range of 0.6 to 1, which ensures the structural strength of the sealing plate 6 and avoids the problem of the overall strength of the cover plate structure being deteriorated due to the opening of the welding through hole 301. An insulating member 7 is connected to the lower side of each sealing plate 6 to ensure the insulation between the sealing plate 6 and the electrode group 2 and the connecting piece 5 inside the battery cell. In addition, by providing the insulating member 7 and the sealing plate 6 for snap-fitting, the assembly of the insulating member 7 and the sealing plate 6 is facilitated, and the snap-fit connection form has good stability and high reliability, thereby ensuring the stability of the cover plate structural performance.

[0055] Specifically, the two welding through holes 301 are located between the two poles 4 .

[0056] In one embodiment, there are multiple slots 610, and the number of buckles 710 is equal to the number of slots 610. The multiple buckles 710 correspond one-to-one with the multiple slots 610 to improve the stability of the assembly of the sealing plate 6 and the insulating member 7. Preferably, there are three slots 610 and three buckles 710.

[0057] In one embodiment, the slot 610 includes a first slot section 611 and a second slot section 612, the first slot section 611 is connected to the lower end of the second slot section 612, the projection area of the first slot section 611 on the lower surface of the sealing plate 6 is smaller than the projection area of the second slot section 612 on the lower surface of the sealing plate 6; the buckle 710 includes two clamping parts 701, the two clamping parts 701 are spaced apart along the first direction to form a clearance space 702 between the two clamping parts 701, each clamping part 701 includes a connecting section 711 and a hook 712, one end of the connecting section 711 is connected to the insulating part body 720 of the insulating part 7 and the other end is connected to the hook 712, each hook 712 extends in a direction away from the other hook 712, the connecting sections 711 of the two clamping parts 701 cooperate with the first slot section 611 together, and the hooks 712 of the two clamping parts 701 cooperate with the second slot section 612 together. Among them, the lower end refers to Figure 6 At the end of the "downward" direction indicated by the middle arrow, the projection area of the groove section on the lower surface of the sealing plate 6 is equal to the cross-sectional area of the groove section on the cross section perpendicular to the center line; the first direction refers to Figures 10 to 12The arrow in the middle indicates the "first direction". The first slot section 611 of the slot 610 is located at the lower end of the second slot section 612, and the slot 610 opens downward, that is, the first slot section 611 is close to the open end of the slot 610. By setting the cross-sectional area of the first slot section 611 to be smaller than the cross-sectional area of the second slot section 612, and by setting the buckle 710 to include two spaced-apart clamping parts 701, and the hooks 712 on the two clamping parts 701 extend in opposite directions, when the buckle 710 is inserted into the slot 610, In the embodiment, the inner wall of the first slot section 611 squeezes the hook 712, and the connecting section 711 is slightly elastically deformed. The two hooks 712 approach each other to facilitate the hook 712 to pass through the first slot section 611. When the hook 712 enters the second slot section 612, the connecting section 711 rebounds, and the hook 712 is supported in the second slot section 612. The first slot section 611 limits the downward movement of the hook 712, thereby realizing the connection between the buckle 710 and the slot 610. The stability of the connecting structure after assembly is better.

[0058] In one embodiment, the ratio between the groove depth t1 of the first groove section 611 and the thickness T1 of the sealing plate 6 is: 0.1≤t1 / T1≤0.55, the ratio between the groove depth t2 of the second groove section 612 and the thickness T1 of the sealing plate 6 is: 0.2≤t2 / T1≤0.8, and (t1+t2) / T1≤0.9. It should be noted that if the ratio between the groove depth t1 of the first groove section 611 and the thickness T1 of the sealing plate 6 is too small, or the ratio between the groove depth t2 of the second groove section 612 and the thickness T1 of the sealing plate 6 is too large, the groove depth of the first groove section 611 is relatively too small, the size of the hook 712 along the groove depth direction is too large, the first groove section 611 has a poor limiting ability on the hook 712, and the buckle 710 can easily fall out of the groove 610; if the ratio between the groove depth t1 of the first groove section 611 and the thickness T1 of the sealing plate 6 is too large, or the ratio between the groove depth t2 of the second groove section 612 and the thickness T1 of the sealing plate 6 is too small, the size of the hook 712 along the groove depth direction is correspondingly too small, the strength of the hook 712 is insufficient, and it is also easy for the buckle 710 to fall out of the groove 610. Therefore, by limiting the ratio between the groove depth t1 of the first groove section 611 and the thickness T1 of the sealing plate 6 to be within the range of 0.1 to 0.55, and the ratio between the groove depth t2 of the second groove section 612 and the thickness T1 of the sealing plate 6 to be within the range of 0.2 to 0.8, the strength of the fit between the clip 710 and the groove 610 is ensured, thereby ensuring that the sealing plate 6 and the insulating member 7 are tightly fitted. At the same time, by limiting the ratio between the total groove depth t1+t2 of the groove 610 and the thickness T1 of the sealing plate 6 to (t1+t2) / T1 less than or equal to 0.9, it is avoided that the total groove depth of the groove 610 is too large, which leads to too low structural strength of the sealing plate 6, thereby further ensuring the reliability of the sealing plate 6 and improving the reliability of the cover plate structure.

[0059] In one embodiment, the thickness T1 of the sealing plate 6 is in the range of 1.5 mm ≤ T1 ≤ 2.0 mm; the depth t1 of the first groove section 611 is in the range of 0.2 mm to 0.8 mm; the depth t2 of the second groove section 612 is in the range of 0.4 mm to 1 mm. It should be noted that the thickness of the sealing plate 6, the depth of the first groove section 611, and the depth of the second groove section 612 all refer to the thickness of the sealing plate 6, the depth of the first groove section 611, and the depth of the second groove section 612. Figures 8 and 9 The size in the direction of "up and down" indicated by the middle arrow. If the thickness T1 of the sealing plate 6 is less than 1.5mm, the sealing plate 6 is too thin, its own strength is weak, and its reliability is poor. If the thickness T1 of the sealing plate 6 is greater than 2.0mm, the sealing plate 6 is too heavy and the cost is high. By limiting the groove depth t1 of the first groove section 611 to be within the range of 0.2mm to 0.8mm, and the groove depth t2 of the second groove section 612 to be within the range of 0.4mm to 1mm, the strength of the fit between the buckle 710 and the groove 610 is guaranteed, thereby ensuring that the sealing plate 6 and the insulating part 7 are closely fitted. At the same time, by limiting the thickness T1 of the sealing plate 6 to be within the range of 1.5mm to 2.0mm, the strength of the sealing plate 6 itself is guaranteed, and sufficient space is provided for the setting of the groove 610, further ensuring the stability of the snap fit with the insulating part 7.

[0060] In one embodiment, the inner wall of the first slot section 611 is inclined, and the area of the open end of the first slot section 611 is smaller than the cross-sectional area of the end connected to the second slot section 612; the connecting section 711 is inclined, and its inclination angle is the same as the inclination angle of the inner wall of the first slot section 611. The inclined inner wall of the first slot section 611 provides a guide for the buckle 710 to enter the slot 610, facilitating the buckle 710 to enter the slot 610. After the buckle 710 enters the slot 610, the inclined inner wall of the first slot section 611 fits in place with the inclined connecting section 711 of the buckle 710. The opening area of the slot 610 is smaller than the cross-sectional area of the inner slot section of the slot 610, thereby preventing the buckle 710 from falling out and further improving the stability after assembly.

[0061] In one embodiment, the angle θ between the inner wall of the first slot section 611 and the up-down direction is in the range of 10°≤θ≤80°. Figure 9The arrow in the middle indicates the direction of "up and down". If the angle θ between the inner wall of the first groove section 611 and the up and down direction is less than 10°, the inclination angle of the inner wall of the first groove section 611 relative to the up and down direction is too small, close to being perpendicular to the lower surface of the sealing plate 6. The guiding effect of the inclined surface and the locking effect on the buckle 710 are not obvious, making the assembly of the buckle 710 more difficult and easy to fall out of the groove 610. If the angle θ between the inner wall of the first groove section 611 and the up and down direction is greater than 80°, the inclination angle of the inner wall of the first groove section 611 relative to the up and down direction is too large, resulting in an excessively large cross-sectional area of the second groove section 612. Correspondingly, the two hooks of the buckle 710 are far apart from each other, and the locking function cannot be effectively performed. Therefore, by setting the angle θ between the inner wall of the first groove section 611 and the up and down direction to a value within the range of 10° to 80°, the stability and reliability of the locking fit between the groove 610 and the buckle 710 are ensured.

[0062] In one embodiment, further combined Figure 12 As shown, the distance W1 between the two sides of the two clamping parts 701 that are close to each other along the first direction ranges from 1 mm to 5 mm. The distance W1 between the two sides of the two clamping parts 701 that are close to each other is the distance between the two sides of the two clamping parts 701 and the clearance space 702 along the first direction. Figure 12 The dimension in the "first direction" indicated by the arrow in the middle. When the buckle 710 is installed in the slot 610, the two engaging portions 701 are squeezed by the inner wall of the slot 610 and tilted toward the clearance space 702. If W1 is less than 1 mm, the two engaging portions 701 are too close to each other, and there is insufficient space for the hook 712 to move, making it difficult for the buckle 710 to enter the slot 610. If W1 is greater than 5 mm, the two engaging portions 701 are too far apart, and the buckle 710 is insufficiently strong, making it easy to fall out of the slot 610. Therefore, by setting the distance W1 between the adjacent sides of the two engaging portions 701 to a value within the range of 1 mm to 5 mm, the elasticity of the buckle 710 can be guaranteed, allowing the buckle 710 to enter the slot 610 smoothly, while also ensuring the reliability of the engagement between the buckle 710 and the slot 610.

[0063] In one embodiment, the distance W2 between the two sides of the roots of the two clamping parts 701 that are away from each other along the first direction is in the range of 2 mm to 7.5 mm. The root of the clamping part 701 refers to the position where the clamping part 701 is connected to the insulating body 720, and the distance W2 between the two sides of the two clamping parts 701 that are away from each other refers to the distance W2 between the roots of the buckles 710 along the first direction. Figure 12The maximum dimension of the "first direction" indicated by the middle arrow. If the distance W2 between the two sides of the roots of the two clamping parts 701 that are away from each other is less than 2mm, the size of the root of the clamp 710 is too small, making it difficult to form during processing, and the process yield is low; if the distance W2 between the two sides of the roots of the two clamping parts 701 that are away from each other is greater than 7.5mm, the size of the root of the clamp 710 is too large, resulting in insufficient fit between the clamp 710 and the slot 610. When the battery cell is vibrated, there is a risk that the clamp 710 will fall off, affecting product performance. Therefore, by setting the distance W2 between the two sides of the roots of the two clamping parts 701 that are away from each other within the range of 2mm to 7.5mm, it can be ensured that the clamp 710 is easy to form, reduce processing difficulty, and improve production yield, while also ensuring stable fit between the clamp 710 and the slot 610, thereby improving the safety of the battery cell.

[0064] In one embodiment, the maximum dimension W3 of the root of the connecting section 711 along the first direction is in the range of 0.35 mm ≤ W3 ≤ 1.2 mm. Figure 12 The middle arrow indicates the "first direction." By limiting the dimension W3 of the base of the connecting segment 711 along the first direction to a value within the range of 0.35 mm to 1.2 mm, it is possible to avoid both the problem of insufficient strength due to an undersized base of the connecting segment 711 and the reduced elasticity of the engaging portion 701 due to an oversized base of the connecting segment 711. This ensures that the base of the buckle 710 has sufficient strength to protect it from damage during assembly and disassembly, while also ensuring that the buckle 710 has sufficient elastic deformation capability to smoothly enter the engaging slot 610, thereby ensuring a secure engaging effect.

[0065] In one embodiment, the dimension W4 of the lower surface of the hook 712 along the first direction has a value range of W4 ≥ 0.5 mm. The hook 712 is stuck in the second groove section 612, and the lower surface of the hook 712 abuts against the upper surface of the first groove section 611. If the dimension W4 of the hook 712 along the first direction is less than 0.5 mm, the dimension of the hook 712 extending into the second groove section 612 is too small and it is easy to fall out. Therefore, by limiting the dimension W4 of the hook 712 along the first direction to be greater than or equal to 0.5 mm, it is ensured that the hook 712 will not easily fall out of the second groove section 612, ensuring the snap fit effect, achieving a stable connection between the insulating member 7 and the sealing plate 6, and ensuring the assembly strength of the sealing plate 6 and the insulating member 7.

[0066] It should be noted that the distance W1 between the two sides of the two engaging portions 701 close to each other and the dimension W4 of the hook 712 along the first direction must satisfy W1 greater than or equal to twice W4 to ensure that the clearance space 702 provides enough space for the hook 712 to move.

[0067] In one embodiment, the circumferential edge of the open end of the slot 610 is set as a first guide surface 613, and the side edge of the hook 712 away from the insulating body 720 and away from the clearance space 702 is constructed as a second guide surface 713. The second guide surface 713 cooperates with the first guide surface 613 to provide guidance for the installation of the buckle 710 in the slot 610. The first guide surface 613 is constructed on the edge formed by the intersection of the lower surface of the sealing plate 6 and the inner wall of the card slot 610, and the second guide surface 713 is constructed on the edge formed by the intersection of the upper surface of the hook 712 and the side of the hook 712 away from the other hook 712. When the buckle 710 is assembled into the card slot 610, the buckle 710 is inserted into the card slot 610 from the upper side of the sealing plate 6 downward. The first guide surface 613 and the second guide surface 713 provide guidance for the buckle 710 to move into the card slot 610, ensuring that the buckle 710 can be smoothly installed in the card slot 610, facilitating the buckle 710 to be assembled into place, and helping to improve assembly efficiency.

[0068] Preferably, on the cross section along the center line of the slot 610 (eg Figure 9 As shown), the first guide surface 613 is rounded, and the rounded corners are relatively smooth, so that the first guide surface 613 has a smooth transition, which is more conducive to the buckle 710 being smoothly installed in the card slot 610.

[0069] In one embodiment, the distance L1 between the two welding through holes 301 is ≥5mm. It should be noted that two welding through holes 301 are provided on the cover body 3, one welding through hole 301 corresponds to the positive ear of the electrode group 2 and the other welding through hole 301 corresponds to the negative ear of the electrode group 2, so as to realize the welding operation of the positive ear and a connecting piece, and the negative ear and another connecting piece respectively through the two welding through holes 301; each welding through hole 301 corresponds to a sealing plate 6, and the sealing plate 6 is welded to the inner wall of the welding through hole 301. The two welding through holes 301 are spaced apart along the length direction of the cover body 3, and the position between the two welding through holes 301 is a part of the cover body 3, which is conducive to improving the structural strength, wherein the length direction refers to the extension direction of the longer side of the cover body 3, that is, Figure 15 The arrow in the middle indicates the "first direction." If the distance between the two welding holes 301 is less than 5 mm, the portion of the cover body 3 located between the two welding holes 301 will lack strength. Furthermore, when the inner walls of the welding holes 301 are welded to the sealing plate 6, the heat-affected zones generated by the welding at the two welding holes 301 are too close together, affecting each other and thus affecting the welding quality. Therefore, by setting the distance L1 between the two welding holes 301 to be greater than or equal to 5 mm, the structural strength of the cover body 3 can be maintained while preventing the heat-affected zones at the two welding holes 301 from affecting each other when welding the sealing plate 6 at the welding holes 301, thereby improving the welding yield.

[0070] In one embodiment, along the width direction of the cover body 3, the size of the cover body 3 is L0, and the distance from the edge of the welding through hole 301 to the edge of the cover body 3 is L2, where L2 ≥ 5 mm and 2 × L2 > 0.2 × L0. Figure 2 The arrow in the middle indicates the "width direction." The distance from the edge of the welding through-hole 301 to the edge of the cover plate body 3 is the size of the physical portion of the cover plate body 3 corresponding to the welding through-hole 301 along the width direction. If the distance L2 from the edge of the welding through-hole 301 to the edge of the cover plate body 3 along the width direction is less than 5 mm, or if the total size of the physical portions on both sides of the welding through-hole 301 (2×L2) is less than or equal to 0.2×L0, the size of the physical portion corresponding to the welding through-hole 301 is too small, resulting in insufficient connection strength. Therefore, by setting the distance L2 from the edge of the welding through-hole 301 to the edge of the cover plate body 3 and the width L0 of the cover plate body 3 to satisfy the relationship L2 ≥ 5 mm and 2×L2 > 0.2×L0, sufficient strength of the cover plate body 3 can be ensured, thereby improving the reliability of the cover plate structure.

[0071] It should be noted that the cover body 3 is a plain aluminum plate. Since the cover body 3 has an additional welding through hole 301 compared to the traditional cover, in order to ensure the strength of the cover body remains unchanged, the thickness of the cover body 3 needs to be increased by 15% to 45% compared to the traditional cover body.

[0072] In one embodiment, a pole hole is provided on the cover body 3, and the pole 4 includes a first pole segment, a second pole segment and a third pole segment connected in sequence, the outer contour of the second pole segment is smaller than the outer contours of the first pole segment and the third pole segment, the second pole segment is passed through the pole hole, the first pole segment is limited to the upper side of the cover body, and the third pole segment is limited to the lower side of the cover body. The cover structure also includes: a sealing ring 8, which is sleeved on the outer peripheral side of the second column section of the pole 4 and is squeezed between the second column section and the pole hole to ensure the sealing between the pole 4 and the cover body 3; a first plastic part 901, which is arranged between the upper surface of the cover body 3 and the first column section to ensure insulation between the pole 4 and the upper surface of the cover body 3; a second plastic part 902, which is arranged between the lower surface of the cover body 3 and the third column section to ensure insulation between the pole 4 and the lower surface of the cover body 3, as well as insulation between the cover body 3 and the pole group 2. By arranging the sealing ring 8, the first plastic part 901 and the second plastic part 902 between the cover body 3 and the pole 4, the insulation and sealing between the pole 4 and the cover body 3 are ensured.

[0073] In one embodiment, a liquid injection hole 302 is further provided on the cover body 3 to inject electrolyte into the battery cell. Preferably, the liquid injection hole 302 is located between the two welding through holes 301 .

[0074] According to another aspect of an embodiment of the present invention, a battery cell is provided, comprising: a housing 1, a pole group 2, the aforementioned cover structure, and two connecting pieces 5. The housing 1 has an open end; the pole group 2 is disposed within the housing 1 and has two sets of tabs 201; two welding holes 301 on the cover structure correspond one-to-one with the two sets of tabs 201; and two connecting pieces 5 correspond one-to-one with the two sets of tabs 201, each connecting piece 5 being connected between a set of tabs 201 and a pole post 4.

[0075] Specifically, one of the two poles 4 is a positive pole and the other is a negative pole; each pole group 2 has two pole ears on the side facing the cover body 3, one is a positive pole ear and the other is a negative pole ear, the positive pole is connected to the positive pole ear, and the negative pole is connected to the negative pole ear; one of the two connecting pieces 5 is connected between the positive pole and the positive pole ear, and the other is connected between the negative pole and the negative pole ear.

[0076] It should be noted that, during the battery cell assembly process, the pole 4, the connecting piece 5, the sealing ring 8, the first plastic part 901 and the second plastic part 902 are first assembled to the cover body 3 to form an integral cover structure; then the pole group 2 is installed in the housing 1, and then the cover structure is assembled to the open end of the housing 1. At this time, Figures 17 to 19 As shown, the pole ear 201 on the pole group 2 is along Figure 19 The tab 201 extends in the "up and down" direction indicated by the middle arrow, and the tab 201 passes through the connecting piece 5 vertically in the up and down direction; the tab 201 is bent through the welding through hole 301 on the cover body 3, and the tab 201 is bent 90° and fits with the upper surface of the connecting piece 5. Then, the welding head of the welding equipment passes through the welding through hole 301 on the cover body 3 to weld the tab 201 and the connecting piece 5, thereby realizing the connection between the tab 201 and the connecting piece 5. The structural form after the tab 201 and the connecting piece 5 are welded is shown as follows: Figures 21 to 23 As shown; Finally, the sealing plate 6 and the insulating member 7 are assembled into one and then placed in the welding through-hole 301, and the outer peripheral wall of the sealing plate 6 is welded to the inner peripheral wall of the welding through-hole 301 to achieve the sealing of the sealing plate 6 to the welding through-hole 301, and the assembly of the battery cell is completed. The structural diagram of the assembled battery cell is shown in Figures 13 to 15 shown.

[0077] The battery cell of this embodiment can fully ensure the connection strength between the sealing plate 6 and the insulating member 7 by setting the relevant parameters of the clamping fit between the sealing plate 6 and the insulating member 7, improve the reliability of the connection between the sealing plate 6 and the insulating member 7, ensure the insulation performance of the electrode group 2 and the sealing plate 6, and improve the reliability of the battery cell.

[0078] The battery cell of this embodiment reduces the process of welding the connecting piece 5 and the electrode group 2 in advance, as well as the process of bending the connecting piece 5 , thereby improving the internal space utilization of the battery cell and enhancing production efficiency.

[0079] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A cover plate structure, characterized in that: include: The cover plate body is provided with two spaced-apart welding through holes, each of which is adapted to correspond to a partial area on a connecting piece and a group of tabs, and the thickness of the cover plate body is T0; two poles, the poles being arranged on the cover body and passing through the cover body; Two sealing plates, each of which is disposed in one of the welding through holes to seal the welding through holes, a slot being configured on the lower side of the sealing plate, and a thickness of the sealing plate being T1, wherein 0.6≤T1 / T0≤1; Two insulating members, each of which is arranged on the lower side of one of the sealing plates, are provided with a buckle corresponding to the slot, and the buckle is engaged with the slot.

2. The cover plate structure according to claim 1, characterized in that: The clamping groove includes a first groove section and a second groove section, the first groove section is connected to the lower end of the second groove section, and the projected area of the first groove section on the lower surface of the sealing plate is smaller than the projected area of the second groove section on the lower surface of the sealing plate; The buckle includes two clamping parts, which are spaced apart along a first direction to form a clearance space between the two clamping parts. Each of the clamping parts includes a connecting section and a hook. One end of the connecting section is connected to the insulating part body of the insulating part and the other end is connected to the hook. Each hook extends in a direction away from the other hook. The connecting sections of the two clamping parts cooperate with the first slot section together, and the hooks of the two clamping parts cooperate with the second slot section together.

3. The cover plate structure according to claim 2, characterized in that: The ratio between the groove depth t1 of the first groove section and the thickness T1 of the sealing plate is: 0.1≤t1 / T1≤0.55, the ratio between the groove depth t2 of the second groove section and the thickness T1 of the sealing plate is: 0.2≤t2 / T1≤0.8, and (t1+t2) / T1≤0.

9.

4. The cover plate structure according to claim 3, characterized in that: The thickness T1 of the sealing plate ranges from 1.5 mm to 2.0 mm; the depth t1 of the first groove section ranges from 0.2 mm to 0.8 mm; and the depth t2 of the second groove section ranges from 0.4 mm to 1 mm.

5. The cover plate structure according to claim 2, characterized in that: The inner wall of the first slot section is inclined, and the area of the open end of the first slot section is smaller than the cross-sectional area of the end connected to the second slot section; the connecting section is inclined, and its inclination angle is the same as the inclination angle of the inner wall of the first slot section.

6. The cover plate structure according to claim 5, characterized in that: The angle θ between the inner wall of the first groove section and the up-down direction is in the range of 10°≤θ≤80°; And / or, the distance W1 between the two sides of the two clamping portions that are close to each other along the first direction is in the range of 1 mm to 5 mm; And / or, a distance W2 between two sides of the roots of the two clamping portions that are away from each other along the first direction has a value ranging from 2 mm to 7.5 mm.

7. The cover plate structure according to claim 2, characterized in that: The maximum dimension W3 of the root of the connecting section along the first direction is in the range of 0.35 mm ≤ W3 ≤ 1.2 mm; And / or, a dimension W4 of the lower surface of the hook along the first direction has a value range of: W4 ≥ 0.5 mm.

8. The cover plate structure according to claim 2, characterized in that: The circumferential edge of the open end of the slot is set as a first guide surface, and the side edge of the hook away from the insulating body and away from the clearance space is constructed as a second guide surface, and the second guide surface cooperates with the first guide surface to provide guidance for the buckle to be installed in the slot.

9. The cover plate structure according to any one of claims 1 to 8, characterized in that: The distance L1 between the two welding through holes is ≥5mm; And / or, along the width direction of the cover plate body, the size of the cover plate body is L0, and the distance from the edge of the welding through hole to the edge of the cover plate body is L2, wherein L2≥5mm and 2×L2>0.2×L0.

10. A battery cell, characterized in that: include: a housing having an open end; A pole group is arranged inside the shell, and the pole group has two sets of pole lugs; The cover plate structure according to any one of claims 1 to 9, wherein the two welding through holes on the cover plate structure correspond one-to-one to the two groups of tabs; Two connecting pieces, the two connecting pieces correspond to the two groups of pole lugs one by one, and each connecting piece is connected between a group of pole lugs and one pole.

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