Cover plate assembly and battery cell

Abstract

The utility model relates to the technical field of batteries, and discloses a cover plate assembly and a battery cell. The cover plate assembly comprises: a top cover sheet provided with a pole hole; the pole is arranged in the pole hole in a penetrating manner, the pole comprises a first pole part and a second pole part which are connected in the axial direction, the cross sectional area of the first pole part is larger than that of the second pole part, a first convex ring surrounding the second pole part is arranged at one end, close to the second pole part, of the first pole part, and the first convex ring and the second pole part are arranged in a spaced manner in the radial direction; the connecting piece is arranged on one side of the top cover piece, the connecting piece comprises a connecting hole and a second convex ring, the second convex ring is arranged around the connecting hole, the second column part is inserted into the connecting hole, and the second convex ring is inserted between the first convex ring and the second column part; the sealing ring is arranged on the peripheral side of the first protruding ring in a sleeving mode and located between the connecting piece and the top cover piece and between the connecting piece and the first column part. The problem that the sealing ring is damaged by welding laser in the welding process of the connecting piece and the pole is solved, and the sealing performance is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to cover plate subassembly and electric core. BACKGROUND

[0002] The cover plate subassembly is arranged on the opening end of the electric core shell, and comprises a top cover sheet, a pole, a connecting sheet, an upper plastic, a sealing ring and a lower plastic. The pole is arranged in the through hole of the top cover sheet, the first part of the sealing ring is compressed between the connecting sheet and the top cover sheet, and the second part is compressed between the connecting sheet and the pole, and the connecting sheet and the pole are welded. In the prior art, a connecting hole matched with the pole is formed on the connecting sheet, and the pole is inserted into the connecting hole, and then the pole and the connecting sheet are welded from the side of the connecting sheet away from the pole. However, since the pole and the connecting sheet are radially matched, there may be a radial gap, so when the connecting sheet and the pole are laser welded, the laser will pass through the radial gap and hit the area where the sealing ring is located, thereby damaging the sealing ring and affecting the safety of the electric core. SUMMARY

[0003] Therefore, the utility model provides a cover plate subassembly and an electric core to solve the problem of laser welding damage to the sealing ring during welding of the connecting sheet and the pole.

[0004] In a first aspect, the utility model provides a cover plate subassembly, which comprises: a top cover sheet having a pole hole; a pole arranged in the pole hole, the pole comprising a first column part and a second column part connected along an axial direction, the cross-sectional area of the first column part being larger than that of the second column part, a first protruding ring around the second column part being arranged on one end of the first column part close to the second column part, and the first protruding ring and the second column part being arranged radially apart; a connecting sheet arranged on one side of the top cover sheet, the connecting sheet comprising a connecting hole and a second protruding ring, the second protruding ring being arranged around the connecting hole, the second column part being inserted into the connecting hole, and the second protruding ring being inserted between the first protruding ring and the second column part; and a sealing ring arranged around the outer periphery of the first protruding ring and between the connecting sheet and the top cover sheet and between the connecting sheet and the first column part.

[0005] Beneficial effects: By setting the first convex ring around the second column part on the pole column, setting the second convex ring around the connecting hole on the connecting piece, and inserting the second convex ring into the first ring groove formed between the first convex ring and the second column part, the sealing ring is sleeved on the side of the first convex ring away from the second column part, so that the sealing ring is separated from the second column part through the first convex ring and the second convex ring, and the connecting piece is engaged with the pole column, so that the matching surface between the connecting piece and the pole column has multiple bends, thereby effectively isolating the leaked laser from the gap between the second column part and the inner wall of the connecting hole during the welding process of the connecting piece and the pole column, thereby avoiding damage to the sealing ring by the leaked laser, and further ensuring the sealing performance of the sealing ring.

[0006] In an alternative embodiment, the pole column and the connecting piece are gap-fitted in the thickness direction of the cover plate assembly.

[0007] Beneficial effects: By gap-fitting the pole column and the connecting piece in the thickness direction of the cover plate assembly, even if the manufacturing precision of each part is low, the part of the first plastic part between the abutting section of the pole column and the flange of the connecting piece, the part of the top cover piece, and the part of the second plastic part can have better fit, thereby ensuring the sealing effect of the dynamic seal between the connecting piece and the top cover piece on the sealing ring, blocking the liquid leakage path, and preventing the battery cell from leaking.

[0008] In an alternative embodiment, the fitting gap between the pole column and the connecting piece is t, wherein 0 < t ≤ 0.125 mm.

[0009] Beneficial effects: By setting the fitting gap t between the pole column and the connecting piece to be greater than 0 and less than or equal to 0.125 mm, a reasonable fitting gap between the connecting piece and the pole column is ensured, thereby reducing the precision requirements of each component in the cover plate assembly and ensuring the sealing effect of the sealing ring.

[0010] In an alternative embodiment, the connecting piece further includes a piece body, the second convex ring is connected and arranged on the piece body, the second convex ring is arranged on the side of the piece body facing the top cover piece, and the second convex ring is formed by the piece body protruding around the edge of the connecting hole.

[0011] Beneficial effects: By setting the second convex ring to be formed by the piece body protruding around the edge of the connecting hole, the inner ring of the second convex ring has the same shape and size as the connecting hole, which facilitates the processing and molding of the connecting piece and facilitates the cooperation with the first ring groove on the pole column, and the inner ring of the first ring groove coincides with the outer periphery of the second column part, thereby facilitating the processing and molding of the pole column.

[0012] In an alternative embodiment, the size of the first convex ring in the axial direction of the pole column is H1, wherein the value range of H1 is: 0.3 mm ≤ H1 ≤ 1 mm.

[0013] And / or, the ring width of the first convex ring is W1, wherein the value range of W1 is: 0.5mm≤W1≤1.5mm.

[0014] Beneficial effect: By setting the size of the first convex ring protruding relative to the first column part to be between 0.3mm and 1mm, the first convex ring can not only have good blocking effect on laser, thereby avoiding the damage of the sealing ring caused by the leakage of laser during the welding of the pole piece and the connecting piece, ensuring the sealing performance of the sealing ring, but also can ensure the deformation limiting ability of the first convex ring to the flanging of the connecting piece, thereby avoiding the deformation of the flanging and affecting the sealing performance of the sealing ring, and further ensuring the sufficient extrusion of the first column part and the flanging to the sealing ring, thereby further ensuring the sealing performance of the sealing ring.

[0015] By setting the ring width W1 of the first convex ring to be within the range of 0.5mm to 1.5mm, the first convex ring can not only have sufficient structural strength to limit the deformation of the flanging, thereby ensuring the sealing performance of the sealing ring, but also can avoid occupying too much space of the sealing ring, thereby ensuring sufficient space between the first column part and the flanging to accommodate the sealing ring, thereby further ensuring the sealing performance of the sealing ring.

[0016] In an optional embodiment, the first column part includes an abutting section and a plug-in section connected and arranged in an axial direction, the cross-sectional area of the abutting section is greater than that of the plug-in section, the plug-in section is arranged in the pole hole, and the abutting section is located on the side of the top cover sheet away from the connecting piece, and the second column part is connected to one end of the plug-in section away from the abutting section.

[0017] Beneficial effect: One end of the pole is limited by the abutting section on one side of the top cover sheet, and the other end of the pole is limited by the connecting piece on the other side of the top cover sheet, thereby realizing the connection of the pole on the top cover sheet.

[0018] In an optional embodiment, the cover plate assembly further includes a first plastic part and a second plastic part; the first plastic part includes a first main body part, the first main body part is annular and arranged between the lower surface of the abutting section and the top cover sheet, the thickness of the first main body part is t1, and the manufacturing tolerance of the first main body part is Δt1; the second plastic part includes a second main body part, the second main body part is arranged between the connecting piece and the top cover sheet, the thickness of the second main body part is t3, and the manufacturing tolerance of the second main body part is Δt3; the thickness of the part of the top cover sheet between the first main body part and the second plastic part is t2, and the manufacturing tolerance is Δt2; wherein,

[0019] Beneficial effects: can compensate for the manufacturing error of each component, so that even if the size of each component exists certain deviation, the cooperation of the pole and the connecting piece can meet the requirements, the qualified rate and consistency of the product are improved, the production cost and difficulty are reduced, and the first plastic part, the top cover piece and the second plastic part are tightly attached along the up-down direction, so that the dynamic sealing has good sealing effect and effectively blocks the liquid leakage path.

[0020] In an alternative embodiment, the first plastic part further comprises a third protruding ring connected to the inner ring of the first main body part and located between the plug-in section and the inner wall of the pole hole; the sealing ring has a first ring part, a second ring part and a third ring part in turn along the direction from the inner ring to the outer ring thereof, the first ring part is compressed between the connecting piece and the first column part, the second ring part is arranged corresponding to the third protruding ring, and the third ring part is compressed between the connecting piece and the top cover piece.

[0021] Beneficial effects: the planar area of the connecting piece is used to extrude and seal the sealing ring, which reduces the manufacturing difficulty of the piece main body, is conducive to improving the manufacturing precision, and facilitates the assembly of the cover plate assembly, thereby improving the product quality.

[0022] In an alternative embodiment, the total ring width of the sealing ring is W2; the ring width of the first ring part is W3, and the relationship between W3 and W2 satisfies the relationship: 1 / 3≤W3 / W2<1 / 2.

[0023] And / or, the ring width of the third ring part is W4, and the relationship between W4 and W2 satisfies the relationship: 1 / 3≤W4 / W2<1 / 2.

[0024] Beneficial effects: by setting W3 / W2 to be greater than or equal to 1 / 3 and less than 1 / 2, the sealing property of the part of the sealing ring compressed between the connecting piece and the first column part can be guaranteed, and the sealing property of the part of the sealing ring compressed between the connecting piece and the top cover piece can be guaranteed, thereby improving the overall sealing property and avoiding liquid leakage of the battery cell.

[0025] By setting W4 / W2 to be greater than or equal to 1 / 3 and less than 1 / 2, the sealing property of the part of the sealing ring compressed between the connecting piece and the top cover piece can be guaranteed, and the sealing property of the part of the sealing ring compressed between the connecting piece and the first column part can be guaranteed, thereby improving the overall sealing property and avoiding liquid leakage of the battery cell.

[0026] In a second aspect, the utility model further provides a battery cell, which comprises: a shell having an open end; a pole group arranged in the shell; and the cover plate assembly described above, which is arranged on the open end of the shell. Because the battery cell comprises the cover plate assembly, it has the same effects as the cover plate assembly, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0028] Figure 1 A structure diagram of a cover plate assembly of an embodiment of the present application is shown in the figure.

[0029] Figure 2 A top view of the cover plate assembly shown in the figure. Figure 1

[0030] A sectional view in the direction of A-A in the figure. Figure 3 Figure 1

[0031] Figure 4 A local enlarged diagram of B in the figure. Figure 3

[0032] A local enlarged diagram of C in the figure. Figure 5 Figure 3

[0033] Figure 6 A structure diagram of a pole of an embodiment of the present application is shown in the figure.

[0034] Figure 7 A top view of the pole shown in the figure. Figure 6

[0035] A sectional view in the direction of D-D in the figure. Figure 8 Figure 7 A structure diagram of a top cover sheet of an embodiment of the present application is shown in the figure.

[0036] Figure 9 A structure diagram of a connecting sheet of an embodiment of the present application is shown in the figure.

[0037] Figure 10 A structure diagram of a first plastic part of an embodiment of the present application is shown in the figure.

[0038] Figure 11 A front view of the first plastic part shown in the figure.

[0039] Figure 12 Figure 11 A front view of the first plastic part shown in the figure.

[0040] Figure 13 A sectional view of a traditional cover plate assembly.

[0041] ​​​​​​Figure 14 for Figure 13 A magnified view of part of F.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Top cover plate; 101. Pole post hole; 102. Explosion-proof valve hole; 2. Pole post; 201. First post part; 2011. Abutting section; 2012. Insertion section; 202. Second post part; 203. First convex ring; 204. First annular groove; 3. Connecting piece; 301. Connecting hole; 302. Second convex ring; 303. Piece body; 4. Sealing ring; 401. First ring part; 402. Second ring part; 403. Third ring part; 5. First plastic part; 501. First main body part; 502. Third convex ring; 503. Extension part; 6. Second plastic part; 601. Second main body part. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0045] like Figures 13 to 14 The diagram shows a cross-sectional view of a cover plate assembly in the related technology. The first part of the sealing ring 4 is compressed between the connecting piece 3 and the top cover piece 1, and the second part is compressed between the connecting piece 3 and the pole post 2. Along the axial direction of the pole post 2, there is a gap t between the connecting piece 3 and the pole post 2. Due to the radial fit problem of the connecting hole 301 between the pole post 2 and the connecting piece 3, there may be a radial gap between the pole post 2 and the hole wall of the connecting hole 301. The axial gap t between the connecting piece 3 and the pole post 2 connects this radial gap with the space where the sealing ring 4 is located. During laser welding of the pole post 2 and the connecting piece 3, the welding position is as follows... Figure 14 As shown in a1, after the laser passes through the radial gap, it hits the gap t and, after refraction, may damage the sealing ring 4. Additionally, a flange is formed on the main body 303 of the connecting piece 3 in the area away from the second convex ring 302. When the cover plate assembly is subjected to gas pressure inside the battery cell, the flange of the connecting piece 3 may open and deform, with the opening direction as shown in the figure. Figure 13As shown in B1, further affect the compression amount of the sealing ring 4 between the connecting sheet 3 and the top cover sheet 1, affect the sealing performance; and in order to make the flanging of the connecting sheet 3 not to be deformed, or the sealing ring 4 still has better sealing effect after deformation, the connecting sheet 3 needs to have a deeper penetration when welded with the pole 2, thereby increasing the welding difficulty; in addition, the thickness of the flanging needs to be slightly high in precision, otherwise the sealing performance of the part of the sealing ring 4 between the connecting sheet 3 and the top cover sheet 1 is affected.

[0046] The embodiments of the utility model will be described below in combination with Figures 1 to 12 , the embodiments of the utility model.

[0047] According to the embodiments of the utility model, on the one hand, a cover plate assembly is provided, which comprises: a top cover sheet 1, a pole 2, a connecting sheet 3 and a sealing ring 4. The top cover sheet 1 is provided with a pole hole 101; the pole 2 is arranged in the pole hole 101, and the pole 2 comprises a first column part 201 and a second column part 202 which are arranged in an axial direction, the cross-sectional area of the first column part 201 is larger than that of the second column part 202, a first convex ring 203 is arranged on one end of the first column part 201 close to the second column part 202 and surrounds the second column part 202, and the first convex ring 203 and the second column part 202 are arranged in a radial direction; the connecting sheet 3 is arranged on one side of the top cover sheet 1, and the connecting sheet 3 comprises a connecting hole 301 and a second convex ring 302, the second convex ring 302 surrounds the connecting hole 301, the second column part 202 is arranged in the connecting hole 301, and the second convex ring 302 is arranged between the first convex ring 203 and the second column part 202; and the sealing ring 4 is arranged on the outer circumferential side of the first convex ring 203 and between the connecting sheet 3 and the top cover sheet 1 and between the connecting sheet 3 and the first column part 201.

[0048] Wherein, the axial direction refers to the direction of the axis of the pole 2, i.e. Figures 3 to 4 the direction of the "up and down" indicated by the arrow; the radial direction refers to the radial direction of the pole 2, which is perpendicular to the axial direction of the pole 2; the cross-sectional area refers to the area of the cross section perpendicular to the axis of the pole 2; the first convex ring 203 is formed by the part of the end face of one end of the first column part 201 close to the second column part 202 protruding away from the first column part 201; the outer circumferential side of the first convex ring 203 refers to the side of the second convex ring 302 away from the second column part 202, i.e. the outer ring surface of the first convex ring 203; the pole 2 and the connecting sheet 3 are welded, preferably laser welded.

[0049] By means of the cover plate assembly, the first protruding ring 203 is arranged around the second column part 202 on the pole post 2, the second protruding ring 302 is arranged around the connecting hole 301 on the connecting sheet 3, the second protruding ring 302 is inserted into the first ring groove 204 formed between the first protruding ring 203 and the second column part 202, and the sealing ring 4 is sleeved on the side of the first protruding ring 203 away from the second column part 202. Thus, the sealing ring 4 is separated from the second column part 202 through the first protruding ring 203 and the second protruding ring 302, the connecting sheet 3 is engaged with the pole post 2, the fitting surface between the connecting sheet 3 and the pole post 2 has a plurality of bends, and thus the laser leaked from the gap between the second column part 202 and the inner wall of the connecting hole 301 during the welding process of the connecting sheet 3 and the pole post 2 can be effectively isolated, so as to avoid the damage of the leaked laser to the sealing ring 4, and further to ensure the sealing performance of the sealing ring 4.

[0050] It should be noted that, further in combination with Figure 4 and Figure 9 , the connecting hole 301 is a through hole, and the laser is welded from the side of the connecting sheet 3 away from the top cover sheet 1 along the periphery of the second column part 202 during the welding process of the connecting sheet 3 and the pole post 2. The specific welding position is shown as a1 in Figure 4 , and the radial gap between the inner wall of the connecting hole 301 and the pole post 2 is also separated from the sealing ring 4 by the first protruding ring 203 and the second protruding ring 302. Therefore, it is difficult for the laser to reach the space where the sealing ring 4 is located.

[0051] In some embodiments, further in combination with Figure 4 and Figure 10 , the connecting sheet 3 further comprises a sheet body 303, the second protruding ring 302 is arranged on one side of the sheet body 303 facing the top cover sheet 1, and the second protruding ring 302 is formed by protruding from the edge of the connecting hole 301 of the sheet body 303 towards the top cover sheet 1. By forming the second protruding ring 302 by protruding from the edge of the connecting hole 301 of the sheet body 303, the upper surface of the second protruding ring 302 is higher than the upper surface of the sheet body 303, and the inner ring of the second protruding ring 302 has the same shape and size as the connecting hole 301, which facilitates the processing and forming of the connecting sheet 3, facilitates the cooperation with the first ring groove 204 on the pole post 2, and makes the inner ring of the first ring groove 204 coincide with the outer periphery of the second column part 202, thereby facilitating the processing and forming of the pole post 2. Wherein, the upper surface refers to the surface in the direction of “up” indicated by the arrow in Figure 4 , that is, the surface of the connecting sheet 3 facing the top cover sheet 1.

[0052] It should be noted that, the area of the sheet body 303 except the area corresponding to the second protruding ring 302 is formed into a flange. When the cover plate assembly is subjected to the gas pressure inside the battery cell, the flange area of the connecting sheet 3 is limited by the first protruding ring 203 on the pole post 2, and it is difficult for the flange area to move alongFigure 3 The direction of the arrow "b1" is the direction of the opening deformation, which improves the deformation resistance of the connecting piece 3, and does not need to rely only on the welding between the connecting piece 3 and the pole 2 to limit the deformation of the piece body 303, so as to reduce the requirement for the welding penetration depth, thereby reducing the processing difficulty, and being beneficial to improve the welding quality and efficiency. The planar area formed by the upper surface of the flange is in extrusion with the third ring part 403 of the sealing ring 4 on the lower surface of the top cover piece 1, to form a dynamic seal; and the planar area where the upper surface of the flange is located is in extrusion with the first ring part 401 of the sealing ring 4 on the pole 2, to form a static seal; wherein the dynamic seal refers to the change of the compression amount of the sealing ring during the working process of the battery cell; and the static seal refers to the invariability of the compression amount of the sealing ring during the working process of the battery cell.

[0053] Further combined Figure 5 As shown, the dynamic seal is used to block the liquid leakage path E1, and the static seal is used to block the liquid leakage path E2; the liquid leakage path E1 passes through the gap between the second plastic part 6 and the top cover piece 1 and / or the gap between the second plastic part 6 and the connecting piece 3, the gap between the sealing ring 4 and the top cover piece 1 in sequence, and then passes through the gap between the first plastic part 5 and the top cover piece 1 and / or the gap between the first plastic part 5 and the pole 2 to the outside of the battery cell; the liquid leakage path E2 passes through the gap between the second column part 202 and the connecting hole 301, the gap between the second protruding ring 302 and the first ring groove 204, the gap between the first column part 201 and the flange, and the gap between the sealing ring 4 and the pole 2 in sequence, and then passes through the gap between the first plastic part 5 and the top cover piece 1 and / or the gap between the first plastic part 5 and the pole 2 to the outside of the battery cell. The cooperation mode of the pole 2 and the connecting piece 3 in the embodiment can guarantee the sealing performance of the dynamic seal and the static seal.

[0054] Specifically, further combined Figure 4 As shown, along the radial direction of the pole 2, the first ring groove 204 is formed between the first protruding ring 203 and the second column part 202, and the second protruding ring 302 is inserted into the first ring groove 204. The cooperation gap between the pole 2 and the connecting piece 3 refers to that, along the radial direction of the pole 2, Figure 4 Along the "up and down" direction indicated by the arrow, there is a gap between the lower surface of the first ring groove 204 of the pole 2 and the upper surface of the second protruding ring 302 of the connecting piece 3, and there is a gap between the lower surface of the first protruding ring 203 of the pole 2 and the upper surface of the flange of the connecting piece 3.

[0055] In some embodiments, the pole 2 and the connecting piece 3 are gap-cooperated along the thickness direction of the cover plate assembly. Wherein, the thickness direction refers to Figures 3 to 4The direction of "up and down" indicated by the arrow. The cover plate assembly is assembled by multiple parts, along the thickness direction of the cover plate assembly, the abutting section 2011 of the pole 2 and the flange of the connecting piece 3 are provided with the part of the first plastic part 5, the part of the top cover piece 1 and the part of the second plastic part 6, if the first plastic part 5, the top cover piece 1 and the second plastic part 6 have gaps between each other along the thickness direction due to manufacturing tolerances, a liquid leakage path E1 as shown in the figure may be formed, so that the sealing performance of the dynamic seal of the sealing ring 4 between the connecting piece 3 and the top cover piece 1 is poor. Figure 5

[0056] Therefore, by setting the gap fit between the pole 2 and the connecting piece 3 along the thickness direction of the cover plate assembly, even if the manufacturing precision of each part is low, the part of the first plastic part 5, the part of the top cover piece 1 and the part of the second plastic part 6 between the abutting section 2011 of the pole 2 and the flange of the connecting piece 3 can have better fit, thereby ensuring the sealing effect of the dynamic seal of the sealing ring 4 between the connecting piece 3 and the top cover piece 1, blocking the liquid leakage path E1, and preventing the battery from leaking.

[0057] At the same time, by setting the fit gap between the connecting piece 3 and the pole 2, it can also ensure that the static seal of the sealing ring 4 between the connecting piece 3 and the pole 2 has a reasonable compression amount, thereby ensuring that the performance of the static seal meets the requirements.

[0058] In some embodiments, the fit gap between the pole 2 and the connecting piece 3 is t, wherein 0

[0059] Therefore, by setting the fit gap t between the pole 2 and the connecting piece 3 to be greater than 0 and less than or equal to 0.125mm, it ensures that the connecting piece 3 and the pole 2 have a reasonable fit gap, thereby both reducing the precision requirements of each component in the cover plate assembly and ensuring the sealing effect of the sealing ring 4.

[0060] Preferably, the value of t is 1.0mm.

[0061] ​In some embodiments, the dimension of the first convex ring 203 along the axial direction of the pole post 2 is H1, wherein the value of H1 ranges from 0.3mm ≤ H1 ≤ 1mm. The axial direction of the pole post 2 along... Figures 3 to 4 The arrow points in the "up and down" direction. If H1 is less than 0.3mm, the height of the first convex ring 203 is too small, the depth of the first annular groove 204 formed on the pole post 2 is too small, and the height of the second convex ring 302 that can be inserted into the first annular groove 204 to cooperate with the pole post 2 is too small, resulting in poor laser blocking effect. During the welding process between the connecting piece 3 and the pole post 2, the laser may still pass through the gap between the second post 202 and the hole wall of the connecting hole 301, the gap between the second convex ring 302 and the first annular groove 204, and the gap between the first convex ring 203 and the flange in sequence. Then, it reaches the area where the sealing ring 4 is located, thereby damaging the sealing ring 4. Furthermore, when the cover plate assembly is subjected to the gas pressure inside the cell, the first convex ring 203 has too little restraining effect on the connecting piece 3, and the flange is easy to open and deform. If H1 is greater than 1mm, the height dimension of the first convex ring 203 is too large, resulting in the flange thickness being too small, the structural strength of the connecting piece 3 is weak, and the flange is also easy to open and deform. It will also cause the distance between the first column 201 and the flange to be too large, resulting in too little compression of the sealing ring 4 and poor sealing performance.

[0062] Therefore, by setting the size of the protrusion of the first convex ring 203 relative to the first post 201 to be between 0.3mm and 1mm, it is possible to ensure that the first convex ring 203 has a good blocking effect on the laser, thereby avoiding laser leakage damage to the sealing ring 4 during the welding process between the pole post 2 and the connecting piece 3, ensuring the sealing performance of the sealing ring 4, and ensuring the ability of the first convex ring 203 to limit the deformation of the flange of the connecting piece 3. At the same time, it is also possible to ensure the structural strength of the connecting piece 3, thereby avoiding the flange opening and deformation that would affect the sealing performance of the sealing ring 4, and ensuring that the first post 201 and the flange fully compress the sealing ring 4, further ensuring the sealing performance of the sealing ring 4.

[0063] Optionally, H1 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm. Preferably, H1 is 0.5mm.

[0064] In some embodiments, further combined Figure 4 As shown, the width of the first convex ring 203 is W1, where the value of W1 ranges from 0.5mm to 1.5mm. The first convex ring 203 is annular, and the ring width refers to the spacing between the inner and outer rings. Figures 3 to 4 In the cross-sectional view of the cover plate assembly shown, the ring width of the first convex ring 203 is... Figure 4The dimension in the "width direction" indicated by the middle arrow. If W1 is less than 0.5mm, the ring width of the first convex ring 203 is too small, the structural strength of the first convex ring 203 is insufficient, and the first convex ring 203 is prone to deformation when the cover plate assembly is subjected to the internal gas pressure of the cell. This results in insufficient restraint on the connecting piece 3, and the flange of the connecting piece 3 is prone to... Figure 3 The deformation in the direction of b1 shown affects the compression of the sealing ring 4 and the dynamic sealing performance of the sealing ring 4. If H1 is greater than 1.5mm, the ring width of the first convex ring 203 is too large, occupying too much space of the sealing ring 4, resulting in too little part of the sealing ring 4 between the first column 201 and the flange, and poor static sealing performance.

[0065] Therefore, by setting the ring width W1 of the first convex ring 203 to be within the range of 0.5mm to 1.5mm, it is possible to ensure that the first convex ring 203 has sufficient structural strength, thereby limiting the opening deformation of the flange and ensuring the sealing performance of the sealing ring 4. At the same time, it is possible to avoid the first convex ring 203 occupying too much space of the sealing ring 4, ensuring that there is enough space between the first column 201 and the flange to accommodate the sealing ring 4, thereby further ensuring the sealing performance of the sealing ring 4.

[0066] Optionally, W1 can be 0.5mm, 0.7mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, or 1.5mm. Preferably, W1 is 1.0mm.

[0067] Preferably, the connecting hole 301 is a circular hole, the second column portion 202 is cylindrical, the first convex ring 203 is a circular ring, and the ring width of the first convex ring 203 is the radial dimension of the first convex ring 203 along the second column portion 202. Correspondingly, the pole hole 101 is a circular hole.

[0068] In some embodiments, the top cover plate 1 is also provided with an explosion-proof valve hole 102, which is used to install an explosion-proof plate to form an explosion-proof valve and improve the safety of the battery cell.

[0069] In some embodiments, further combined Figure 4 and Figure 6 , Figure 8As shown, the first column portion 201 includes an abutment section 2011 and an insertion section 2012 connected along the axial direction. The cross-sectional area of ​​the abutment section 2011 is larger than the cross-sectional area of ​​the insertion section 2012. The insertion section 2012 passes through the pole hole 101. The abutment section 2011 is located on the side of the top cover plate 1 away from the connecting plate 3. The second column portion 202 is connected to the end of the insertion section 2012 away from the abutment section 2011. It should be noted that the cross-sectional area of ​​the abutment section 2011 is larger than the opening area of ​​the pole hole 101. The abutment section 2011 cannot pass through the pole hole 101. The insertion section 2012 is inserted into the pole hole 101. The second post 202 is connected to the end of the insertion section 2012 away from the abutment section 2011. The end of the second post 202 away from the first post 201 is welded to the connecting piece 3. Thus, one end of the pole 2 is limited to one side of the top cover plate 1 by the abutment section 2011, and the other end of the pole 2 is limited to the other side of the top cover plate 1 by the connecting piece 3, thereby realizing the connection of the pole 2 on the top cover plate 1.

[0070] In some embodiments, the number of electrode holes 101 on the top cover plate 1 is two, and correspondingly, the number of electrode posts 2 is two, one of which is a positive electrode post and the other is a negative electrode post. The figure shown in this embodiment is the positive electrode post. The matching relationship between the various components at the negative electrode post is the same as that at the positive electrode post, and will not be described again here.

[0071] In some embodiments, the cover assembly further includes a first plastic part 5 and a second plastic part 6; further combined with Figure 4 As shown, the first plastic part 5 includes a first main body 501, which is annular and disposed between the lower surface of the abutment section 2011 and the top cover plate 1. The thickness of the first main body 501 is t1, and the manufacturing tolerance of the first main body 501 is Δt1. The second plastic part 6 includes a second main body 601, which is disposed between the connecting piece 3 and the top cover plate 1. The thickness of the second main body 601 is t3, and the manufacturing tolerance of the second main body 601 is Δt3. The thickness of the portion of the top cover plate 1 corresponding to the first main body 501 is t2, and the manufacturing tolerance is Δt2. The lower surface refers to Figure 4 The surface in the direction indicated by the middle arrow ("down"); thickness refers to the area along... Figure 4 The dimensions in the direction indicated by the middle arrow, which is "up" or "down".

[0072] It should be noted that the first plastic part 5, the second plastic part 6, and the top cover plate 1 all have manufacturing tolerances during the manufacturing process. This is addressed by setting a clearance t between the pole post 2 and the connecting plate 3, and t satisfies the relationship between t and the manufacturing tolerances of each component. The manufacturing errors of each component can be compensated, so that even if the sizes of each component have certain deviations, the cooperation of the pole and the connecting piece can meet the requirements, the qualified rate and consistency of the product are improved, the production cost and difficulty are reduced, and the distance T between the lower surface of the abutting section 2011 of the pole 2 and the piece body 303 of the connecting piece 3 is equal to t1+t2+t3, that is, the first plastic part 5, the top cover piece 1 and the second plastic part 6 are tightly attached in the up-down direction, so that the dynamic sealing has good sealing effect and effectively blocks the liquid leakage path E1. The values of Δt1, Δt2 and Δt3 are each ±0.5 mm.

[0073] In some embodiments, further in combination Figure 4 As shown, the first plastic part 5 further comprises a third protruding ring 502 connected to the inner ring of the first body part 501 and located between the insertion section 2012 and the inner wall of the pole hole 101; the sealing ring 4 has a first ring part 401, a second ring part 402 and a third ring part 403 in turn along the direction from the inner ring to the outer ring thereof, the first ring part 401 is compressed between the connecting piece 3 and the first column part 201, the second ring part 402 is arranged corresponding to the third protruding ring 502, and the third ring part 403 is compressed between the connecting piece 3 and the top cover piece 1. The first ring part 401 of the sealing ring 4 is compressed between the upper surface of the piece body 303 of the connecting piece 3 and the lower surface of the first column part 201 to form a static seal to block the liquid leakage path E1, the third ring part 403 is compressed between the upper surface of the piece body 303 and the lower surface of the top cover piece 1 to form a dynamic seal, and the second ring part 402 is located between the upper surface of the piece body 303 and the lower surface of the third protruding ring 502, so that the entire lower surface of the sealing ring 4 abuts against the upper surface of the piece body 303. By using the planar area of the connecting piece 3 to extrude and seal the sealing ring 4, the manufacturing difficulty of the piece body 303 is reduced, which is conducive to improving the manufacturing precision and facilitating the assembly of the cover plate assembly, thereby improving the product quality.

[0074] Specifically, the first plastic part 5 is an upper plastic for ensuring the insulation between the pole 2 and the top cover piece 1, and the second plastic part 6 is a lower plastic for ensuring the insulation between the top cover piece 1 and the connecting piece 3 and between the top cover piece 1 and the pole group.

[0075] In some embodiments, the first plastic part 5 further comprises an extension part 503 connected to the outer ring of the first body part 501 and extending away from the third protruding ring 502, and the extension part 503 surrounds the outer circumferential side of the abutting section 2011, thereby further ensuring the insulation between the pole 2 and the top cover piece 1.

[0076] In some embodiments, further in combination Figure 4As shown, the total ring width of the sealing ring 4 is W2, and the ring width of the first ring part 401 is W3, wherein the relationship between W3 and W2 satisfies the formula: 1 / 3≤W3 / W2<1 / 2. It should be noted that the total ring width of the sealing ring 4 refers to the distance between the inner ring and the outer ring of the sealing ring 4, that is, the distance between the inner ring of the first ring part 401 and the outer ring of the third ring part 403; the ring width of the first ring part 401 refers to the distance between the inner ring and the outer ring of the first ring part 401. If W3 / W2 is less than 1 / 3, the portion of the sealing ring 4 compressed between the connecting piece 3 and the first column part 201 is too small, the sealing performance at this position is poor, and liquid leakage is prone to occur; if W3 / W2 is greater than or equal to 1 / 2, the portion of the sealing ring 4 compressed between the connecting piece 3 and the first column part 201 is too much, and correspondingly, the ring width of the third ring part 403 is too small, and the sealing performance of the portion of the sealing ring 4 compressed between the connecting piece 3 and the top cover piece 1 is poor.

[0077] Therefore, by setting W3 / W2 to be greater than or equal to 1 / 3 and less than 1 / 2, the sealing performance of the portion of the sealing ring 4 compressed between the connecting piece 3 and the first column part 201 can be guaranteed, and the sealing performance of the portion of the sealing ring 4 compressed between the connecting piece 3 and the top cover piece 1 can also be guaranteed, thereby improving the overall sealing performance and avoiding liquid leakage of the battery cell.

[0078] In some embodiments, the ring width W3 of the first ring part 401 is in the range of 1.2mm≤W3≤1.8mm, so as to ensure that the first ring part 401 has a reasonable ring width. Optionally, W3 is 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm or 1.8mm, etc. Preferably, W3 is 1.2mm.

[0079] In some embodiments, the ring width of the third ring part 403 is W4, and the relationship between W4 and W2 satisfies the formula: 1 / 3≤W4 / W2<1 / 2. The ring width of the third ring part 403 refers to the distance between the inner ring and the outer ring of the third ring part 403, if W4 / W2 is less than 1 / 3, the portion of the sealing ring 4 compressed between the connecting piece 3 and the top cover piece 1 is too small, and the sealing performance at this position is poor; if W4 / W2 is greater than or equal to 1 / 2, the portion of the sealing ring 4 compressed between the connecting piece 3 and the first column part 201 is too small, and the sealing performance at this position is poor. Therefore, by setting W4 / W2 to be greater than or equal to 1 / 3 and less than 1 / 2, the sealing performance of the portion of the sealing ring 4 compressed between the connecting piece 3 and the top cover piece 1 can be guaranteed, and the sealing performance of the portion of the sealing ring 4 compressed between the connecting piece 3 and the first column part 201 can also be guaranteed, thereby improving the overall sealing performance and avoiding liquid leakage of the battery cell.

[0080] In some embodiments, W4 is greater than or equal to 1.0 mm. If W4 is less than 1.0 mm, the ring width of the third ring portion 403 is too small, and the portion of the sealing ring 4 compressed between the connecting tab 3 and the top cover tab 1 is too small, and the sealing performance of the portion is poor. Therefore, by limiting the ring width W4 of the third ring portion 403 to be greater than or equal to 1.0 mm, the sealing performance of the portion of the sealing ring 4 compressed between the connecting tab 3 and the top cover tab 1 can be ensured, thereby avoiding liquid leakage from the liquid leakage path E1 and improving the safety of the battery cell.

[0081] The cover plate assembly of the embodiment can ensure that leaked laser light does not damage the sealing ring 4 when the pole post 2 and the connecting tab 3 are laser welded, by adding the first protruding ring 203 spaced from the second post portion 202 on the pole post 2, and inserting the second protruding ring on the connecting tab 3 into the first ring groove 204 between the second post portion 202 and the first protruding ring 203.

[0082] The cover plate assembly of the embodiment forms dynamic sealing by the planar region of the connecting tab 3 and the third ring portion 403 of the sealing ring 4 extruding the top cover tab 1, and forms static sealing by the planar region of the connecting tab 3 and the first ring portion 401 of the sealing ring 4 extruding the first post portion 201 of the pole post 2, thereby reducing the manufacturing precision of the tab body 303 height. By setting the connecting tab 3 and the pole post 2 to be clearance-fitted along the axial direction of the pole post 2, the performance of the static sealing and the dynamic sealing can be ensured to meet the requirements. Moreover, the sealing is performed by using the planar region of the connecting tab 3 to compress the sealing ring 4, thereby reducing the manufacturing difficulty of the tab body 303 height of the connecting tab 3. When the cover plate assembly is subjected to the gas pressure inside the battery cell, the tab body 303 region is limited by the first protruding ring 203 of the pole post 2 and is less likely to be deformed by being stretched, so that the requirement for the welding penetration depth can be reduced.

[0083] According to the embodiments of the utility model, on the other hand, a battery cell is also provided, which comprises a shell, a pole group and the above-mentioned cover plate assembly. The shell has an open end; the pole group is arranged in the shell; and the cover plate assembly is arranged on the open end of the shell.

[0084] Although the embodiments of the utility model have been described in conjunction with the drawings, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that, include: The top cover plate (1) has an electrode post hole (101); The pole post (2) is inserted into the pole post hole (101). The pole post (2) includes a first column portion (201) and a second column portion (202) connected along the axial direction. The cross-sectional area of ​​the first column portion (201) is larger than the cross-sectional area of ​​the second column portion (202). A first convex ring (203) is provided on the first column portion (201) near the second column portion (202) and surrounds the second column portion (202). The first convex ring (203) and the second column portion (202) are arranged radially spaced. A connecting piece (3) is disposed on one side of the top cover piece (1). The connecting piece (3) includes a connecting hole (301) and a second protruding ring (302). The second protruding ring (302) is disposed around the connecting hole (301). The second post (202) is inserted into the connecting hole (301). The second protruding ring (302) is inserted between the first protruding ring (203) and the second post (202). The sealing ring (4) is sleeved on the outer periphery of the first convex ring (203) and is located between the connecting piece (3) and the top cover piece (1), and between the connecting piece (3) and the first column (201).

2. The cover plate assembly according to claim 1, characterized in that, Along the thickness direction of the cover plate assembly, the pole post (2) and the connecting piece (3) are in clearance fit.

3. The cover plate assembly according to claim 2, characterized in that, The fitting gap between the pole post (2) and the connecting piece (3) is t, where 0 < t ≤ 0.125 mm.

4. The cover plate assembly according to claim 1, characterized in that, The connecting piece (3) also includes a piece body (303), and the second protruding ring (302) is connected to the piece body (303). The second protruding ring (302) is disposed on the side of the piece body (303) facing the top cover piece (1), and the second protruding ring (302) is formed by protruding from the edge of the connecting hole (301).

5. The cover plate assembly according to claim 1, characterized in that, The dimension of the first convex ring (203) along the axial direction of the pole post (2) is H1, wherein the value of H1 is in the range of 0.3mm≤H1≤1mm; And / or, the ring width of the first convex ring (203) is W1, wherein the value of W1 is in the range of 0.5mm≤W1≤1.5mm.

6. The cover plate assembly according to any one of claims 1 to 5, characterized in that, The first column (201) includes an abutment section (2011) and an insertion section (2012) connected along the axial direction. The cross-sectional area of ​​the abutment section (2011) is larger than that of the insertion section (2012). The insertion section (2012) passes through the pole hole (101). The abutment section (2011) is located on the side of the top cover plate (1) away from the connecting piece (3). The second column (202) is connected to the end of the insertion section (2012) away from the abutment section (2011).

7. The cover plate assembly according to claim 6, characterized in that, The cover plate assembly further includes: a first plastic part (5) and a second plastic part (6); The first plastic part (5) includes a first main body (501), which is annular and disposed between the lower surface of the abutment section (2011) and the top cover (1). The thickness of the first main body (501) is t1, and the manufacturing tolerance of the first main body (501) is Δt1. The second plastic part (6) includes a second main body (601), which is disposed between the connecting piece (3) and the top cover piece (1). The thickness of the second main body (601) is t3, and the manufacturing tolerance of the second main body (601) is Δt3. The thickness of the portion of the top cover (1) located between the first main body (501) and the second plastic part (6) is t2, and the manufacturing tolerance is Δt2; in, 8. The cover plate assembly according to claim 7, characterized in that, The first plastic part (5) further includes a third protruding ring (502), which is connected to the inner ring of the first main body (501) and is located between the insertion section (2012) and the inner wall of the pole hole (101). The sealing ring (4) has a first ring portion (401), a second ring portion (402) and a third ring portion (403) in sequence along the direction from its inner ring to its outer ring. The first ring portion (401) is compressed between the connecting piece (3) and the first post portion (201). The second ring portion (402) is correspondingly provided with the third convex ring (502). The third ring portion (403) is compressed between the connecting piece (3) and the top cover piece (1).

9. The cover plate assembly according to claim 8, characterized in that, The total circumferential width of the sealing ring (4) is W2; The ring width of the first ring (401) is W3, wherein W3 and W2 satisfy the relationship: 1 / 3≤W3 / W2<1 / 2; And / or, the ring width of the third ring (403) is W4, and W4 and W2 satisfy the relationship: 1 / 3≤W4 / W2<1 / 2.

10. A battery cell, characterized in that, include: The shell has an open end; The electrode assembly is disposed within the housing; The cover assembly according to any one of claims 1 to 9, wherein the cover assembly covers the opening end of the housing.

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