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 cover plate provided with a through hole; the pole assemblies are respectively arranged at the through holes of the positive electrode and the negative electrode, each pole assembly comprises a connecting piece, a pole and a sealing assembly, the connecting piece is provided with a connecting hole and is positioned below the cover plate, the pole comprises a first pole section, a second pole section and a third pole section which are different in outer diameter from top to bottom, the pole penetrates through the through hole, and the outer wall of the third pole section is connected with the inner wall of the connecting hole; the pole and the connecting hole are respectively abutted against and matched with the cover plate through a sealing assembly; the outer wall of the third column section is connected with the inner wall of the connecting hole in a welded mode, the connecting face is the annular face, and when the third column section and the connecting hole are vertically staggered due to errors in the assembling process, stable connection of the third column section and the connecting hole can still be guaranteed. And stable and effective sealing can be carried out at the intersection position of the two liquid leakage paths, so that the liquid leakage risk at the pole is reduced.

Description

Technical Field

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

[0002] With the rapid development of new energy technologies, power batteries, due to their excellent properties, have been widely used in various fields. Safety during the use of power batteries is an important indicator. Power batteries must not only have high capacity but also good safety. The cover plate assembly is a key component of the power battery cell, and its reliability directly affects the normal use of the cell.

[0003] At present, the existing cover plate assembly usually includes a cover plate, a pole and a connecting plate. Through holes are opened on the cover plate at the positions corresponding to the positive and negative poles. The lower end face of the pole and the upper end face of the connecting plate respectively form connecting surfaces. After the corresponding pole passes through the through hole, it is welded and fixed by its own connecting surface and the connecting surface of the connecting plate. Since assembly errors are inevitable in the assembly process of the cover plate assembly, the connection method of the pole and the connecting plate of this type of cover plate assembly has poor reliability, and gaps are easily generated between the lower end face of the pole and the upper end face of the connecting plate, which poses a safety risk. Utility Model Content

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

[0005] In the first aspect, the utility model provides a cover plate assembly, comprising: a cover plate, which is respectively provided with through holes corresponding to the positive pole and the negative pole; a pole assembly, which is respectively arranged at the through holes of the positive pole and the negative pole, the pole assembly comprising a connecting piece, a pole and a sealing assembly, the connecting piece having a connecting hole and being located below the cover plate, the pole comprising a first pole segment, a second pole segment and a third pole segment with different outer diameters from top to bottom, the pole passing through the through hole, the outer wall of the third pole segment being connected to the inner wall of the connecting hole, the sealing assembly being located between the pole and the through hole, the pole and the connecting hole being respectively abutted and fitted with the cover plate through the sealing assembly.

[0006] Beneficial effects: A connecting hole is provided on the connecting piece, and the pole is welded to the inner wall of the connecting hole through the outer wall of its third column section. Since the connecting surface between the pole and the connecting hole is an annular surface extending in the up-down direction, when the two are dislocated up and down due to errors during assembly, this connection form can still ensure a stable connection between the pole and the connecting piece, and can avoid the phenomenon of separation of the pole and the connecting piece due to errors. In addition, the connecting piece and the multi-segment pole are respectively abutted against the cover plate through sealing rings to form a labyrinth-type sealing form, which can perform stable and effective sealing at the intersection of the two leakage paths, reducing the risk of leakage at the pole, and effectively solving the problem of poor reliability of the connection method between the pole and the connecting piece in the existing cover assembly.

[0007] In an optional embodiment, the outer diameters of the first column segment, the second column segment and the third column segment decrease successively, the connecting surface of the first column segment and the second column segment forms a first step surface, and the connecting surface of the second column segment and the third column segment forms a second step surface.

[0008] Beneficial effects: This type of pole is easy to process and can be directly positioned and matched with corresponding components through its own step surface, making it easy to install and position.

[0009] In an optional embodiment, the sealing assembly includes an upper plastic, a lower plastic and a sealing ring. The first step surface is abutted against the cover plate through the upper plastic, the connecting piece is abutted against the second step surface and the bottom surface of the cover plate through the sealing ring, and the lower plastic is located between the top surface of the connecting piece and the bottom surface of the cover plate.

[0010] Beneficial effects: This split-type sealing assembly has a simple structure and is easy to install and manufacture. The sealing ring is respectively abutted against the second step surface and the bottom surface of the cover plate through the connecting piece to form a double sealing form, which can perform stable and effective sealing at the intersection of the two leakage paths.

[0011] In an optional embodiment, the sealing ring is simultaneously in contact with the top surface of the connecting piece, the second step surface, the outer wall of the second column section, the upper plastic, the inner wall of the through hole, the bottom surface of the cover plate and the lower plastic.

[0012] Beneficial effect: This type of sealing ring abuts against multiple adjacent components and forms a reliable seal, which can effectively prevent leakage along the surface of the sealing ring and improve the sealing reliability.

[0013] In an optional embodiment, there is a gap between the inner ring of the sealing ring and the outer wall of the third column segment.

[0014] Beneficial effect: The gap can provide space for spatter particles during the welding process, preventing excessive particles from falling onto the outer wall of the sealing ring and damaging it, thereby improving the stability and reliability of the welding process between the pole and the connecting piece.

[0015] In an alternative embodiment, the bottom of the third column segment is formed with a groove from bottom to top.

[0016] Beneficial effect: this form of third column segment meets the connection function while effectively reducing the weight of the pole.

[0017] In an alternative embodiment, the through hole is sequentially formed with a first hole segment and a second hole segment from top to bottom, the inner diameter of the first hole segment is larger than that of the second hole segment, the connecting surface of the first hole segment and the second hole segment forms a matching surface, the stepped surface is abutted and matched with the matching surface through the sealing ring, and the cover plate is abutted and matched with the inner wall of the first hole segment through the upper plastic.

[0018] Beneficial effect: this form of through hole is more convenient for the installation of the pole, the first hole segment can conveniently position the radial position of the pole, and in addition, this form of through hole has more contact surfaces with the upper plastic, so that the local sealing and insulation reliability are higher.

[0019] In an alternative embodiment, the upper plastic includes a first ring segment, a second ring segment and a third ring segment sequentially connected from top to bottom, the first ring segment is located between the outer wall of the first column segment and the inner wall of the first hole segment, the second ring segment is located between the first stepped surface and the matching surface, and the third ring segment is located between the outer wall of the second column segment and the inner wall of the through hole.

[0020] Beneficial effect: this form of upper plastic can effectively limit the upward movement trend of the sealing ring along the axial direction.

[0021] In an alternative embodiment, the ratio of the minimum height of the compressed sealing ring to the height before compression is in the range of 0.225 to 0.45, and / or the pole of the pole assembly corresponding to the negative electrode is a negative pole, the negative pole is sequentially formed with a first metal layer and a second metal layer from top to bottom, the first metal layer forms the first column segment, and the second metal layer forms the second column segment and the third column segment.

[0022] Beneficial effect: this form of sealing ring has more stable and reliable sealing effect, since the sealing ring is located at the intersection of the two liquid leakage paths, the leaked liquid can only contact the second metal layer, and there is no risk of electrolytic reaction with the first metal layer and the second metal layer at the same time, so this form of negative pole can meet the use requirements, and the structure is simple and reliable, facilitating processing and manufacturing.

[0023] In a second aspect, the utility model also provides a kind of electric core assembly, it includes: shell, inside has accommodating cavity and top has opening;Electric core is set in accommodating cavity and has tab;Above-mentioned cover plate assembly is set in the top of shell and is used to block accommodating cavity, and the connecting sheet of cover plate assembly is connected with corresponding tab respectively. BRIEF DESCRIPTION OF DRAWINGS

[0024] 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.

[0025] Figure 1 This is a top view of a cover plate assembly according to an embodiment of the present utility model;

[0026] Figure 2 for Figure 1 A schematic cross-sectional view of the positive electrode of the cover plate assembly shown;

[0027] Figure 3 for Figure 2 A cross-sectional view showing a partial location of the cover assembly;

[0028] Figure 4 for Figure 1 A schematic cross-sectional view of the negative electrode of the cover plate assembly shown;

[0029] Figure 5 for Figure 4 A cross-sectional view of a portion of the cover assembly is shown.

[0030] Description of reference numerals:

[0031] 1. Cover plate; 101. Through hole; 1011. First hole section; 1012. Second hole section; 1013. Mating surface;

[0032] 2. Connecting piece; 201. Connecting hole;

[0033] 3. Pole; 301. First column segment; 302. Second column segment; 303. Third column segment; 304. First step surface; 305. Second step surface; 306. First metal layer; 307. Second metal layer; 308. Groove; 309. Avoidance space;

[0034] 4. Upper plastic; 5. Lower plastic; 6. Sealing ring; 7. Explosion-proof valve; 8. Liquid filling port. DETAILED DESCRIPTION

[0035] 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.

[0036] The following combination Figures 1 to 5 , describing the embodiments of the present utility model.

[0037] According to an embodiment of the present utility model, on the one hand, a cover plate assembly is provided, including: a cover plate 1 and a pole assembly, the cover plate 1 is respectively provided with through holes 101 corresponding to the positive pole and the negative pole, the pole assembly is respectively arranged at the through holes 101 of the positive pole and the negative pole, the pole assembly includes a connecting piece 2, a pole 3 and a sealing assembly, the connecting piece 2 has a connecting hole 201 and is located below the cover plate 1, the pole 3 includes a first column segment 301, a second column segment 302 and a third column segment 303 with different outer diameters from top to bottom, the pole 3 is passed through the through hole 101, the outer wall of the third column segment 303 is connected to the inner wall of the connecting hole 201, the sealing assembly is located between the pole 3 and the through hole 101, and the pole 3 and the connecting hole 201 are respectively abutted and matched with the cover plate 1 through the sealing assembly.

[0038] In the related art, since the pole is usually fixed by welding its own lower end surface to the upper end surface of the connecting piece, the leakage path of this type of cover assembly mainly exists between the lower plastic and the pole piece. Therefore, a sealing ring is usually set between the upper end surface of the connecting piece and the lower end surface of the cover. This sealing form is difficult to effectively seal the cover assembly in this embodiment.

[0039] In this embodiment, since the connection surface between the pole 3 and the connection hole 201 is an annular surface extending in the up-down direction, there is also a certain risk of leakage at this annular surface. Therefore, in this embodiment, there is not only a leakage path between the lower plastic and the pole piece at the position of the pole 3, but also a leakage path at the annular surface.

[0040] The cover plate assembly of this embodiment is used, and a connecting hole 201 is provided on the connecting piece 2. The pole 3 is welded to the inner wall of the connecting hole 201 through the outer wall of its own third column segment 303. Since the connection surface between the pole 3 and the connecting hole 201 is an annular surface extending in the up-down direction, when the two are misaligned up and down due to errors during assembly, this connection form can still ensure the stable connection between the pole 3 and the connecting piece 2, and can avoid the phenomenon of separation of the pole 3 and the connecting piece 2 due to errors. In addition, the connecting piece 2 and the multi-segment pole 3 are respectively abutted and matched with the cover plate 1 through the sealing ring 6 to form a labyrinth-type sealing form, which can perform stable and effective sealing at the intersection of the two leakage paths, reducing the risk of leakage at the pole 3, and effectively solving the problem of poor reliability of the connection method between the pole and the connecting piece in the existing cover plate assembly.

[0041] Among them, the above refers to Figure 3 The arrow in the middle points to the "up" direction, and the arrow below points to the Figure 3 The arrow in the middle points to the "down" direction.

[0042] In one possible embodiment, the outer diameters of the first column segment 301, the second column segment 302, and the third column segment 303 decrease successively. The connecting surface of the first column segment 301 and the second column segment 302 forms a first step surface 304, and the connecting surface of the second column segment 302 and the third column segment 303 forms a second step surface 305. This type of pole 3 is easy to process and can also be directly positioned and matched with corresponding components through its own step surface, which facilitates installation and positioning.

[0043] It can be understood that, as an alternative embodiment, the outer diameters of the second column segment 302 and the third column segment 303 can be equal or increase successively.

[0044] In one possible embodiment, the sealing assembly includes an upper plastic 4, a lower plastic 5 and a sealing ring 6. The first step surface 304 is abutted against the cover plate 1 through the upper plastic 4, and the connecting piece 2 is abutted against the second step surface 305 and the bottom surface of the cover plate 1 through the sealing ring 6. The lower plastic 5 is located between the top surface of the connecting piece 2 and the bottom surface of the cover plate 1. This split-form sealing assembly has a simple structure and is easy to install and manufacture. The sealing ring 6 is abutted against the second step surface 305 and the bottom surface of the cover plate 1 through the connecting piece 2, forming a double sealing form, which can perform stable and effective sealing at the intersection of the two leakage paths.

[0045] Specifically, if Figure 2 As shown, the second column segment 302 and the third column segment 303 of the pole 3 pass through the through hole 101 , and the first column segment 301 is positioned and matched with the upper portion of the cover plate 1 .

[0046] In one possible embodiment, the sealing ring 6 is simultaneously in contact with the top surface of the connecting piece 2, the second step surface 305, the outer wall of the second column section 302, the upper plastic 4, the inner wall of the through hole 101, the bottom surface of the cover plate 1 and the lower plastic 5. This type of sealing ring 6 abuts against multiple adjacent components and forms a reliable seal, which can effectively prevent liquid from leaking along the surface of the sealing ring 6 and improve the sealing reliability.

[0047] Specifically, if Figure 2 and Figure 3 As shown, a portion of the sealing ring 6 is squeezed into between the outer wall of the second column section 302 and the inner wall of the through hole 101, and abuts against the upper plastic 4. This type of sealing ring 6 can effectively fit tightly with the surrounding outer wall.

[0048] In a possible implementation, a gap is provided between the inner circle of the sealing ring 6 and the outer wall of the third column segment 303, which can provide space for the splashing particles during the welding process of the joint between the third column segment 303 and the connecting plate 2, so as to prevent too many particles from falling on the outer wall of the sealing ring 6 during the welding process and causing damage to the outer wall of the sealing ring 6, and to improve the stability and reliability of the welding process of the pole 3 and the connecting plate 2.

[0049] In the third column segment 303, the outer diameter of the third column segment 303 is smaller than the outer diameter of the second column segment 302, and the inner diameter of the lower plastic 5 is greater than or equal to the outer diameter of the second column segment 302. The connecting surface between the third column segment 303 and the second column segment 302, the outer wall of the third column segment 303, the top surface of the connecting plate 2, and the inner wall surface of the lower plastic 5 form an avoiding space 309.

[0050] Specifically, the connecting surface between the second column segment 302 and the third column segment 303 can be a curved surface with waves, or a ring-shaped plane, which can be selected according to the convenience of the manufacturing process.

[0051] Preferably, as shown in Figure 4 , the connecting surface between the second column segment 302 and the third column segment 303 is a ring-shaped plane.

[0052] In a possible implementation, the bottom of the third column segment 303 is formed with a groove 308 from bottom to top. The third column segment 303 in this form can meet the connection function while effectively reducing the weight of the pole 3.

[0053] In the third column segment 303, the outer diameter of the third column segment 303 is smaller than the outer diameter of the second column segment 302, and the inner diameter of the lower plastic 5 is greater than or equal to the outer diameter of the second column segment 302. The connecting surface between the third column segment 303 and the second column segment 302, the outer wall of the third column segment 303, the top surface of the connecting plate 2, and the inner wall surface of the lower plastic 5 form an avoiding space 309. Figure 2 Figure 4 In the third column segment 303, the outer diameter of the third column segment 303 is smaller than the outer diameter of the second column segment 302, and the inner diameter of the lower plastic 5 is greater than or equal to the outer diameter of the second column segment 302. The connecting surface between the third column segment 303 and the second column segment 302, the outer wall of the third column segment 303, the top surface of the connecting plate 2, and the inner wall surface of the lower plastic 5 form an avoiding space 309.

[0054] In a possible implementation, the wall thickness of the third column segment 303 corresponding to the negative electrode is greater than or equal to 1.05 mm, and / or the wall thickness of the third column segment 303 corresponding to the positive electrode is greater than or equal to 1.1 mm. The third column segment 303 in this form can meet the structural strength requirement while also being able to guarantee the current passing capacity.

[0055] ​In a possible implementation, the through hole 101 sequentially comprises a first hole section 1011 and a second hole section 1012 from top to bottom, the inner diameter of the first hole section 1011 is greater than that of the second hole section 1012, the connecting surface of the first hole section 1011 and the second hole section 1012 forms a matching surface 1013, the stepped surface is abutted and matched with the matching surface 1013 through the sealing ring 6, and the cover plate 1 is abutted and matched with the inner wall of the first hole section 1011 through the upper plastic 4. The through hole 101 in this form is more convenient for the installation of the pole 3, the first hole section 1011 can conveniently position the radial position of the pole 3, and in addition, the through hole 101 in this form has more contact surfaces with the upper plastic 4, so that the local sealing and insulation reliability is higher.

[0056] In a possible implementation, as shown in Figure 3 and Figure 5 , the upper plastic 4 comprises a first ring section, a second ring section and a third ring section connected in sequence from top to bottom, the first ring section is located between the outer wall of the first column section 301 and the inner wall of the first hole section 1011, the second ring section is located between the first stepped surface 304 and the matching surface 1013, and the third ring section is located between the outer wall of the second column section 302 and the inner wall of the through hole 101. The upper plastic 4 in this form can effectively limit the upward movement trend of the sealing ring 6 along the axial direction.

[0057] In a possible implementation, the ratio of the minimum height of the sealing ring 6 after compression to the height before compression ranges from 0.225 to 0.45. The sealing effect of the sealing ring 6 in this form is more stable and reliable.

[0058] In a possible implementation, the pole 3 of the pole assembly corresponding to the negative electrode is a negative pole, the negative pole sequentially comprises a first metal layer 306 and a second metal layer 307 from top to bottom, the first metal layer 306 forms the first column section 301, and the second metal layer 307 forms the second column section 302 and the third column section 303. Since the sealing ring 6 is located at the intersection of the two liquid leakage paths, the leaked liquid can only contact the second metal layer 307, and there is no risk of electrolytic reaction with the first metal layer 306 and the second metal layer 307 at the same time. Therefore, the negative pole in this form can meet the use requirements, and the structure is simple and reliable, facilitating processing and manufacturing.

[0059] Specifically, the specific materials of the first metal layer 306 and the second metal layer 307 are not strictly limited here, and can be selected according to the existing materials of the negative pole.

[0060] Preferably, the pole 3 of the pole assembly corresponding to the positive electrode is a positive pole, and the positive pole and the negative pole both form a basic structure through 90° bending and hole shrinking of corresponding conductive plates, and are formed after removing the external excess material.

[0061] Furthermore, the upper plastic 4 corresponding to the positive electrode is a weak conductor or an insulating member, and the upper plastic 4 corresponding to the negative electrode is an insulating member.

[0062] In one possible implementation, Figure 1 As shown, the cover assembly also includes an explosion-proof valve 7 and a liquid injection port 8. The liquid injection port 8 is located on the cover 1. The cover 1 is provided with a mounting groove for installing the explosion-proof valve 7, wherein the explosion-proof valve 7 includes a valve body located in the mounting groove and an explosion-proof membrane covering the opening of the mounting groove.

[0063] According to an embodiment of the present invention, on the other hand, a battery cell assembly is provided, which includes: a shell, a battery cell and the above-mentioned cover assembly, the shell has a accommodating cavity inside and an opening at the top, the battery cell is arranged in the accommodating cavity and has a pole ear, the cover assembly is arranged on the top of the shell and is used to seal the accommodating cavity, and the connecting pieces 2 of the cover assembly are respectively connected to the corresponding pole ears.

[0064] 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 assembly, characterized in that: include: The cover plate (1) is provided with through holes (101) corresponding to the positive electrode and the negative electrode respectively; A pole assembly is provided at the through hole (101) of the positive pole and the negative pole, respectively. The pole assembly comprises a connecting piece (2), a pole (3) and a sealing assembly. The connecting piece (2) has a connecting hole (201) and is located below the cover plate (1). The pole (3) comprises, from top to bottom, a first pole section (301), a second pole section (302) and a third pole section (303) with different outer diameters. The pole (3) is passed through the through hole (101). The outer wall of the third pole section (303) is connected to the inner wall of the connecting hole (201). The sealing assembly is located between the pole (3) and the through hole (101). The pole (3) and the connecting hole (201) are respectively abutted and matched with the cover plate (1) through the sealing assembly.

2. The cover plate assembly according to claim 1, wherein: The outer diameters of the first column segment (301), the second column segment (302) and the third column segment (303) decrease successively; the connecting surface of the first column segment (301) and the second column segment (302) forms a first step surface (304); and the connecting surface of the second column segment (302) and the third column segment (303) forms a second step surface (305).

3. The cover plate assembly according to claim 2, wherein: The sealing assembly comprises an upper plastic (4), a lower plastic (5) and a sealing ring (6); the first step surface (304) is in contact with the cover plate (1) through the upper plastic (4); the connecting piece (2) is in contact with the second step surface (305) and the bottom surface of the cover plate (1) through the sealing ring (6); and the lower plastic (5) is located between the top surface of the connecting piece (2) and the bottom surface of the cover plate (1).

4. The cover plate assembly according to claim 3, wherein: The sealing ring (6) is simultaneously in contact with the top surface of the connecting piece (2), the second step surface (305), the outer wall of the second column section (302), the upper plastic (4), the inner wall of the through hole (101), the bottom surface of the cover plate (1) and the lower plastic (5).

5. The cover plate assembly according to claim 3, wherein: There is a gap between the inner ring of the sealing ring (6) and the outer wall of the third column section (303).

6. The cover plate assembly according to any one of claims 1 to 5, characterized in that: A groove (308) is formed at the bottom of the third column section (303) from bottom to top.

7. The cover plate assembly according to any one of claims 3 to 5, characterized in that: The through hole (101) is composed of a first hole section (1011) and a second hole section (1012) from top to bottom. The inner diameter of the first hole section (1011) is larger than the inner diameter of the second hole section (1012). The connecting surfaces of the first hole section (1011) and the second hole section (1012) form a mating surface (1013). The first step surface (304) is in contact with the mating surface (1013) through the sealing ring (6). The cover plate (1) is in contact with the inner wall of the first hole section (1011) through the upper plastic (4).

8. The cover plate assembly according to claim 7, wherein: The upper plastic (4) comprises a first ring segment, a second ring segment and a third ring segment connected in sequence from top to bottom, wherein the first ring segment is located between the outer wall of the first column segment (301) and the inner wall of the first hole segment (1011), the second ring segment is located between the first step surface (304) and the matching surface (1013), and the third ring segment is located between the outer wall of the second column segment (302) and the inner wall of the through hole (101).

9. The cover plate assembly according to any one of claims 3 to 5, characterized in that: The ratio of the minimum height of the sealing ring (6) after compression to the height before compression ranges from 0.225 to 0.

45. And / or, the pole (3) of the pole assembly corresponding to the negative pole is a negative pole, and the negative pole comprises, from top to bottom, a first metal layer (306) and a second metal layer (307), the first metal layer (306) forming the first pole segment (301), and the second metal layer (307) forming the second pole segment (302) and the third pole segment (303).

10. A battery cell assembly, characterized in that: include: A shell having an accommodating cavity inside and an opening at the top; A battery cell, disposed in the accommodating cavity and having a tab; The cover plate assembly according to any one of claims 1 to 9 is provided on the top of the shell and is used to seal the accommodating cavity, and the connecting pieces (2) of the cover plate assembly are respectively connected to the corresponding tabs.

Images