Battery pack and battery cell

Abstract

The utility model discloses a kind of battery monomer, including shell and cover plate, mounting hole is provided on the cover plate, pole is provided at mounting hole, the pole includes the first pole part and the second pole part connected together, the first pole part is installed in the outside of the cover plate, the position for connecting the second pole part is provided with placement slot in the first pole part, the second pole part includes connecting portion, the connecting portion is welded in the placement slot, and weld is formed in the welding position, the height of the weld is H, width is W;The edge of the connecting portion and the interval distance of the slot side wall of the placement slot are L, the range of L / (W*H) is 0.1-18.The battery monomer of the utility model guarantees the safe and reliable connection of pole and aluminum row, and the sealing reliability of the contact surface of pole and cover plate is better.The utility model further provides a kind of battery pack.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery pack and a battery cell. Background Technology

[0002] In the field of electric vehicles, the battery is the power source and energy storage and supply device for the vehicle. A battery includes a battery casing and multiple individual battery cells housed within it. Each battery cell includes a casing and a cover, with terminals located on the cover. (See reference...) Figure 1 The pole includes a first pole part 02 and a second pole part 01. The second pole part 01 is welded to the first pole part 02. The first pole part 02 is installed at the pole mounting hole position of the cover plate 03.

[0003] In the prior art, the second pole post 01 is welded to the upper surface of the first pole post 02. During welding, due to the influence of welding stress, the edge of the first pole post 02 away from the second pole post 01 is prone to warping, which will affect the electrical connection between the subsequent pole post and the aluminum busbar, and also affect the sealing performance of the installation position of the first pole post 02 and the cover plate 03. Utility Model Content

[0004] In view of this, the present invention provides a battery cell that reduces the transmission of welding stress to the edge of the terminal post, reduces the deformation of the terminal post edge caused by welding, avoids the impact of the edge deformation of the terminal post on the connection between the terminal post and the aluminum busbar, and improves the sealing reliability of the contact surface between the terminal post and the cover plate.

[0005] This utility model also provides a battery pack.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A battery cell includes a casing and a cover plate. The cover plate has mounting holes, and a terminal post is provided at the mounting holes. The terminal post includes a first terminal post portion and a second terminal post portion connected together. The first terminal post portion is installed on the outside of the cover plate. A placement groove is provided at the position where the first terminal post portion connects to the second terminal post portion. The second terminal post portion includes a connecting portion. The connecting portion is welded into the placement groove, and a weld is formed at the welding position. The height of the weld is H and the width is W. The distance between the edge of the connecting portion and the sidewall of the placement groove is L, and the range of L / (W*H) is 0.1-18.

[0008] As can be seen from the above technical solution, the battery cell provided by this utility model, by setting a gap L between the welding position of the connecting part and the side wall of the placement groove, avoids the direct transmission of welding stress to the edge of the electrode post, reducing the impact of welding stress on the edge shape of the electrode post; at the same time, by limiting the width of the gap and the parameters of the weld at the welding position, the width of the gap can be adjusted according to the changes in the weld parameters, ensuring welding quality while reducing the transmission of welding stress to the edge of the electrode post, minimizing the edge deformation of the first electrode post caused by welding, thereby avoiding the edge deformation of the first electrode post from affecting the electrical connection between the electrode post and the aluminum busbar. By reducing the edge deformation of the first electrode post, the sealing reliability of the contact surface between the first electrode post and the cover plate is better, improving the sealing performance of the battery cell.

[0009] This utility model also provides a battery pack, including a plurality of battery cells, wherein the battery cells are those described above.

[0010] The battery pack of this utility model includes the aforementioned battery cells, and therefore has the advantages of the aforementioned battery cells, which will not be repeated here. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the connection structure between the first pole piece and the second pole piece in the prior art;

[0013] Figure 2 A schematic diagram of the structure of a single battery cell from one angle provided in an embodiment of this utility model;

[0014] Figure 3 This is a structural schematic diagram of a battery cell from another angle provided in an embodiment of the present invention;

[0015] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure at position AA in the middle;

[0016] Figure 5 for Figure 4 A partially enlarged structural diagram of part B in the diagram;

[0017] Figure 6 A partial cross-sectional view of the mounting hole location on the cover plate provided in an embodiment of this utility model;

[0018] Figure 7 A cross-sectional structural schematic diagram of the welding positions of the first pole post and the second pole post provided in an embodiment of this utility model;

[0019] Figure 8 A schematic diagram of the structure of the first pole post provided in an embodiment of this utility model;

[0020] Figure 9 A cross-sectional view of the CC position of the first pole piece provided in an embodiment of this utility model;

[0021] Figure 10 A cross-sectional structural schematic diagram of the welding positions of the first pole post and the second pole post provided in another embodiment of the present utility model;

[0022] Figure 11 A cross-sectional structural schematic diagram of the welding positions of the first pole post and the second pole post provided in another embodiment of the present utility model;

[0023] Figure 12 A cross-sectional structural schematic diagram of the welding positions of the first pole post and the second pole post provided in the fourth embodiment of this utility model;

[0024] Figure 13 A cross-sectional structural schematic diagram of the welding positions of the first pole post and the second pole post provided in the fifth embodiment of this utility model;

[0025] Figure 14 This is a cross-sectional structural diagram showing the welding positions of the first pole post and the second pole post provided in the sixth embodiment of this utility model.

[0026] in:

[0027] 01. Second pole piece, 02. First pole piece, 03. Cover plate.

[0028] 1. Cover plate,

[0029] 101. Mounting holes

[0030] 2. Pole post,

[0031] 201. First pole post; 2011. Placement groove; 2012. Through hole; 2013. Stress buffer groove; 2014. Groove sidewall; 202. Second pole post; 2021. Connecting part.

[0032] 3. Shell,

[0033] 4. Insulating sleeve,

[0034] 5. Sealing ring,

[0035] 6. Welds. Detailed Implementation

[0036] This utility model discloses a battery cell that reduces the transmission of welding stress to the edge of the terminal post, reduces the deformation of the terminal post edge caused by welding, avoids the impact of the edge deformation of the terminal post on the connection between the terminal post and the aluminum busbar, and improves the sealing reliability of the contact surface between the terminal post and the cover plate.

[0037] This utility model also discloses a battery pack.

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this embodiment is not limited to this. A battery cell typically includes a battery casing, a cell, an adapter plate, and an electrolyte. The battery casing is used to house the cell and electrolyte, and generally includes a casing body and a cover plate. At least one positive electrode post and at least one negative electrode post are disposed on the casing and / or the cover plate. The cell includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and a separator. The separator is located between adjacent positive and negative electrode plates to insulate them. At least one end of the electrode assembly has a tab, and one end of the adapter plate is electrically connected to the tab, and the other end is electrically connected to the electrode post.

[0040] See Figures 1 to 9 The battery cell of this utility model includes a housing 3 and a cover plate 1. The housing 3 includes a receiving chamber, and the cover plate 1 is connected to the top of the housing 3 to seal the receiving chamber. The cover plate 1 has a mounting hole 101, and a terminal post 2 is provided at the mounting hole 101, passing through the mounting hole 101. The terminal post 2 includes a first terminal post portion 201 and a second terminal post portion 202 connected together. The first terminal post portion 201 is installed on the outside of the cover plate 1, and the second terminal post portion 202 passes through the mounting hole 101. A placement groove 2011 is provided at the position where the first terminal post portion 201 connects to the second terminal post portion 202. The second terminal post portion 202 includes a connecting portion 2021, which is welded to the placement groove 2011 by a weld 6. The receiving chamber is used to accommodate the battery cell assembly. The weld 6 may or may not cover the edge of the connecting portion 2021.

[0041] Wherein, the height of weld 6 is H and the width is W; the distance between the edge of the connecting part 2021 and the side wall 2014 of the placement groove 2011 is L, that is, there is a gap a between the edge of the connecting part 2021 and the side wall 2014 of the placement groove 2011, such as Figure 7 As shown, the range of L / (W*H) is 0.1-18. If the value of L / (W*H) is too large, it indicates that the distance L between the edge of the connecting part 2021 and the sidewall 2014 of the groove is too large, the weld 6 is too small, the welding quality of the first pole part 201 and the second pole part 202 is poor, and the connection is unreliable. If the value of L / (W*H) is too small, it indicates that the distance L between the edge of the connecting part 2021 and the sidewall 2014 of the groove is too small, that is, the gap is too small, more welding stress is transferred to the edge of the pole 2, and the edge of the pole 2 is prone to warping. Since the weld 6 is irregularly shaped when welded, and the weld 6 is set close to the edge of the connecting part 2021, the distance L between the edge of the connecting part 2021 and the sidewall 2014 of the groove (i.e., the width of the gap a) is regarded as the distance between the weld 6 and the sidewall 2014 of the groove. The height H of weld 6 is the total height of the material solidified after melting during welding, and the width W of weld 6 is the width of the weld (molten material) at the contact position between the connection part 2021 and the bottom surface of the placement groove 2011.

[0042] The battery cell of this invention establishes a gap a between the welding position of the connecting part 2021 and the side wall 2014 of the placement groove 2011, thus preventing welding stress from being directly transmitted to the edge of the electrode post 2 and reducing the impact of welding stress on the edge shape of the electrode post 2. Simultaneously, by comprehensively limiting the width of the gap a and the parameters of the weld 6 at the welding position, the width of the gap a is adjusted according to the changes in the parameters of the weld 6. This ensures welding quality while reducing the transmission of welding stress to the edge of the electrode post 2, minimizing edge deformation of the first electrode post 201 caused by welding. This prevents edge deformation of the first electrode post 201 from affecting the electrical connection between the electrode post 2 and the aluminum busbar. By reducing edge deformation of the first electrode post 201, the sealing reliability of the contact surface between the first electrode post 201 and the cover plate 1 is improved, thus enhancing the sealing performance of the battery cell.

[0043] Since the first pole piece 201 and the second pole piece 202 are laser welded, the weld seam 6 will protrude from the surface of the connecting part 2021. To avoid the protruding weld seam 6 affecting the electrical connection between the pole piece 2 and the aluminum busbar, the top surface of the connecting part 2021 is lower than the top surfaces of the first pole piece 201 and the second pole piece 202. Figure 7 As shown. The aforementioned top surfaces are the surfaces of the receiving chambers away from the housing 3. The first pole post 201 is disposed around the mounting hole 101.

[0044] Furthermore, the second pole post 202 also includes a main body, with a connecting portion 2021 disposed on the outer edge of the main body to facilitate welding of the second pole post 202 to the first pole post 201. The top surface of the main body is higher than the top surface of the connecting portion 2021, and the top surface of the main body is higher than the top surface of the first pole post 201, thereby facilitating the connection between the main body of the second pole post 202 and the aluminum busbar. To avoid affecting the main body of the second pole post 202 during laser welding, the weld 6 is disposed near the edge of the connecting portion 2021, such as... Figure 7 As shown in the image.

[0045] To reduce the impact of welding stress on the edge shape of the first pole post 201, and to prevent the weld 6 from protruding above the placement groove 2011 and affecting safe use, the depth of the placement groove 2011 is greater than the height of the weld 6. It is understandable that since part of the weld 6 is located in the connecting part 2021 and another part is located at the bottom of the placement groove 2011, the depth of the placement groove 2011 is greater than the height of the weld 6. This ensures that the weld 6 is below the top of the placement groove 2011, which is the top surface of the first pole post 201.

[0046] Specifically, the placement slot 2011 is positioned near the mounting hole 101, such as... Figure 5 As shown, the placement groove 2011 is arranged around the mounting hole 101. The placement groove 2011 includes a groove sidewall 2014 and a groove bottom surface connected together, and the groove sidewall 2014 is provided once, thus making the placement groove 2011 an L-shaped groove. The groove bottom surface is located at the position of the groove sidewall 2014 near the mounting hole 101, as shown. Figure 8 and Figure 9 As shown. In order to facilitate the second pole post 202 to pass through the mounting hole 101, a through hole 2012 is provided at the center of the first pole post 201. The through hole 2012 is provided corresponding to the mounting hole 101. The second pole post 202 is connected to the mounting hole 101 after passing through the through hole 2012.

[0047] To further improve the stress transmission from the welding of the connecting part 2021 and the first pole post 201 to the edge of the first pole post 201, a stress buffer groove 2013 is provided on the bottom surface of the placement groove 2011 between the edge of the connecting part 2021 and the groove sidewall 2014, such as... Figures 10 to 12 As shown. By setting a stress buffer groove 2013 on the bottom surface of the placement groove 2011, the transmission of welding stress during partial welding of the weld 6 on the first pole post 201 can be effectively interrupted, thereby avoiding edge deformation of the first pole post 201. Since the edge of the first pole post 201 is the edge of the pole post 2, the warping deformation of the edge of the pole post 2 caused by welding can be avoided. The pole post 2 can be a square pole post, a cylindrical pole post, or other irregularly shaped pole posts, which is not limited here.

[0048] In one embodiment, the stress buffer groove 2013 is an annular groove surrounding the mounting hole 101, thereby allowing the stress buffer groove 2013 to surround the periphery of the weld 6, providing a better welding stress blocking effect. At least one stress buffer groove 2013 is provided. The number of stress buffer grooves 2013 is determined by a technician based on the width L of the gap a. The cross-section of the stress buffer groove 2013 can be arc-shaped, triangular, or rectangular. (Refer to...) Figure 10 and Figure 11 As shown, the stress buffer groove 2013 has a rectangular cross-section. The difference between the two is that... Figure 10 A stress buffer groove 2013 is installed in the middle. Figure 11 Two stress buffer grooves are provided in the middle (2013). (Refer to...) Figure 12 The stress buffer groove 2013 has a triangular cross-section. In other embodiments, the cross-section of the stress buffer groove 2013 may also adopt other commonly used shapes, which are not limited here. Furthermore, the groove depth of the stress buffer groove is not less than the welding depth of the weld on the bottom surface of the placement groove.

[0049] In one specific embodiment, multiple stress buffer grooves 2013 are provided, where "multiple" refers to two or more. The multiple stress buffer grooves 2013 are spaced apart by a set distance, and different stress buffer grooves 2013 are arranged in parallel. Providing multiple stress buffer grooves 2013 will have a better effect on blocking welding stress, but the processing cost will be higher. Therefore, it is preferable to provide only one stress buffer groove 2013.

[0050] During laser welding, the laser welds the first pole piece 201 and the second pole piece 202 along the direction parallel to the mounting hole 101. To reduce laser damage to the laser from reflections from the sidewall 2014 during laser welding, the sidewall 2014 is designed as an inclined wall surface, such as... Figure 13 As shown, the sidewall 2014 of the placement slot 2011 is an inclined wall surface that gradually moves away from the second pole post 202 from the bottom to the top. In this embodiment, the distance between the edge of the connecting portion 2021 and the bottom of the sidewall 2014 is L. In another embodiment, as... Figure 14 As shown, the junction line between the groove sidewall 2014 and the top surface of the first pole post 201 is rounded.

[0051] Specifically, the height H of weld 6 ranges from 0.2 to 1.5 mm, preferably from 0.5 to 1.2 mm. The width W of weld 6 ranges from 0.5 to 2.0 mm, preferably from 1 to 1.5 mm. The distance L between the edge of the connecting part 2021 and the sidewall 2014 of the placement groove 2011 ranges from 0.1 to 2 mm, preferably from 0.5 to 1 mm.

[0052] To improve the insulation and sealing of the terminal post 2 connection point, the battery cell also includes an insulating sleeve 4 and a sealing ring 5, such as... Figure 5 As shown, the insulating sleeve 4 and the sealing ring 5 are disposed between the cover plate 1 and the pole post 2. The insulating sleeve 4 is disposed on the side of the sealing ring 5 away from the receiving chamber of the housing 3, and the sealing ring 5 is disposed close to the receiving chamber of the housing 3.

[0053] The battery cell of this utility model reduces the edge deformation of the first electrode post 201 caused by welding, that is, the deformation of the edge of the electrode post 2, thereby avoiding the edge deformation of the first electrode post 201 from affecting the electrical connection between the electrode post 2 and the aluminum busbar. The small edge deformation of the first electrode post 201 makes the sealing reliability of the contact surface between the first electrode post 201 and the cover plate 1 better, thus improving the sealing performance of the battery cell.

[0054] This utility model also provides a battery pack, including a plurality of battery cells, wherein the battery cells are those described above.

[0055] In the description of this solution, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this solution, "multiple" means two or more, unless otherwise explicitly specified.

[0056] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery cell, comprising a casing and a cover plate, wherein the cover plate has mounting holes and an electrode post is disposed at the mounting holes, characterized in that, The pole post includes a first pole post portion and a second pole post portion connected together. The first pole post portion is installed on the outside of the cover plate. A placement groove is provided at the position of the first pole post portion for connecting the second pole post portion. The second pole post portion includes a connecting portion. The connecting portion is welded into the placement groove and a weld is formed at the welding position. The height of the weld is H and the width is W. The distance between the edge of the connecting portion and the side wall of the placement groove is L, and the range of L / (W*H) is 0.1-18.

2. The battery cell according to claim 1, characterized in that, The top surface of the connecting part is lower than the top surfaces of the first pole post and the second pole post; The first pole post is wound around the mounting hole.

3. The battery cell according to claim 1 or 2, characterized in that, The second pole post also includes a main body, and the connecting part is disposed on the outer edge of the main body; The top surface of the main body is higher than the top surface of the connecting part, and the top surface of the main body is higher than the top surface of the first pole post.

4. The battery cell according to claim 1, characterized in that, The depth of the placement groove is greater than the height of the weld.

5. The battery cell according to claim 1, characterized in that, The sidewall of the placement slot is an inclined wall that gradually moves away from the second pole post from the bottom to the top, and the distance between the edge of the connecting part and the bottom of the sidewall of the slot is L.

6. The battery cell according to claim 1, characterized in that, The placement groove is located close to the mounting hole, and the placement groove is arranged around the mounting hole; The placement groove includes a groove sidewall and a groove bottom surface. The placement groove is an L-shaped groove, and the groove bottom surface is located on the groove sidewall near the mounting hole.

7. The battery cell according to claim 1 or 6, characterized in that, A stress buffer groove is provided on the bottom surface of the placement groove between the edge of the connecting part and the side wall of the groove.

8. The battery cell according to claim 7, characterized in that, The stress buffer groove is an annular groove arranged around the mounting hole, and at least one stress buffer groove is provided.

9. The battery cell according to claim 7, characterized in that, The cross-section of the stress buffer groove is arc-shaped, triangular, or rectangular.

10. The battery cell according to claim 7, characterized in that, Multiple stress buffer grooves are provided, with a set distance between them, and different stress buffer grooves are arranged in parallel.

11. The battery cell according to claim 7, characterized in that, The depth of the stress buffer groove is not less than the welding depth of the weld on the bottom surface of the placement groove.

12. The battery cell according to claim 1, characterized in that, The height H of the weld is in the range of 0.2-1.5mm, the width W of the weld is in the range of 0.5-2.0mm, and the distance L between the edge of the connection and the side wall of the placement groove is in the range of 0.1-2mm.

13. The battery cell according to claim 1, characterized in that, The electrode post can be square, cylindrical, or irregularly shaped.

14. The battery cell according to claim 1, characterized in that, It also includes an insulating sleeve and a sealing ring, which are disposed between the cover plate and the pole post.

15. A battery pack comprising a plurality of battery cells, characterized in that, The battery cell is the battery cell described in any one of claims 1-14.

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