Battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery pack. The battery cell comprises a shell, two pole columns, a pole group and two connecting pieces. Two mounting holes and two welding through holes are formed in the first side wall of the shell; the two poles are respectively arranged in the two mounting holes; the pole group is arranged in the shell, and the pole group is provided with pole lugs which correspond to the pole columns and have the same polarity as the pole columns; the conducting wire is arranged between the pole and the pole group and conductively connects the pole and the tab with the same polarity; the connecting piece comprises a pole connecting part and a tab connecting part, the pole connecting part is provided with a boss, the boss is welded with the pole, an expansion groove is formed in the position, corresponding to the boss, of the inner surface of the connecting piece, and the tab connecting part of each polarity is welded with the tab of the corresponding polarity through a welding through hole. According to the utility model, the internal space of the battery cell occupied by the whole pole and the connecting piece can be reduced, and the filling of electrolyte can be increased by forming the capacity expansion groove, so that the energy density of the battery cell can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell and a battery pack. Background Art

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in the field of electric vehicles.

[0003] The connecting piece in the battery cell plays a role in conducting the electric energy of the electrode group to the electrode terminal. During the assembly process of the battery cell, it is necessary to weld the connecting piece and the electrode tab of the electrode group.

[0004] In the traditional battery cell solution, holes are opened on the cover plate, the electrode terminals and the connecting pieces are arranged on the cover plate, and the connecting pieces and the electrode terminals are welded to meet the over-current capacity of the battery cell; at the same time, the strength of the electrode terminals and the connecting pieces needs to be satisfied. Therefore, the electrode terminals and the connecting pieces need to be made larger, resulting in more materials used and a larger occupation of the internal space of the battery cell, affecting the internal capacity of the battery cell. Summary of the Utility Model

[0005] In view of this, the utility model provides a battery cell and a battery pack to solve the problem that the electrode terminals and the connecting pieces occupy a relatively large internal space of the battery cell and affect the internal capacity of the battery cell.

[0006] On the one hand, the utility model provides a battery cell, which includes a housing, two electrode terminals, an electrode group and two connecting pieces. Two mounting holes and two welding through holes are provided on the first side wall of the housing; the two electrode terminals are respectively arranged in the two mounting holes; the electrode group is arranged in the housing, and the electrode group is provided with an electrode tab having the same polarity as the electrode terminal corresponding to each electrode terminal; it is arranged between the electrode terminal and the electrode group to conductively connect the electrode terminal and the electrode tab with the same polarity; the connecting piece includes a pole connection part and an ear connection part, the pole connection part is provided with a boss, the boss is welded to the electrode terminal, and an expansion groove is formed on the inner surface of the connecting piece at a position corresponding to the boss, and each ear connection part of each polarity is welded to the corresponding ear of the corresponding polarity through a welding through hole.

[0007] Beneficial effects: For the battery cell provided by the utility model, the electrode terminal and the connecting piece are welded to meet the over-current capacity of the battery cell. The boss is arranged on the pole connection part, which can strengthen the strength of the connecting piece, and the expansion groove is formed on the inner surface of the connecting piece at a position corresponding to the boss, which can reduce the overall material used for the connecting piece, reduce the overall space occupied by the electrode terminal and the connecting piece inside the battery cell, and by forming the expansion groove, the filling of the electrolyte can be increased, which is beneficial to improving the energy density of the battery cell.

[0008] In an optional embodiment, the electrode terminal includes an electrode terminal body, the electrode terminal body is arranged in the mounting hole, and the electrode terminal body is welded to the boss.

[0009] In an alternative embodiment, the terminal post further includes a convex post protruding from the inner surface of the terminal post body; the terminal post connection part is provided with a socket hole, the convex post and the socket hole are matched and inserted, and the outer peripheral wall of the convex post and the inner peripheral wall of the socket hole are seam-welded to achieve electrical connection.

[0010] In an alternative embodiment, the terminal post further includes a limiting convex edge, the limiting convex edge is arranged on the outer surface of the terminal post body, and the limiting convex edge is arranged on the outer end face of the mounting hole.

[0011] In an alternative embodiment, the height that the inner surface of the convex post protrudes from the inner surface of the terminal post body is H, and H≥1.2mm.

[0012] In an alternative embodiment, the convex post has a cylindrical structure, the radius of the convex post is R, and R≥1.5mm.

[0013] In an alternative embodiment, the terminal post connection part includes a connection piece body, a convex platform is arranged on the outer surface of the connection piece body, and the socket hole penetrates through the convex platform.

[0014] In an alternative embodiment, a welding groove surrounding the socket hole is arranged on the inner surface of the convex platform; the outer surface of the convex platform abuts against the inner surface of the terminal post body, and the convex platform and the terminal post body are penetration-welded through the welding groove.

[0015] In an alternative embodiment, the outer peripheral surface of the convex platform and the outer peripheral surface of the terminal post body form a combined outer column surface, the outer surface of the connection piece body is arranged opposite to the inner surface of the first side wall; the battery cell further includes a sealing ring, the sealing ring includes a sealing ring body and a sealing convex edge arranged on the outer wall of the sealing ring body, the sealing ring body is sleeved between the inner wall of the mounting hole and the combined outer column surface, and the sealing convex edge is arranged between the inner surface of the first side wall and the outer surface of the connection piece body.

[0016] On the other hand, the present invention also provides a battery pack, including a plurality of battery cells according to any one of the above technical solutions.

[0017] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of a terminal post in a battery cell according to an embodiment of the present invention;

[0020] Figure 2 The Figure 1 axial sectional view of the pole column shown along its axis;

[0021] Figure 3 Schematic structural diagram of a connection piece in a battery cell according to an embodiment of the present utility model from a first perspective;

[0022] Figure 4 The Figure 3 top view of the connection piece shown;

[0023] Figure 5 The Figure 4 sectional view taken along line A-A in

[0024] Figure 6 The Figure 3 schematic structural diagram of the connection piece from a second perspective shown;

[0025] Figure 7 Schematic structural diagram of a battery cell in a first assembly state provided by an embodiment of the present utility model;

[0026] Figure 8 Schematic structural diagram of a battery cell in a second assembly state provided by an embodiment of the present utility model;

[0027] Figure 9 Schematic structural diagram of a battery cell in a third assembly state provided by an embodiment of the present utility model;

[0028] Figure 10 The Figure 9 top view of the battery cell shown;

[0029] Figure 11 The Figure 10 sectional view taken along line B-B in

[0030] Figure 12 The Figure 11 partial enlarged view in

[0031] Explanation of reference numerals:

[0032] 1. Housing; 101. First side wall; 102. Welding through hole; 2. Pole column; 21. Positive pole column; 22. Negative pole column; 201. Pole column body; 202. Convex column; 203. Limiting convex edge; 3. Electrode group; 301. Tab; 3011. Bending part; 4. Connection piece; 401. Pole column connection part; 4011. Connection piece body; 4012. Convex platform; 4013. Insertion hole; 4014. Expansion groove; 4015. Welding groove; 402. Tab connection part; 5. Sealing ring; 501. Sealing ring body; 502. Sealing convex edge; 6. First plastic part; 7. Second plastic part; 8. Seam welding; 9. Sealing plate; 10. Explosion-proof valve. Detailed implementation manners

[0033] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0034] The following combines Figures 1 to 12 to describe the embodiments of the present utility model.

[0035] According to an embodiment of the present utility model, on the one hand, a battery cell is provided, which includes a housing 1, two pole columns 2, a pole group 3 and two connecting pieces 4. Two mounting holes and two welding through holes 102 are provided on the first side wall 101 of the housing 1; the two pole columns 2 are respectively arranged in the two mounting holes; the pole group 3 is arranged in the housing 1, and the pole group 3 is provided with pole tabs 301 having the same polarity as the corresponding pole column 2 for each pole column 2; the connecting piece 4 is arranged between the pole column 2 and the pole group 3 to electrically connect the pole column 2 and the pole tab 301 of the same polarity; the connecting piece 4 includes a pole column connecting portion 401 and a pole tab connecting portion 402. The pole column connecting portion 401 is provided with a boss 4012, the boss 4012 is welded to the pole column 2, and an expansion groove 4014 is formed on the inner surface of the connecting piece 4 at a position corresponding to the boss 4012. The pole tab connecting portion 402 on each polarity side is respectively welded to the pole tab 301 of the corresponding polarity through a welding through hole 102.

[0036] Specifically, the two pole columns 2 are respectively a positive pole column 21 and a negative pole column 22.

[0037] For the battery cell provided by the embodiment of the present utility model, structures such as the pole column 2 and the connecting piece 4 are arranged on the housing 1, and by providing two welding through holes 102, the positive pole column 21 is welded to the pole column connecting portion 401 of a connecting piece 4, and the pole tab 301 on the positive pole side is welded to the pole tab connecting portion 402 of this connecting piece 4 through the welding through hole 102 on the positive pole side. Similarly, the negative pole column 22 is welded to the pole column connecting portion 401 of the other connecting piece 4, and the pole tab 301 on the negative pole side is welded to the pole tab connecting portion 402 of this connecting piece 4 through the welding through hole 102 on the negative pole side. Two welding through holes 102 are opened on the housing 1, so that the housing 1 between the two welding through holes 102 is still integrated, which can ensure the strength of the housing 1.

[0038] The battery cell provided by the embodiment of the present utility model has the pole post 2 and the connecting piece 4 welded to meet the over-current capacity of the battery cell. The pole post connecting portion 401 is provided with a boss 4012, which can strengthen the strength of the connecting piece 4. And a bulging groove 4014 is formed at the position corresponding to the boss 4012 on the inner surface of the connecting piece 4, which can reduce the overall material consumption of the connecting piece 4 and the space occupied by the pole post 2 and the connecting piece 4 inside the battery cell. By forming the bulging groove 4014, the filling of the electrolyte can be increased, which is beneficial to improving the energy density of the battery cell.

[0039] The first side wall 101 of the housing 1 is any side wall of the housing 1.

[0040] In some embodiments, the housing 1 is a hollow square housing 1, including two relatively arranged first side walls 101 and two relatively arranged second side walls. The area of the first side wall 101 is smaller than the area of the second side wall.

[0041] In other embodiments, the housing 1 is a hollow square housing 1, one end of the housing 1 is provided with an open end, a cover plate is installed at the open end, and the side wall opposite to the open end is the first side wall 101.

[0042] It should be noted that the "inner surface of the connecting piece 4" is in the state of a complete battery cell. The side of the connecting piece 4 facing the electrode group 3 is the inner surface of the connecting piece 4. On the contrary, the side of the connecting piece 4 facing away from the electrode group 3 is the outer surface of the connecting piece 4. Specifically, in Figure 5 the upper surface of the connecting piece 4 is the outer surface of the connecting piece 4, and the lower surface of the connecting piece 4 is the inner surface of the connecting piece 4. The inner and outer surfaces of other components are understood in the same way.

[0043] In some embodiments, the pole post 2 includes a pole post body 201, the pole post body 201 is arranged in the mounting hole, and the pole post body 201 and the boss 4012 are welded.

[0044] The pole post body 201 is arranged in the mounting hole of the housing 1 to realize the positioning and installation of the pole post 2. The pole post body 201 and the boss 4012 are welded, which can realize the fixed connection and over-current conduction between the connecting piece 4 and the pole post body 201.

[0045] In some embodiments, the pole post 2 further includes a convex post 202 protruding from the inner surface of the pole post body 201; the pole post connecting portion 401 is provided with a plugging hole 4013, the convex post 202 and the plugging hole 4013 are matched and plugged, and the outer peripheral wall of the convex post 202 and the inner peripheral wall of the plugging hole 4013 are seam-welded 8 to realize electrical connection.

[0046] The assembly of the pole 2 and the connecting piece 4 is realized by inserting the convex post 202 on the inner surface of the pole body 201 into the insertion hole 4013 of the pole connecting part 401. The insertion fit between the convex post 202 and the insertion hole 4013 can play a role in assembly limit, preventing the pole 2 and the connecting piece 4 from displacing under the working scenario of vibration and affecting the over-current capacity of the welding mark. In addition, the seam welding 8 is performed on the outer peripheral wall of the convex post 202 and the inner peripheral wall of the insertion hole 4013, which plays the role of over-current between the pole 2 and the connecting piece 4. Due to the limiting effect between the convex post 202 and the insertion hole 4013 and the use of seam welding 8, the welding quality between the pole 2 and the connecting piece 4 is good, the over-current capacity is strong, it can effectively resist vibration, and ensure that the cell still has good over-current capacity under the working scenario of vibration.

[0047] In some embodiments, the pole 2 further includes a limiting convex edge 203, which is arranged on the outer surface of the pole body 201 and at the outer end face of the mounting hole.

[0048] By arranging the limiting convex edge 203 on the outer surface of the pole body 201, the limiting convex edge 203 can press on the outer end face of the mounting hole, that is, the outer surface of the first side wall 101 of the housing 1, so as to form a limit and ensure the assembly accuracy between the pole 2 and the housing 1.

[0049] In some embodiments, the height H of the inner surface of the convex post 202 protruding from the inner surface of the pole body 201 satisfies H≥1.2mm.

[0050] By controlling the height H of the inner surface of the convex post 202 protruding from the inner surface of the pole body 201 within the range of being greater than or equal to 1.2mm, not only can the self-strength of the pole 2 be improved, but also the manufacturing difficulty of the convex post 202 can be reduced.

[0051] In some embodiments, the convex post 202 is of a cylindrical structure, and the radius of the convex post 202 is R, where R≥1.5mm.

[0052] By controlling the radius of the convex post 202 within the range of being greater than or equal to 1.5mm, the self-strength of the pole 2 can be improved to prevent deformation during welding. At the same time, the larger the radius of the convex post 202, the larger the seam welding 8 area between the convex post 202 and the insertion hole 4013, and the stronger the over-current capacity between the pole 2 and the connecting piece 4.

[0053] In some embodiments, the pole connecting part 401 includes a connecting piece body 4011, a convex platform 4012 is arranged on the outer surface of the connecting piece body 4011, and the insertion hole 4013 penetrates through the convex platform 4012.

[0054] With such a setting, a stepped structure is formed between the boss 4012 and the connecting piece body 4011, which can improve the self-strength of the connecting piece 4 and enhance the ability of the connecting piece 4 to resist welding thermal deformation.

[0055] The insertion hole 4013 penetrates through the boss 4012. The insertion hole 4013 cooperates with the convex post 202 of the pole column 2, and the convex post 202 is inserted into the insertion hole 4013 of the connecting piece 4. Further, the inner surface of the convex post 202 is flush with the inner surface of the boss 4012.

[0056] In some embodiments, a welding groove 4015 surrounding the insertion hole 4013 is provided on the inner surface of the boss 4012; the outer surface of the boss 4012 abuts against the inner surface of the pole column body 201, and the boss 4012 and the pole column body 201 are penetration-welded through the welding groove 4015.

[0057] By providing the welding groove 4015 on the inner surface of the boss 4012 and the welding groove 4015 surrounding the insertion hole 4013, it is convenient to perform penetration welding on the boss 4012 and the pole column body 201 at the welding groove 4015 to realize the connection of the pole column connection part 401 of the pole column 2 and the connecting piece 4. The penetration welding at the welding groove 4015 can play a fixing role between the pole column 2 and the connecting piece 4, strengthen the overall structural strength of the pole column 2 and the connecting piece 4, and also improve the current-carrying capacity between the pole column 2 and the connecting piece 4. Moreover, the connecting piece 4 can be used to compress the sealing ring 5 provided in the installation hole to improve the sealing effect, which will be specifically introduced below.

[0058] In some embodiments, the outer peripheral surface of the boss 4012 and the outer peripheral surface of the pole column body 201 form a combined outer column surface, and the outer surface of the connecting piece body 4011 is disposed opposite to the inner surface of the first side wall 101; the battery cell further includes a sealing ring 5, and the sealing ring 5 includes a sealing ring body 501 and a sealing convex edge 502 provided on the outer wall of the sealing ring body 501. The sealing ring body 501 is sleeved between the inner wall of the installation hole and the combined outer column surface, and the sealing convex edge 502 is disposed between the inner surface of the first side wall 101 and the outer surface of the connecting piece body 4011.

[0059] By providing the sealing ring 5, the sealing ring body 501 is sleeved between the inner wall of the installation hole and the combined outer column surface to form a seal along the axial direction of the installation hole. The sealing convex edge 502 is disposed between the inner surface of the first side wall 101 and the outer surface of the connecting piece body 4011. According to the foregoing content, the boss 4012 of the connecting piece 4 and the pole column body 201 are penetration-welded at the welding groove 4015, which can cause the connecting piece body 4011 to compress the sealing convex edge 502 against the inner surface of the first side wall 101 of the housing 1, thereby improving the sealing performance.

[0060] In some embodiments, the two welding through-holes 102 are disposed between the two mounting holes. The tab connecting portions 402 of the two connecting plates 4 are arranged close to each other.

[0061] Specifically, the tab 301 is led out from the electrode group 3, and is turned over by 90° to form a bent portion 3011. The bent portion 3011 is pressed on the tab connecting portion 402 of the connecting plate 4, and then the bent portion 3011 and the tab connecting portion 402 are welded.

[0062] In some embodiments, the battery cell further includes a first plastic part 6 and a second plastic part 7. The first plastic part 6 is pressed between the limiting flange 203 of the pole column 2 and the outer surface of the first side wall 101, insulatingly connecting the pole column 2 and the housing 1. The second plastic part 7 is disposed on the inner surface of the first side wall 101, insulatingly connecting the connecting plate 4 and the housing 1.

[0063] In some embodiments, the battery cell further includes two sealing plates 9. The two sealing plates 9 are respectively connected to the two welding through-holes 102 to package the first side wall 101, realizing the sealing of the battery cell.

[0064] In some embodiments, the battery cell further includes an explosion-proof valve 10. The explosion-proof valve 10 is disposed on the first side wall 101 of the housing 1 and is located between the two welding through-holes 102.

[0065] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including a plurality of battery cells according to any one of the above embodiments.

[0066] Since the battery pack includes the battery cell and has the same effects as the battery cell, they will not be described in detail herein.

[0067] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing, on the first side wall of which there are provided two mounting holes and two welding through-holes; Two pole columns, which are respectively arranged in the two mounting holes; A pole group, which is arranged in the housing, and the pole group is provided with pole tabs having the same polarity as that of each pole column corresponding to each pole column; Two connecting pieces, which are arranged between the pole columns and the pole group to conductively connect the pole columns and the pole tabs with the same polarity; the connecting piece includes a pole column connecting portion and a pole tab connecting portion, the pole column connecting portion is provided with a boss, the boss is welded to the pole column, and an expansion groove is formed on the inner surface of the connecting piece at a position corresponding to the boss, and each pole tab connecting portion of each polarity is welded to the pole tab of the corresponding polarity through one of the welding through-holes.

2. The battery cell according to claim 1, wherein The pole column includes a pole column body, the pole column body is arranged in the mounting hole, and the pole column body is welded to the boss.

3. The battery cell according to claim 2, characterized in that, The pole column further includes a protruding column protruding from the inner surface of the pole column body; the pole column connecting portion is provided with a plugging hole, the protruding column is matched with and plugged into the plugging hole, and the outer peripheral wall of the protruding column and the inner peripheral wall of the plugging hole are seam-welded to achieve conductive connection.

4. The battery cell according to claim 3, characterized in that, The pole column further includes a limiting convex edge, the limiting convex edge is arranged on the outer surface of the pole column body, and the limiting convex edge is arranged on the outer end surface of the mounting hole.

5. The battery cell according to claim 3 or 4, characterized in that, The height by which the inner surface of the protruding column protrudes from the inner surface of the pole column body is H, and H≥1.2mm.

6. The battery cell according to claim 5, wherein, The protruding column is of a cylindrical structure, and the radius of the protruding column is R, and R≥1.5mm.

7. The battery cell according to claim 3 or 4, characterized in that, The pole column connecting portion includes a connecting piece body, the boss is arranged on the outer surface of the connecting piece body, and the plugging hole penetrates through the boss.

8. The battery cell according to claim 5, wherein, The inner surface of the boss is provided with a welding groove surrounding the plugging hole; The outer surface of the boss abuts against the inner surface of the pole column body, and the boss and the pole column body are penetration-welded through the welding groove.

9. The battery cell according to claim 7, wherein The outer peripheral surface of the boss and the outer peripheral surface of the pole column body form a combined outer cylindrical surface, and the outer surface of the connecting piece body is arranged opposite to the inner surface of the first side wall; The battery cell further includes a sealing ring, the sealing ring includes a sealing ring body and a sealing convex edge arranged on the outer wall of the sealing ring body, the sealing ring body is sleeved between the inner wall of the mounting hole and the combined outer cylindrical surface, and the sealing convex edge is arranged between the inner surface of the first side wall and the outer surface of the connecting piece body.

10. A battery pack, characterized in that, Including a plurality of battery cells according to any one of claims 1 to 9.

Images