A full-tab cylindrical power battery and a preparation method thereof

Abstract

The application provides a full-tab cylindrical power battery and a preparation method thereof. The battery comprises a battery shell, a pole and a first current collector, wherein the battery shell is provided with an opening; the pole comprises a pole body and an annular flange part; the pole body penetrates through the battery shell and is away from the opening; the pole body is electrically insulated from the battery shell; a liquid injection hole is formed in the pole body; the pole body locally extends into the liquid injection hole to form the annular flange part; the first current collector comprises a first current collector body and a riveting part; the first current collector body is located in the battery shell and abuts against the pole; the first current collector body locally extends into the liquid injection hole to form the riveting part; the riveting part is riveted on the annular flange part; and a through hole is formed in the first current collector and penetrates through the first current collector body and the riveting part. In the structure, the pole and the current collector are connected through a riveting structure, and there is no welding point, so that the problems such as residual welding slag in the battery, scratch of the winding core by the welding head and welding stress deformation are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery production, and particularly relates to a full-tab cylindrical power battery and a preparation method thereof. BACKGROUND

[0002] The cylindrical battery is a common battery type, which mainly has a battery shell, a winding core, a current collecting disc, a pole and a sealing element and the like, and when the winding core is connected with the current collecting disc and the pole, a welding method is usually used. However, the welding method has certain technical problems.

[0003] The patent application with the application publication number CN113921765A discloses a cylindrical lithium battery and a preparation method thereof, and relates to the technical field of lithium batteries. The cylindrical lithium battery comprises a steel shell and a cylindrical pole group. The steel shell comprises a steel shell base and an open end arranged opposite to the steel shell base. The cylindrical pole group comprises a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet is provided with a positive electrode tab, and the negative electrode sheet is provided with a negative electrode tab. The negative electrode sheet, the separator and the positive electrode sheet are sequentially stacked and wound into the cylindrical pole group. The positive electrode tab and the negative electrode tab are arranged at two ends of the cylindrical pole group, and the end where the negative electrode tab is located faces the steel shell base. The cylindrical pole group is placed into the steel shell. The positive electrode tab is led out from the open end and is welded and connected with a positive electrode terminal. The steel shell base is conductively connected with the negative electrode tab through laser welding.

[0004] In the above technical solution, the positive electrode tab is welded with the positive electrode current collecting disc, and the positive electrode current collecting disc is welded with the positive electrode terminal (positive electrode pole). In this preparation method, there are many welding points in the battery, and the welding points are prone to failure during the assembly and use of the battery, which may cause short circuit risk. For the pole fixed by the part of the rivet structure, the pole needs to be riveted to connect the top cover of the battery, which may cause the pole and the winding core to shake during the riveting process, and may also cause the welding point to fail. In addition, in this preparation method, it is difficult to position the positive electrode pole and the positive electrode current collecting disc concentrically. If there is a deviation in welding, the parts may be scrapped, which affects the yield.

[0005] The patent application with the application publication number CN114914515A discloses a lithium battery and a preparation method thereof. The lithium battery comprises a shell, a winding core, a positive electrode current collecting disc, an insulating ring and a cover assembly. The shell is provided with an accommodating cavity, and the winding core is arranged in the accommodating cavity. The positive electrode of the winding core is located at an open end. The positive electrode current collecting disc comprises a first disc body and a first protrusion. The first disc body is connected with the positive electrode of the winding core, and the first protrusion extends axially along the first disc body. The insulating ring is sleeved on the first disc body. The cover assembly comprises a rivet, a cover plate, an insulating assembly and a sealing rivet. The rivet is provided with a first through hole, and the first protrusion is arranged on the inner wall surface of the first through hole. The cover plate is connected with the insulating ring and the rivet through the insulating assembly. The sealing rivet is arranged in the first through hole and is in close contact with the first protrusion. The positive electrode of the winding core is directly welded with the positive electrode current collecting disc, and the positive electrode current collecting disc is directly welded with the rivet and the sealing rivet through the first protrusion.

[0006] In the aforementioned technical solution, a first protrusion is provided on the first disk body of the positive electrode current collector, and is fixedly connected to the first protrusion by rivets and sealing pins. The rivets are equivalent to positive electrode posts, the first protrusion is located in the first through hole of the rivet, and the sealing pin is located in the first protrusion to cooperate with the rivets to clamp and fix the first protrusion. When assembling the sealing pin, the first protrusion needs to be enlarged first to facilitate the installation of the sealing pin. However, this process has high requirements for the quality of the first protrusion; otherwise, enlarging the hole can easily cause the first protrusion to tear, affecting the sealing effect. Moreover, the first protrusion plays a role in carrying current, and tearing will also affect the current carrying capacity. Secondly, in order to ensure the stability of the assembly, the rivets, sealing pins, and first protrusion need to be welded and fixed. The stress generated by welding can easily cause the rivets, sealing pins, and first protrusion to deform against each other. After the weld cools down, the battery is at risk of failure.

[0007] For some batteries, the positive terminal is pre-integrated into the battery casing, requiring welding of the positive current collector to the positive terminal inside the battery. This connection method necessitates inserting an ultrasonic torque welding head into the battery for welding, which can easily leave welding slag inside the battery, affecting its safety performance. Secondly, in some battery welding processes, the ultrasonic torque welding head is inserted into the battery from the negative terminal. The welding head needs to pass through the center hole of the core before welding the positive current collector to the positive terminal, and then the negative terminal cover is installed for sealing after welding. This welding method has the problem of the welding head easily scratching the core. If this damages the core separator, it can lead to battery failure and pose a safety hazard.

[0008] As can be seen from the above, the main problem with the current cylindrical battery module connection structure lies in the connection method between the current collector and the terminal, and therefore needs to be improved. Summary of the Invention

[0009] In view of this, the present invention proposes a cylindrical power battery with multiple tabs and its preparation method, which has the advantages of fewer solder joints, stable sealing structure and no damage to the battery.

[0010] The technical solution of this invention is implemented as follows:

[0011] On one hand, the present invention provides a cylindrical power battery with multiple tabs and a method for preparing the same, comprising a battery casing, terminals, and a first current collector, wherein,

[0012] The battery casing has an opening;

[0013] The electrode post includes the electrode post body and the annular flange portion;

[0014] The pole body penetrates through the battery shell far from the opening end, the pole body is electrically insulated from the battery shell, a liquid injection hole is formed on the pole body, and the pole body partially extends into the liquid injection hole to form an annular flange part;

[0015] The first current collector disc includes a first current collector disc body and a riveting part, the first current collector disc body is located in the battery shell and abuts against the pole, the first current collector disc body partially extends into the liquid injection hole to form the riveting part, and the riveting part is riveted on the annular flange part; a through hole is formed on the first current collector disc and penetrates through the first current collector disc body and the riveting part.

[0016] On the basis of the above technical scheme, preferably, a plurality of grooves are arranged in an annular array on one end of the riveting part inserted into the liquid injection hole.

[0017] On the basis of the above technical scheme, preferably, an inclined chamfer is arranged on one side of the annular flange part facing the first current collector disc.

[0018] On the basis of the above technical scheme, preferably, the sealing rubber plug further includes a first sealing part and a second sealing part, wherein,

[0019] The first sealing part is located in the liquid injection hole and abuts against the riveting part;

[0020] The first sealing part extends into the through hole to form the second sealing part.

[0021] On the basis of the above technical scheme, preferably, the first sealing part is provided with a containing groove corresponding to the riveted part of the riveting part, and an inner surface of the containing groove abuts against the riveting part.

[0022] On the basis of the above technical scheme, preferably, the sealing rubber plug further includes an aluminum sheet, the aluminum sheet abuts against one end of the sealing rubber plug away from the riveting part, and the aluminum sheet is welded and fixed with the pole.

[0023] On the basis of the above technical scheme, preferably, a plurality of stress grooves are formed in the middle of the aluminum sheet.

[0024] On the basis of the above technical scheme, preferably, the sealing rubber plug further includes a sealing member, the sealing member is arranged between the battery shell and the pole, and is used to electrically insulate the battery shell and the pole.

[0025] On the basis of the above technical scheme, preferably, the sealing rubber plug further includes a winding core, a second current collector disc and a cover plate, wherein,

[0026] The winding core is located in the battery shell, and one end of the winding core is electrically connected with the first current collector disc;

[0027] The second current collector disc is electrically connected with the negative electrode end of the winding core;

[0028] The cover plate seals the opening.

[0029] In another aspect, the application provides a method for manufacturing the full-tab cylindrical power battery, comprising the following steps:

[0030] S1, first installing a pole on the battery shell;

[0031] S2, winding the pole piece to form a winding core, rubbing the tabs of the winding core flat, and then welding the first current collector plate and the second current collector plate at opposite ends of the winding core;

[0032] S3, after the first current collector plate, the second current collector plate and the winding core are welded together, they are loaded into the battery shell through an opening, the first current collector plate enters the battery shell first, and the riveting part is inserted into the liquid injection hole of the pole until it is riveted to the annular flange part;

[0033] S4, the second current collector plate is pressed to make the first current collector plate tightly abut against the pole, and then the riveting part is riveted to the annular flange part;

[0034] S5, the cover plate is welded to the battery shell to seal the opening, and the cover plate is electrically connected to the second current collector plate;

[0035] S6, electrolyte is injected into the full-tab cylindrical power battery through the liquid injection hole of the pole;

[0036] S7, the liquid injection hole is sealed.

[0037] The full-tab cylindrical power battery of the application has the following beneficial effects compared with the prior art:

[0038] (1) By providing the riveting part on the first current collector plate and inserting and riveting the riveting part in the pole, the assembly does not need to be welded, so there is no problem of welding point failure, scratch of the winding core, residual welding slag in the battery and deformation of the assembly caused by welding stress; and during assembly, the first current collector plate is tightly contacted with the pole and then riveted, so the riveting part is not easy to loosen, and the failure probability can be significantly reduced.

[0039] (2) By providing the groove on the riveting part, the riveting part can be more convenient to rivet, and the riveting part can be prevented from being torn.

[0040] (3) By using the sealing rubber plug to seal the liquid injection hole of the pole and providing the accommodation groove on the sealing rubber plug to accommodate the riveting part of the riveting part, the sealing rubber plug can press and hold the riveting part after installation, and the riveting stability can be further improved to prevent the riveting part from loosening.

[0041] (4) By using the aluminum sheet to fix the sealing rubber plug and providing the stress groove on the aluminum sheet, the stress groove can release the welding stress during welding to prevent the pole from being deformed to affect the sealing effect. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only need to be some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0043] Figure 1 A perspective view of the full-tab cylindrical power battery of the present application;

[0044] Figure 2 An axial cross-sectional structure view of the full-tab cylindrical power battery of the present application;

[0045] Figure 3 An exploded structure view of the full-tab cylindrical power battery of the present application;

[0046] Figure 4 A structure view of the full-tab cylindrical power battery of the present application at point A; Figure 2

[0047] Figure 5 A structure view of the full-tab cylindrical power battery of the present application at point B; Figure 2

[0048] Figure 6 A structure view of the sealing plug of the full-tab cylindrical power battery of the present application;

[0049] Figure 7 A structure view of the aluminum sheet of the full-tab cylindrical power battery of the present application;

[0050] Figure 8 A structure view of the pole post cross section of the full-tab cylindrical power battery of the present application;

[0051] Figure 9 A structure view of the first current collector plate of the full-tab cylindrical power battery of the present application;

[0052] Figure 10 A structure view of the riveting part before flip riveting of the full-tab cylindrical power battery of the present application;

[0053] Figure 11 A structure view of the riveting part after flip riveting of the full-tab cylindrical power battery of the present application;

[0054] Figure 12 A structure view of the riveting part of the riveting ring flange part of the full-tab cylindrical power battery of the present application;

[0055] Figure 13 A structure view of the battery shell cross section of the full-tab cylindrical power battery of the present application;

[0056] ​​In the figure: battery casing 1, opening 101, terminal post 2, terminal post body 21, annular flange 22, liquid injection hole 201, chamfer 202, first collector plate 3, first collector plate body 31, riveting part 32, through hole 301, groove 302, sealant plug 4, first sealing part 41, second sealing part 42, receiving groove 401, aluminum sheet 5, stress groove 501, sealing element 6, core 7, second collector plate 8, cover plate 9, insulating plate 10, riveting block 11. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0058] Example 1:

[0059] like Figures 1-13 As shown, the all-tab cylindrical power battery of the present invention includes a battery casing 1, a terminal post 2, a first current collector 3, a sealing plug 4, an aluminum sheet 5, a sealing element 6, a core 7, a second current collector 8, and a cover plate 9.

[0060] The battery casing 1 has an opening 101; the terminal post 2 includes a terminal post body 21 and an annular flange portion 22; the terminal post body 21 penetrates the end of the battery casing 1 away from the opening 101, and the terminal post body 21 is electrically insulated from the battery casing 1.

[0061] The terminal post 2 can be connected to the battery casing 1 by riveting. The riveting fixing structure has the advantages of convenient connection and stable structure.

[0062] Specifically, the sealing element 6 of this all-tab cylindrical power battery is set between the battery housing 1 and the terminal 2 to electrically insulate the battery housing 1 and the terminal 2; a riveting block 11 is provided on the terminal 2. When the terminal 2 is riveted, the terminal 2 is riveted onto the riveting block 11 and the sealing element 6 is pressed against the riveting block 11.

[0063] The structure of the seal 6 in this device is not limited. It can be injection molded or sealed using conventional plastic, sealing ring or other components to insulate the terminal post 2 and the battery casing 1.

[0064] In the drawings, S is the center hole of the core 7. In the existing welding method, the ultrasonic torque welding head is inserted into the center hole S from the negative electrode end of the battery to weld the pole 2 and the first current collector 3. When working, the welding head is easy to scratch the core 7 and cause damage, and is easy to leave welding slag, which will affect the safety performance of the battery. In addition, the precision of internal welding is difficult to control.

[0065] In order to solve the problems existing in the welding of the existing pole and the pole current collector, in the present technology, the pole and the current collector are connected by a riveting process.

[0066] Specifically, the pole body 21 is provided with a liquid injection hole 201, and the pole body 21 locally extends into the liquid injection hole 201 to form an annular flange portion 22; the first current collector 3 includes a first current collector body 31 and a riveting portion 32, the first current collector body 31 is located in the battery shell 1 and abuts against the pole 2, and the first current collector body 31 locally extends into the liquid injection hole 201 to form the riveting portion 32, and the riveting portion 32 is riveted on the annular flange portion 22; the first current collector 3 is provided with a through hole 301 penetrating through the first current collector body 31 and the riveting portion 32.

[0067] Further, as shown in Figure 8 In order to improve the convenience of inserting the riveting portion 32 into the pole 2, a bevel chamfer 202 is arranged on the side of the annular flange portion 22 facing the first current collector 3. The bevel chamfer 202 can play a guiding role, facilitating the insertion of the riveting portion 32 into the liquid injection hole 201 of the pole 2, and can avoid the riveting portion 32 from being offset by impacting the pole 2 during assembly.

[0068] As described above, in the assembly process, the first current collector 3 is inserted into the liquid injection hole 201 of the pole 2 through the riveting portion 32, and then the riveting portion 32 is riveted to the annular flange portion 22. The shape of the first current collector 3 is as shown in Figure 9 The shape of the riveting portion 32 before riveting is as shown in Figure 10 The shape after riveting is as shown in Figure 11 The riveting connection structure is as shown in Figure 12 This kind of connection structure does not need welding, so it can avoid the technical problems caused by welding, such as welding slag residue, welding stress deformation, and the easy scratching of the core 7 caused by the insertion of the welding head during welding. At the same time, the riveting portion 32 can realize the concentric positioning of the first current collector 3 and the pole 2, which is conducive to improving the stability of the assembly connection and the convenience of subsequent assembly.

[0069] Since the riveting portion 32 is outwardly riveted against the annular flange portion 22 of the pole 2, in order to improve the convenience of riveting, a plurality of grooves 302 are arranged on the end of the riveting portion 32 inserted into the liquid injection hole 201, and the plurality of grooves 302 are arranged in an annular array on the riveting portion 32. In this way, the riveting of the riveting portion 32 is very convenient, and tearing does not occur, which can ensure the structural stability.

[0070] In order to maximize the structural stability of the riveting portion 32, the depth of the groove 302 is set to be the same as the length of the riveted portion of the riveting portion 32. In order to avoid the riveting structure being not stable due to the too long groove 302, and at the same time, to improve the current carrying capacity of the riveting portion 32.

[0071] In order to avoid the first current collector 3 from contacting the battery shell 1 due to vibration and other factors, an insulating plate 10 is arranged between the first current collector 3 and the battery shell 1 to insulate and isolate the battery shell 1 and the first current collector 3.

[0072] In the technical solution, a sealing plug 4 is also arranged, as shown in Figure 4 and Figure 6 The sealing plug 4 includes a first sealing portion 41 and a second sealing portion 42, wherein the first sealing portion 41 is located in the liquid injection hole 201 and abuts against the riveting portion 32; the first sealing portion 41 extends into the through hole 301 to form the second sealing portion 42. In this way, the sealing plug 4 can completely seal the liquid injection hole 201 to prevent liquid leakage.

[0073] Further, the first sealing portion 41 is provided with a receiving groove 401 corresponding to the riveted portion of the riveting portion 32, and the inner surface of the receiving groove 401 abuts against the riveting portion 32. In this way, the height of the sealing plug 4 can be reduced to prevent affecting the finished product height of the battery, and the riveting portion 32 can be better limited.

[0074] After the sealing plug 4 is used to seal the liquid injection hole 201, the sealing plug 4 needs to be further fixed, so an aluminum sheet 5 is arranged on the sealing plug 4, the aluminum sheet 5 abuts against the end of the sealing plug 4 away from the riveting portion 32, and the aluminum sheet 5 is welded and fixed with the pole 2. In this way, the aluminum sheet 5 can prevent the sealing plug 4 from falling off.

[0075] However, since the aluminum sheet 5 is fixed by welding, stress will be generated due to temperature difference during welding, as shown in Figure 7 In order to avoid the deformation of the aluminum sheet 5 causing the top surface of the pole 2 to be uneven, a plurality of stress grooves 501 are arranged in the middle of the aluminum sheet 5. In this way, during welding, the aluminum sheet 5 will expand into the stress grooves 501 to release the welding stress, thereby avoiding the phenomenon of the aluminum sheet 5 being drummed up.

[0076] The winding core 7 is located in the battery shell 1, and one end of the winding core 7 is electrically connected with the first current collector 3; the second current collector 8 is electrically connected with the negative electrode end of the winding core 7; and the cover plate 9 seals the opening 101.

[0077] The preparation method of the full-tab cylindrical power battery comprises the following steps:

[0078] S1, first, installing the pole 2 on the battery shell 1;

[0079] S2, winding the pole piece to form the winding core 7, rubbing the tabs of the winding core 7 flat, and then welding the first current collector 3 and the second current collector 8 opposite to each other at two ends of the winding core 7;

[0080] S3, after the first current collector 3, the second current collector 8 and the winding core 7 are welded into one body, the first current collector 3 is first put into the battery shell 1, and then the riveting part 32 is inserted into the liquid injection hole 201 of the pole 2;

[0081] S4, the second current collector 8 is pressed to make the first current collector 3 tightly abut against the pole 2, and then the riveting part 32 is riveted and fixed to the annular flange part 22;

[0082] S5, the cover plate 9 is welded with the battery shell 1 to seal the opening 101, and the cover plate 9 is electrically connected with the second current collector 8;

[0083] S6, injecting electrolyte into the full-tab cylindrical power battery through the liquid injection hole 201 of the pole 2;

[0084] S7, sealing the liquid injection hole 201.

[0085] In the technical solution, the first current collector 3 is used as the positive current collector of the battery, and the pole 2 is used as the positive pole of the battery.

[0086] Embodiment two:

[0087] The difference between the technical solution and embodiment one is that, in the technical solution, the first current collector 3 is used as the negative current collector of the battery, and the pole 2 is used as the negative pole of the battery.

[0088] Embodiment three:

[0089] The difference between the technical solution and the above embodiments is that the electrical connectors of the positive electrode and the negative electrode of the battery are both the first current collector 3 and the pole 2.

[0090] The above is only a preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A full tabbed cylindrical power cell, characterized by, The battery shell (1), the pole (2), the first current collector (3) and the sealing plug (4) are included, wherein, The battery shell (1) is provided with an opening (101); The pole (2) includes a pole body (21) and an annular flange portion (22); The pole body (21) penetrates one end of the battery shell (1) away from the opening (101), the pole body (21) is electrically insulated from the battery shell (1), the pole body (21) is provided with a liquid injection hole (201), and the pole body (21) partially extends into the liquid injection hole (201) to form the annular flange portion (22); The first current collector (3) includes a first current collector body (31) and a riveting portion (32), the first current collector body (31) is located in the battery shell (1) and abuts against the pole (2), the first current collector body (31) partially extends into the liquid injection hole (201) to form the riveting portion (32), and the riveting portion (32) is riveted on the annular flange portion (22); the first current collector (3) is provided with a through hole (301) penetrating the first current collector body (31) and the riveting portion (32); A plurality of grooves (302) are annularly arranged on one end of the riveting portion (32) inserted into the liquid injection hole (201); The sealing plug (4) includes a first sealing portion (41) and a second sealing portion (42), wherein the first sealing portion (41) is located in the liquid injection hole (201) and abuts against the riveting portion (32); the first sealing portion (41) extends into the through hole (301) to form the second sealing portion (42).

2. The full tabbed cylindrical power cell of claim 1, wherein: An inclined chamfer (202) is arranged on one side of the annular flange portion (22) facing the first current collector (3).

3. The full-ledge cylindrical power cell of claim 1, wherein: The first sealing portion (41) is provided with a receiving groove (401) corresponding to the riveted portion of the riveting portion (32), and an inner surface of the receiving groove (401) abuts against the riveting portion (32).

4. The full-ledge cylindrical power cell of claim 1, wherein: An aluminum sheet (5) is further included, the aluminum sheet (5) abuts against one end of the sealing plug (4) away from the riveting portion (32), and the aluminum sheet (5) is welded and fixed with the pole (2).

5. The full-ledge cylindrical power cell of claim 4, wherein: A plurality of stress grooves (501) are arranged in the middle of the aluminum sheet (5).

6. The full-ledge cylindrical power cell of claim 1, wherein: A sealing member (6) is further included, the sealing member (6) is arranged between the battery shell (1) and the pole (2) to electrically insulate the battery shell (1) and the pole (2).

7. The full-ledge cylindrical power cell of claim 1, wherein: A winding core (7), a second current collector (8) and a cover plate (9) are further included, wherein, The winding core (7) is located in the battery shell (1), and one end of the winding core (7) is electrically connected with the first current collector (3); The second current collector (8) is electrically connected with a negative electrode end of the winding core (7); The cover plate (9) seals the opening (101).

8. A method of manufacturing the full-tab cylindrical power battery according to claim 7, characterized in that, The following steps are included: S1, first, install the pole (2) on the battery shell (1); S2, winding the pole piece to form the winding core (7), rubbing the tab of the winding core (7), and welding the first and second current collectors (3, 8) at the two ends of the winding core (7); S3, after the first and second current collectors (3, 8) and the winding core (7) are welded into one, the first current collector (3) is inserted into the battery shell (1) through the opening (101), until the riveting part (32) is inserted into the liquid injection hole (201) of the pole post (2); S4, applying pressure to the second current collector (8) to make the first current collector (3) tightly abut against the pole post (2), and then riveting the riveting part (32) to the annular flange part (22); S5, welding the cover plate (9) and the battery shell (1) to seal the opening (101), and the cover plate (9) is electrically connected with the second current collector (8); S6, injecting electrolyte into the whole-tab cylindrical power battery through the liquid injection hole (201) of the pole post (2); S7, sealing the liquid injection hole (201).

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