Composite pole and battery cover plate

Abstract

The utility model provides a kind of composite pole and battery cover, composite pole includes the first pole body and the second pole body of different material, first pole body is connected with battery cell component, second pole body is connected with electric equipment;Second pole body includes first section and second section, first section is connected in the end of second section away from first pole body, the diameter of first section is greater than the diameter of second section, the end surface of first section towards first pole body is in abutment with riveting ring of battery cover.When riveting ring and composite pole riveting, in addition to the first pole body directly contacted with riveting equipment will produce larger deformation, the end of second section towards first pole body will also produce larger deformation, the deformation degree of the connecting area of first pole body and second section is substantially the same, the joint surface area structure of first pole body and second pole body is stable, not easy to fall off, improve battery performance and safety.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a composite electrode post and battery cover. Background Technology

[0002] Square batteries are a commonly used structure for lithium-ion power batteries. They generally include a casing, cell assembly, and cover plate. The cell assembly is located inside the casing, and the cover plate covers the open end of the casing. The cover plate includes the cover plate body, the negative electrode post, and the positive electrode post. In order to simultaneously meet the welding requirements of the internal tabs and the external busbar, the negative electrode post is usually designed as a copper-aluminum composite post. One end of the copper material of the negative electrode post is located inside the casing and is welded to the tabs or leads of the cell assembly; the other end of the aluminum material of the negative electrode post is located outside the casing and is welded to the busbar.

[0003] In existing technologies, the copper and aluminum segments of the negative electrode post are connected by friction welding. This involves rotating and frictionally welding the copper and aluminum segments together, resulting in slow production efficiency and a higher unit price for the negative electrode post. Furthermore, when riveting one end of the copper segment of the negative electrode post, the riveting block only engages with and fixes the copper segment, leading to significant deformation of the copper. Since copper is harder than aluminum, the copper-aluminum composite area is prone to deformation under stress, posing a risk of detachment from the copper-aluminum interface. This seriously affects battery safety and performance. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the defects in the prior art where the riveting block only cooperates and is fixed with the material segment that directly cooperates with the riveting equipment, which leads to the risk of detachment at the interface of different material segments during the riveting of the composite pole, affecting battery safety and battery performance. The present invention provides a composite pole and battery cover plate.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A composite electrode post includes a first electrode post and a second electrode post, wherein the first electrode post is made of a different material from the second electrode post, the first electrode post is used to connect to a battery cell assembly, and the second electrode post is used to connect to an electrical device.

[0007] The first pole piece is disposed on one end face of the second pole piece along the axial direction of the composite pole piece, and the end of the first pole piece away from the second pole piece is a riveting end for cooperating with riveting equipment;

[0008] The second electrode post includes a first post segment and a second post segment. The first post segment is connected to the end of the second post segment away from the first electrode post. The diameter of the first post segment is larger than the diameter of the second post segment. The end face of the first post segment facing the first electrode post is used to abut against the riveting ring of the battery cover.

[0009] In this design, the riveting ring abuts against the end face of the first column segment facing the first electrode post. Therefore, when the riveting ring is riveted to the composite electrode post, in addition to the first electrode post which is in direct contact with the riveting equipment undergoing significant deformation, the end face of the second column segment facing the first electrode post will also undergo significant deformation. That is, the deformation of the connection area between the first electrode post and the second column segment is approximately the same, thereby ensuring the structural stability of the joint area between the first electrode post and the second electrode post, making it less prone to detachment, and improving battery performance and safety.

[0010] Preferably, the first electrode post and the second electrode post are integrally formed.

[0011] In this solution, the one-piece molding method simplifies the processing, reduces processing difficulty and time, eliminates potential connection weaknesses caused by separate welding or assembly, further improves the structural integrity and mechanical strength of the composite pole, and ensures the stability of the current transmission path.

[0012] Preferably, the copper-aluminum composite plate forms the first pole piece and the second pole piece, wherein the first pole piece is made of copper and the second pole piece is made of aluminum.

[0013] In this solution, the copper-aluminum composite plate is an existing finished material that can be used directly. The first and second pole pieces are formed by stamping or other methods, reducing processing difficulty and time.

[0014] Preferably, the outer peripheral surface of the end of the second column segment facing the first pole column is in the same curved surface as the outer peripheral surface of the first pole column.

[0015] In this solution, the above-mentioned arrangement ensures that the first pole piece has sufficient area to contact the riveting equipment, while also preventing increased costs due to an excessively large first pole piece.

[0016] Preferably, the composite pole further includes a third pole connected to the end of the second pole away from the first pole, the third pole being made of the same material as the second pole, and the cross-sectional area of ​​the third pole in a first plane being greater than the cross-sectional area of ​​the second pole in the first plane; wherein the first plane is perpendicular to the axis of the composite pole.

[0017] In this design, the third electrode post increases the connection area and strength with external electrical equipment. This reduces contact resistance, increases current carrying capacity, enhances the stability of the mechanical connection, and improves the overall performance and reliability of the battery pack.

[0018] Preferably, the second pole piece and the third pole piece are integrally formed; or, the second pole piece and the third pole piece are separate structures.

[0019] In this solution, the one-piece molding method facilitates processing and shortens production time. The split structure can save on the amount of metal composite panels used, reducing material costs.

[0020] Preferably, when the second pole piece and the third pole piece are a separate structure, the third pole piece is provided with a first through hole, the first through hole is through both ends of the composite pole piece in the axial direction, the first through hole is a countersunk hole, and the countersunk of the first through hole is located on the side of the first through hole away from the first pole piece.

[0021] The first column segment has a first protrusion at the end away from the first pole body. The first protrusion extends radially from the outer peripheral surface of the first column segment toward the outside of the second pole body. The second pole body passes through the first through hole, and the first protrusion abuts against the countersunk step surface of the first through hole.

[0022] In this design, the above-mentioned arrangement facilitates the positioning between the second and third pole pieces, and the countersunk step of the first through hole provides support for the second pole piece, thereby improving the structural strength.

[0023] A battery cover includes a riveting ring and a composite terminal as described above, the composite terminal passing through the riveting ring, the riveting ring abutting against one end face of the first post segment facing the first terminal body, and the riveting ring being connected to the first terminal body.

[0024] In this design, the riveting ring abuts against the end face of the first column segment facing the first electrode post. Therefore, when the riveting ring is riveted to the composite electrode post, in addition to the first electrode post which is in direct contact with the riveting equipment undergoing significant deformation, the end face of the second column segment facing the first electrode post will also undergo significant deformation. That is, the deformation of the connection area between the first electrode post and the second column segment is approximately the same, thereby ensuring the structural stability of the joint area between the first electrode post and the second electrode post, making it less prone to detachment, and improving battery performance and safety.

[0025] Preferably, the riveting ring includes a riveting ring body, a second boss, a second through hole, and a third through hole. The second through hole penetrates both ends of the riveting ring body in the axial direction of the composite pole, and the third through hole penetrates both ends of the second boss in the axial direction of the composite pole. The second boss extends radially from the wall of the second through hole toward the interior of the second through hole. The second through hole and the third through hole are coaxial and interconnected.

[0026] The second boss abuts against the first column segment at one end face of the composite pole axially toward the first column segment; after the riveting ring is riveted to the composite pole, the second column segment deforms to form a stepped portion, and the second boss abuts against the stepped portion at one end face of the composite pole axially away from the first column segment, and the outer peripheral surface of the stepped portion and the outer peripheral surface of the first pole body abut against the wall of the second through hole.

[0027] In this solution, the step portion formed after the deformation of the second column segment and the first column segment are used to lock the position of the second boss in the axial direction of the composite pole, thereby fixing the composite pole and the rivet ring.

[0028] Preferably, the second through hole is a countersunk hole, the countersunk end of the second through hole is located at the end of the second through hole away from the second pole piece, the outer peripheral surface of the first pole piece abuts against the hole wall of the second through hole, and the end face of the first pole piece away from the second pole piece is flush with the stepped surface of the countersunk end of the second through hole.

[0029] In this design, the countersunk surface of the first electrode post and the second through hole is flush, facilitating welding operations at the junction of the first electrode post, the second through hole, and the through hole. Since weld joints are generally not perfectly smooth, the countersunk surface of the second through hole prevents the weld joint from contacting other parts of the battery cell assembly, improving reliability. The stepped surface of the countersunk surface of the second through hole also limits the operating distance of the riveting equipment, preventing excessive pressure on the second boss.

[0030] The positive and progressive effects of this utility model are as follows: the riveting ring abuts against the end face of the first column segment facing the first electrode post. Therefore, when the riveting ring is riveted to the composite electrode post, in addition to the first electrode post which is in direct contact with the riveting equipment undergoing a large deformation, the end face of the second column segment facing the first electrode post will also undergo a large deformation. That is, the deformation degree of the connection area between the first electrode post and the second column segment is approximately the same, thereby ensuring the structural stability of the joint area between the first electrode post and the second electrode post, making it less likely to fall off, and improving battery performance and safety. Attached Figure Description

[0031] Figure 1 This is an exploded view of part of the structure of the secondary battery in Embodiment 1 of this utility model.

[0032] Figure 2 This is another exploded view of a portion of the structure of the secondary battery in Embodiment 1 of this utility model.

[0033] Figure 3 This is a schematic diagram of the internal structure of a secondary battery according to Embodiment 1 of this utility model.

[0034] Figure 4This is a schematic diagram of the structure of the composite pole and the riveting ring in Embodiment 1 of this utility model.

[0035] Figure 5 This is a schematic diagram of the internal structure of the composite pole before deformation in Embodiment 1 of this utility model.

[0036] Figure 6 This is a schematic diagram of the internal structure of the composite pole after deformation in Embodiment 1 of this utility model.

[0037] Figure 7 This is a three-dimensional structural diagram of the composite pole after deformation in Embodiment 1 of this utility model.

[0038] Figure 8 This is an exploded view of part of the structure of the secondary battery in Embodiment 2 of this utility model.

[0039] Figure 9 This is another exploded view of part of the structure of the secondary battery in Embodiment 2 of this utility model.

[0040] Figure 10 This is a schematic diagram of the internal structure of a secondary battery according to Embodiment 2 of this utility model.

[0041] Figure 11 This is a schematic diagram of the structure of the composite pole and the riveting ring in Embodiment 2 of this utility model.

[0042] Figure 12 This is a schematic diagram of the internal structure of the composite pole before deformation in Embodiment 1 of this utility model.

[0043] Figure 13 This is a schematic diagram of the internal structure of the composite pole after deformation in Embodiment 1 of this utility model.

[0044] Figure 14 This is a three-dimensional structural diagram of the composite pole after deformation in Embodiment 1 of this utility model.

[0045] Explanation of reference numerals in the attached figures:

[0046] Cover plate body 1

[0047] First positive electrode through-hole 11

[0048] First negative electrode through-hole 12

[0049] Lower plastic 2

[0050] Positive electrode post 3

[0051] Negative electrode post 4

[0052] First pole piece 41

[0053] Second pole piece 42

[0054] First column segment 421

[0055] Second column segment 422

[0056] Step section 4221

[0057] First protrusion 423

[0058] Third pole body 43

[0059] First through hole 431

[0060] Countersunk head 4311 for the first through hole

[0061] Positive electrode plastic 51

[0062] Second positive electrode through-hole 511

[0063] Plastic 52 on the negative electrode

[0064] Second negative electrode through-hole 521

[0065] Positive electrode riveting ring 6

[0066] Negative electrode riveting ring 7

[0067] Rivet ring body 71

[0068] Second protrusion 72

[0069] Second through hole 73

[0070] Countersunk head 731 for the second through hole

[0071] The second through hole 732

[0072] Third through hole 74

[0073] Positive electrode sealing ring 81

[0074] Third positive electrode through-hole 811

[0075] Negative electrode sealing ring 82

[0076] Third negative electrode through-hole 821

[0077] Positive pin 91

[0078] Fourth positive electrode through-hole 911

[0079] Negative pin 92

[0080] Fourth negative electrode through hole 921 Detailed Implementation

[0081] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment as an example.

[0082] Example 1

[0083] like Figures 1-4 As shown, this embodiment discloses a secondary battery, including a casing, a battery cover, and a cell assembly. The cell assembly is disposed inside the casing, and the battery cover is disposed on the open end of the casing to form a sealed receiving space.

[0084] like Figures 1-4 As shown, the battery cover includes a cover body 1, a lower plastic 2, a positive electrode post 3, a negative electrode post 4, a positive upper plastic 51, a negative upper plastic 52, a positive riveting ring 6, a negative riveting ring 7, a positive sealing ring 81, and a negative sealing ring 82. The lower plastic 2, the positive riveting ring 6, and the negative riveting ring 7 are all located at the end of the cover body 1 facing the receiving space. The positive upper plastic 51 and the negative upper plastic 52 are both located at the end of the cover body 1 facing the external space of the secondary battery. The positive electrode post 3 and the negative electrode post 4 both pass through the cover body 1. The end of the positive electrode post 3 and the negative electrode post 4 facing the receiving space is electrically connected to the battery cell assembly, and the end of the positive electrode post 3 and the negative electrode post 4 facing the external space of the secondary battery is connected to the electrical equipment. The positive electrode sealing ring 81 is used to achieve insulation between the positive electrode post 3 and the positive electrode riveting ring 6 and the cover plate body 1, and the negative electrode sealing ring 82 is used to achieve insulation between the negative electrode post 4 and the negative electrode riveting ring 7 and the cover plate body 1.

[0085] Specifically, such as Figure 1 and Figure 2 As shown, the cover plate body 1 has a first positive electrode through hole 11 and a first negative electrode through hole 12. The positive electrode plastic 51 has a second positive electrode through hole 511, and the negative electrode plastic 52 has a second negative electrode through hole 521. The positive electrode sealing ring 81 has a third positive electrode through hole 811, and the negative electrode sealing ring 82 has a third negative electrode through hole 821. The first positive electrode through hole 11, the second positive electrode through hole 511, the third positive electrode through hole 811, the first negative electrode through hole 12, the second negative electrode through hole 521, and the third negative electrode through hole 821 all penetrate at both ends in the thickness direction of the cover plate body 1 to allow the corresponding positive electrode post 3 and negative electrode post 4 to pass through. The thickness direction of the cover plate body 1 is the axial direction of the positive electrode post 3 and the negative electrode post 4.

[0086] Plastic 51 on the positive electrode and plastic 52 on the negative electrode are disposed on the end face of the cover plate body 1 facing the external space of the secondary battery. Plastic 51 on the positive electrode is sandwiched between the cover plate body 1 and the positive electrode post 3 in the axial direction of the positive electrode post 3, and plastic 52 on the negative electrode is sandwiched between the cover plate body 1 and the negative electrode post 4 in the axial direction of the negative electrode post 4. A positive electrode sealing ring 81 is sleeved on the outer periphery of the positive electrode post 3. One end of the positive electrode sealing ring 81 extends into the first positive electrode through hole 11 and abuts against the end face of the plastic 51 on the positive electrode facing the receiving space. The other end of the positive electrode sealing ring 81 is sandwiched between the cover plate body 1 and the positive electrode riveting ring 6 in the axial direction of the positive electrode post 3, thereby achieving insulation between the positive electrode post 3 and the positive electrode riveting ring 6 and the cover plate body 1. The negative electrode sealing ring 82 is sleeved on the outer periphery of the negative electrode post 4. One end of the negative electrode sealing ring 82 extends into the first negative electrode through hole 12 and abuts against the end face of the plastic 52 on the negative electrode facing the receiving space. The other end of the negative electrode sealing ring 82 is clamped between the cover plate body 1 and the negative electrode riveting ring 7 in the axial direction of the negative electrode post 4, thereby achieving insulation between the negative electrode post 4 and the negative electrode riveting ring 7 and the cover plate body 1.

[0087] like Figures 1-4 As shown, the battery cell assembly is connected to the positive electrode riveting ring 6 and the negative electrode riveting ring 7 via the positive electrode pin 91 and the negative electrode pin 92, respectively. Specifically, the positive electrode pin 91 is provided with a fourth positive electrode through hole 911, which is sleeved on the outer periphery of the positive electrode riveting ring 6. The opening of the fourth positive electrode through hole 911 facing the receiving space is welded to the outer edge of the positive electrode riveting ring 6 facing the receiving space, thereby realizing the electrical connection between the battery cell assembly and the positive electrode riveting ring 6. Since the positive electrode riveting ring 6 is riveted and fixed to the positive electrode post 3, the electrical connection between the positive electrode riveting ring 6 and the positive electrode post 3 is realized through the positive electrode riveting ring 6. The negative electrode pin 92 is provided with a fourth negative electrode through hole 921, which is sleeved on the outer periphery of the negative electrode riveting ring 7. The opening of the fourth negative electrode through hole 921 facing the receiving space is welded to the outer edge of the negative electrode riveting ring 7 facing the receiving space, thereby realizing the electrical connection between the battery cell assembly and the negative electrode riveting ring 7. Since the negative electrode riveting ring 7 is riveted and fixed to the negative electrode post 4, the electrical connection between the negative electrode riveting ring 7 and the negative electrode post 4 is realized through the negative electrode riveting ring 7.

[0088] In this embodiment, the positive electrode post 3 is a single-material electrode structure, with both the positive electrode post 3 and the positive electrode riveting ring 6 made of aluminum. The negative electrode post 4 is a composite electrode, specifically a copper-aluminum composite electrode. The copper segment in the negative electrode post 4 is connected to the negative electrode riveting ring 7, and the aluminum segment in the negative electrode post 4 is connected to the external electrical equipment. The negative electrode riveting ring 7 is made of copper to better connect with the copper segment in the negative electrode post 4.

[0089] In other alternative implementations, the materials for the positive electrode post 3 and the negative electrode post 4 can also be other conventional electrode materials.

[0090] Specifically, such as Figure 4 and Figure 5 As shown, the negative electrode post 4 includes a first electrode post 41, a second electrode post 42, and a third electrode post 43. The first electrode post 41 is made of a different material than the second electrode post 42, while the third electrode post 43 is made of the same material as the second electrode post 42. The first electrode post 41 is made of copper, while the second electrode post 42 and the third electrode post 43 are made of aluminum. The first electrode post 41 and the third electrode post 43 are respectively located at opposite ends of the second electrode post 42 along the axial direction of the negative electrode post 4. The first electrode post 41 is located at the end of the second electrode post 42 facing the receiving space along the axial direction of the negative electrode post 4, and the third electrode post 43 is located at the end of the second electrode post 42 facing the external space of the secondary battery along the axial direction of the negative electrode post 4. The first electrode post 41 is connected to the battery cell assembly, and the second electrode post 42 is connected to the electrical device through the third electrode post 43.

[0091] Furthermore, such as Figure 4 and Figure 5 As shown, the cross-sectional area of ​​the third electrode post 43 in the first plane (the first plane is perpendicular to the axis of the negative electrode post 4) is larger than that of the second electrode post 42 in the first plane. The third electrode post 43 is axially positioned at the end of the negative electrode plastic 52 away from the cover plate body 1. The negative electrode plastic 52 is axially sandwiched between the cover plate body 1 and the third electrode post 43. The first electrode post 41 and the second electrode post 42 pass through the first negative electrode through hole 12, the second negative electrode through hole 521, and the third negative electrode through hole 821. The third electrode post 43 can increase the connection area and connection strength with external electrical equipment. This can reduce contact resistance, improve current carrying capacity, enhance the stability of mechanical connection, and improve the overall performance and reliability of the battery pack.

[0092] In this embodiment, the second pole piece 42 and the third pole piece 43 are integrally formed, which is convenient to process and requires less time. In other alternative embodiments, the second pole piece 42 and the third pole piece 43 can also be separate structures, that is, they are formed separately and then connected by welding or other methods.

[0093] In this embodiment, the end of the first pole piece 41 away from the second pole piece 42 is a riveting end for cooperating with the riveting equipment. The riveting equipment applies pressure to the end face of the first pole piece 41 facing the receiving space, so that the negative pole piece 4 is deformed according to the shape of the negative riveting ring 7.

[0094] Specifically, such as Figures 5-7As shown, the second pole post 42 includes a first pole segment 421 and a second pole segment 422. The first pole segment 421 is connected to the end of the second pole segment 422 away from the first pole post 41. The diameter of the first pole segment 421 is larger than the diameter of the second pole segment 422. The portion of the first pole segment 421 that extends radially beyond the second pole segment 422 in the negative pole post 4 forms a contact surface that abuts against the negative pole riveting ring 7.

[0095] like Figure 4 As shown, the negative electrode riveting ring 7 includes a riveting ring body 71, a second boss 72, a second through hole 73, and a third through hole 74. The second through hole 73 penetrates both ends of the riveting ring body 71 in the axial direction of the negative electrode post 4, and the third through hole 74 penetrates both ends of the second boss 72 in the axial direction of the negative electrode post 4. The second boss 72 extends radially from the hole wall of the second through hole 73 toward the interior of the second through hole 73. The second through hole 73 and the third through hole 74 are coaxial and interconnected.

[0096] like Figure 5 As shown, before the negative electrode post 4 is riveted to the negative electrode riveting ring 7, the diameter of the second post segment 422 is equal everywhere, and the end face of the first electrode post 41 facing the receiving space is a smooth surface. Figure 4 , Figure 6 and Figure 7 As shown, when riveting the negative electrode post 4 to the negative electrode riveting ring 7, the negative electrode riveting ring 7 is first fitted onto the outer periphery of the negative electrode post 4, so that the end face of the second protrusion 72 facing the first column segment 421 in the axial direction of the negative electrode post 4 abuts against the first column segment 421. Then, the riveting equipment is controlled to apply pressure to the first electrode body 41, so that the first electrode body 41 and the second column segment 422 are deformed. The second column segment 422 deforms to form a stepped portion 4221. The end face of the second protrusion 72 away from the first column segment 421 in the axial direction of the negative electrode post 4 abuts against the stepped portion 4221. The outer peripheral surface of the stepped portion 4221 and the outer peripheral surface of the first electrode body 41 both abut against the wall of the second through hole 73. The stepped portion 4221 formed after the deformation of the second column segment 422 and the first column segment 421 lock the position of the second protrusion 72 in the axial direction of the negative electrode post 4, thereby fixing the negative electrode post 4 and the negative electrode riveting ring 7.

[0097] After riveting is completed, the first pole post 41 and the negative pole riveting ring 7 are further welded together to secure them. Specifically, as shown... Figure 4As shown, in this embodiment, the second through hole 73 is a countersunk hole. The countersunk end 731 of the second through hole is located at the end of the second through hole 73 away from the second electrode post 42. The outer peripheral surface of the first electrode post 41 abuts against the wall of the through hole 732 of the second through hole. The end face of the first electrode post 41 away from the second electrode post 42 is flush with the stepped surface of the countersunk end 731 of the second through hole, so as to facilitate the welding operation at the junction of the first electrode post 41, the countersunk end 731 of the second through hole, and the through hole. Since the welding point is generally not flat, the countersunk end 731 of the second through hole can prevent the welding point from contacting other parts of the cell assembly, thus improving reliability. The stepped surface of the countersunk end 731 of the second through hole can also limit the operating distance of the riveting equipment and prevent excessive compression of the second boss 72.

[0098] In other alternative embodiments, the second through hole 73 can also be a common through hole structure, with the end face of the first pole post 41 facing the receiving space flush with the end of the second through hole 73 facing the receiving space, to facilitate welding operations.

[0099] Furthermore, in this embodiment, the outer peripheral surface of the end of the second column segment 422 facing the first pole column 41 is in the same curved surface as the outer peripheral surface of the first pole column 41, so as to prevent the first pole column 41 from being too small, ensure that the first pole column 41 has enough area to contact the riveting equipment, and also prevent the increase in material cost caused by the first pole column 41 being too large.

[0100] In other alternative embodiments, the diameter of the first pole post 41 may be greater than or less than the diameter of the end of the second column segment 422 facing the first pole post 41, so as to always ensure that the riveting device only contacts the first pole post 41.

[0101] In this design, the negative electrode riveting ring 7 abuts against the end face of the first column segment 421 facing the first electrode post 41. Therefore, when the negative electrode riveting ring 7 is riveted to the negative electrode post 4, in addition to the first electrode post 41, which is in direct contact with the riveting equipment, undergoing significant deformation, the end of the second column segment 422 facing the first electrode post 41 also undergoes significant deformation. That is, the deformation degree of the connection area between the first electrode post 41 and the second column segment 422 is approximately the same, thereby ensuring the structural stability of the joint surface area of ​​the first electrode post 41 and the second electrode post 42. Moreover, the stress point between the negative electrode post 4 and the negative electrode riveting ring 7 is transferred to the area where the step portion 4221 of the second column segment 422 abuts against the second protrusion 72 of the negative electrode riveting ring 7, avoiding stress on the joint surface of the first electrode post 41 and the second electrode post 42, making the joint surface area of ​​the first electrode post 41 and the second electrode post 42 less prone to detachment, thus improving battery performance and safety.

[0102] In this embodiment, the first electrode post 41, the second electrode post 42, and the third electrode post 43 are integrally formed, specifically by stamping on a copper-aluminum composite plate to form the negative electrode post 4. The copper-aluminum composite plate is an existing finished material that can be directly used, reducing processing difficulty and time.

[0103] The one-piece molding method simplifies processing, reduces processing difficulty and time, eliminates potential connection weaknesses caused by separate welding or assembly, further improves the structural integrity and mechanical strength of the negative electrode post 4, and ensures the stability of the current transmission path.

[0104] In other alternative embodiments, the first pole piece 41 and the second pole piece 42 can also be formed separately and then fixed by welding.

[0105] In other alternative implementations, if the negative electrode post 4 is made of other materials, a metal composite plate of the corresponding material can be selected.

[0106] Example 2

[0107] The negative electrode post 4 in this embodiment is basically the same as that in embodiment 1, except that the second electrode post 42 and the third electrode post 43 are separate structures.

[0108] like Figures 8-14 As shown, the third pole post 43 is provided with a first through hole 431, which extends through both ends of the negative pole post 4 in the axial direction. The first through hole 431 is a countersunk hole, and the countersunk end 4311 of the first through hole is located on the side of the first through hole 431 away from the first pole post 41. The first column segment 421 is provided with a first boss 423 at the end away from the first pole post 41. The first boss 423 extends radially from the outer peripheral surface of the first column segment 421 along the second pole post 42 towards the outside of the first column segment 421. The second pole post 42 passes through the first through hole 431. The first boss 423 abuts against the stepped surface of the countersunk end 4311 of the first through hole to facilitate the positioning between the second pole post 42 and the third pole post 43. The stepped surface of the countersunk end 4311 of the first through hole provides support for the second pole post 42 and improves the structural strength.

[0109] The outer edge of the end of the second pole post 42 away from the receiving space is welded and fixed to the port of the first through hole 431 away from the receiving space, so as to fix the position of the second pole post 42 and the third pole post 43.

[0110] In this embodiment, the second pole piece 42 and the third pole piece 43 are designed as a separate structure, which can save the amount of metal composite plate used and reduce material costs.

[0111] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship of the device or component shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0112] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A composite electrode, characterized in that, It includes a first electrode post and a second electrode post. The first electrode post is made of a different material than the second electrode post. The first electrode post is used to connect to the battery cell assembly, and the second electrode post is used to connect to the electrical equipment. The first pole piece is disposed on one end face of the second pole piece along the axial direction of the composite pole piece, and the end of the first pole piece away from the second pole piece is a riveting end for cooperating with riveting equipment; The second electrode post includes a first post segment and a second post segment. The first post segment is connected to the end of the second post segment away from the first electrode post. The diameter of the first post segment is larger than the diameter of the second post segment. The end face of the first post segment facing the first electrode post is used to abut against the riveting ring of the battery cover.

2. The composite electrode as described in claim 1, characterized in that, The first pole piece and the second pole piece are integrally formed.

3. The composite electrode as described in claim 2, characterized in that, The copper-aluminum composite plate forms the first pole piece and the second pole piece, wherein the first pole piece is made of copper and the second pole piece is made of aluminum.

4. The composite electrode as described in claim 1, characterized in that, The outer peripheral surface of the end of the second column facing the first pole column is in the same curved surface as the outer peripheral surface of the first pole column.

5. The composite electrode as described in claim 2, characterized in that, The composite pole also includes a third pole connected to the end of the second pole away from the first pole. The material of the third pole is the same as that of the second pole. The cross-sectional area of ​​the third pole in a first plane is greater than that of the second pole in the first plane. The first plane is perpendicular to the axis of the composite pole.

6. The composite electrode as described in claim 5, characterized in that, The second pole piece and the third pole piece are integrally formed; or, the second pole piece and the third pole piece are separate structures.

7. The composite electrode as described in claim 6, characterized in that, When the second pole piece and the third pole piece are a separate structure, the third pole piece is provided with a first through hole. The first through hole passes through both ends of the composite pole piece in the axial direction. The first through hole is a countersunk hole, and the countersunk of the first through hole is located on the side of the first through hole away from the first pole piece. The first column segment has a first protrusion at the end away from the first pole body. The first protrusion extends radially from the outer peripheral surface of the first column segment toward the outside of the second pole body. The second pole body passes through the first through hole, and the first protrusion abuts against the countersunk step surface of the first through hole.

8. A battery cover, characterized in that, It includes a rivet ring and a composite pole as described in any one of claims 1-7, the composite pole passing through the rivet ring, the rivet ring abutting against one end face of the first pole segment facing the first pole body, and the rivet ring being connected to the first pole body.

9. The battery cover as described in claim 8, characterized in that, The riveting ring includes a riveting ring body, a second boss, a second through hole, and a third through hole. The second through hole penetrates both ends of the riveting ring body in the axial direction of the composite pole. The third through hole penetrates both ends of the second boss in the axial direction of the composite pole. The second boss extends radially from the wall of the second through hole toward the interior of the second through hole. The second through hole and the third through hole are coaxial and interconnected. The second boss abuts against the first column segment at one end face of the composite pole axially toward the first column segment; after the riveting ring is riveted to the composite pole, the second column segment deforms to form a stepped portion, and the second boss abuts against the stepped portion at one end face of the composite pole axially away from the first column segment, and the outer peripheral surface of the stepped portion and the outer peripheral surface of the first pole body abut against the wall of the second through hole.

10. The battery cover as described in claim 9, characterized in that, The second through hole is a countersunk hole. The countersunk end of the second through hole is located at the end of the second through hole away from the second pole body. The outer peripheral surface of the first pole body abuts against the hole wall of the second through hole. The end face of the first pole body away from the second pole body is flush with the stepped surface of the countersunk end of the second through hole.

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