Pole structure, battery cell and battery pack

Abstract

The utility model relates to battery technical field discloses pole structure, electric core and battery package. Pole structure includes pole bottom plate and at least two pole post bodies arranged on pole bottom plate, and pole post body and pole bottom plate are integrally connected, and the pole post body before assembly includes the assembly column section with the cover plate body of electric core adaptation and the riveting column section with riveting block of electric core riveting adaptation, along X direction, the size of assembly column section is C, and the unit is mm, along Y direction, the size of assembly column section is A, and the unit is mm, satisfies: 1 less than or equal to C / A less than or equal to 3. The utility model provides pole structure, and pole bottom plate can provide greater area with tab welding, significantly increases the area of printing, reduces the current density, avoids local overheating, improves the overcurrent capacity, satisfies the demand of fast charging high current, improves the structural strength of pole, and reliable crimping of riveting column section and riveting block can be ensured again, and the riveting yield is high.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to electrode structure, battery cell and battery pack. Background Technology

[0002] In recent years, with the rapid development of new energy vehicles and energy storage technologies, lithium-ion batteries have become the mainstream choice for power batteries due to their high energy density, long cycle life, and environmental friendliness. To shorten charging time, fast charging technology has become a key research focus in the industry, which places higher demands on the battery's overcurrent capacity, heat dissipation performance, and structural reliability.

[0003] In battery cell structure design, traditional riveted cover plates typically use a single terminal or two independent terminals to achieve current transmission. However, with the increase in fast charging current, the cross-sectional area of ​​a single terminal is limited, resulting in excessively high current density, which can easily lead to local overheating and increased resistance. While the bipolar design can shunt current, the discrete terminals weaken the structural strength and further reduce the overcurrent capacity due to uneven current distribution. Moreover, the solder area between the terminal base plate and the tab of the bipolar design is limited, making it difficult to meet the requirements of high-power fast charging.

[0004] Therefore, how to improve the current carrying capacity of the electrode while ensuring structural strength has become a key issue that current lithium-ion battery fast charging technology urgently needs to solve. Utility Model Content

[0005] In view of this, the present invention provides a terminal structure, a battery cell, and a battery pack to solve the problem of poor current carrying capacity of the terminal.

[0006] In a first aspect, this utility model provides an electrode post structure, including an electrode post base plate and at least two electrode post bodies disposed on the electrode post base plate, wherein the electrode post bodies and the electrode post base plate are integrally connected; the electrode post body before assembly includes an assembly post segment adapted to the cover plate body of the battery cell and a riveting post segment adapted to the riveting block of the battery cell; along the X direction, the dimension of the assembly post segment is C, in mm, and along the Y direction, the dimension of the assembly post segment is A, in mm, satisfying: 1≤C / A≤3.

[0007] Beneficial effects: The electrode post structure provided by this utility model integrates two or more electrode posts that are traditionally separate. That is, two or more electrode post bodies are set on a base plate of an electrode post, and the base plate and the post bodies are connected as a whole. The base plate of the electrode post can provide a larger welding area with the electrode tab, thereby significantly increasing the welding area, reducing the current density, avoiding local overheating, improving the overcurrent capacity, and meeting the high current requirements of fast charging.

[0008] Furthermore, the integrated connection between the electrode post and the base plate reduces contact resistance and improves conductivity. Simultaneously, the design of multiple electrode posts allows for higher current carrying capacity within a limited space. The integrated connection between the electrode post and the base plate avoids the structural weakening issues associated with traditional separate bipolar electrode systems, thus enhancing the structural strength of the electrode posts.

[0009] Finally, this embodiment of the invention also limits the dimensional ratio C / A of the assembly column segment in two directions to within the range of 1 to 3. If the value of C / A is too small, less than 1, it will reduce the current carrying capacity of the column, and its use is not recommended; if the value of C / A is too large, greater than 3, it will result in a low riveting yield between the column and the cell. Therefore, this embodiment of the invention requires 1≤C / A≤3, which ensures both a high current carrying capacity of the column and reliable crimping between the riveting column segment and the riveting block, resulting in a high riveting yield.

[0010] In one alternative implementation, along the Y direction, the dimension of the pole base plate is B, in mm, which satisfies: 4mm≤A≤B-3mm.

[0011] In one optional embodiment, the two pole posts located at both ends have a distance D along the X direction between the assembly column of the pole post and the edge of the pole post base plate on the corresponding side, satisfying: D≥1.5mm.

[0012] In one alternative implementation, the spacing between adjacent assembly column segments along the X direction is E, in mm, which satisfies: E≥3mm.

[0013] In one optional embodiment, the cross-sectional shape of the assembly column segment along the XY plane is circular with a radius of r, satisfying: 2r=C=A; or, the cross-sectional shape of the assembly column segment along the XY plane is racetrack-shaped, including two oppositely arranged straight edge segments and an arc segment connecting the two straight edge segments, with the straight edge segments arranged along the X direction.

[0014] In one alternative implementation, the pole structure is made of pure copper or pure aluminum.

[0015] In one optional embodiment, the pole base plate includes a base plate body and a base plate column segment protruding from the base plate body. An assembly column segment is disposed on the base plate column segment. The cross-sectional dimensions of the base plate column segment along the XY plane are the same as those of the assembly column segment. The pole base plate is made of copper, and the pole column body is made of aluminum.

[0016] In one optional implementation, along the Z direction, the dimension by which the base plate column protrudes beyond the main body of the base plate is F, in mm, satisfying: F≥0.2mm.

[0017] Secondly, this utility model also provides a battery cell, including a housing, an electrode assembly, and a cover plate assembly. The housing has a receiving cavity, and the housing is provided with at least one open end communicating with the receiving cavity; the electrode assembly is disposed in the receiving cavity, and the electrode assembly has a positive electrode tab and a negative electrode tab leading out; the cover plate assembly is disposed at the open end of the housing, and encapsulates the electrode assembly inside the housing; the cover plate assembly includes a positive electrode post and a negative electrode post, at least one of the positive electrode post and the negative electrode post having the electrode post structure described in any of the above technical solutions, the positive electrode post being welded to the positive electrode tab, and the negative electrode post being welded to the negative electrode tab.

[0018] Beneficial effects: The cover assembly of the battery cell is used to seal the openings of the cell casing, serving to seal and protect the internal components of the battery, preventing chemical leakage and the impact of the external environment on the battery. The terminals of the cover assembly provide a path for current inflow and outflow, ensuring current conduction during the charging and discharging process of the battery cell.

[0019] Since the battery cell includes a terminal structure, it has all the technical benefits of a terminal structure, so I will not go into details here.

[0020] Thirdly, this utility model also provides a battery pack, including multiple battery cells from more than one technical solution, with adjacent battery cells welded together via a busbar.

[0021] Beneficial effects: Since the battery pack includes the cells, it has all the technical benefits of the cells, which will not be elaborated here. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of two independent poles in the related technology;

[0024] Figure 2 for Figure 1 The diagram shows the weld marks of the electrode post after assembly and welding to the electrode lug.

[0025] Figure 3 This is an axial section view of a pole post structure according to an embodiment of the present invention before riveting;

[0026] Figure 4 for Figure 3 The diagram shows the axial section of the pole structure after riveting.

[0027] Figure 5 This is an axial section view of another pole post structure of this utility model before riveting;

[0028] Figure 6 for Figure 5 The diagram shows the axial section of the pole structure after riveting.

[0029] Figure 7 This is a perspective view of a pole post structure according to an embodiment of the present utility model;

[0030] Figure 8 This is a perspective view of another pole post structure according to an embodiment of the present utility model;

[0031] Figure 9 for Figure 8 A schematic diagram of each dimension in the top view of the pole structure shown;

[0032] Figure 10 This is a schematic diagram of the weld marks of a pole post structure after assembly and welding to the pole lug, according to an embodiment of the present utility model.

[0033] Figure 1 and Figure 2 Explanation of reference numerals in the attached figures:

[0034] 101', Base plate of pole post; 102', Pole post body; 2', Solder mark.

[0035] Figures 3 to 10 Explanation of reference numerals in the attached figures:

[0036] 1. Pole column structure; 101. Pole column base plate; 1011. Base plate main body; 1012. Base plate column segment; 102. Pole column body; 1021. Assembly column segment; 1022. Riveted column segment; 2. Welding marks. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0038] In related technologies, there are solutions that use two independent poles, such as... Figure 1 and Figure 2 As shown, both terminals include a terminal base plate 101' and a terminal body 102'. In these designs, the terminal can only provide a limited welding area to the tab, that is, the area of ​​the solder mark 2' after welding to the tab is limited, resulting in weak current carrying capacity and difficulty in meeting the requirements of high-power fast charging. In addition, discrete terminals also weaken the structural strength.

[0039] To address the aforementioned technical issues, it is urgent to design a new pole structure 1 to optimize the current transmission path, reduce contact resistance, ensure stability and safety under high current, and guarantee the structural strength of the pole.

[0040] The following is combined Figures 3 to 10 The following describes embodiments of the present invention.

[0041] According to an embodiment of the present invention, in a first aspect, a pole post structure 1 is provided, including a pole post base plate 101 and at least two pole post bodies 102 disposed on the pole post base plate 101, wherein the pole post bodies 102 and the pole post base plate 101 are integrally connected; the pole post body 102 before assembly includes an assembly column segment 1021 adapted to the cover plate body of the battery cell and a riveting column segment 1022 adapted to the riveting block of the battery cell; the dimension of the assembly column segment 1021 along the X direction is C, in mm, and the dimension of the assembly column segment 1021 along the Y direction is A, in mm, satisfying: 1≤C / A≤3.

[0042] Specifically, refer to Figure 9 In the diagram, the X direction represents the length of the pole post base plate 101, and the Y direction represents the width of the pole post base plate 101. Along the X direction, the dimension C of the assembly column segment 1021 is also the length of the pole post assembly column segment 1021, and is also the distance between the center points of the two arc segments. Along the Y direction, the dimension A of the assembly column segment 1021 is also the width of the pole post assembly column segment 1021, and is also the perpendicular distance between the two straight edge segments.

[0043] The electrode post structure 1 provided by this utility model integrates two or more electrode posts of the traditional split type into one unit. That is, two or more electrode post bodies 102 are provided on one electrode post base plate 101, and the electrode post base plate 101 and the post bodies are integrally connected. The electrode post base plate 101 can provide a larger welding area with the electrode lug, thereby significantly increasing the welding area 2 (from the existing...). Figure 2 The length of solder mark 2 shown is increased to Figure 10 The solder mark 2 shown in the figure is of a length that reduces the current density, avoids local overheating, improves the overcurrent capacity, and meets the high current requirements of fast charging.

[0044] Furthermore, the integral connection between the electrode post 102 and the electrode base plate 101 reduces contact resistance and improves conductivity. Simultaneously, the design of multiple electrode posts 102 allows for higher current carrying capacity within a limited space. The integral connection between the electrode post 102 and the electrode base plate 101 avoids the weakening of the electrode structure 1 caused by the traditional separate bipolar electrode design, thus improving the structural strength of the electrode.

[0045] Finally, this embodiment of the invention also limits the dimensional ratio C / A of the assembly post segment 1021 in two directions to within the range of 1 to 3. If the value of C / A is too small, less than 1, it will reduce the current carrying capacity of the post, and its use is not recommended; if the value of C / A is too large, greater than 3, it will result in a low riveting yield between the post and the cell. Therefore, this embodiment of the invention requires 1≤C / A≤3, which ensures both a high current carrying capacity of the post and reliable crimping between the riveting post segment 1022 and the riveting block, resulting in a high riveting yield.

[0046] After the terminal post is assembled, the riveting post segment 1022 of the terminal post will be riveted to the riveting block of the battery cell, and deformation will occur. The structure before riveting is as follows: Figure 3 or Figure 5 As shown, the structure after riveting is as follows Figure 4 , Figure 6 , Figure 7 or Figure 8 As shown, this section is still the riveted column section 1022.

[0047] In some embodiments, along the Y direction, the dimension of the pole base plate 101 is B, in mm, which satisfies: 4mm≤A≤B-3mm.

[0048] Specifically, along the Y direction, the dimension B of the pole base plate 101 is also the width of the pole base plate 101.

[0049] In this embodiment, A is required to be ≥ 4mm, that is, the width of the assembly column 1021 of the pole post is not less than 4mm. Otherwise, if the width of the pole post is too small, it will increase the difficulty of riveting the pole post and the riveting block, and the structural strength of the pole post 102 itself will also be weakened, so it is not recommended to use it.

[0050] In this embodiment, A ≤ B - 3 mm is required, that is, (B - A) / 2 ≥ 1.5 mm, referring to... Figure 9 Along the Y direction, that is, along the width direction of the electrode base plate 101, the single-side distance between the electrode assembly column 1021 and the electrode base plate 101 should not be less than 1.5mm. Otherwise, when the sealing ring of the battery cell is assembled on the electrode column body 102, the remaining space of the electrode base plate 101 along the Y direction cannot support the sealing ring, thus failing to guarantee the sealing effect of the battery cell.

[0051] In some embodiments, the distance between the assembly column segment 1021 of the two pole posts 102 located at both ends and the edge of the pole post base plate 101 on the corresponding side along the X direction is D, which satisfies: D≥1.5mm.

[0052] Reference Figure 9In this embodiment, the distance between the mounting segment 1021 of the pole post and the edge of the pole post base plate 101 is defined along the X direction, that is, along the length direction of the pole post base plate 101. Since both ends of the mounting segment 1021 along the X direction are arc segments, the center point of the arc segment is the most prominent edge, and D is the vertical distance from the center point of the arc segment to the edge of the pole post base plate 101 on the corresponding side. Two or more pole post pillars 102 are symmetrically distributed on the pole post base plate 101 along the X direction, and the side distance between the pole post pillars 102 on both sides and the side edge of the pole post base plate 101 is D.

[0053] In this embodiment, D is limited to not less than 1.5mm. Otherwise, when the sealing ring of the battery cell is assembled on the electrode post 102, the remaining space of the electrode post base plate 101 in the X direction cannot support the sealing ring, thus failing to guarantee the sealing effect of the battery cell.

[0054] In some embodiments, along the X direction, the spacing between adjacent assembly column segments 1021 is E, in mm, which satisfies: E≥3mm.

[0055] Specifically, refer to Figure 9 Since both ends of the assembly column segment 1021 are arc segments along the X direction, the distance between adjacent assembly column segments 1021 is the minimum distance between the arc segments of two adjacent assembly column segments 1021. The center point of the arc segment is the most prominent position. Therefore, E is also the distance between the center points of the arc segments of two adjacent assembly column segments 1021.

[0056] Since each terminal post needs to be installed in the terminal post mounting hole of the cover plate body, and a sealing ring needs to be fitted between each terminal post and the cover plate body for sealing, in this embodiment, the spacing E of the assembly post segments 1021 of adjacent terminals is further limited to ensure that it is not less than 3mm. Otherwise, it will be difficult to assemble two adjacent sealing rings, thereby affecting the sealing effect of the battery cell.

[0057] In some embodiments, the cross-sectional shape of the assembly column segment 1021 along the XY plane is circular with a radius of r, satisfying: 2r=C=A; or, the cross-sectional shape of the assembly column segment 1021 along the XY plane is racetrack-shaped, including two oppositely arranged straight edge segments and an arc segment connecting the two straight edge segments, the straight edge segments being arranged along the X direction.

[0058] Specifically, the cross-section of the XY plane, that is, the plane perpendicular to the axial direction of the assembly column segment 1021.

[0059] In some embodiments, the pole is circular. (See reference...) Figure 7 Specifically, before assembly, the assembly column segment 1021 of the pole column 102 is a cylinder, so the length and width of the assembly column segment 1021 are equal, and the length and width of the assembly column segment 1021 are also the diameter of the assembly column segment 1021.

[0060] In other embodiments, the pole post is racetrack shaped. (See reference...) Figure 8 Specifically, before assembly, the cross-sectional shape of the assembly column segment 1021 along the XY plane is racetrack-shaped. When the radius of the arc segments at both ends is also r, the cross-sectional area of ​​the racetrack-shaped pole is larger than that of the circular pole, resulting in stronger current carrying capacity.

[0061] In some embodiments, the pole structure 1 is made of pure copper or pure aluminum.

[0062] In a battery cell, the terminals are divided into positive terminals and negative terminals. When terminal structure 1 is a positive terminal, the terminal is made of pure aluminum. When terminal structure 1 is a negative terminal, the terminal is made of pure copper.

[0063] In some embodiments, the pole base plate 101 includes a base plate body 1011 and a base plate column segment 1012 protruding from the base plate body 1011. An assembly column segment 1021 is disposed on the base plate column segment 1012. The cross-sectional dimensions of the base plate column segment 1012 along the XY plane are the same as those of the assembly column segment 1021. The pole base plate 101 is made of copper, and the pole column body 102 is made of aluminum.

[0064] In some embodiments, the negative electrode post is a copper-aluminum composite electrode post. That is, the electrode post base plate 101 (base plate body 1011 and base plate post segment 1012) is made of copper, and the electrode post body 102 is made of aluminum. For this composite electrode post, an integral molding structure can be achieved using existing processing techniques, such as machining or cold heading.

[0065] In some embodiments, along the Z direction, the dimension of the base plate column segment 1012 protruding from the base plate body 1011 is F, in mm, and satisfies: F≥0.2mm.

[0066] Specifically, the Z direction is the axial direction of the base plate column segment 1012 or the assembly column segment 1021.

[0067] In this embodiment, the dimension F of the bottom plate column segment 1012 protruding from the bottom plate body 1011 is further limited, requiring it to be no less than 0.2mm. In this way, in the cell structure, after the sealing ring is installed on the electrode post, it can cooperate with the sealing ring to prevent the electrolyte from entering the copper-aluminum interface and avoid the formation of a galvanic cell that would lead to corrosion.

[0068] According to an embodiment of the present invention, in a second aspect, a battery cell is also provided, comprising a housing, an electrode assembly, and a cover plate assembly. The housing has a receiving cavity, and the housing is provided with at least one open end communicating with the receiving cavity; the electrode assembly is disposed within the receiving cavity, and the electrode assembly has a positive electrode tab and a negative electrode tab leading out; the cover plate assembly is disposed at the open end of the housing, and encapsulates the electrode assembly within the housing; the cover plate assembly includes a positive electrode post and a negative electrode post, at least one of the positive electrode post and the negative electrode post being electrode post structure 1 as described in any of the above embodiments, the positive electrode post being welded to the positive electrode tab, and the negative electrode post being welded to the negative electrode tab.

[0069] The cover assembly of the battery cell is used to seal the openings in the cell casing, serving to seal and protect the internal components of the battery, preventing chemical leakage and the impact of the external environment on the battery. The terminals of the cover assembly provide a path for current to flow in and out, ensuring current conduction during the charging and discharging process of the battery cell.

[0070] Since the battery cell includes electrode structure 1, it has all the technical effects of electrode structure 1, which will not be elaborated here.

[0071] According to an embodiment of the present invention, in a third aspect, a battery pack is also provided, comprising a plurality of battery cells as described in the above embodiments, wherein adjacent battery cells are welded together via a busbar.

[0072] Since the battery pack includes the battery cells and has all the technical benefits of the battery cells, it will not be elaborated here.

[0073] Although 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 pole post structure, characterized in that, It includes a base plate and at least two pole posts disposed on the base plate, wherein the pole posts and the base plate are integrally connected; the pole posts before assembly include an assembly column segment adapted to the cover plate body of the battery cell and a riveting column segment adapted to the riveting block of the battery cell. Along the X direction, the dimension of the assembly column segment is C, in mm. Along the Y direction, the dimension of the assembly column segment is A, in mm. satisfy: 1≤C / A≤3.

2. The pole post structure according to claim 1, characterized in that, Along the Y direction, the dimension of the pole post base plate is B, in mm, which satisfies: 4mm≤A≤B-3mm.

3. The pole post structure according to claim 1 or 2, characterized in that, The two pole posts located at both ends, with the distance D between the assembly column segment of the pole post and the edge of the corresponding pole post base plate along the X direction, satisfy: D≥1.5mm.

4. The pole post structure according to claim 1 or 2, characterized in that, Along the X direction, the spacing between adjacent assembly column segments is E, in mm, and satisfies: E≥3mm.

5. The pole post structure according to claim 1 or 2, characterized in that, The cross-sectional shape of the assembled column segment along the XY plane is circular with radius r, satisfying: 2r=C=A; Alternatively, the cross-sectional shape of the assembly column segment along the XY plane is racetrack-shaped, including two oppositely arranged straight edge segments and an arc segment connecting the two straight edge segments, wherein the straight edge segments are arranged along the X direction.

6. The pole post structure according to claim 1 or 2, characterized in that, The pole structure is made of pure copper or pure aluminum.

7. The pole post structure according to claim 1 or 2, characterized in that, The pole base plate includes a base plate body and a base plate column segment protruding from the base plate body. The assembly column segment is disposed on the base plate column segment. The cross-sectional dimensions of the base plate column segment along the XY plane are the same as those of the assembly column segment. The pole base plate is made of copper, and the pole column body is made of aluminum.

8. The pole post structure according to claim 7, characterized in that, Along the Z direction, the dimension by which the base plate column protrudes beyond the main body of the base plate is F, in mm, and satisfies: F≥0.2mm.

9. A battery cell, characterized in that, include: A housing having a receiving cavity, the housing having at least one open end communicating with the receiving cavity; A pole assembly is disposed within the receiving cavity, and the pole assembly has a positive electrode tab and a negative electrode tab leading out; A cover plate assembly is disposed at the open end of the housing and encapsulates the electrode group within the housing; the cover plate assembly includes a positive electrode post and a negative electrode post, at least one of the positive electrode post and the negative electrode post being an electrode post structure as described in any one of claims 1 to 8, the positive electrode post being welded to the positive electrode tab, and the negative electrode post being welded to the negative electrode tab.

10. A battery pack, characterized in that, It includes multiple battery cells as described in claim 9, with adjacent battery cells welded together via a busbar.

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