An s-shaped tab

Abstract

The utility model discloses a kind of S-shaped tab, it is related to lithium battery field, the cross section of the S-shaped tab is set to S-shaped structure, the cross section is respectively provided with cross section top horizontal width W1, cross section bottom horizontal width W2, cross section left side ladder horizontal width W3, cross section right side ladder horizontal width W4, cross section left side ladder vertical height H1, cross section right side ladder vertical height H2 and cross section right side ladder bottom vertical height H3, the surface of the S-shaped tab has reinforcing rib, for enhancing the mechanical strength of tab, reduce the deformation and wrinkle phenomenon of tab in winding process;The utility model effectively improves the problem that tab is wrinkled at lithium battery R angle, also avoids the discharge obstruction of formation gas caused by R angle blocking liquid injection hole, improves the performance and safety of battery.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a novel S-shaped tab structure for lithium batteries with high overcurrent requirements and wound structure. Background Technology

[0002] As electronic devices and electric vehicles place increasingly higher demands on lithium-ion battery performance, the width of lithium-ion battery tabs is gradually increasing to meet overcurrent requirements. This increased tab width presents a significant challenge in reconciling the spacing between the tabs and the radius (R-angle) of the wound core, as well as the spacing between the tabs and the electrolyte injection port. If the tabs are too close to the R-angle, the electrode sheets will wrinkle due to the tabs pulling during welding and assembly; if the tabs are too close to the electrolyte injection port, they will obstruct the port, hindering the venting of gas generated during formation. Both issues not only affect the battery's appearance but may also lead to reduced battery capacity and shortened cycle life. Therefore, finding a solution that ensures adequate overcurrent while avoiding obstructing the electrolyte injection port or being too close to the R-angle has become a pressing technical challenge in the lithium-ion battery manufacturing industry.

[0003] In high-energy-density fast charge / discharge systems, the tab width is generally large to ensure overcurrent, making tab spacing design a challenge. When the tab spacing is small, there is a risk of obstructing the injection port and hindering the discharge of formation gas; when the tab spacing is large, the tab is close to the electrode core's radius (R-angle), causing severe wrinkling of the electrode sheet at the tab location due to tab stress during welding. To solve this problem, this invention designs S-shaped tabs instead of the commonly used rectangular or trapezoidal tabs, ensuring overcurrent while avoiding obstructing the injection port and being too close to the radius (R-angle). Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies, effectively improve the problem of wrinkled electrode sheets at the R-corner of lithium batteries, and avoid obstruction of gas discharge caused by the R-corner blocking the injection hole, thereby improving battery performance and safety.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An S-shaped electrode lug, wherein the cross-section of the S-shaped electrode lug is configured as an S-shaped structure, and the cross-section is respectively provided with a horizontal width W1 at the top of the cross-section, a horizontal width W2 at the bottom of the cross-section, a horizontal width W3 of the step on the left side of the cross-section, a horizontal width W4 of the step on the right side of the cross-section, a vertical height H1 of the step on the left side of the cross-section, a vertical height H2 of the step on the right side of the cross-section, and a vertical height H3 at the bottom of the step on the right side of the cross-section.

[0007] Preferably, the horizontal width W1 at the top of the cross section is equal to the horizontal width W2 at the bottom of the cross section, and the horizontal width W3 of the stepped section on the left side of the cross section is less than 1 / 2 of the core thickness.

[0008] Preferably, the vertical height H1 of the step on the left side of the cross section is proportional to the required welding area.

[0009] Preferably, the vertical height H2 of the step on the right side of the cross section is greater than the sum of the overhang of the electrode and the diaphragm and the winding tolerance.

[0010] Preferably, the horizontal width W4 of the step on the right side of the cross section and the vertical height H3 of the bottom of the step on the right side of the cross section define the position of the electrode edge, and the distance between the edge of the S-shaped electrode and the injection hole needs to be greater than the sum of the electrode winding neatness tolerance and the protective adhesive application tolerance.

[0011] Preferably, the horizontal width W1 at the top of the cross section, the horizontal width W2 at the bottom of the cross section, the horizontal width W3 of the step on the left side of the cross section, and the horizontal width W4 of the step on the right side of the cross section are adjustable and satisfy the condition that the vertical height H3 at the bottom of the step on the right side of the cross section is greater than the vertical height H1 of the step on the left side of the cross section, and (W1-W4) 2 +(H3-H1) 2 ≥W1 2 .

[0012] Preferably, the surface of the S-shaped electrode has reinforcing ribs.

[0013] Preferably, the S-shaped tabs are symmetrically assembled onto the battery cell.

[0014] Preferably, the reinforcing rib extends along the length of the electrode tab and its height is 0.1-0.3 times the thickness of the electrode tab; the number of the reinforcing ribs is proportional to the size of the electrode tab and is evenly distributed on the surface of the S-shaped electrode tab.

[0015] Furthermore, compared to the prior art, the advantages of this utility model are as follows:

[0016] 1. By changing the shape of the tab from rectangular or trapezoidal to "S" shape and adding reinforcing ribs to the surface of the tab, the contradiction between the distance between the tab and the R-corner and the distance between the tab and the injection hole is significantly resolved. This not only solves the problem of the electrode wrinkling at the R-corner but also avoids the swelling of the battery caused by insufficient venting after formation, thus improving the appearance quality and internal structural stability of the battery.

[0017] 2. S-shaped tabs have a larger width design space than rectangular tabs, which can meet higher tab current requirements.

[0018] 3. The reinforcing rib design enhances the mechanical strength of the electrode tabs and reduces their deformation during winding.

[0019] 4. The S-shaped tab structure is compatible with existing lithium battery manufacturing processes, requiring no large-scale modification of existing equipment, and has good application prospects. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an S-shaped electrode proposed in this utility model.

[0021] Figure 2 This is a top view of the battery cell proposed in this utility model.

[0022] Figure 3 This is a side view of the battery cell proposed in this utility model.

[0023] Figure 4 This is a top view of the battery cell assembly proposed in this utility model.

[0024] Figure 5 This is a side view of the battery cell assembly proposed in this utility model.

[0025] In the diagram: 1-battery cell, 2-S-shaped tab. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0027] like Figure 1-5 As shown, an S-shaped electrode 2 has an S-shaped cross-section. The cross-section is provided with a horizontal width W1 at the top, a horizontal width W2 at the bottom, a horizontal width W3 on the left side, a horizontal width W4 on the right side, a vertical height H1 on the left side, a vertical height H2 on the right side, and a vertical height H3 at the bottom of the right side. The S-shaped electrode 2 designed in this invention replaces the commonly used rectangular or trapezoidal electrode, so that the electrode does not block the injection hole or approach the R-angle while ensuring flow.

[0028] The horizontal width W1 at the top of the cross section is equal to the horizontal width W2 at the bottom of the cross section. Because the horizontal width W3 of the stepped section on the left side of the cross section depends on the core thickness and the position of the injection hole, and the radius of the core R-angle is 1 / 2 of the core thickness, in order to ensure that the side edge of the S-shaped tab 2 does not exceed the side edge of the core, the horizontal width W3 of the stepped section on the left side of the cross section is less than 1 / 2 of the core thickness.

[0029] The S-shaped tab 2 has reinforcing ribs on its surface. The reinforcing ribs extend along the length of the S-shaped tab 2 and their height is 0.1-0.3 times the thickness of the S-shaped tab 2. The number of reinforcing ribs varies with the size of the S-shaped tab 2 and they are evenly distributed on the surface of the S-shaped tab 2 to enhance the mechanical strength of the S-shaped tab 2 and reduce the deformation and wrinkling of the S-shaped tab 2 during the winding process.

[0030] The vertical height H1 of the step on the left side of the cross section is proportional to the welding area requirement, and its width can be increased as the welding area requirement increases. To avoid the pulling of the R-angle electrode sheet by the welding of the S-shaped electrode 2 while ensuring the welding area requirement, the vertical height H1 of the step on the left side of the cross section should be as small as possible.

[0031] The vertical height H2 of the step on the right side of the cross section depends on the overhang of the electrode and the separator. The vertical height H2 of the step on the right side of the cross section is greater than the sum of the overhang of the electrode and the separator and the winding tolerance.

[0032] The horizontal width W4 of the step on the right side of the cross section and the vertical height H3 of the bottom of the step on the right side of the cross section define the edge position of the S-shaped tab 2. The distance between the edge of the S-shaped tab 2 and the injection hole must be greater than the sum of the winding neatness tolerance and the protective adhesive tolerance of the S-shaped tab 2.

[0033] The horizontal widths W1 at the top of the cross section, W2 at the bottom of the cross section, W3 on the left side of the cross section, and W4 on the right side of the cross section are adjustable and satisfy the condition that the vertical height H3 at the bottom of the right side of the cross section is greater than the vertical height H1 on the left side of the cross section, and (W1-W4) 2 +(H3-H1) 2 ≥W1 2 To ensure stable overcurrent.

[0034] The surface of the S-shaped tab 2 has reinforcing ribs.

[0035] The S-shaped tabs 2 are symmetrically assembled onto the battery cell 1.

[0036] The reinforcing rib extends along the length of the S-shaped tab 2, and its height is 0.1-0.3 times the thickness of the S-shaped tab 2. The number of the reinforcing ribs is proportional to the size of the S-shaped tab 2 and is evenly distributed on the surface of the S-shaped tab 2. It is used to enhance the mechanical strength of the S-shaped tab 2 and reduce the deformation and wrinkling of the tab during the winding process.

[0037] The specific implementation method is as follows:

[0038] S1. Laser die-cutting of S-shaped electrode tabs 2: Using electrode sheets with blank edges, S-shaped electrode tabs 2 are formed in the blank areas by laser die-cutting; In this embodiment, the negative electrode tabs are: W1=W2=50mm, W3=W4=4mm, H1=12mm, H2=5mm, H3=8mm, and reinforcing ribs are processed on the surface of the S-shaped electrode tabs 2; The positive electrode tabs are: W1=W2=50mm, W3=W4=4mm, H1=12mm, H2=8mm, H3=8mm, and reinforcing ribs are processed on the surface of the S-shaped electrode tabs 2.

[0039] S2. Battery winding and packaging: In the winding machine, the die-cut positive electrode sheet, die-cut negative electrode sheet, and separator are wound to obtain the electrode core. Then, the S-shaped electrode tab 2 is connected and fixed to the top cover by laser welding, and the top cover of the battery is welded and sealed to form a complete lithium battery.

[0040] Through the above embodiments, the present invention effectively improves the problem of electrode wrinkling at the R-corner of lithium battery, and avoids the obstruction of formation gas discharge caused by the R-corner blocking the liquid injection hole, thereby improving the performance and safety of the battery.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An S-shaped electrode tab, characterized in that: The cross-section of the S-shaped electrode is provided with the following dimensions: top horizontal width W1, bottom horizontal width W2, left step horizontal width W3, right step horizontal width W4, left step vertical height H1, right step vertical height H2, and right step bottom vertical height H3.

2. An S-shaped electrode tab according to claim 1, characterized in that: The horizontal width W1 at the top of the cross section is equal to the horizontal width W2 at the bottom of the cross section, and the horizontal width W3 of the stepped section on the left side of the cross section is less than 1 / 2 of the core thickness.

3. An S-shaped electrode tab according to claim 1, characterized in that: The vertical height H1 of the step on the left side of the cross section is proportional to the required welding area.

4. An S-shaped electrode tab according to claim 1, characterized in that: The vertical height H2 of the step on the right side of the cross section is greater than the sum of the overhang of the electrode and the diaphragm and the winding tolerance.

5. An S-shaped electrode tab according to claim 1, characterized in that: The horizontal width W4 of the step on the right side of the cross section and the vertical height H3 of the bottom of the step on the right side of the cross section define the position of the edge of the S-shaped electrode ear. The distance between the edge of the S-shaped electrode ear and the injection hole must be greater than the sum of the winding neatness tolerance of the S-shaped electrode ear and the protective adhesive tolerance.

6. An S-shaped electrode tab according to claim 5, characterized in that: The horizontal widths W1 at the top of the cross section, W2 at the bottom of the cross section, W3 on the left side of the cross section, and W4 on the right side of the cross section are adjustable and satisfy the condition that the vertical height H3 at the bottom of the right side of the cross section is greater than the vertical height H1 on the left side of the cross section, and (W1-W4) 2 +(H3-H1) 2 ≥W1 2 .

7. An S-shaped electrode tab according to claim 5, characterized in that: The surface of the S-shaped electrode has reinforcing ribs.

8. An S-shaped electrode tab according to claim 5, characterized in that: The S-shaped tabs are symmetrically assembled onto the battery cell.

9. An S-shaped electrode tab according to claim 7, characterized in that: The reinforcing rib extends along the length of the S-shaped electrode tab, and its height is 0.1-0.3 times the thickness of the S-shaped electrode tab; the number of the reinforcing ribs is proportional to the size of the S-shaped electrode tab and is evenly distributed on the surface of the S-shaped electrode tab.

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