Collecting plate and cylindrical battery cell

Abstract

The utility model discloses a collector plate and a cylindrical battery cell, and relates to the technical field of novel batteries. The current collecting disc specifically comprises a circular current collecting disc body, and the circular current collecting disc body is sequentially provided with a first contact area and a welding area from the circle center to the outer side, wherein the first contact area can abut against a non-welding tab on the inner side of the end of a cylindrical roll core, and the welding area can be welded with a roll core to be welded on the cylindrical roll core. The utility model aims to increase the contact area between the current collecting plate and a cylindrical roll core tab and reduce the polarization of the battery.

Description

Technical Field

[0001] The utility model relates to the technical field of new battery, and particularly relates to a current collector plate and a cylindrical battery cell. Background Art

[0002] With the rapid development of modern technology and the booming growth of the global electric vehicle market, the demand for high-performance and fast-charging lithium-ion batteries is increasing day by day. Lithium-ion batteries are widely used in portable electronic devices, electric vehicles and energy storage systems due to their high energy density, long cycle life and relatively low self-discharge rate. However, the urgent market demand for faster charging speed has promoted the continuous progress of battery technology, especially the innovation in charging rate and battery structure design.

[0003] The structure of a traditional cylindrical lithium-ion battery usually consists of positive and negative electrode materials, a separator and an electrolyte. The positive and negative electrode materials are separated by the separator and wound together to form a cylindrical winding core. Although this design is relatively mature, during the fast charging process, the problem of uneven current density distribution inside the battery is particularly prominent. Especially due to the existence of the central hole formed by winding and the liquid injection channel, there is a large non-contact area between the inner tab (the extended part of the electrode) and the current collector plate, which causes the current to mainly pass through a small number of welding areas. This design will generate a local high current density during high-rate charging, promoting an increase in battery polarization, thereby affecting the charging efficiency and cycle stability of the battery, and even causing lithium plating in the battery and affecting the safety of the battery in extreme cases.

[0004] Therefore, how to increase the contact area between the existing current collector plate and the tab of the cylindrical winding core and reduce battery polarization has become a technical problem to be solved urgently. Summary of the Utility Model

[0005] The main object of the utility model is to provide a current collector plate and a cylindrical battery cell, aiming to increase the contact area between the existing current collector plate and the tab of the cylindrical winding core and reduce battery polarization.

[0006] To achieve the above object, the utility model provides a current collector plate, which includes a circular current collector plate body. The circular annular current collector plate body is sequentially provided with a first contact area that can abut against the non-welded tab on the inner side of the end of the cylindrical winding core and a welding area that can be welded to the winding core to be welded on the cylindrical winding core from the center to the outer side.

[0007] In an embodiment of the present application, when the circular current collector plate body is a negative circular current collector plate body, a through hole corresponding to the central hole of the cylindrical winding core is provided at the center of the circular current collector plate body.

[0008] In an embodiment of the present application, a second contact area is further provided on the circular current collector plate body, which can abut against the non-welded tab on the outer side of the end of the cylindrical core, and the second contact area is located outside the welding area.

[0009] In an embodiment of the present application, an identification member for indicating the installation position is further provided on the circular current collector plate, and the identification member is located outside the second contact area.

[0010] In an embodiment of the present application, the identification is a through hole.

[0011] In an embodiment of the present application, the through hole is at least one of a circle, a triangle, an ellipse, and a rhombus.

[0012] In an embodiment of the present application, the horizontal heights of the first contact area and the second contact area are equal.

[0013] In an embodiment of the present application, the difference between the horizontal height of the first contact area and the welding area is A, and 0.3 mm ≥ A ≥ 0.05 mm.

[0014] The present application also discloses a cylindrical battery cell, including a cylindrical core and a current collector plate as described in any one of the above, in which the tab to be welded is welded to the cylindrical core; the height of the non-welded tab protruding from the inner side of the end of the cylindrical core is B, and 1 mm ≥ B ≥ 0.1 mm.

[0015] In an embodiment of the present application, the area of the plane where the non-welded tab is located on the inner side of the end of the cylindrical core is equal to the area of the first contact area.

[0016] By adopting the above technical solution, through the contact area and the welding area, the distribution of current inside the battery can be effectively optimized, the problems of local overheating and too high current density can be reduced, thereby improving the charge and discharge efficiency and cycle stability of the battery. It not only ensures the stability of the electrical connection but also reduces the risk of tab damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present utility model will be described in detail below with reference to specific embodiments and the accompanying drawings, where:

[0018] Figure 1 is the front view of the positive current collector plate of the present utility model;

[0019] Figure 2 is the top view of the positive current collector plate of the present utility model;

[0020] Figure 3 is the front view of the negative current collector plate of the present utility model;

[0021] Figure 4 is the top view of the negative current collector plate of the present utility model;

[0022] 10, via; 20, first contact area; 30, welding area; 40, second contact area; 50, identification member. Detailed implementation manners

[0023] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present utility model and do not constitute a limitation to the present utility model.

[0024] As Figures 1 to 4 shown, in order to achieve the above objectives, the present utility model provides a current collector plate, which includes a circular current collector plate body. The circular annular current collector plate body is successively provided with a first contact area 20 that can abut against the non-welded tab on the inner side of the end of the cylindrical core and a welding area 30 that can be welded to the tab to be welded on the cylindrical core from the center to the outer side direction.

[0025] Specifically, the first contact area 20 abuts against the non-welded tab on the inner side of the end of the cylindrical core. The first contact area 20 forms a good electrical connection with the non-welded tab through physical pressing. Such a design avoids the unstable connection caused by the traditional welding method and improves the uniformity of current distribution inside the battery.

[0026] The welding area 30 is located outside the first contact area 20. The welding area 30 is an area for realizing welded connection with the tab of the core to be welded. Through the stable welding of the welding area 30 and the tab, the current collector plate can effectively absorb and distribute the current transmitted from the battery tab and ensure the uniform distribution of current inside the battery.

[0027] By adopting the above technical solution, through the contact area and the welding area 30, the distribution of current inside the battery can be effectively optimized, the problems of local overheating and too high current density can be reduced, thereby improving the charge and discharge efficiency and cycle stability of the battery. It not only ensures the stability of the electrical connection but also reduces the risk of tab damage.

[0028] In an embodiment of the present application, when the circular current collector plate body is a negative circular current collector plate body, a via 10 corresponding to the central hole of the cylindrical core is provided at the center of the circular current collector plate body.

[0029] Specifically, when the current collector plate is a negative current collector plate, a via 10 is provided at the center of the circular current collector plate body. The diameter of the via 10 is adapted to the central hole of the cylindrical core to achieve precise alignment with the central hole of the cylindrical core. By providing the via 10, it is convenient for the distribution of the electrolyte and the discharge of the internal gas during the charge and discharge process of the battery, which helps to maintain the balance of the internal pressure of the battery. The first contact area 20 is provided outside the via 10.

[0030] In an embodiment of the present application, a second contact area 40 is further provided on the circular current collector plate body, which can abut against the non-welded tab on the outer side of the end of the cylindrical core, and the second contact area 40 is located outside the welding area 30.

[0031] Specifically, a second contact area 40 is provided on the circular current collector plate body. The second contact area 40 is arranged outside the welding area 30 and is used to abut against the non-welded tab on the outer side of the end of the cylindrical core. A connection is established with the non-welded tab on the outer side of the end of the cylindrical core by means of physical contact.

[0032] Adopting the above technical solution, by additionally providing the second contact area 40 outside the welding area 30, not only the contact area with the core tab is increased, but also it helps to further reduce the local current density and optimize the current distribution inside the battery. Especially under high-rate charge and discharge conditions, the heat concentration and polarization degree inside the battery can be significantly reduced, and the performance and life of the battery are improved.

[0033] In an embodiment of the present application, an identification member 50 for indicating the installation position is further provided on the circular current collector plate, and the identification member 50 is located outside the second contact area 40.

[0034] Adopting the above technical solution, through the indication of the identification member 50, the operator can easily identify the correct installation direction and position of the current collector plate, effectively avoiding errors during the installation process, such as reverse or offset, thereby accelerating the assembly process and improving production efficiency.

[0035] In an embodiment of the present application, the identification is a perforation.

[0036] Adopting the above technical solution, compared with other marking methods such as printing or stickers, the perforation, as a physical form of identification, is not easily worn or faded during long-term use. This ensures the persistent visibility of the identification, is not affected by environmental factors such as temperature and humidity, is conducive to maintaining the persistent clarity of the identification, and further ensures the correct indication function. By directly perforating the current collector plate during the manufacturing process to form the identification, the subsequent processing steps required in production, such as printing the identification, can be reduced, thereby simplifying the entire production process and reducing production costs.

[0037] In an embodiment of the present application, the perforation is at least one of a circle, a triangle, an ellipse, and a rhombus.

[0038] In an embodiment of the present application, the horizontal heights of the first contact area 20 and the second contact area 40 are equal.

[0039] With the above technical solution, the contact areas at the same horizontal height can ensure uniform force distribution when stressed, avoiding local stress concentration caused by height differences, thereby enhancing the mechanical stability and durability of the entire structure.

[0040] In an embodiment of the present application, the difference in horizontal height between the first contact area 20 and the welding area 30 is A, where 0.3 mm ≥ A ≥ 0.05 mm.

[0041] Specifically, the height difference between the contact area and the welding area 30 can ensure stable contact between the first contact area 20 and the non-welded tab, helping to reduce the contact resistance, thereby improving the efficiency and stability of electrical connection.

[0042] The present application also discloses a cylindrical battery cell, including a cylindrical wound core and a current collector plate as described in any one of the above, where the welding area 30 is welded to the tab to be welded on the cylindrical wound core; the height of the non-welded tab protruding from the inner side of the end of the cylindrical wound core is B, where 1 mm ≥ B ≥ 0.1 mm.

[0043] Specifically, a cylindrical battery cell includes a cylindrical wound core and a current collector plate. The welding area 30 on the current collector plate is welded to the tab to be welded on the cylindrical wound core to ensure connection stability. The first contact area 20 on the current collector plate abuts against the non-welded tab on the inner side of the end of the cylindrical wound core, and the second contact area 40 on the current collector plate abuts against the non-welded tab on the outer side of the end of the cylindrical wound core, so that the current distribution in the cylindrical battery cell is more uniform. The height of the non-welded tab on the inner side of the end of the cylindrical wound core is between 1 mm and 0.1 mm, which facilitates the connection of the tab to the first contact area 20.

[0044] In an embodiment of the present application, the area of the plane where the non-welded tab on the inner side of the end of the cylindrical wound core is located is equal to the area of the first contact area 20.

[0045] With the above technical solution, when the area of the plane where the non-welded tab is located is the same as the area of the first contact area 20, it can ensure that the electrical connection is evenly distributed over the entire contact surface, helping to reduce the contact resistance, thereby improving the current flow efficiency and the overall performance of the battery.

[0046] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A collecting plate, characterized in that: The circular collector disc body comprises a first contact area which can abut against the non-welding pole ear inside the end of the cylindrical winding core and a welding area which can be welded with the winding core to be welded on the cylindrical winding core.

2. The collecting plate according to claim 1, characterized in that: When the circular current collecting disc body is a negative electrode circular current collecting disc body, a through hole corresponding to the central hole of the cylindrical winding core is provided at the center of the circular current collecting disc body.

3. The collecting plate according to claim 2, characterized in that: The circular collector plate body is also provided with a second contact area which can abut against the non-welding pole ear outside the end of the cylindrical winding core, and the second contact area is located outside the welding area.

4. The collecting plate according to claim 3, characterized in that: The circular collecting plate is also provided with an identification piece for indicating the installation position, and the identification piece is located outside the second contact area.

5. The collecting plate according to claim 4, characterized in that: The mark is a hollow hole.

6. The collecting plate according to claim 5, characterized in that: The hollow holes are at least one of circular, triangular, elliptical, and rhombus-shaped.

7. The collecting plate according to claim 4, characterized in that: The first contact area and the second contact area have the same level.

8. The collecting plate according to claim 1, characterized in that: The difference between the levels of the first contact area and the welding area is A, 0.3mm≥A≥0.05mm.

9. A cylindrical battery cell, characterized in that: A collector disk comprising a cylindrical winding core and a welding zone welded to the cylindrical winding core and a pole ear to be welded as claimed in any one of claims 1 to 8; the height of the non-welded pole ear on the inner side of the end of the cylindrical winding core extending out is B, 1mm≥B≥0.1mm.

10. The cylindrical battery cell according to claim 9, characterized in that: The area of ​​the plane where the non-welded pole ear is located inside the end of the cylindrical winding core is equal to the area of ​​the first contact area.

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