Cylindrical lithium ion battery collector plate with dynamic structure and cylindrical lithium ion battery

Abstract

The utility model relates to a cylindrical lithium ion battery collector plate with a dynamic structure. The cylindrical lithium ion battery collector plate comprises a metal substrate and a welding terminal, the metal matrix is of an annular structure, the inner circumference of the metal matrix is electrically connected with a plurality of thermal deformation pieces which are distributed in a circumferential mode, and the ends, away from the metal matrix, of the thermal deformation pieces extend towards the middle of the metal matrix and are electrically connected with the welding terminals. According to the utility model, the plurality of thermal deformation parts are arranged in the metal matrix, and the volume of the thermal deformation parts is increased when the temperature of the battery rises, so that the contact area between the current collecting disc and the tab is increased, and the overcurrent capability of the battery cell is improved; and meanwhile, continuous welding of the collector plate and the tab is realized by utilizing the metal substrate with an annular structure, so that the welding difficulty is reduced, the length of a welding wire is reduced, and the welding efficiency and the yield are improved while the overcurrent capability is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a cylindrical lithium-ion battery current collecting plate and a cylindrical lithium-ion battery with a dynamic structure. Background Art

[0002] Multi-electrode large cylindrical lithium-ion batteries are currently a key development direction for power batteries. They reserve positive and negative electrode foils of different shapes at both ends of the electrode, then mechanically flatten the foils radially, then laser weld the collector plate to the flattened foil end face, and then weld the collector plate to the terminal to achieve electrical conductivity. Compared with traditional small cylindrical lithium-ion batteries, large cylindrical batteries have greater single cell energy and higher rate performance.

[0003] To maintain leading rate performance advantages, large cylindrical battery cells require sufficient effective welding area between the flattened end faces and the current collector plates. However, while guiding the flow, the current collector plates typically reserve channels to increase electrolyte wetting of the core. This poses a huge challenge to the laser welding process, indirectly increasing the cost of the battery cell manufacturing process while sacrificing the core's current handling capacity. A solution is needed to reduce welding costs while ensuring the cell's current handling capacity. Utility Model Content

[0004] Based on this, in order to solve the technical problems existing in the current collecting tray of large cylindrical battery cells, the utility model provides a cylindrical lithium-ion battery current collecting tray and a cylindrical lithium-ion battery with a dynamic structure.

[0005] The utility model provides a cylindrical lithium-ion battery collector with a dynamic structure, which includes a metal base and a welding terminal; the metal base has an annular structure, and a plurality of circumferentially distributed thermal deformation parts are electrically connected to the inner periphery of the metal base, and the thermal deformation parts extend from one end of the metal base to the middle of the metal base and are all electrically connected to the welding terminal.

[0006] The utility model arranges multiple thermal deformation parts in the metal matrix. When the battery temperature rises, the volume of the thermal deformation parts increases, thereby increasing the contact area between the collecting plate and the pole ear and improving the flow capacity of the battery cell. At the same time, the metal matrix with an annular structure is used to realize continuous welding of the collecting plate and the pole ear, which reduces the welding difficulty, reduces the welding wire length, ensures the flow capacity, and improves the welding efficiency and yield.

[0007] As a further improvement of the above solution of the present invention, the metal base is in a circular ring structure.

[0008] As a further improvement to the above-mentioned solution of the present invention, a gap is left between any two adjacent thermally deformed parts to form an infiltration hole. This reserved infiltration hole does not cause a dispersed weld area, nor does it affect the welding efficiency and yield of the outer metal matrix. The overall area is smaller, occupying less space within the battery cell, which can increase the electrolyte retention capacity of the cylindrical battery cell and improve the electrolyte infiltration efficiency.

[0009] As a further improvement of the above solution of the utility model, the thermal deformation member is in the shape of a fan, rectangle, ellipse or irregular polygon;

[0010] And / or, the thermal deformation part is made of a memory alloy material having a phase transition temperature of 25°C-55°C;

[0011] And / or, the thermally deformable part and the metal substrate are electrically connected by means of conductive adhesive, ultrasonic welding or laser welding;

[0012] And / or, the thermally deformable member and the welding terminal are electrically connected by means of conductive adhesive, ultrasonic welding or laser welding.

[0013] As a further improvement of the above solution of the present invention, a plurality of thermal deformation protrusions are arranged at intervals on one side of the thermal deformation member.

[0014] As a further improvement of the above solution of the present invention, a plurality of thermal deformation protrusions are distributed on the thermal deformation protrusion.

[0015] As a further improvement of the above solution of the present invention, the thermally deformed protrusion has a triangular, square or semicircular cross-section.

[0016] As a further improvement of the above solution of the present invention, the thermally deformable protrusion has a triangular, square or semicircular cross-section.

[0017] As a further improvement of the above solution of the present invention, the thickness of the thermal deformation piece is 0.2-0.5 mm, the height of the thermal deformation protrusion is 20-100 μm, and the height of the thermal deformation bump is 5-20 μm.

[0018] The utility model provides a cylindrical lithium-ion battery, which comprises the cylindrical lithium-ion battery current collecting disk with the dynamic structure as described above.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The utility model sets multiple thermal deformation parts in the metal matrix. The volume of the thermal deformation parts increases when the battery temperature rises, thereby increasing the contact area between the collecting plate and the tab and improving the flow capacity of the battery cell. At the same time, the metal matrix with an annular structure is used to realize continuous welding of the collecting plate and the tab, which reduces the welding difficulty and the length of the welding wire, ensuring the flow capacity while improving the welding efficiency and yield.

[0021] 2. In the present invention, a gap is left between any two adjacent thermally deformed parts to form an infiltration hole. The infiltration hole does not cause the welding area to be dispersed, does not affect the welding efficiency and yield of the outer ring metal matrix, has a smaller overall area, occupies less space inside the battery cell, can improve the liquid retention capacity of the cylindrical battery cell, and increase the infiltration efficiency of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a dynamic cylindrical lithium-ion battery current collecting disk proposed in an embodiment of the present utility model;

[0023] Figure 2 for Figure 1 Schematic diagram of the structure of the medium-heat deformation part.

[0024] Reference numerals: 1. metal substrate; 2. welding terminal; 3. thermally deformed part; 31. thermally deformed protrusion; 32. thermally deformed bump; 4. wetting hole. DETAILED DESCRIPTION

[0025] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to facilitate a more thorough and comprehensive understanding of the disclosure of the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0027] Reference Figure 1 This embodiment provides a cylindrical lithium-ion battery current collector with a dynamic structure, which is applied to a cylindrical lithium-ion battery and includes a metal substrate 1 and a welding terminal 2.

[0028] The metal base 1 is annular in shape. The outer diameter of the metal base 1 forms the outer diameter of the entire collecting plate. The inner diameter of the metal base 1 can be adjusted according to actual needs (current capacity, welding process window, welding efficiency, etc.). The metal base 1 can be made of copper, aluminum, or nickel-plated copper.

[0029] The inner periphery of the metal base 1 is electrically connected to a plurality of circumferentially distributed thermal deformation parts 3. The thermal deformation parts 3 are made of a memory alloy material with a phase transition temperature of 25°C-55°C, such as tini memory alloy. The thermal deformation parts 3 can deform with temperature changes, expand when the temperature rises, and contract when the temperature drops. In this embodiment, the thermal deformation parts 3 are fan-shaped. Of course, in other embodiments, as long as the use requirements are met, the thermal deformation parts 3 can also be rectangular, elliptical or irregular polygonal structures. In this embodiment, the thermal deformation parts 3 are electrically connected to the metal base 1 by laser welding. Of course, in other embodiments, the thermal deformation parts 3 can also be electrically connected to the metal base 1 by thermal conductive glue or ultrasonic welding.

[0030] Combine Figure 2 Multiple thermally deformable protrusions 31 are arranged side by side and spaced apart on one side of the thermally deformable element 3. Each thermally deformable protrusion 31 is also provided with multiple thermally deformable bumps 32. Both thermally deformable protrusions 31 and thermally deformable bumps 32 are made of a memory alloy with a phase transition temperature of 25°C-55°C, such as tinny memory alloy. These protrusions 31 and thermally deformable bumps 32 are capable of deforming in response to temperature changes, expanding when the temperature rises and contracting when the temperature drops. The shape and structure of the thermally deformable protrusions 31 and thermally deformable bumps 32 are not specifically limited. The thermally deformable element 3 may have a triangular, square, or semicircular cross-section, and similarly, the thermally deformable bumps 32 may also have a triangular, square, or semicircular cross-section.

[0031] In this embodiment, to ensure the performance of the current collecting plate, the thickness of the thermal deformation member 3 is 0.2-0.5 mm, the height of the thermal deformation protrusion 31 is 20-100 μm, and the height of the thermal deformation bump 32 is 5-20 μm.

[0032] In this embodiment, to promote electrolyte infiltration, a gap is left between any two adjacent thermally deformable parts 3 to form an infiltration hole 4. The width of the infiltration hole 4 is reasonably set according to actual requirements (flow capacity, infiltration requirements).

[0033] Welding terminals 2 are positioned at the center of the metal base 1 and are electrically connected to the ends of the multiple thermally deformable components 3 facing away from the metal body. Electrical connection between the welding terminals 2 and the thermally deformable components 3 can be achieved using conductive adhesive, ultrasonic welding, or laser welding. The current collector plate connects the winding tabs to the cell terminals via the welding terminals 2. The welding terminals 2 can be made of copper, aluminum, or nickel-plated copper.

[0034] When the cylindrical lithium-ion battery current collector of the dynamic structure provided in this embodiment is applied to a cylindrical lithium-ion battery, the side of the thermally deformable part 3 provided with the thermally deformable protrusion 31 is arranged toward the pole ear, and the difficulty of laser welding is reduced by continuously welding the current collector and the pole ear on the metal substrate 1; the current collector is required to have the ability to conduct electrons throughout the body, and during the charge and discharge process of the battery, electrons migrate from the current collector (copper foil or aluminum foil) along the pole ear to the metal substrate 1 and the thermally deformable part 3, and then gather from the thermally deformable part 3 to the welding terminal 2, forming a loop with the external circuit through the welding terminal 2. During use, when the battery temperature rises, the thermal deformation of the thermally deformable member 3, the thermally deformable protrusion 31, and the thermally deformable bump 32 causes the volume to increase, automatically increasing the contact area between the collector plate and the tab. When the battery temperature drops, the thermal deformation of the thermally deformable member 3, the thermally deformable protrusion 31, and the thermally deformable bump 32 causes the contact area between the collector plate and the tab to decrease automatically, thereby ensuring effective contact area between the thermally deformable member 3 and the winding core tab, improving the current flow capacity of the battery cell and meeting rate performance requirements. This embodiment reduces the volume of the collector plate, increases the available space inside the battery cell, and improves the electrolyte retention capacity of the battery cell. The reserved infiltration hole 4 does not affect the welding efficiency and yield of the outer ring metal base 1 and the tab, while also improving the electrolyte infiltration efficiency.

[0035] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of this invention are for the purpose of describing specific embodiments only and are not intended to limit this invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A cylindrical lithium-ion battery current collecting plate with a dynamic structure, characterized in that: It comprises a metal base (1) and a welding terminal (2); the metal base (1) is annular in structure, the inner periphery of the metal base (1) is electrically connected to a plurality of circumferentially distributed thermal deformation parts (3), and the thermal deformation parts (3) extend from one end of the metal base (1) toward the middle of the metal base (1) and are all electrically connected to the welding terminal (2).

2. The cylindrical lithium-ion battery current collecting plate with a dynamic structure according to claim 1, characterized in that: The metal base (1) is in a circular ring structure.

3. The cylindrical lithium-ion battery current collecting plate with a dynamic structure according to claim 1, characterized in that: A gap is left between any two adjacent thermally deformed parts (3) to form an infiltration hole (4).

4. The cylindrical lithium-ion battery current collecting disk with a dynamic structure according to claim 1, characterized in that: The thermally deformed part (3) is in the shape of a fan, rectangle, ellipse or irregular polygon; And / or, the thermal deformation member (3) is made of a memory alloy material having a phase transition temperature of 25° C. to 55° C.; and / or, the thermally deformable member (3) and the metal base (1) are electrically connected by means of conductive adhesive, ultrasonic welding or laser welding; And / or, the thermal deformation member (3) and the welding terminal (2) are electrically connected by means of conductive glue, ultrasonic welding or laser welding.

5. The cylindrical lithium-ion battery current collecting plate with a dynamic structure according to claim 2, characterized in that: A plurality of thermal deformation protrusions (31) are arranged at intervals on one side of the thermal deformation member (3).

6. The cylindrical lithium-ion battery current collecting plate with a dynamic structure according to claim 5, characterized in that: A plurality of thermally deformable protrusions (32) are distributed on the thermally deformable protrusion (31).

7. The cylindrical lithium-ion battery current collecting disk with a dynamic structure according to claim 5, characterized in that: The thermally deformed protrusion (31) has a triangular, square or semicircular cross section.

8. The cylindrical lithium-ion battery current collecting disk with a dynamic structure according to claim 6, characterized in that: The thermally deformed protrusion (32) has a triangular, square or semicircular cross section.

9. The cylindrical lithium-ion battery current collecting plate with a dynamic structure according to claim 6, characterized in that: The thickness of the thermal deformation piece (3) is 0.2-0.5 mm, the height of the thermal deformation protrusion (31) is 20-100 μm, and the height of the thermal deformation bump (32) is 5-20 μm.

10. A cylindrical lithium-ion battery, characterized in that: It comprises a cylindrical lithium-ion battery current collecting disk with a dynamic structure according to any one of claims 1 to 9.

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