Tab, tab sheet and battery

Abstract

In order to solve the connection problem of upper and lower layer metal of composite current collector, realize the communication of metal coating on both sides of the composite current collector, reduce the weight of the battery, and improve the energy density and safety of the battery, the utility model provides an electrode lug for connecting with the composite current collector, the electrode lug includes a metal piece, the metal piece includes a first electrode lug inner connecting part, a bending part, a second electrode lug inner connecting part and an electrode lug outer connecting part, the first electrode lug inner connecting part is connected with the metal layer on one side of the composite current collector, the second electrode lug inner connecting part is connected with the metal layer on the other side of the composite current collector, the bending part is connected with the first electrode lug inner connecting part and the second electrode lug inner connecting part, and the composite current collector is at least partially located in the bending part, and the electrode lug outer connecting part is connected with one end of the first electrode lug inner connecting part away from the bending part.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically relating to a tab, an electrode sheet, and a battery. Background Technology

[0002] Current collectors play a crucial role in carrying and collecting the current generated by the battery's active materials, significantly impacting the capacity, rate capability, and cycle life of lithium-ion batteries. Reducing current collector thickness has become a major development trend to improve battery energy density. However, excessively thin current collectors not only increase costs but also easily lead to problems such as wrinkling and breakage during manufacturing processes. Therefore, metal current collectors cannot be infinitely thinned. New composite structure current collectors offer significant advantages in improving battery safety, energy density, and cycle life.

[0003] Composite current collectors are a novel type of composite foil with a "sandwich" structure. The middle layer is a polymer base film, with aluminum or copper plated on both sides, corresponding to the aluminum and copper foils of the positive and negative electrodes in lithium-ion batteries. Because the upper and lower metal layers of the composite current collector are not connected, currently, conductive sheets are needed to connect the upper and lower metal plating layers before soldering them to the electrode tabs. This connection method requires conductive sheets to be connected to the metal layers on each side, which not only increases the battery weight and reduces its energy density but also affects the reliability of the soldering. In severe cases, weak soldering can lead to perforation, affecting battery performance. Utility Model Content

[0004] The purpose of this invention is to provide a tab, electrode, and battery to achieve connectivity between the metal coatings on both sides of the composite current collector, thereby reducing battery weight and improving battery energy density and safety.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0006] On the one hand, this utility model provides an electrode tab for connecting to a composite current collector. The electrode tab includes a metal part, which includes a first electrode tab inner part, a bent part, a second electrode tab inner part, and an electrode tab outer part.

[0007] The inner part of the first electrode tab is used to connect to the metal layer on one side of the composite current collector, and the inner part of the second electrode tab is used to connect to the metal layer on the other side of the composite current collector; the bent part connects the inner part of the first electrode tab and the inner part of the second electrode tab.

[0008] The outer part of the electrode tab is connected to the end of the inner part of the first electrode tab away from the bent part.

[0009] Optionally, the area of ​​the inner portion of the first electrode tab is the same as the area of ​​the inner portion of the second electrode tab. This ensures that the current magnitude of the upper and lower metal layers is substantially consistent.

[0010] Optionally, the inner portion of the first electrode lug includes a first connecting portion and a second connecting portion. One end of the first connecting portion is connected to the outer portion of the electrode lug, and the other end of the first connecting portion is connected to one end of the second connecting portion. The other end of the second connecting portion is connected to the bent portion. An included angle A is formed between the first connecting portion and the second connecting portion, where 30°≤A≤150°. The first connecting portion and the second connecting portion can be strip-shaped, rectangular, polygonal, or wavy.

[0011] Optionally, the metal component further includes a reinforcing portion disposed at the included angle A, and the reinforcing portion is connected to the first connecting portion and the second connecting portion respectively. The reinforcing portion may be triangular or fan-shaped, and the reinforcing portion can enhance the strength of the electrode tab.

[0012] Optionally, the connection between the first connecting portion and the second connecting portion is smooth. This prevents the tab corner from being too sharp and piercing the electrode plate or diaphragm.

[0013] Optionally, the electrode tab further includes electrode tab adhesive, which covers the outer periphery of the outer part of the electrode tab. The electrode tab adhesive serves to provide insulation, protection, support, and fixation.

[0014] Optionally, the tab adhesive is in the form of a strip, and the extending direction of the tab adhesive is parallel to the extending direction of the inner part of the second tab.

[0015] Optionally, the material of the metal part is selected from aluminum, nickel-plated copper, and nickel.

[0016] Optionally, when the metal part is made of aluminum, Al ≥ 99.5%;

[0017] Alternatively, when the metal part is made of copper plated with nickel, Cu ≥ 99.8% and Ni ≥ 99.5%;

[0018] Alternatively, if the metal part is made of nickel, Ni ≥ 99.5%.

[0019] On the other hand, the present invention provides an electrode sheet, including a composite current collector and the aforementioned electrode tab, wherein the outer portion of the electrode tab is connected to one side of the composite current collector in the width direction, or the outer portion of the electrode tab is connected to one side of the composite current collector in the length direction.

[0020] Optionally, the external tab is connected to one side of the composite current collector in the width direction, and the width of the bent portion is smaller than the width of the composite current collector in the width direction; or,

[0021] The external tab is connected to one side of the composite current collector along its length, and the length of the bent portion is less than the length of the composite current collector and less than the length of the empty foil area of ​​the composite current collector along its length.

[0022] On the other hand, this utility model provides a battery including the aforementioned electrode.

[0023] Optionally, the battery is a digital battery, and the thickness of the tab is 40~120μm.

[0024] Optionally, the battery is a power battery, and the thickness of the tab is 150~400μm.

[0025] In this invention, the inner part of the first tab and the inner part of the second tab are connected by a bending portion. The inner part of the first tab is used to connect the metal layer on one side of the composite current collector, and the inner part of the second tab is used to connect the metal layer on the other side of the composite current collector, thereby achieving communication between the metal layers on both sides of the composite current collector. This reduces the mass of the conductive sheet during ordinary electrode welding, thereby reducing the weight of the battery. This application ensures a firm electrode welding on the basis of effective connection of the upper and lower metal layers, and further reduces the weight of the battery, improving the energy density and safety of the battery. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the electrode tab in one embodiment of the present invention when it is not bent;

[0028] Figure 2 This is a schematic diagram of the structure of the electrode tab in another embodiment of the present invention when it is not bent;

[0029] Figure 3 This is a schematic diagram of the structure of the electrode tab in one embodiment of the present invention when it is not bent;

[0030] Figure 4 This is a schematic diagram of the structure of the electrode tab after bending in one embodiment of this utility model;

[0031] Figure 5 This is a schematic diagram of the front structure of the electrode sheet in one embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the back structure of the electrode sheet in one embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the structure of the electrode sheet in one embodiment of the present invention.

[0034] In the figure: 1. Composite current collector, 2. Metal part, 3. Inner part of the first electrode tab, 4. Bending part, 5. Inner part of the second electrode tab, 6. Outer part of the electrode tab, 7. Electrode tab adhesive, 31. First connecting part, 32. Second connecting part, 33. Reinforcing part. Detailed Implementation

[0035] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit its scope.

[0036] One embodiment of this utility model provides an electrode tab for connecting to a composite current collector 1. The electrode tab includes a metal part 2, which includes a first electrode tab inner part 3, a bent part 4, a second electrode tab inner part 5, and an electrode tab outer part 6.

[0037] The first tab inner connection 3 is used to connect to the metal layer on one side of the composite current collector 1, and the second tab inner connection 5 is used to connect to the metal layer on the other side of the composite current collector 1; the bending part 4 connects the first tab inner connection 3 and the second tab inner connection 5.

[0038] The outer part 6 of the electrode tab is connected to the end of the inner part 3 of the first electrode tab away from the bent part 4.

[0039] In this embodiment, the first tab inner connection part 3 and the second tab inner connection part 5 are connected by the bending part 4. The first tab inner connection part 3 is used to connect the metal layer on one side of the composite current collector 1, and the second tab inner connection part 5 is used to connect the metal layer on the other side of the composite current collector 1, thereby realizing the connection between the metal layers on both sides of the composite current collector 1. This reduces the mass of the conductive sheet during ordinary electrode welding, thereby reducing the weight of the battery. This application ensures that the tab welding is firm on the basis of effective connection of the upper and lower metal layers, and further reduces the weight of the battery, thereby improving the energy density and safety of the battery.

[0040] Specifically, when connecting the electrode tab to the composite current collector 1, the inner part 3 of the first electrode tab is placed on one side of the composite current collector 1, and the inner part 5 of the second electrode tab is bent to the other side of the composite current collector 1 through the bending part 4. Then, the inner part 3 of the first electrode tab, the composite current collector 1 and the inner part 5 of the second electrode tab are connected to realize the connection between the composite current collector 1 and the electrode tab.

[0041] In one specific embodiment, the area of ​​the inner portion 3 of the first electrode tab is the same as the area of ​​the inner portion 5 of the second electrode tab. This ensures that the current magnitude of the upper and lower metal layers of the battery remains essentially the same.

[0042] In some embodiments, the first inner tab portion 3 includes a first connecting portion 31 and a second connecting portion 32. One end of the first connecting portion 31 is connected to the outer tab portion 6, and the other end of the first connecting portion 31 is connected to one end of the second connecting portion 32. The other end of the second connecting portion 32 is connected to the bending portion 4. An included angle A is formed between the first connecting portion 31 and the second connecting portion 32, where 30°≤A≤150°. By setting the included angle between the first connecting portion 31 and the second connecting portion 32, the outer tab portion 6 can be disposed on one side or one end of the composite current collector 1.

[0043] In some embodiments, the first connecting portion 31 and the second connecting portion 32 are strip-shaped.

[0044] In some embodiments, the metal part 2 further includes a reinforcing portion 33, which is disposed at the included angle A and connects the first connecting portion 31 and the second connecting portion 32 respectively. The reinforcing portion 33 can enhance the strength of the electrode tab.

[0045] In some embodiments, the reinforcing part 33 is triangular.

[0046] In some embodiments, the reinforcing part 33 is fan-shaped.

[0047] In some embodiments, the connection between the first connecting portion 31 and the second connecting portion 32 is smooth. This prevents the corners of the tab from being too sharp and piercing the electrode plate or diaphragm.

[0048] In some embodiments, the electrode tab further includes electrode tab adhesive 7, which covers the outer periphery of the outer portion 6 of the electrode tab. The electrode tab adhesive 7 serves to provide insulation, protection, support, and fixation.

[0049] In some embodiments, the tab adhesive 7 is strip-shaped, and the extending direction of the tab adhesive 7 is parallel to the extending direction of the inner part of the second tab 5.

[0050] In some embodiments, the material of the metal part 2 is selected from aluminum, nickel-plated copper, and nickel.

[0051] In some embodiments, when the metal part 2 is made of aluminum, Al ≥ 99.5%, that is, when the metal part is made of aluminum, the aluminum content is ≥ 99.5%.

[0052] Alternatively, when the metal part 2 is made of copper plated with nickel, Cu ≥ 99.8% and Ni ≥ 99.5%, that is, when the metal part is made of copper plated with nickel, the copper content is ≥ 99.8% and the nickel content is ≥ 99.5%.

[0053] Alternatively, when the metal part 2 is made of nickel, Ni ≥ 99.5%, that is, when the metal part is made of nickel, the nickel content is ≥ 99.5%.

[0054] One embodiment of this utility model provides an electrode sheet, including a composite current collector 1 and the aforementioned electrode tab. The outer portion 6 of the electrode tab is connected to one side of the composite current collector 1 in the width direction, or the outer portion 6 of the electrode tab is connected to one side of the composite current collector 1 in the length direction. Specifically, the composite current collector 1 is provided with an empty foil area and an active material layer coating area. An active material layer is provided on the active material layer coating area. The electrode tab is located in the empty foil area and is spaced apart from the active material layer.

[0055] In some embodiments, the external tab 6 is connected to one side of the composite current collector 1 in the width direction, and the width of the bent portion 4 is smaller than the width of the composite current collector 1 in the width direction.

[0056] In some embodiments, the external tab 6 is connected to one side of the composite current collector 1 along its length, and the length of the bent portion 4 is less than the length of the composite current collector 1 and less than the length of the empty foil area of ​​the composite current collector 1 along its length.

[0057] One embodiment of this utility model provides a battery including the aforementioned electrode sheets.

[0058] In some embodiments, the tab is applied to a digital battery, and the thickness of the tab is 40~120μm.

[0059] In some embodiments, the tab is applied to a power battery, and the thickness of the tab is 150~400μm.

[0060] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A type of electrode, characterized in that, For connection with composite current collector (1), the electrode includes a metal part (2), the metal part (2) includes a first electrode inner part (3), a bent part (4), a second electrode inner part (5) and an electrode outer part (6). The first tab inner connection part (3) is used to connect the metal layer on one side of the composite current collector (1), and the second tab inner connection part (5) is used to connect the metal layer on the other side of the composite current collector (1); the bending part (4) connects the first tab inner connection part (3) and the second tab inner connection part (5). The outer part (6) of the electrode tab is connected to the end of the inner part (3) of the first electrode tab away from the bent part (4).

2. The electrode tab according to claim 1, characterized in that, The area of ​​the inner part (3) of the first electrode ear is the same as the area of ​​the inner part (5) of the second electrode ear.

3. The electrode tab according to claim 1, characterized in that, The first electrode inner part (3) includes a first connecting part (31) and a second connecting part (32). One end of the first connecting part (31) is connected to the electrode outer part (6), and the other end of the first connecting part (31) is connected to one end of the second connecting part (32). The other end of the second connecting part (32) is connected to the bending part (4). An included angle A is formed between the first connecting part (31) and the second connecting part (32), where 30°≤A≤150°.

4. The electrode tab according to claim 3, characterized in that, The metal part (2) also includes a reinforcing part (33), which is disposed at the included angle A and is connected to the first connecting part (31) and the second connecting part (32) respectively.

5. The electrode tab according to claim 3, characterized in that, The first connecting part (31) and the second connecting part (32) are smoothly connected at the connection point.

6. The electrode tab according to claim 1, characterized in that, The electrode also includes electrode adhesive (7), which covers the outer periphery of the outer part (6) of the electrode.

7. The electrode tab according to claim 6, characterized in that, The tab adhesive (7) is strip-shaped, and the extension direction of the tab adhesive (7) is parallel to the extension direction of the inner part (5) of the second tab.

8. An electrode sheet, characterized in that, Includes a composite current collector (1) and an electrode as described in any one of claims 1 to 7, wherein the electrode external portion (6) is connected to one side of the composite current collector (1) in the width direction, or the electrode external portion (6) is connected to one side of the composite current collector (1) in the length direction.

9. The electrode sheet according to claim 8, characterized in that, The external tab (6) is connected to one side of the composite current collector (1) in the width direction, and in the width direction of the composite current collector (1), the width of the bent portion (4) is smaller than the width of the composite current collector (1); or, The external tab (6) is connected to one side of the composite current collector (1) along its length, and the length of the bent part (4) is less than the length of the composite current collector (1) along its length.

10. A battery, characterized in that, Includes the electrode as described in claim 8 or 9.

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