Adapter sheet, secondary battery, battery pack, and electronic device

Abstract

The utility model provides an adapter plate, which is used for electrically connecting an electrode assembly and a top cover, and comprises a main body part comprising a main body tab welding part and a main body top cover welding part which are connected with each other; the supporting part is connected with the main body part through the flexible part, and the flexible part is used for enabling the supporting part to be folded relative to the main body part, so that the main body part and the supporting part clamp a tab of the electrode assembly between the main body part and the supporting part. The utility model aims to provide an adapter piece, a secondary battery, a battery pack and an electronic device, so as to at least improve the safety of the secondary battery.

Description

Technical Field

[0001] The utility model relates to an adapter sheet, a secondary battery, a battery pack and an electronic device. Background Art

[0002] Currently, the connection between the tab and the terminal of two or more battery cells inside a battery is mainly achieved through an adapter sheet. After the tabs of the same polarity of the battery cells are ultrasonically welded to the adapter sheet, the adapter sheet is then laser welded to the corresponding terminal. Summary of the Utility Model

[0003] Aiming at the problems existing in the related art, the purpose of the present utility model is to provide an adapter sheet, a secondary battery, a battery pack and an electronic device, so as to at least improve the safety of the secondary battery.

[0004] To achieve the above purpose, the present utility model provides an adapter sheet for electrically connecting an electrode assembly and a top cover, including: a main body part, including a connected main body tab welding part and a main body top cover welding part; a support part and a flexible part, the support part is connected to the main body part through the flexible part, and the flexible part is used to fold the support part relative to the main body part, so that the main body part and the support part clamp the tab of the electrode assembly therebetween.

[0005] In some embodiments, the ratio of the thickness of the main body part to the thickness of the support part ranges from 0.2 to 5.

[0006] In some embodiments, the support part includes a support tab welding part corresponding to the main body tab welding part and a support top cover welding part corresponding to the main body top cover welding part.

[0007] In some embodiments, the width of the support tab welding part is less than 2 / 3 of the height of the tab from the tab starting edge to the tab welding mark area.

[0008] In some embodiments, the width of the main body tab welding part and the width of the support tab welding part are greater than the width of the tab welding mark area.

[0009] In some embodiments, the main body part includes two main body tab welding parts, the main body top cover welding part and the two main body tab welding parts define a main body notch penetrating the main body part, and the main body notch separates the two main body tab welding parts; the support part includes two support tab welding parts, the support top cover welding part and the two support tab welding parts define a support notch penetrating the support part, and the support notch separates the two support tab welding parts. When the main body part and the support part clamp the tab therebetween, projected along the clamping direction, the main body notch and the support notch coincide.

[0010] In some embodiments, the main body top cover welding part and the support top cover welding part are symmetric about the flexible part.

[0011] An embodiment of the present application further provides a secondary battery, including: a battery case including a top cover; an electrode assembly accommodated in the battery case, including a main body of the battery cell and a tab protruding from the main body of the battery cell; a transfer piece according to any one of the above, a main body tab welding part electrically connecting the tab, a main body top cover welding part electrically connecting the top cover, the main body tab welding part being located between the tab and the top cover, and a support part being located between the tab and the main body of the battery cell.

[0012] An embodiment of the present application further provides a battery pack including the above secondary battery.

[0013] An embodiment of the present application further provides an electronic device including the above battery pack.

[0014] The beneficial technical effects of the present utility model are as follows:

[0015] Embodiments of the present application do not require the use of auxiliary solder pads, thereby reducing the process and improving the assembly efficiency. The main body part and the support part of the transfer piece sandwich the tab of the electrode assembly therebetween, which can reduce the risk of tab cracking while ensuring the welding strength between the tab and the transfer piece, and improve the welding yield. Further, when the electrode assemblies are combined and bundled, the support part provides support for the bent part of the tab, preventing the tab from bending downward due to stress and inserting into the electrode assembly, improving the yield of the manufacturing and high-voltage insulation test (hi-pot) of the electrode assembly and the secondary battery, and improving the safety of the electrode assembly and the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS [[ID=I5]]

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 An electron microscope image of a battery in the prior art is shown.

[0018] Figure 2 An electrical device according to an embodiment of the present application is shown.

[0019] Figures 3 to 6 Transfer pieces of different shapes according to the present application are shown.

[0020] Figure 7 Shows Figure 6 A side view of the transfer piece of the illustrated embodiment.

[0021] Figure 8 Shows Figure 5 The connection between the transfer piece of the illustrated embodiment and the electrode assembly.

[0022] Figure 9 shows Figure 6 and Figure 7 the connection between the adapter plate and the electrode assembly of the illustrated embodiment.

[0023] Figure 10 shows a secondary battery according to an embodiment of the present application. Detailed implementation manners

[0024] For a better understanding of the spirit of the embodiments of the present application, the following further explains it in conjunction with some preferred embodiments of the present application.

[0025] Embodiments of the present application will be described in detail below. Throughout the specification of the present application, the same or similar components and components having the same or similar functions are denoted by like reference numerals. The embodiments of the related drawings described herein are illustrative, diagrammatic, and are used to provide a basic understanding of the present application. The embodiments of the present application should not be construed as a limitation of the present application.

[0026] As used herein, the terms "substantially", "essentially", "substantive" and "about" are used to describe and account for minor variations. When used in conjunction with an event or circumstance, the terms can refer to instances where the event or circumstance occurs precisely and instances where the event or circumstance occurs very nearly.

[0027] In this specification, unless specifically specified or limited otherwise, relative terms such as: "central", "longitudinal", "lateral", "front", "rear", "right", "left", "inner", "outer", "lower", "higher", "horizontal", "vertical", "above", "below", "upper", "lower", "top", "bottom" and their derivative terms (such as "horizontally", "downwardly", "upwardly", etc.) should be construed as referring to the directions described in the discussion or depicted in the drawings. These relative terms are for convenience of description only and do not require the present application to be constructed or operated in a specific direction.

[0028] For ease of description, "first", "second", "third", etc. may be used herein to distinguish different components of a figure or a series of figures. "First", "second", "third", etc. are not intended to describe corresponding components.

[0029] In the prior art, an auxiliary solder tab is needed to strengthen the welding between the tab and the adapter plate, so as to improve the welding strength. However, the use of the auxiliary solder tab will increase the process steps and reduce the assembly efficiency. If the auxiliary solder tab is removed and the tab is directly welded to the adapter plate, since the copper foil used for the tab is relatively thin, it is easy to crack the tab during welding while ensuring the welding strength. Otherwise, a certain welding strength needs to be sacrificed to avoid cracking of the tab. In addition, referring to Figure 1 In the dashed box area 1 of

[0030] The present utility model provides an electronic device 1000. For the convenience of description in the following embodiments, the electronic device 1000 is taken as an example of a vehicle for illustration. Referring to Figure 2 , a battery pack 1002 is arranged inside the vehicle. The battery pack 1002 can be arranged at the bottom or head or tail of the vehicle body 1001. The battery pack 1002 can be used for power supply of the vehicle. For example, the battery pack 1002 can be used as the operating power source of the vehicle. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical energy support. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc., but not limited thereto. The working part is the vehicle body, and the battery pack 1002 is arranged at the bottom of the vehicle body and provides electrical energy support for the running of the vehicle or the operation of the electrical components inside the vehicle. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spaceship, etc.; the working part can obtain the electrical energy of the battery pack 1002 and is a unit component that performs corresponding work, such as the fan blade rotation unit of a fan, the dust suction working unit of a vacuum cleaner, etc. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy and an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinding wheel, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator and a planer, etc. The embodiments of the present application do not make special restrictions on the above-mentioned electronic device 1000.

[0031] Figures 3 to 6 shows a top view of the adapter plate 150 of different shapes in the present application, Figure 7 shows Figure 6 a side view of the adapter plate 150 of the embodiment shown in Figure 8 shows Figure 5The adapter piece 150 of the illustrated embodiment is connected to the electrode assembly 120. Figure 9 is shown Figure 6 and Figure 7 The adapter piece 150 of the illustrated embodiment is connected to the electrode assembly 120. In Figure 8 and Figure 9 the left adapter piece 150 (showing its shape when not folded) is connected to the positive electrode tabs of two electrode assemblies 120, for example, and the right adapter piece 150 (showing its shape after folding) is connected to the negative electrode tabs of two electrode assemblies 120, for example. The two adapter pieces 150 are symmetrically arranged, and the flexible parts 30 are located on both sides to avoid interference during folding. Figure 10 Fig. shows a secondary battery 100 according to an embodiment of the present application.

[0032] The secondary battery 100 includes a battery housing 170, an electrode assembly 120, and a terminal post 140. The battery housing 170 includes a top cover 172, an end wall, and a side wall surrounding the end wall. As long as a stable sealing and electrical connection relationship can be formed, the connection between the end wall and the side wall can be achieved in various ways. For example, it can be integrally stamped, integrally cast, or separately welded. The surrounding of the side wall is not limited. It can surround in a cylindrical or prismatic shape, or surround along any other closed-loop contour that can match the end wall. A receiving cavity is formed in the battery housing 170 for receiving the electrode assembly 120, the electrolyte, and other necessary battery components. Specifically, the diameter of the battery housing 170 can be determined according to the specific size of the electrode assembly 120. The material of the battery housing 170 can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. In order to prevent the battery housing 170 from rusting during long-term use, an anti-rust material such as metal nickel can also be plated on the surface of the battery housing 170.

[0033] The electrode assembly 120 is accommodated within the battery case 170. The electrode assembly 120 is a component in the secondary battery 100 where an electrochemical reaction occurs. One or more electrode assemblies 120 may be included within the battery case 170. The electrode assembly 120 includes stacked and / or wound positive electrode plates, a first separator, negative electrode plates, and a second separator. The positive electrode plate includes a positive current collector and a positive active material layer coated on the positive current collector. A first coated area coated with the positive active material layer and a first uncoated area not coated with the positive active material layer are formed on the positive current collector. The first coated area and the first uncoated area are arranged along the height direction H of the electrode assembly 120. The first uncoated area extends to outside the separator at one end in the height direction H of the secondary battery 100 and forms a bent positive electrode tab. The negative electrode plate includes a negative current collector and a negative active material layer coated on the negative current collector. A second coated area coated with the negative active material layer and a second uncoated area not coated with the negative active material layer are formed on the negative current collector. The second coated area and the second uncoated area are arranged along the height direction H of the electrode assembly 120. The second uncoated area also extends to outside the separator at one end in the height direction H of the secondary battery 100 and forms a bent negative electrode tab. The first separator and the second separator are disposed between the positive electrode plate and the negative electrode plate to isolate the positive active material layer and the negative active material layer. Taking the lithium-ion secondary battery 100 as an example, the material of the positive current collector may be aluminum. The positive active material layer includes a positive active material, and the positive active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The material of the negative current collector may be copper. The negative active material layer includes a negative active material, and the negative active material may be carbon or silicon, etc. The base material of the first separator and the second separator may be PP (polypropylene) or PE (polyethylene), etc. To protect and insulate the battery cell, an insulating film may also be coated outside the battery cell, and the insulating film may be synthesized from PP, PE, PET, PVC, or other polymer materials.

[0034] Furthermore, in the present utility model, the positive electrode tab and the negative electrode tab face and are electrically connected to the top cover 172. The top cover 172 is sealingly installed on the side wall of the battery case 170; the outer edge shape of the top cover 172 corresponds to the shape of the side wall opening, and the installation method of the top cover 172 includes but is not limited to mechanical sealing or welding sealing.

[0035] See Figures 3 to 7, an embodiment of the present application provides an adapter piece 150 for electrically connecting an electrode assembly 120 and a top cover 130. The adapter piece 150 includes a main body portion 10, a support portion 20, and a flexible portion 30. The main body portion 10 includes a main body tab welding portion 12 and a main body top cover welding portion 14 that are connected; the support portion 20 is connected to the main body portion 10 through the flexible portion 30, and the flexible portion 30 is used to fold the support portion 20 relative to the main body portion 10 so that the main body portion 10 and the support portion 20 clamp the tab 122 of the electrode assembly 120 therebetween. The main body portion 10, the support portion 20, and the flexible portion 30 may be integrally formed, that is, the materials of the three are the same, and the thickness of the flexible portion 30 in the thickness direction T (see Figure 7 ) and the width in the width direction W are both smaller than those of the main body portion 10 and the support portion 20. Therefore, the flexible portion 30 is softer, and the adapter piece 150 can be folded here. The embodiment of the present application does not need to use an auxiliary solder piece, thereby reducing the process and improving the assembly efficiency. The main body portion 10 and the support portion 20 of the adapter piece 150 clamp the tab 122 of the electrode assembly 120 therebetween, which can ensure the welding strength between the tab 122 and the adapter piece 150 while reducing the risk of the tab 122 cracking during welding and improving the welding yield. Further, when the electrode assemblies 120 are combined and bundled, the support portion 20 provides support for the bending portion of the tab 122, preventing the tab 122 from bending downward due to stress and inserting into the electrode assembly 120, improving the manufacturing and high-voltage insulation test (hi-pot) yield of the electrode assembly 120 and the secondary battery 100, and improving the safety of the electrode assembly 120 and the secondary battery 100.

[0036] See Figure 7 and Figure 10 , along the width direction W, the ratio of the thickness of the main body portion 10 to the thickness of the support portion 3 ranges from 0.2 to 5, and the total thickness of the main body portion 10 and the support portion 3 meets the maximum over-current capacity during the operation of the secondary battery 100. The limit difference between the thickness of the main body portion 10 and the thickness of the support portion 3 is 5 times. When the ratio is within this range, the support ability and support effect on the tab 122 are satisfied.

[0037] See Figures 3 to 7 , the support portion 20 also includes a support tab welding portion 22 corresponding to the main body tab welding portion 12 and a support top cover welding portion 24 corresponding to the main body top cover welding portion 14. During welding, the main body tab welding portion 12, the support tab welding portion 22 are welded to the tab 122 together, and the main body top cover welding portion 14, the support top cover welding portion 24 are welded to the top cover 172 together.

[0038] See Figure 8 and Figure 9, the width of the support tab welding part 22 is less than 2 / 3 of the height of the tab 122 from the tab starting edge 1222 to the tab welding mark area 1224, and the widths of the main tab welding part 12 and the support tab welding part 22 are both greater than the width of the tab welding mark area 1224. When the width of the support tab welding part 22 is within this range, it satisfies the support effect on the bending area of the tab 122 when the tab 122 is bent.

[0039] See Figures 3 to 9 , the main body part 10 includes two main tab welding parts 12, a main body top cover welding part 14, and the two main tab welding parts 12 define a main body notch 16 penetrating the main body part 10. The main body notch 16 separates the two main tab welding parts 12; the support part 20 includes two support tab welding parts 22, a support top cover welding part 24, and the two support tab welding parts 22 define a support notch 26 penetrating the support part 20. The support notch 26 separates the two support tab welding parts 22. When the main body part 10 and the support part 20 sandwich the tab 122 between them, projected along the sandwiching direction, the main body notch 16 and the support notch 26 coincide. It can be understood that there is an alignment deviation between the support part 20 and the main body part 10 when the support part 20 is folded. See Figure 8 and Figure 9 , the widths of the main body notch 16 and the support notch 26 determine the distance between the tabs 122 of the two electrode assemblies 120.

[0040] See Figure 3 、 Figure 6 、 Figure 9 , the main body top cover welding part 14 and the support top cover welding part 24 can be symmetrical about the flexible part 30. See Figure 4 、 Figure 5 and Figure 8 , the support top cover welding part 24 can be set wider than the main body top cover welding part 14. See Figure 3 , the main body part 10 can be symmetrical with the support part 20. See Figures 4 to 9 , the support part 20 is wider than the main body part 10 to have a better support effect on the tab 122.

[0041] See Figure 10, embodiments of the present application further provide a secondary battery 100. The secondary battery 100 includes a battery housing 170, a connecting tab 150, and an electrode assembly 120. The battery housing 170 includes a top cover 172. The electrode assembly 120 is accommodated in the battery housing 170 and includes a battery cell main body 124 and tabs 122 protruding from the battery cell main body 124. The main tab welding portion 12 of the connecting tab 150 is electrically connected to the tab 122, and the main top cover welding portion 14 is electrically connected to the top cover 172. The main tab welding portion 12 is located between the tab 122 and the top cover 172, and the support portion 20 is located between the tab 122 and the battery cell main body 124. The secondary battery 100 can be a lithium-ion battery, a sodium-ion battery, or an electrochemical device with the same structure and principle. The main body portion 10 and the support portion 20 of the connecting tab 150 sandwich the tab 122 of the electrode assembly 120 therebetween. First, for example, an ultrasonic welding process is used to weld the tab 122 to the main tab welding portion 12 and the support tab welding portion 22. After welding is completed, the electrode assembly 120 and the connecting tab 150 are placed into the battery housing 170, and the top cover 172 is welded to the main top cover welding portion 14 and the support top cover welding portion 24. The tab 122 is located between the main body portion 10 and the support portion 20, which can ensure the welding strength between the tab 122 and the connecting tab 150 while reducing the risk of the tab 122 cracking during welding and improving the welding yield. When two (the present application is not limited to this quantity) electrode assemblies 120 shown in the figure are combined and bundled, the support portion 20 provides support for the bending portion of the tab 122 below the tab 122, preventing the tab 122 from bending downward due to stress and inserting into the electrode assembly 120, thereby improving the safety of the electrode assembly 120 and the secondary battery 100.

[0042] Embodiments of the present application further provide a battery pack 1002, including the above-mentioned secondary battery 100, and the battery pack 1002 can have the beneficial effects described above with respect to the secondary battery 100.

[0043] Embodiments of the present application further provide an electronic device 1000, including the above-mentioned battery pack 1002, and the electronic device 1000 can have the beneficial effects described above with respect to the connecting tab 150, the secondary battery 100, and the battery pack 1002.

[0044] The foregoing is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An adapter piece for electrically connecting an electrode assembly and a top cover, characterized in that Comprising: A main body part, including a connected main body tab welding part and a main body top cover welding part; A support part and a flexible part, the support part is connected to the main body part through the flexible part, and the flexible part is used to fold the support part relative to the main body part so that the main body part and the support part clamp the tab of the electrode assembly therebetween.

2. The adapter sheet according to claim 1, characterized in that, The ratio range of the thickness of the main body part to the thickness of the support part is 0.2 to 5.

3. The adapter sheet according to claim 1, wherein The support part includes a support tab welding part corresponding to the main body tab welding part and a support top cover welding part corresponding to the main body top cover welding part.

4. The adapter piece according to claim 3, characterized in that, The width of the support tab welding part is less than 2 / 3 of the height of the tab from the tab starting edge to the tab welding mark area.

5. The adapter sheet according to claim 4, wherein The width of the main body tab welding part and the width of the support tab welding part are greater than the width of the tab welding mark area.

6. The adapter piece according to claim 3, characterized in that, The main body part includes two main body tab welding parts, and the main body top cover welding part and the two main body tab welding parts define a main body notch penetrating through the main body part, and the main body notch separates the two main body tab welding parts; The support part includes two support tab welding parts, and the support top cover welding part and the two support tab welding parts define a support notch penetrating through the support part, and the support notch separates the two support tab welding parts. When the main body part and the support part clamp the tab therebetween, in the projection along the clamping direction, the main body notch and the support notch coincide.

7. The adapter sheet according to claim 3, characterized in that, The main body top cover welding part and the support top cover welding part are symmetric about the flexible part.

8. A secondary battery, characterized in that, Comprising: A battery housing, including a top cover; An electrode assembly, accommodated in the battery housing, including a cell main body and tabs protruding from the cell main body; The adapter plate according to any one of claims 1 to 7, the main body tab welding part is electrically connected to the tab, the main body top cover welding part is electrically connected to the top cover, the main body tab welding part is located between the tab and the top cover, and the support part is located between the tab and the cell main body.

9. A battery pack, characterized in that, Including the secondary battery according to claim 8.

10. An electronic device, characterized in that, Including the battery pack according to claim 9.

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