Battery

Abstract

The utility model provides a battery. The battery comprises a shell; the cover plate is connected with a first pole assembly; the naked battery cell comprises a battery cell body and a first tab; the battery cell body comprises two battery cell side surfaces which are oppositely arranged along a first direction; the first tab comprises a connecting part, a first bending part, a transition part, a second bending part and a fixing part which are connected in sequence, the connecting part is connected with the battery cell body, and the fixing part is connected with the first pole assembly; the first protection layer is connected to the plate surface, close to the shell, of the first tab, and the first protection layer extends from the second bending part to the side surface of the battery cell along the extension direction of the first tab; and the second protection layer is connected to one side, far away from the first tab, of the first protection layer, and the second protection layer is located between the second bending part and the first bending part along the extension direction of the first tab. According to the battery provided by the invention, when the first tab is bent into the relatively regular S-shaped structure under the limiting action of the second protective layer, the risks of shell contact short circuit and inverted insertion of the tab into the battery cell are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a battery. BACKGROUND

[0002] The battery can include a shell, a cover plate and a bare cell, the shell and the cover plate form a containing space, and the bare cell is arranged in the containing space. One end of the bare cell close to the cover plate is formed with a tab, and the tab is welded with a pole assembly on the cover plate to form an electrical connection between the bare cell and the pole assembly.

[0003] When the cover plate is connected with the shell, the tab will be bent in the containing space. If the bending shape of the tab is not limited, it is difficult for the tab to form a preset shape after bending, and the tab may be short-circuited by touching the shell (directly contacting the metal shell), and the tab may be inserted into the cell in reverse. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the purpose of the present application is to provide a battery to at least partially solve the problem of short circuit caused by the tab touching the shell and the tab being inserted into the cell in reverse due to the unstable bending shape of the tab.

[0005] To achieve the above purpose, the present application provides a battery, which comprises: a shell; a cover plate, which forms a containing space together with the shell; a first pole assembly connected with the cover plate; a bare cell arranged in the containing space, the bare cell comprising a cell body and a first tab; the cell body comprising a cell end face close to the cover plate and two cell side faces oppositely arranged along a first direction; the first tab comprising a connecting portion, a first bending portion, a transition portion, a second bending portion and a fixing portion connected in sequence along a second direction, the connecting portion being connected with the cell body, and the fixing portion being connected with the first pole assembly; the first bending portion and the second bending portion are both bent along the first direction, and the bending direction of the first bending portion is opposite to that of the second bending portion; the first direction is the thickness direction of the bare cell, and the second direction is perpendicular to the cell end face; a first protective layer connected to the tab close to the plate surface of the shell, the first protective layer extending from the second bending portion to the cell side face along the extension direction of the first tab; a second protective layer connected to the side of the first protective layer away from the first tab, the second protective layer being located between the second bending portion and the first bending portion along the extension direction of the first tab.

[0006] Optionally, the first protective layer comprises a first base layer and a first adhesive layer, and the first base layer is adhered to the surface of the first tab through the first adhesive layer; along the thickness direction of the first tab, the first adhesive layer is located at least in the second bending portion and the connecting position of the connecting portion and the cell body in the orthographic projection of the first tab.

[0007] Optionally, the second protective layer comprises a second base layer and a second adhesive layer, the second base layer is bonded to the surface of the first protective layer through the second adhesive layer; the elastic modulus of the second base layer is greater than the elastic modulus of the first base layer, and / or; the yield strength of the second base layer is greater than the yield strength of the first base layer.

[0008] Optionally, the first base layer and / or the second base layer is an insulating layer.

[0009] Optionally, the first adhesive layer covers the surface of the first base layer close to the first tab.

[0010] Optionally, along a third direction, the first protective layer and / or the second protective layer extends to the edge of the first tab; the third direction is perpendicular to the first direction and the second direction.

[0011] Optionally, along the second direction, the second protective layer is located in the projection of the battery core body.

[0012] Optionally, the ratio of the thickness of the first protective layer to the thickness of the second protective layer is 1:2-3:50.

[0013] Optionally, the thickness of the second protective layer is 0.1-0.5mm.

[0014] Optionally, the edge of the second protective layer along the third direction is perpendicular to the edge of the first tab along the second direction.

[0015] As can be seen from the above, the battery provided by the present application, the first protective layer covers the exposed surface of the first tab towards the shell and the connection between the first tab and the battery core body, the first protective layer can protect the first tab, avoid damage to the first tab itself or the connection between the first tab and the battery core body caused by pulling or scratching. At the same time, the position of the first tab provided with the second protective layer is less likely to bend than other positions of the first tab, which can limit the positions of the first bending part and the second bending part through the support provided by the second protective layer to the first tab, and regulate the bending shape of the first tab. When the first tab is bent into a relatively regular S-shaped structure under the limitation of the second protective layer, the risk of short circuit and tab insertion into the battery core can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the application or the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the related art description. Obviously, the drawings in the following description only are the embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0017] Figure 1 Part of the battery of the embodiment of the application is shown in the figure.

[0018] Figure 2 Part of the battery of the embodiment of the application is shown in the figure. Figure 1 Enlarged schematic view of part A in the figure.

[0019] Figure 3 Part of the battery of the embodiment of the application is shown in the figure. Figure 2 Part of the battery of the embodiment of the application is shown in the figure.

[0020] Figure 4 Part of the battery of the embodiment of the application is shown in the figure.

[0021] Figure 5 Part of the battery of the embodiment of the application is shown in the figure.

[0022] Explanation of reference signs:

[0023] 100, shell; 200, cover plate; 300, first pole assembly; 400, containing space;

[0024] 500, bare battery cell; 510, battery cell body; 511, battery cell end face; 512, battery cell side face; 520, first tab; 521, connecting part; 522, first bending part; 523, transition part; 524, second bending part; 525, fixing part;

[0025] 600, first protective layer; 700, second protective layer. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the application more clear, the following will further describe the application in combination with specific embodiments and with reference to the drawings.

[0027] It should be noted that: unless otherwise specified, the relative arrangement of the components, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the application.

[0028] At the same time, it should be understood that, in order to facilitate the description, the size of each part shown in the drawings is not drawn according to the actual proportional relationship.

[0029] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0030] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] Figure 1 A partial schematic diagram of the battery is shown, such as Figure 1 The battery provided in this embodiment includes a housing 100, a cover plate 200 and a bare cell 500. For example, the housing 100 may be a square tube structure, that is, the housing 100 is a rectangular parallelepiped and has a longitudinal direction (such as Figure 1 The battery comprises two cover plates 200 , which are respectively covered on the two openings of the housing 100 .

[0032] Figure 2 Shown Figure 1 The enlarged schematic diagram of part A is as follows: Figure 2 The cover plate 200 and the shell 100 together form a receiving space 400, and the bare cell 500 is disposed in the receiving space 400. The bare cell 500 includes a cell body 510, which can be a structure composed of multiple positive electrode sheets, multiple negative electrode sheets, and a separator for isolating the positive and negative electrode sheets (the structure can be a laminated structure or a wound structure). The structure includes two cell end faces 511 arranged opposite to each other and close to the cover plate 200. A portion of each positive electrode sheet extends out of one of the cell end faces 511, and the protruding portions of the multiple positive electrode sheets are stacked and connected to form a positive electrode tab. The positive electrode tab is connected to the electrode assembly on the adjacent cover plate 200, and the electrode assembly forms the external positive electrode of the battery. Similarly, a portion of each negative electrode sheet extends out of the other cell end face 511, and the protruding portions of the multiple positive electrode sheets are stacked and connected to form a negative electrode tab. The positive electrode tab is connected to the electrode assembly on the adjacent cover plate 200, and the electrode assembly forms the external negative electrode of the battery.

[0033] For example, the first electrode tab 520 of this embodiment can be a positive electrode tab or a negative electrode tab. Accordingly, when the first electrode tab 520 is a positive electrode tab, the first electrode column assembly 300 can serve as an external positive electrode of the battery; when the first electrode tab 520 is a negative electrode tab, the first electrode column assembly 300 can serve as an external negative electrode of the battery.

[0034] The applicant has found that if the first tab 520 can be bent into a more regular S-shaped structure, the risks of the first tab 520 short-circuiting the shell and the tab being inserted upside down into the battery cell can be reduced.

[0035] Specifically, Figure 3 Shown Figure 2 The partial cutaway diagram of the BB section is as follows: Figure 2 and Figure 3 , the battery cell body 510 also includes a first direction (such as Figure 3 The first tab 520 includes two battery cell side surfaces 512 arranged opposite to each other along the second direction (e.g., the X direction). Figure 3 The first direction is the thickness direction of the bare cell 500, and the second direction is perpendicular to the cell end face 511.

[0036] The first bending portion 522 and the second bending portion 524 are both bent along the first direction, and the bending direction of the first bending portion 522 is opposite to the bending direction of the second bending portion 524. Compared to the first bending portion 522, the second bending portion 524 is closer to the housing 100.

[0037] Exemplarily, the first pole assembly 300 passes through the cover plate 200, with one end thereof located on the outside of the cover plate 200 (i.e., the side of the cover plate 200 away from the accommodating space 400) for electrically connecting to an external circuit; the other end is located on the inside of the cover plate 200 (i.e., inside the accommodating space 400) for welding to the first pole ear 520.

[0038] The applicant has discovered that in order to bend the first tab 520 into a relatively regular S-shaped structure, it is necessary to define the positions of the first bend 522 and the second bend 524. If the first bend 522 is not bent according to the predetermined position, the second bend 524 may be brought closer to the housing 100, which may cause a short circuit. If the bending radius of the second bend 524 is too large, the second bend 524 may contact the positive or negative electrode sheet in the cell body 510, resulting in the tab being inserted upside down into the cell.

[0039] Therefore, in order to limit the positions of the first bending part 522 and the second bending part 524, Figure 4 A partial perspective view of the battery is shown as Figure 3 And Figure 4 The battery of the embodiment further comprises a first protective layer 600 connected to the plate surface of the first tab 520 close to the shell 100, the first protective layer 600 extending from the second bending part 524 to the side surface 512 of the battery cell along the extension direction of the first tab 520; and a second protective layer 700 connected to the side of the first protective layer 600 away from the first tab 520, the second protective layer 700 being located between the second bending part 524 and the first bending part 522 along the extension direction of the first tab 520.

[0040] For example, the first protective layer 600 and the second protective layer 700 can be adhesive tapes.

[0041] For example, the first protective layer 600 and the second protective layer 700 can be insulating adhesive tapes.

[0042] Since the fixing part 525 needs to be exposed to facilitate electrical connection with the first pole assembly 300, the first protective layer 600 can cover the second bending part 524, the transition part 523, the first bending part 522, the connecting part 521 and part of the side surface 512 of the battery cell (the part of the side surface 512 close to the end surface 511 of the battery cell and corresponding to the first tab 520 in position). The first protective layer 600 can protect the first tab 520 from damage caused by pulling or scratching. Of course, since the first protective layer 600 is connected to the first tab 520 and the battery cell body 510 at the same time, the first protective layer 600 can also protect the connecting part 521 and the connecting position of the battery cell body 510, preventing the first tab 520 and the battery cell body 510 from being broken due to pulling, and ensuring that the battery cell body 510 can be reliably electrically connected to the first pole assembly 300 through the first tab 520.

[0043] The second protective layer 700 is located between the first bending part 522 and the second bending part 524. The presence of the second protective layer 700 makes the thickness of the area between the first bending part 522 and the second bending part 524 thicker, and this area is less likely to bend than the first bending part 522 and the second bending part 524 when the first tab 520 is bent. In other words, along the extension direction of the first tab 520, the edge of the second protective layer 700 close to the cover plate 200 can define the boundary of the second bending part 524, and the edge of the second protective layer 700 close to the battery cell body 510 can define the boundary of the first bending part 522. In this way, the positions of the first bending part 522 and the second bending part 524 can be limited, and accordingly, the first tab 520 can be limited to a relatively regular S-shaped structure.

[0044] The battery provided by the embodiment is provided with the first protection layer 600 covering the exposed surface of the first tab 520 towards the shell 100 and the connection position of the first tab 520 and the battery body 510. The first protection layer 600 can protect the first tab 520 from being damaged by pulling or scratching or the connection position of the first tab 520 and the battery body 510 from being broken. Meanwhile, the position of the first tab 520 provided with the second protection layer 700 is less likely to be bent than other positions of the first tab 520. The second protection layer 700 can limit the positions of the first bending part 522 and the second bending part 524 by providing support to the first tab 520, and regulate the bending shape of the first tab 520. When the first tab 520 is bent into a relatively regular S-shaped structure under the limitation of the second protection layer 700, the risk of short circuit and the risk of the first tab 520 being inserted into the battery body 510 in reverse can be reduced.

[0045] In some embodiments, the first protection layer 600 comprises a first base layer and a first adhesive layer. The first base layer is attached to the surface of the first tab 520 through the first adhesive layer. In the thickness direction of the first tab 520, the first adhesive layer is located at least in the second bending part 524 and the connection position of the connection part 521 and the battery body 510.

[0046] In the embodiment, the first adhesive layer is arranged at least at the starting end and the position close to the ending end of the extension direction of the first base layer, so as to ensure that the first protection layer 600 can be reliably connected with the first tab 520 and the battery body 510. The middle part of the first protection layer 600 corresponds to the transition part 523 of the first tab 520. Since the second protection layer 700 is located outside the first protection layer 600 (away from the first tab 520), it not only limits the bending of the first tab 520, but also limits the first protection layer 600. The middle part of the first protection layer 600 can be bent along with the bending of the first tab 520, that is, the middle part of the first protection layer 600 can be close to or even attached to the surface of the first tab 520.

[0047] Therefore, in the embodiment, even if the first adhesive layer is not arranged at the middle part of the first base layer, the first protection layer 600 as a whole can be attached to the first tab 520 under the limitation of the second protection layer 700, so as to ensure that the first protection layer 600 can better protect the first tab 520. Moreover, it helps to reduce the assembly difficulty and the setting cost of the first protection layer 600, and is conducive to mass production.

[0048] In some embodiments, the second protective layer 700 includes a second base layer and a second adhesive layer, and the second base layer is bonded to the surface of the first protective layer 600 through the second adhesive layer; the elastic modulus of the second base layer is greater than the elastic modulus of the first base layer, and / or; the yield strength of the second base layer is greater than the yield strength of the first base layer.

[0049] The second base layer has a large elastic modulus and yield strength, which can prevent the second protective layer 700 from bending easily when the first pole tab 520 is bent, so that the second protective layer 700 can provide structural support for the first pole tab 520, thereby limiting the first bending portion 522 and the second bending portion 524 to preset positions, so that the first pole tab 520 can stably form a relatively regular S-shaped structure.

[0050] In some embodiments, the first base layer and / or the second base layer is an insulating layer.

[0051] Exemplarily, the second base layer can be made of PET.

[0052] When the first base layer is an insulating layer, even if the second bending portion 524 contacts the housing 100 , the first protective layer 600 covers the second bending portion 524 , so the first base layer can isolate the second bending portion 524 from the housing 100 , further preventing a short circuit.

[0053] When the second base layer is an insulating layer, even if the transition portion 523 is pressed down to contact the connecting portion 521 , the second base layer can also isolate the transition portion 523 and the connecting portion 521 , thereby further preventing the tab from being inserted upside down into the battery cell.

[0054] In some embodiments, the first adhesive layer covers the surface of the first base layer adjacent to the first electrode tab 520 .

[0055] The first adhesive layer covers the entire surface of the first base layer close to the first pole tab 520, further improving the connection strength between the first base layer and the surface of the first pole tab 520, ensuring that the entire first base layer can fit the surface of the first pole tab 520, and ensuring that the first protective layer 600 can better protect the first pole tab 520 and the connection between the first pole tab 520 and the battery cell body 510.

[0056] Figure 5 A schematic diagram showing the first tab 520 in an unfolded state before being bent is shown. Figure 5 , along the third direction (such as Figure 5 The first protective layer 600 and / or the second protective layer 700 extends to the edge of the first electrode tab 520; the third direction is perpendicular to the first direction and the second direction.

[0057] The third direction is the width direction of the first electrode tab 520 .

[0058] The first protective layer 600 or the second protective layer 700 extends to the edge of the first tab 520 in the third direction, that is, in the width direction of the first tab 520, the first protective layer 600 or the second protective layer 700 completely covers the plate surface of the first tab 520.

[0059] When the first protective layer 600 completely covers the exposed plate surface of the first tab 520, the first protective layer 600 can form more comprehensive protective coverage for the first tab 520, further improving the protection of the first tab 520 by the first protective layer 600.

[0060] When the second protective layer 700 extends to the edge of the first tab 520 in the third direction, the second protective layer 700 can support a larger area between the first bending part 522 and the second bending part 524 of the first tab 520. When the first tab 520 is bent, the positions of the first bending part 522 and the second bending part 524 can be better defined, so that the first tab 520 can form a more regular S-shaped structure more stably.

[0061] As Figure 3 In some embodiments, in the second direction, the orthographic projection of the second protective layer 700 on the battery body 510 is located in the battery end surface 511.

[0062] When the orthographic projection of the second protective layer 700 on the battery body 510 is located in the battery end surface 511, the second bending part 524 can be farther away from the shell 100, thereby further reducing the possibility of contact between the second bending part 524 and the shell 100 and reducing the risk of short circuit caused by touching the shell.

[0063] In some embodiments, the ratio of the thickness of the first protective layer 600 to the thickness of the second protective layer 700 is 1:2-3:50.

[0064] If the thickness of the first protective layer 600 is large, the first tab 520 as a whole will not be easy to bend, which will hinder the connection of the cover plate 200 and the shell 100, which obviously does not meet the requirements of the battery preparation process. Therefore, the thickness of the first protective layer 600 is limited to ensure that the first protective layer 600 can reliably protect the first tab 520 without hindering the bending of the first tab 520, so that the first tab 520 can form a more regular S-shaped structure more stably.

[0065] In some embodiments, the thickness of the second protective layer 700 is 0.1mm to 0.5mm.

[0066] The thickness of the second protective layer 700 is limited in this embodiment, which can ensure that the second protective layer 700 has a certain elastic modulus and yield strength. When the first tab 520 is bent, the second protective layer 700 can be prevented from being bent too much, and the first tab 520 can be reliably supported and limited by the second protective layer 700, so that the first tab 520 can form a more regular S-shaped structure more stably.

[0067] As Figure 5 In some embodiments, the edge of the second protective layer 700 along the third direction (for example, the Y direction in FIG. 16) is perpendicular to the edge of the first tab 520 along the second direction (for example, the Z direction in FIG. 16). Figure 5 Figure 5 In some embodiments, the edge of the second protective layer 700 along the third direction (for example, the Y direction in FIG. 16) is perpendicular to the edge of the first tab 520 along the second direction (for example, the Z direction in FIG. 16).

[0068] In this embodiment, the edge of the second protective layer 700 along the length direction can be perpendicular to the edge of the first tab 520 along the extension direction. When the first bent portion 522 and the second bent portion 524 are positionally limited by the edge of the second protective layer 700 along the length direction, the edge of the first bent portion 522 and the edge of the second bent portion 524 can also be made more straight, which helps the first tab 520 to form a more regular S-shaped structure more stably, and the two sides of the S-shaped structure along the third direction have the same shape.

[0069] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims.

[0070] Each of the embodiments in the present application is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0071] The description of the present application is given for the purpose of illustration and description, and is not exhaustive or limiting to the forms disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are chosen and described in order to better illustrate the principles and practical application of the present application, and to enable those of ordinary skill in the art to understand the present application in order to design various embodiments with various modifications for specific purposes.

[0072] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary, and is not intended to limit the scope of the present application to these examples; the technical features of the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other changes to the different aspects of the embodiments of the present application as described above. In order to be brief, they are not provided in detail.

[0073] ​While the application has been described in connection with specific embodiments thereof, it will be understood that many modifications, substitutions, and changes will be apparent to those of ordinary skill in the art from the foregoing description.

[0074] It is intended to cover all alternatives, modifications, and variations of this application falling within the scope of the application. Accordingly, any and all such alternatives, modifications and variations should be included within the scope of the present application.

Claims

1. A battery, characterized by, The application relates to a battery cell, which comprises the following parts: a shell; a cover plate which cooperates with the shell to form a containing space; a first pole post assembly connected to the cover plate; a bare battery cell arranged in the containing space, the bare battery cell comprising a battery cell body and a first tab; the battery cell body comprises a battery cell end face close to the cover plate and two battery cell side faces oppositely arranged along a first direction; the first tab comprises a connecting part, a first bending part, a transition part, a second bending part and a fixing part which are sequentially connected along a second direction; the connecting part is connected to the battery cell body; the fixing part is connected to the first pole post assembly; the first bending part and the second bending part are both bent along the first direction, and the bending direction of the first bending part is opposite to that of the second bending part; the first direction is the thickness direction of the bare battery cell, and the second direction is perpendicular to the battery cell end face; a first protective layer connected to the first tab close to the plate face of the shell; the first protective layer extends from the second bending part to the battery cell side face along the extension direction of the first tab; a second protective layer connected to the first protective layer away from the first tab; the second protective layer is located between the second bending part and the first bending part along the extension direction of the first tab.

2. The battery of claim 1, wherein, The first protective layer comprises a first base layer and a first adhesive layer; the first base layer is adhered to the surface of the first tab through the first adhesive layer; along the thickness direction of the first tab, the first adhesive layer is located at least at the second bending part and the connecting position of the connecting part and the battery cell body.

3. The battery of claim 2, wherein, The second protective layer comprises a second base layer and a second adhesive layer; the second base layer is adhered to the surface of the first protective layer through the second adhesive layer; The elastic modulus of the second base layer is greater than that of the first base layer, and / or; The yield strength of the second base layer is greater than that of the first base layer.

4. The battery of claim 3, wherein, The first base layer and / or the second base layer is an insulating layer.

5. The battery of claim 2, wherein, The first adhesive layer covers the surface of the first base layer close to the first tab.

6. The battery of claim 1, wherein, Along a third direction, the first protective layer and / or the second protective layer extends to the edge of the first tab; the third direction is perpendicular to the first direction and the second direction.

7. The battery of claim 1, wherein, Along the second direction, the second protective layer is located in the battery cell end face in the orthographic projection of the battery cell body.

8. The battery of claim 1, wherein, The ratio of the thickness of the first protective layer to that of the second protective layer is 1:2-3:

50.

9. The battery of claim 1, wherein, The thickness of the second protective layer is 0.1-0.5 mm.

10. The battery of claim 1, wherein, The edge of the second protective layer along the third direction is perpendicular to the edge of the first tab along the second direction.

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