Connecting piece, battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, in particular to a connecting piece, a battery cell and a battery pack. The connecting piece comprises a connecting piece main body which is provided with a first connecting part and a second connecting part; the first connecting part is provided with a fusing area and a first connecting area used for being connected with a pole, the second connecting part is provided with a second connecting area used for being connected with a tab, and the fusing area is arranged between the first connecting area and the second connecting area; a concave thinning part is arranged on the fusing region, the surface area of the part, except the thinning part, of the fusing region is 6mm < 2 >-12mm < 2 >, and the thickness of the first connecting part in the fusing region is 0.6-1.5 mm. According to the utility model, the fusing region can be disconnected in time when the battery cell is short-circuited, the structural strength of the fusing region can be ensured, and the reliability of the connecting sheet is improved, so that the use requirement of the connecting sheet when the battery cell is in a normal working state is met, the condition that the connecting sheet is broken under a non-short-circuit condition is avoided, the service life of the battery cell is prolonged, and the reliability of the battery cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a connecting piece, a battery core and a battery pack. Background Art

[0002] In a battery structure, a connecting piece is usually required to connect the pole tab of the pole core to the pole post to achieve electrical connection, thereby connecting the power supply circuit of the battery structure. As a key component connecting the pole post and the pole tab, the connecting piece plays a very important role as a connecting bridge. When the battery short-circuits, the connecting piece disconnects in time, disconnecting the pole post and the pole tab, thereby ensuring the safety performance of the battery. In the prior art, the connecting piece is reduced in the local cross-sectional area to achieve the timely melting of the connecting piece in the event of a battery short-circuit. However, when the local cross-sectional area of ​​the connecting piece is reduced, the strength of the connecting piece is insufficient, resulting in low reliability of the connecting piece. Utility Model Content

[0003] In view of this, the purpose of the present application is to provide a connecting piece, a battery cell and a battery pack to solve the problem that the strength of the area on the existing connecting piece used for melting during a short circuit is insufficient, resulting in low reliability of the connecting piece during normal use.

[0004] A first aspect of the present invention provides a connecting piece, wherein the connecting piece comprises:

[0005] A connecting piece body having a first connecting portion and a second connecting portion connected to each other;

[0006] The first connection portion is formed with a fuse area and a first connection area for connecting to a pole, the second connection portion is formed with a second connection area for connecting to a tab, and the fuse area is provided between the first connection area and the second connection area;

[0007] The melting zone is provided with a concave thinning portion, and the surface area of ​​the melting zone excluding the thinning portion is 3mm 2 ~6mm 2 The thickness of the first connecting portion in the fusing zone is 0.6 mm to 1.5 mm.

[0008] Preferably, the fusing region is formed as a strip-shaped region extending along the first direction, and / or the thinning portion is formed as a strip-shaped hole structure extending along the first direction.

[0009] Preferably, the thinned portion is formed as a through-hole structure penetrating the main body of the first connecting portion.

[0010] Preferably, the thinning portion includes a plurality of through holes, and the plurality of through holes are arranged at intervals along the first direction, wherein the through holes arranged at both ends form a non-closed half-hole structure.

[0011] Preferably, an end portion of the thinned portion in the first direction is arc-shaped.

[0012] Preferably, the connecting piece further comprises:

[0013] A protective member is provided on the first connecting portion, and the protective member covers the fusing zone.

[0014] Preferably, the protective member is an insulating member, and after the fuse zone is broken, the first connecting portion and the second connecting portion are connected via the protective member.

[0015] Preferably, the first connecting portion is formed into a sheet-like structure, and the protective member is formed into an annular structure to cover both the front and back surfaces of the fusing zone.

[0016] A second aspect of the present invention provides a battery cell comprising the connecting piece described in any one of the above technical solutions.

[0017] A third aspect of the present invention provides a battery pack, comprising the cell fuse described in the above technical solution, wherein the fusing time t1 of the fuse is less than the fusing time t2 of the connecting piece and is less than the safety time t3.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The connecting piece of the utility model has a thinning portion provided on the melting area when the battery cell is short-circuited, so that the melting area can disconnect the connection between the first connection area and the second connection area, thereby disconnecting the electrical connection between the pole and the tab, ensuring the safety of the battery cell. The surface area of ​​the melting area excluding the thinning portion is 3mm 2 ~6mm 2 The thickness of the first connecting portion in the fusing area is 0.6mm to 1.5mm. This ensures that the fusing area can be disconnected promptly during a short circuit, while also improving the structural strength of the fusing area and the reliability of the connecting piece. This meets the requirements for the connecting piece to be used in normal working conditions of the battery cell and prevents the connecting piece from breaking in non-short circuit conditions, thereby increasing the service life and reliability of the battery cell. Furthermore, the battery pack assembled from the battery cells also includes a fuse. The fuse's fusing time t1 is less than the connecting piece's fusing time t2, which is less than the safety time t3. This ensures that the battery pack can be used safely while other components of the battery pack can continue to be used after the short-circuited battery cell needs to be replaced, thereby saving energy and costs.

[0020] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic structural diagram of a connecting piece provided in an embodiment of the present utility model;

[0023] Figure 2 A schematic structural diagram of a connecting piece main body in a connecting piece provided in an embodiment of the present utility model;

[0024] Figure 3 A schematic structural diagram of the connecting piece main body in the connecting piece provided by an embodiment of the present utility model from another perspective;

[0025] Figure 4 along Figure 3 Cross-sectional view taken at AA in the middle.

[0026] Icons: 10 - connecting piece body; 11 - first connecting portion; 111 - first connecting area; 112 - melting area; 1121 - thinning portion; 12 - second connecting portion; 121 - second connecting area; 20 - protective member; D1 - first direction. DETAILED DESCRIPTION

[0027] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0028] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0029] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on,” “directly connected to,” “directly coupled to,” “directly over,” or “directly covering” another element, there may be no other elements intervening therebetween.

[0030] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0031] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0032] For ease of description, spatial relational terms such as "above," "upper," "below," and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element would subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations "above" and "below," depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0033] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0034] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0035] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0036] According to a first aspect of the present invention, a connecting piece is provided, which includes a connecting piece body 10 .

[0037] Hereinafter, the specific structures of the above-mentioned components of the connection sheet according to the present embodiment will be described.

[0038] In this embodiment, if Figures 2 to 4 As shown, the connecting piece body 10 is formed into a sheet structure, specifically a metal sheet, to achieve electrical connection between the pole and the tab. Specifically, the connecting piece body 10 has a first connecting portion 11 and a second connecting portion 12 connected to each other. The first connecting portion 11 is formed with a melting area 112 and a first connecting area 111, and the second connecting portion 12 is formed with a second connecting area 121. The first connecting area 111 is used to connect to the pole, and the second connecting portion 12 is used to connect to the tab. The melting area 112 is arranged between the first connecting area 111 and the second connecting area 121. When a short circuit occurs in the battery cell, the melting area 112 is melted, causing the first connecting portion 11 to break at the melting area 112 to separate the connection between the first connecting portion 11 and the second connecting portion 12, thereby disconnecting the electrical connection between the pole and the tab.

[0039] In this embodiment, the connecting piece is provided on the positive electrode side of the battery cell, and the material of the connecting piece may be aluminum, such as Al1060.

[0040] In this embodiment, if Figure 3 and Figure 4As shown, the first connection part 11 and the second connection part 12 are both formed into a thin sheet structure. The first connection part 11 and the second connection part 12 are arranged parallel to each other and are not coplanar. The size of the first connection part 11 in the first direction D1 is smaller than the size of the second connection part 12 in the first direction D1. The melting area 112 is arranged on the first connection part 11, which can ensure that when a short circuit occurs in the battery cell, the connection piece body 10 located in the melting area 112 can be melted in time, thereby ensuring that the first connection part 11 and the second connection part 12 are completely disconnected.

[0041] It should be noted that, in this embodiment, the first direction D1 is perpendicular to the arrangement direction of the first connecting portion 11 and the second connecting portion 12 (ie, the length direction of the connecting piece body 10). Figure 3 Vertical direction of viewing angle.

[0042] In this embodiment, if Figure 1 and Figure 2 As shown, a concave thinning portion 1121 is provided on the melting zone 112, so that the thickness of the portion of the connecting piece body 10 located in the melting zone 112 is less than the thickness of the first connecting zone 111, which helps to melt the melting zone 112 in time when the battery cell is short-circuited, thereby ensuring the safety of the battery cell; in this embodiment, the surface area of ​​the melting zone 112 excluding the thinning portion 1121 is 3mm 2 ~6mm 2 The thickness of the first connecting portion 11 in the melting area 112 is 0.6 mm to 1.5 mm. In this way, while ensuring that the melting area 112 can be disconnected in time when the battery cell is short-circuited, the structural strength of the melting area 112 can be improved, and the reliability of the connecting piece can be improved, thereby meeting the use requirements of the connecting piece of the battery cell under normal working conditions and avoiding the breakage of the connecting piece in non-short-circuit conditions.

[0043] In this embodiment, the surface area of ​​the melting zone 112 excluding the thinning portion 1121 can be 3 mm 2 , 4mm 2 or 6mm 2 In fact, the part of the melting zone 112 excluding the thinned portion 1121 is the main structure for realizing the connection relationship between the first connecting portion 11 and the second connecting portion 12. If the area of ​​this part is too small, the stress it is subjected to is relatively large, and the battery cell or battery pack is prone to cracking when subjected to vibration or impact, thereby causing the battery cell to fail in a non-short-circuit state, and there is a risk of the fuse in the battery pack blowing before the fuse is blown during the battery cell short-circuit test; if the area of ​​this part is too large, the melting zone 112 is prone to fail to break in time, thereby increasing the risk of thermal runaway of the battery cell.

[0044] In addition, if the thickness of the first connecting portion 11 in the melting zone 112 is too small, the strength of the connecting piece will be insufficient. If the thickness is too large, the welding process between the connecting piece and the pole will be difficult, and it will be difficult to weld through, resulting in insufficient tensile strength after welding.

[0045] Furthermore, in this embodiment, Figure 2 and Figure 3 As shown, the melting zone 112 is formed as a strip area extending along the first direction D1, and extends to the two ends of the first connecting part 11 along the first direction D1, and both ends of the melting zone 112 in the length direction extend to the two opposite ends of the first connecting part 11, thereby ensuring that the melting zone 112 can ensure that the first connection area 111 and the second connection area 121 are completely separated when it breaks, thereby achieving the reliability and effectiveness of disconnecting the pole and the tab when the battery cell is short-circuited.

[0046] In a preferred embodiment, Figures 2 to 4 As shown, the thinning portion 1121 is formed as a through-hole structure that passes through the main body of the first connecting portion 11, thereby reducing the length dimension of the connection relationship between the first connecting portion 11 and the second connecting portion 12 in the first direction D1, so as to ensure that the melting zone 112 can be melted in time when the battery cell is short-circuited, and the thickness dimension of the partial structure of the melting zone 112 where the thinning portion 1121 is not set is the same as the thickness dimension of the first connecting portion 11, thereby improving the structural strength of the melting zone 112 and improving the reliability of the connecting piece.

[0047] Furthermore, if Figures 2 to 4 As shown, the thinning portion 1121 includes a plurality of through holes, and the plurality of through holes are arranged at intervals along the first direction D1, so that the two opposite ends of the first connecting portion 11 and the second connecting portion 12 are only partially connected to each other. Among the plurality of through holes arranged at intervals along the first direction D1, the through holes arranged at both ends in the first direction D1 are formed into a non-closed semi-hole structure, that is, the hole wall of the semi-hole structure is not a closed ring, which further helps the fuse area 112 to be completely broken when the battery cell is short-circuited, so as to form effective safety protection for the battery cell and avoid the situation where the edge of the connecting piece fails to be effectively disconnected.

[0048] Preferably, among the plurality of through holes spaced apart along the first direction D1 , at least one through hole has a wall in a closed ring shape, thereby ensuring the structural strength of the fuse region 112 .

[0049] Furthermore, in this embodiment, the distance between the two through holes is equal, thus ensuring that the force applied to the fuse area 112 is uniform.

[0050] Preferably, if Figure 2 and Figure 3As shown, the thinning portion 1121 is formed into a strip-shaped hole structure extending along the first direction D1, so that the extension direction of the thinning portion 1121 is the same as the extension direction of the fuse area 112, so that the 3mm defined above 2 ~6mm 2 The fuse zone 112 except the thinning portion 1121 can be centrally arranged, thereby ensuring the structural strength of the fuse zone 112 and improving the reliability of the connecting piece. Figure 3 As shown, the width L of the thinned portion 1121 is preferably 1 mm to 2 mm to ensure the structural strength of the connecting piece.

[0051] In an optional embodiment, the thinning portion 1121 is formed as a blind hole structure that does not penetrate the connecting piece body 10, so that the thickness of at least part of the connecting piece body 10 located in the fuse zone 112 is smaller than the thickness of the connecting piece body 10 located in the first connection zone 111.

[0052] In a preferred embodiment, the end of the thinning portion 1121 in the first direction D1 is arc-shaped. For example, the thinning portion 1121 is formed into a circular, elliptical or elongated hole structure, which can avoid stress concentration.

[0053] In addition, in this embodiment, Figure 1 As shown, the connecting piece further includes a protective member 20 , which is disposed on the first connecting portion 11 and covers the melting zone 112 , thereby improving the structural strength of the melting zone 112 and further improving the reliability of the connecting piece.

[0054] In a preferred embodiment, Figure 1 As shown, the protective part 20 is an insulating part, that is, the protective part 20 is made of insulating material, for example, the material of the protective part 20 is plastic, so that after the fuse zone 112 breaks, the first connecting part 11 and the second connecting part 12 are connected via the protective part 20, so that after ensuring that the pole and the pole ear are disconnected electrically, the first connecting part 11 and the second connecting part 12 can also be structurally ensured to be in a connected state, avoiding the situation where the structurally separated first connecting part 11 and the second connecting part 12 are overlapped at other positions in the battery cell after the fuse zone 112 breaks, thereby failing to ensure effective power off, which may cause other risks.

[0055] Specifically, in this embodiment, Figure 1As shown, the protective member 20 is formed into an annular structure to cover the front and back sides of the melting zone 112 (i.e., the front and back sides of the plane where the first connecting portion 11 of the sheet structure is located), so as to cover the entire circumference of the melting zone 112, thereby reliably strengthening the structure and ensuring that the first connecting portion 11 and the second connecting portion 12 can be connected via the annular protective member 20 after the melting zone 112 is broken. The connection between the protective member 20 and the melting zone 112 can be bonding or interference fit connection.

[0056] Preferably, the length, width and / or thickness of the protection member 20 are all larger than 0.5 mm on one side of the melting zone 112 , so as to ensure that the protection member 20 completely covers the melting zone 112 .

[0057] According to the connecting piece provided by the utility model, when the battery cell is short-circuited, the thinning portion is provided on the melting area, so that the melting area can disconnect the connection between the first connection area and the second connection area, thereby disconnecting the electrical connection between the pole and the tab, ensuring the safety of the battery cell. The surface area of ​​the melting area excluding the thinning portion is 3mm 2 ~6mm 2 The thickness of the first connecting portion in the fuse zone is 0.6mm to 1.5mm. In this way, while ensuring that the fuse zone can be broken in time when the battery cell is short-circuited, the structural strength of the fuse zone can be improved, and the reliability of the connecting piece can be improved, thereby meeting the use requirements of the connecting piece of the battery cell under normal working conditions and avoiding the connection piece from breaking in non-short-circuit conditions.

[0058] According to the second aspect of the present invention, a battery cell is provided, including the connecting piece as described above. The fuse area on the connecting piece can be broken in time when the battery cell is short-circuited, thereby forming effective safety protection for the battery cell. The fuse area also has sufficient structural strength to avoid the situation where the connecting piece breaks when the battery cell is in normal working state, thereby improving the service life and reliability of the battery cell.

[0059] According to the third aspect of the present invention, a battery pack is provided, including the battery cells and fuses as described above, multiple battery cells are connected to form a battery module, and the battery module is arranged in the shell of the battery pack. The melting time t1 of the fuse of the battery pack is less than the melting time t2 of the connecting piece, which is less than the safety time t3. In this way, when a faulty battery cell occurs, the battery pack is first disconnected from the power supply equipment, and then the connecting piece in the faulty battery cell is disconnected from the melting area, thereby ensuring that other components of the battery pack can continue to be used after the faulty battery cell needs to be replaced, thereby saving energy and cost.

[0060] Next, bending tests and tensile strength tests are conducted on connecting pieces of different sizes to detect the surface area of ​​the fuse zone 112 excluding the thinning portion 1121, which is 3mm. 2 ~6mm2 , whether the limiting condition that the thickness of the first connecting portion 11 in the fuse zone 112 is 0.6mm to 1.5mm is reliable. The inspection standard of the bending test is: when the bending angle is 90°, the connecting piece can be bent at the fuse zone 112 for more than 3 times without breaking, which is considered to be qualified; the inspection standard of the tensile strength test is: when a tensile force is applied to the connecting piece, the tensile strength of the connecting piece is less than 65MPa and the test is unqualified; and short-circuit tests are performed on battery cells and battery packs assembled from connecting pieces of the same size and the same batch respectively. The national standard requirement for the short-circuit test of the battery cell is that the positive and negative poles of the fully charged battery cell are externally short-circuited for 10 minutes, and the external short-circuit resistance should be less than 5mΩ. After observation for 1 hour, there should be no explosion or fire. The test results are shown in the table below:

[0061]

[0062]

[0063] As can be seen from the table above, in Examples 1 to 10, the surface area of ​​the melting zone 112 excluding the thinning portion 1121 is within 3 mm. 2 ~6mm 2 and the thickness of the first connecting portion 11 in the melting zone 112 is within the limited condition range of 0.6mm to 1.5mm, which can meet the tensile strength and bending strength of the connecting piece to meet the detection requirements; in addition, the melting time t2 of the connecting piece lags behind the melting time t1 of the battery pack fuse, so that when a faulty battery cell occurs, it can be ensured that the battery pack is disconnected from the power supply equipment first, and then the connecting piece in the faulty battery cell is disconnected from the melting zone 112.

[0064] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. A connecting piece, characterized in that: The connecting piece includes: A connecting piece body having a first connecting portion and a second connecting portion connected to each other; The first connection portion is formed with a fuse area and a first connection area for connecting to a pole, the second connection portion is formed with a second connection area for connecting to a tab, and the fuse area is provided between the first connection area and the second connection area; The melting zone is provided with a concave thinning portion, and the surface area of ​​the melting zone excluding the thinning portion is 6mm 2 ~12mm 2 The thickness of the first connecting portion in the fusing zone is 0.6 mm to 1.5 mm.

2. The connecting piece according to claim 1, characterized in that The fusing region is formed as a strip-shaped region extending along the first direction, and / or the thinning portion is formed as a strip-shaped hole structure extending along the first direction.

3. The connecting piece according to claim 1, characterized in that The thinned portion is formed as a through-hole structure penetrating the main body of the first connecting portion.

4. The connecting piece according to claim 1, characterized in that The thinning portion includes a plurality of through holes, which are arranged at intervals along a first direction, wherein the through holes arranged at both ends form a non-closed half-hole structure.

5. The connecting piece according to claim 1, characterized in that An end portion of the thinned portion in the first direction is arc-shaped.

6. The connecting piece according to claim 1, characterized in that The connecting piece further comprises: A protective member is provided at the first connecting portion, and the protective member covers the fusing zone.

7. The connecting piece according to claim 6, characterized in that The protective member is an insulating member. After the fuse zone is broken, the first connecting portion and the second connecting portion are connected via the protective member.

8. The connecting piece according to claim 6, characterized in that The first connecting portion is formed into a sheet-like structure, and the protective member is formed into an annular structure to cover both the front and back surfaces of the fusing zone.

9. A battery cell, characterized in that: The connecting piece comprises the connecting piece according to any one of claims 1 to 8.

10. A battery pack, characterized in that: The invention comprises the battery cell and the fuse according to claim 9, wherein the fusing time t1 of the fuse is less than the fusing time t2 of the connecting piece and is less than the safety time t3.

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