Large cylindrical battery connectors, battery modules and battery packs

Abstract

This application belongs to the field of battery technology and discloses a large cylindrical battery connection piece, a battery module, and a battery pack. The large cylindrical battery connection piece is used in a large cylindrical battery in which positive and negative electrodes are located on the same side, and includes a plurality of conductive units (100), each of which includes a positive electrode connection region (110), a negative electrode connection region (120), and a first current limiting region (130) provided between the positive electrode connection region (110) and the negative electrode connection region (120), and adjacent conductive units (100) are electrically connected to each other via a connector (200).

Description

[Technical field]

[0001] This application claims priority from Chinese patent application no. 202220226680.9, filed with the China Patent Office on January 25, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the field of battery technology, such as large cylindrical battery connectors, battery modules and battery packs. [Background technology]

[0003] In order to increase the output voltage or current, in many cases, multiple batteries are connected in series or parallel to form a single assembled battery, and the power of the assembled battery is collected at both terminal fittings, and electrical energy is output to a load through a corresponding circuit. The assembled battery in the related art has a large current during operation, and is prone to current overload during the process of outputting electrical energy, causing the circuit temperature to become too high, resulting in burns to workers or burning the assembled battery, shortening the service life of the battery, and reducing the safety and efficiency of the battery.

[0004] To address the above-mentioned problems, in the related art, a current limiting connector is provided in a battery pack, and when the current in the battery pack is overloaded and the temperature of the circuit rises, the current limiting connector melts to cut off the circuit and protect it. However, this structure only works when an overload current flows through the current limiting connector, and only protects some of the batteries from damage caused by the current overload, has low sensitivity, and the loss caused by the current overload is relatively large. Summary of the Invention

[0005] The present application provides a large cylindrical battery connection piece that can realize series-parallel connection of large cylindrical batteries, provide short circuit protection, cut off current in a timely manner, reduce losses caused by short circuits, and improve the service life and safety of the batteries.

[0006] In a first aspect, embodiments of the present application provide: A large cylindrical battery connection piece used for a large cylindrical battery in which the positive and negative electrodes are located on the same side and which has multiple conductive units, A large cylindrical battery connection piece, in which the conductive unit includes a positive electrode connection region, a negative electrode connection region, and a first current limiting region provided between the positive electrode connection region and the negative electrode connection region, and when the temperature in the circuit is too high, the first current limiting region melts and adjacent conductive units are electrically connected to each other via a connector.

[0007] In one embodiment, the connector is provided with a second current limiting region that melts when the temperature in the circuit becomes too high.

[0008] In one embodiment, a first through hole is provided in the first current limiting region and a second through hole is provided in the second current limiting region.

[0009] In one embodiment, a plurality of the first through holes are provided, and the plurality of first through holes are arranged at intervals along the width direction of the conductive unit.

[0010] In one embodiment, at least one of the first current limiting region and the second current limiting region is provided with a low melting point metal.

[0011] In one embodiment, the large cylindrical battery contact piece satisfies at least one of the following: the thickness of the first current-limiting region is smaller than the thickness of the conductive unit; the thickness of the second current-limiting region is smaller than the thickness of the connector.

[0012] In one embodiment, the first current limiting region has a thickness of 0.8 mm to 1.6 mm.

[0013] In one embodiment, the conductive unit has a convex structure, and a convex portion of the convex structure serves as a first current limiting region.

[0014] In one embodiment, the conductive units form a Z-shaped structure, and the slope of the Z-shaped structure is the first current-limiting region.

[0015] In one embodiment, the conductive unit is provided with a corrugated structure, and the corrugated structure is provided with a first current-limiting region.

[0016] In one embodiment, the material of the conductive unit is copper.

[0017] In one embodiment, the negative connection area includes an arc-shaped notch that mates with the positive post of the larger cylindrical battery.

[0018] In one embodiment, the positive connection region includes an arcuate portion, the outer edge of which can overlap the outer edge of the positive post of the larger cylindrical battery.

[0019] In a second aspect, an embodiment of the present application provides a battery module including a plurality of large cylindrical batteries with positive and negative electrodes located on the same side, and the large cylindrical battery connection piece described above.

[0020] In one embodiment, the large cylindrical batteries are arranged in a plurality of rows, and the large cylindrical batteries in adjacent rows are offset from each other, and the conductive units in adjacent rows are offset from each other.

[0021] In a third aspect, an embodiment of the present application provides a battery pack including the battery module described above.

[0022] The beneficial effects of the present application are as follows: In the present application, the conductive unit is provided with a positive electrode connection region and a negative electrode connection region, and adjacent conductive units are electrically connected through connectors, thereby realizing series and parallel connection of multiple large cylindrical batteries, and the number of conductive units can be adjusted according to the actual needs of the battery module, and the application range is wide. The first through-hole is provided in the first current limiting region, thereby reducing the connection area between the positive electrode connection region and the negative electrode connection region of the conductive unit, and the second through-hole is provided in the second current limiting region, thereby reducing the connection area between the conductive units. When a short circuit or overload occurs in the large cylindrical battery pack, the temperature in the circuit becomes too high, and the first and second current limiting regions melt due to the concentration of thermal stress, which avoids the heat being transmitted to the adjacent large cylindrical batteries through the conductive units, and further reduces the risk of thermal runaway over a wide area, reduces the loss caused by thermal runaway, and effectively protects the safety of the circuit. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a structural schematic diagram of a large cylindrical battery connecting piece provided by an embodiment of the present application. [Diagram 2] FIG. 2 is a structural schematic diagram 2 of a large cylindrical battery connecting piece provided by an embodiment of the present application. [Diagram 3] FIG. 2 is a partially enlarged view of A. In the figure, 100, conductive unit; 110, positive electrode connection region; 120, negative electrode connection region; 121, arc-shaped notch; 130, first current limiting region; 131, first through hole; 200, connector; 210, second current limiting region; 211, second through hole. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the description of this application, unless otherwise clearly specified and limited, the terms "interconnected", "connected" and "fixed" should be understood in a broad sense, for example, may be fixedly connected, detachably connected or integral; may be mechanically connected or electrically connected; may be directly connected, may be indirectly connected via an intermediate medium, may be connected inside two elements or may be an interaction relationship between two elements. Those skilled in the art may understand the specific meaning of the above terms in this application according to the specific situation.

[0025] In this application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature and the second feature being in contact through another feature between them, rather than in direct contact. And a first feature being "above," "upper," and "on the upper surface" of a second feature includes the first feature being directly above and diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. A first feature being "below," "below," and "on the lower surface" of a second feature includes the first feature being directly below and diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than that of the second feature.

[0026] In the description of the present embodiment, orientations or positional relationships such as "upper", "lower", "left", and "right" are based on orientations or positional relationships shown in the drawings, and are intended only to facilitate explanation and operation, and do not indicate or imply that the devices or elements shown have a specific orientation, and must be constructed or operated in a specific orientation, and therefore cannot be understood as limitations on the present application. In addition, the terms "first" and "second" are used only to distinguish between the above and the above embodiments, and have no special meaning.

[0027] The embodiments of the present application provide a large cylindrical battery connection piece that can realize series-parallel connection of large cylindrical batteries, provide short circuit protection, cut off current in a timely manner, reduce losses caused by short circuits, and improve the service life and safety of the batteries.

[0028] Illustratively, as shown in FIG. 1, the large cylindrical battery connection piece is used for a large cylindrical battery in which the positive and negative electrodes are located on the same side, and includes a plurality of conductive units 100, where the conductive unit 100 includes a positive electrode connection region 110 and a negative electrode connection region 120, and the positive electrode connection region 110 and the negative electrode connection region 120 are respectively provided to connect the positive and negative electrodes of two adjacent large cylindrical batteries to realize a series connection of the two adjacent large cylindrical batteries, and a first current limiting region 130 is provided between the positive electrode connection region 110 and the negative electrode connection region 120, and when an extreme situation such as a short circuit occurs in the circuit and the temperature of the circuit is too high, the first current limiting region 130 can melt due to self-heating, thereby quickly cutting off the current between the single large cylindrical batteries, interrupting the current circuit, and playing a role in protecting the circuit. The adjacent conductive units 100 are electrically connected to each other via a connector 200.

[0029] The first current limiting region 130 is provided between the positive electrode connection region 110 and the negative electrode connection region 120, so that when the temperature in the circuit is too high, the first current limiting region 130 can be melted down to protect the large cylindrical batteries connected in series through the single conductive unit 100. Compared with the related art in which multiple batteries share one fuse, the large cylindrical battery connection piece can quickly find the damaged large cylindrical battery after melting occurs, saving manpower and effort, and favoring later maintenance and replacement. By connecting adjacent conductive units 100 using the connector 200, parallel connection between large cylindrical batteries can be realized.

[0030] For example, the connector 200 may be provided with a second current limiting region 210, and when an extreme situation such as a short circuit occurs in the circuit and the temperature of the circuit becomes too high, the second current limiting region 200 can melt due to self-heating, thereby quickly cutting off the current between the large cylindrical batteries of adjacent rows, interrupting the current circuit, protecting the circuit, and improving the safety of the large cylindrical batteries.

[0031] 1, in one embodiment, a first through hole 131 is provided in the first current limiting region 130, and the cross-sectional area of ​​the first current limiting region 130 may be smaller than the cross-sectional areas of the positive electrode connection region 110 and the negative electrode connection region 120. When an extreme situation such as a short circuit occurs in the circuit and the temperature of the circuit is too high, the first current limiting region 130 melts due to the concentration of thermal stress to cut off the current circuit and protect the circuit. Similarly, a second through hole 211 is provided in the second current limiting region 210, and the cross-sectional area of ​​the second current limiting region 210 may be smaller than the cross-sectional area of ​​the connector 200. When an extreme situation such as a short circuit occurs in the circuit and the temperature of the circuit is too high, the second current limiting region 210 melts due to the concentration of thermal stress to cut off the current circuit and protect the circuit.

[0032] 1, the first through holes 131 may be provided at intervals along the width direction of the conductive unit 100, and may have a current limiting portion between adjacent first through holes 131. In this embodiment, as shown in FIG. 1, the first through holes 131 start from one edge along the width direction of the first current limiting region 130 and form a notch structure at the edge of the first current limiting region 130, but depending on the actual width of the first current limiting region 130, the first through holes 131 end at the notch structure or current limiting portion at the other edge along the width direction of the first current limiting region 130. In another embodiment, the first through holes 131 start from the current limiting portion at one edge along the width direction of the first current limiting region 130. Optionally, in this embodiment, the first through holes 131 are provided at equal intervals, and all the current limiting parts have the same cross-sectional area, so as to avoid the current circuit being cut off due to the difference in cross-sectional area of ​​the current limiting parts, which has a smaller cross-sectional area, when the fusing current is not reached, being prematurely fusing, thereby ensuring the normal use of the circuit. The size of the current limiting parts between the adjacent first through holes 131 can be set according to actual needs.

[0033] Optionally, the first current limiting region 130 may be provided with a low melting point metal such as tin, for example, the low melting point metal may be provided in the current limiting portion, and when an extreme situation such as a short circuit occurs in the circuit, the current in the circuit will increase rapidly, and the increase in current will cause the temperature of the circuit to rise, and when the temperature rises to the point where the low melting point metal melts, the alloying process will begin, and the resistance of the alloy area will increase, and the temperature in the current limiting portion will rise rapidly, melting the low melting point metal within a few milliseconds, and the current will be cut off to protect the circuit. The low melting point metal may be fixed to the first current limiting region 130 by welding, or may be provided in the first current limiting region 130 by other methods, and may be provided according to actual needs. The first current limiting region 130 is provided with the first through hole 131 and the low melting point metal, which can play a double protective role for the circuit and improve the safety performance of large cylindrical batteries.

[0034] Optionally, the second current limiting region 210 may be provided with a low melting point metal such as tin, so that when an extreme situation such as a short circuit occurs in the circuit, the current in the circuit will increase rapidly, and as the current increases, the temperature of the circuit will increase, and when the temperature rises to the point where the low melting point metal melts, the alloying process will begin, and the resistance of the alloyed region will increase, causing the temperature in the second current limiting region 210 to rise rapidly, melting the low melting point metal within a few milliseconds, and the current will be interrupted to protect the circuit. The low melting point metal may be fixed to the second current limiting region 210 by welding, or may be provided in the second current limiting region 210 by other means, and may be provided according to actual needs. The second current limiting region 210 is provided with the second through hole 211 and the low melting point metal, which can play a double protective role for the circuit and improve the safety performance of large cylindrical batteries.

[0035] Exemplarily, in another embodiment, the thickness of the first current limiting region 130 may be thinned to be smaller than the thickness of the other parts of the conductive unit 100, i.e., the cross-sectional area of ​​the first current limiting region 130 may be smaller than the cross-sectional area of ​​the other parts of the conductive unit 100, and when an extreme situation such as a short circuit occurs in the circuit, the first current limiting region 130 melts due to the concentration of thermal stress due to its relatively small cross-sectional area, thereby interrupting the current circuit and playing a role in protecting the cell and the circuit. Of course, the thickness of the second current limiting region 210 may be thinned to be smaller than the thickness of the connector 200, i.e., the cross-sectional area of ​​the second current limiting region 210 may be smaller than the cross-sectional area of ​​the connector 200, and when an extreme situation such as a short circuit occurs in the circuit, the second current limiting region 210 melts due to the concentration of thermal stress, thereby playing a role in protecting the cell and the circuit. The thickness of the first current limiting region 130 and the thickness of the second current limiting region 210 may be set according to fusing needs.

[0036] Optionally, the thickness of the first current limiting region may be 0.8 mm to 1.6 mm, for example, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, etc., and may be selected according to the current limit value in the current and the requirement for the circuit fusing current. The thickness of the second current limiting region 210 may also be 0.8 mm to 1.6 mm, for example, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, etc., and may be selected according to the fusing needs.

[0037] Optionally, as shown in FIG. 2 and FIG. 3, in one embodiment, the conductive unit 100 may be provided in a convex structure, and the first current-limiting region 130 may be provided in the convex portion of the convex structure. In one aspect, the first current-limiting region 130 may be provided in the convex portion, which can increase the melting space of the first current-limiting region 130, make the first current-limiting region melt faster, and prevent the large cylindrical battery from being damaged by high temperature generated when the first current-limiting region 130 melts. In another aspect, the positive and negative electrodes of the large cylindrical battery have a certain height difference. In addition, during the use of the battery module, a small relative rattle will occur between the large cylindrical batteries. The conductive unit 100 is usually connected to the positive and negative electrodes of the large cylindrical batteries by welding, and the large cylindrical battery connection pieces will be stretched or compressed with the rattle of the large cylindrical batteries. The conductive unit 100 is configured to have a convex structure, which provides a certain buffer space for the large cylindrical battery connection pieces, prevents the large cylindrical battery connection pieces from being broken, and improves the operation reliability of the large cylindrical battery connection pieces. Optionally, the convex structure is a square structure. In another embodiment, the conductive unit 100 may have a Z-shaped structure, and the first current limiting region 130 may be provided at the inclined part of the Z-shaped structure. In another embodiment, the conductive unit 100 may have a corrugated structure, and the first current limiting region 130 may be provided at the corrugated structure, which can be selected according to actual needs.

[0038] Optionally, in one embodiment, the material of the conductive unit 100 can be copper, which has excellent conductive performance, and copper has relatively high thermal conductivity and corrosion resistance; in other embodiments, other conductive metals can be used, and can be selected according to actual needs.

[0039] For example, since the positive and negative electrodes of the large cylindrical battery are located on the same side, with the positive electrode being a cylindrical protrusion located in the center and the negative electrode being around the protrusion, the negative electrode connection area 120 may be provided with an arc-shaped notch that matches the positive electrode post of the large cylindrical battery. Such a structure may increase the connection area between the negative electrode connection area 120 and the negative electrode of the large cylindrical battery, thereby improving the connection reliability between the negative electrode connection area 120 and the negative electrode of the large cylindrical battery, and thereby improving the operational reliability of the large cylindrical battery connection piece.

[0040] For example, the positive electrode connection area 110 may include an arc-shaped portion, and may be configured such that an outer edge of the arc-shaped portion partially overlaps with an outer edge of the positive electrode post of the large cylindrical battery. In one aspect, this facilitates the realization of pre-positioning of the positive electrode connection area 110 with the positive electrode post of the large cylindrical battery, thereby reducing the difficulty for workers when performing welding. In another aspect, this reduces the size of the positive electrode connection area 110, saves materials, and reduces costs, while ensuring that the connection area between the positive electrode post of the large cylindrical battery and the positive electrode connection area 110 is maximized.

[0041] By providing a first current limiting region 130 and a second current limiting region 210, and by opening a first through hole 131 in the first current limiting region 130 and a second through hole 211 in the second current limiting region 210, the cross-sectional area of ​​the first current limiting region 130 is smaller than the cross-sectional area along the width direction of the conductive unit 100, and the cross-sectional area of ​​the second current limiting region 210 is smaller than the cross-sectional area of ​​the connector 200. When an extreme situation such as a short circuit occurs in the circuit, the first current limiting region 130 and the second current limiting region 210 will melt down due to the concentration of thermal stress, quickly disconnecting the large cylindrical batteries, and timely cutting off the entire battery circuit, playing a role in protecting the large cylindrical batteries, reducing losses caused by thermal runaway, saving costs, and quickly finding out problematic large cylindrical batteries, which is advantageous for later maintenance and replacement.

[0042] An embodiment of the present application further provides a battery module, comprising a large cylindrical battery with positive and negative electrodes located on the same side, and the large cylindrical battery connection piece.

[0043] For example, in one embodiment, the large cylindrical batteries are arranged in a plurality of rows, and the large cylindrical batteries in adjacent rows are offset from each other, and the adjacent conductive units 100 are offset from each other accordingly, which can save assembly space, reduce the size of the battery module, and reduce costs.

[0044] An embodiment of the present application further provides a battery pack including the above-mentioned battery module.

Claims

1. A cylindrical battery connection piece for use in a cylindrical battery in which positive and negative electrodes are located on the same side and which comprises a plurality of conductive units (100), Each of the plurality of conductive units (100) includes a positive electrode connection region (110), a negative electrode connection region (120), and a first current limiting region (130) provided between the positive electrode connection region (110) and the negative electrode connection region (120), and when the temperature reaches the melting point of the first current limiting region (130), the first current limiting region (130) melts down; Among the plurality of conductive units (100), adjacent conductive units (100) are electrically connected to each other via a connector (200), The connector (200) connects the positive electrode connection region (110) of one of the adjacent conductive units (100) to the positive electrode connection region (110) of the other of the adjacent conductive units (100); A second current limiting region (210) is provided in the connector (200), and when the temperature reaches the melting point of the second current limiting region (210), the second current limiting region (210) melts, The cylindrical battery contact piece, wherein the first current limiting region (130) and the second current limiting region (210) each have at least one through hole.

2. 2. The cylindrical battery contact piece according to claim 1, wherein the first current limiting region (130) is provided with a first through hole (131) and the second current limiting region (210) is provided with a second through hole (211).

3. 3. The cylindrical battery connection piece according to claim 2, wherein the first current limiting region (130) is provided with a plurality of the first through holes (131), and the plurality of first through holes (131) are arranged at intervals along the width direction of the conductive unit (100).

4. 3. The cylindrical battery contact piece of claim 2, wherein at least one of the first current limiting region (130) and the second current limiting region (210) is provided with a low melting point metal.

5. The cylindrical battery connection piece satisfies any one of the following conditions: the thickness of the first current-limiting region (130) is less than the thickness of the conductive unit (100); The cylindrical battery contact piece of claim 1 , wherein the thickness of the second current limiting region (210) is less than the thickness of the contact (200).

6. The cylindrical battery contact piece of claim 5, wherein the first current limiting region (130) has a thickness of 0.8 mm to 1.6 mm.

7. 2. The cylindrical battery connection piece according to claim 1, wherein the conductive unit (100) has a convex structure, and a convex portion of the convex structure is a first current limiting region (130).

8. 2. The cylindrical battery connection piece according to claim 1, wherein the conductive unit (100) has a Z-shaped structure when viewed from the side, and a first current limiting region (130) is provided on an inclined portion of the Z-shaped conductive unit (100).

9. 2. The cylindrical battery connection piece of claim 1, wherein the conductive unit (100) has a corrugated structure when viewed from the side, and the first current limiting region (130) is provided in a portion of the corrugated structure of the conductive unit (100).

10. 2. The cylindrical battery contact piece of claim 1, wherein the negative connection area (120) includes an arcuate notch that mates with a positive post of the cylindrical battery.

11. 2. The cylindrical battery contact piece of claim 1, wherein the positive connection region (110) includes an arcuate portion, an outer edge of the arcuate portion being capable of partially overlapping an outer edge of a positive post of the cylindrical battery.

12. A battery module comprising: a plurality of cylindrical batteries having positive and negative electrodes located on the same side; and the cylindrical battery connection piece according to any one of claims 1 to 11.

13. 13. The battery module according to claim 12, wherein the cylindrical batteries are formed into a plurality of row groups, the cylindrical batteries in adjacent row groups are arranged offset from each other, and the conductive units (100) adjacent to each other are arranged offset from each other.

14. A battery pack comprising the battery module according to claim 13.

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