Large cylindrical battery connection piece, battery module, and battery pack

Abstract

To provide a large cylindrical battery connection piece, a battery module, and a battery pack.SOLUTION: A large cylindrical battery connection piece of the present invention is used for a large cylindrical battery in which positive and negative poles are located on the same side, and comprises a plurality of conductive units (100). The conductive units (100) each include a positive pole connection area (110), a negative pole connection area (120), and a first current limiting area (130) provided between the positive pole connection area (110) and the negative pole connection area (120). The adjacent conductive units (100) are electrically connected to each other via a coupler (200).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application claims priority from a Chinese patent application with the application number 202220226680.9 filed with the China National Intellectual Property Administration on January 25, 2022, and all the contents of the above application are incorporated into this application by reference.

[0002] This application relates to the field of battery technology, for example, to large cylindrical battery connection pieces, battery modules, and battery packs.

Background Art

[0003] In order to increase the output voltage and current, in many cases, a plurality of batteries are connected in series or in parallel to form a single battery pack, and the power of the battery pack is aggregated to both terminal fittings, and electrical energy is output to a load through a corresponding circuit. In related technologies, since the current is large during operation of the battery pack, the battery pack is likely to experience an overload current phenomenon during the process of outputting electrical energy, and the temperature of the circuit becomes too high, which may burn the operator or burn out the battery pack, shortening the service life of the battery and reducing the safety and efficiency of the battery.

[0004] To address the above problems, in related technologies, a current-limiting connection piece is provided in the battery pack. When the current in the battery pack becomes overloaded and the temperature of the circuit rises, the current-limiting connection piece usually fuses to cut off the circuit and protect the circuit. However, this structure only works when an overload current flows through the current-limiting piece, protecting only some of the batteries from damage caused by overloading of the current, with low sensitivity and relatively large losses caused by overloading of the current.

Summary of the Invention

[0005] This application provides a large cylindrical battery connection piece that can achieve series-parallel connection of large cylindrical batteries, is provided with short-circuit protection, can cut off the 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 the following: A large cylindrical battery connection piece used in a large cylindrical battery in which the positive and negative electrodes are located on the same side and having a plurality of conductive units, wherein 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; when the temperature in the circuit is too high, the first current limiting region melts, and the adjacent conductive units are electrically connected to each other through a connector. A large cylindrical battery connection piece.

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

[0008] In one embodiment, a first through hole is opened in the first current limiting region, and a second through hole is opened 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 spaced apart along the width direction of the conductive unit.

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

[0011] In one embodiment, the large cylindrical battery connection 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 thickness of the first current limiting region is 0.8 mm to 1.6 mm.

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

[0014] In one embodiment, the conductive unit has a Z-shaped structure, and the inclined portion of the Z-shaped structure serves as a first current limiting region.

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

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

[0017] In one embodiment, the negative electrode connection region includes an arc-shaped notch that matches the positive electrode post of the large cylindrical battery.

[0018] In one embodiment, the positive electrode connection region includes an arc-shaped portion, and the outer edge of the arc-shaped portion can partially overlap with the outer edge of the positive electrode post of the large cylindrical battery.

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

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

[0021] On a third side, 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 this application, a positive electrode connection region and a negative electrode connection region are provided in the conductive unit, and adjacent conductive units are electrically connected via a connector, so that series connection and parallel connection of a plurality of large cylindrical batteries can be realized, and the number of installed conductive units can be adjusted according to the actual needs of the battery module, with a wide range of applications. By opening a first through hole in the first current limiting region, the connection area between the positive electrode connection region and the negative electrode connection region of the conductive unit can be reduced. By opening a second through hole in the second current limiting region, the connection area between the conductive units can be reduced. When a short circuit or overload occurs in a large cylindrical battery pack, the temperature in the circuit becomes too high, and the first current limiting region and the second current limiting region are blown due to the concentration of thermal stress, avoiding the transfer of heat to adjacent large cylindrical batteries through the conductive unit, further reducing the risk of thermal runaway over a wide range, reducing the loss caused by thermal runaway, and effectively protecting the safety of the circuit.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0024] In the description of this application, unless otherwise clearly specified and limited, the terms "associated", "connected", and "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly associated or indirectly associated through an intermediate medium, or it may be the communication inside two elements or the 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, the fact that the first feature is "above" or "below" the second feature may include that the first feature is in direct contact with the second feature, or it may include that the first feature and the second feature are not in direct contact but are in contact through another feature therebetween. And the fact that the first feature is "above", "upward" and "upper surface" of the second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The fact that the first feature is "below", "downward" and "lower surface" of the second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the horizontal height of the first feature is smaller than that of the second feature.

[0026] In the description of this embodiment, the orientation or positional relationship such as "above", "below", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of simplifying the description and operation, and does not indicate or imply that the shown device or element has a specific orientation and must be structured and operated in a specific orientation. Therefore, it cannot be understood as a limitation to this application. Also, the terms "first" and "second" are only used for distinction in the description and have no special meaning.

[0027] The embodiments of the present application can realize the series-parallel connection of large cylindrical batteries, and are provided with short-circuit protection to timely cut off the current, reduce the loss caused by short circuits, and improve the service life and safety of the batteries. A large cylindrical battery connection piece is provided.

[0028] Exemplarily, as shown in FIG. 1, this large cylindrical battery connection piece is used for large cylindrical batteries with the positive and negative electrodes located on the same side, and is provided with a plurality of conductive units 100. Here, the conductive unit 100 includes a positive electrode connection region 110 and a negative electrode connection region 120. 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 the series connection of two adjacent large cylindrical batteries. A first current limiting region 130 is provided between 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 can be blown by self-heating. Thereby, the current between the single large cylindrical batteries can be quickly cut off, the current circuit can be interrupted, and the circuit can be protected. Adjacent conductive units 100 are electrically connected via a connector 200.

[0029] By providing the first current limiting region 130 between the positive electrode connection region 110 and the negative electrode connection region 120, when the temperature in the circuit is too high, the first current limiting region 130 can be blown, and the large cylindrical batteries connected in series through a single conductive unit 100 can be protected. Compared with the case where a plurality of batteries share one fuse in the related art, after the fuse blows, the large cylindrical battery connection piece can quickly find out the damaged large cylindrical battery, saving manpower and effort, which is beneficial for later maintenance and replacement. By connecting adjacent conductive units 100 using the connector 200, the parallel connection between large cylindrical batteries can be realized.

[0030] Exemplarily, a second current limiting region 210 may be provided in 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 200 can be blown by self-heating, thereby quickly cutting off the current between the large cylindrical batteries in the adjacent column group, cutting off the current circuit, playing a role in protecting the circuit, and enhancing the safety of the large cylindrical battery.

[0031] Exemplarily, continuing with reference to FIG. 1, in one embodiment, a first through hole 131 is formed in the first current limiting region 130, and the cross-sectional area of the first current limiting region 130 may be made 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 is blown by the concentration of thermal stress, cutting off the current circuit and playing a role in protecting the circuit. Similarly, a second through hole 211 may be formed in the second current limiting region 210, and the cross-sectional area of the second current limiting region 210 may be made 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 is blown by the concentration of thermal stress, cutting off the current circuit and playing a role in protecting the circuit.

[0032] Exemplarily, continuing with reference to FIG. 1, a plurality of first through holes 131 may be provided at intervals along the width direction of the conductive unit 100 and may have current limiting portions 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. However, depending on the actual width of the first current limiting region 130, the first through holes 131 may end at a notch structure at the other edge along the width direction of the first current limiting region 130 or at a current limiting portion. In another embodiment, the first through holes 131 start from a current limiting portion at one edge along the width direction of the first current limiting region 130. Optionally, in this embodiment, a plurality of first through holes 131 are provided at equal intervals, and the cross-sectional areas of all current limiting portions are the same. Thereby, due to the difference in the cross-sectional areas of the current limiting portions, a relatively small cross-section will not reach the fusing current and will fuse earlier to avoid the interruption of the current circuit and ensure the normal use of the circuit. The size of the current limiting portion between adjacent first through holes 131 can be set according to actual needs.

[0033] Optionally, a low melting point metal such as tin may be provided in the first current limiting region 130. Exemplarily, the low melting point metal may be provided in the current limiting portion. When an extreme situation such as a short circuit occurs in the circuit, the current in the circuit increases rapidly. As the current increases, the temperature of the circuit rises. When the temperature rises until the melting of the low melting point metal occurs, the alloying process starts, the resistance of the alloy region increases, the temperature at the current limiting portion rises rapidly, the low melting point metal is melted within a few milliseconds, the current is interrupted, and the circuit is protected. The low melting point metal may be fixed to the first current limiting region 130 by a welding method or installed in the first current limiting region 130 by other methods, and may be installed according to actual needs. By providing the first through holes 131 and the low melting point metal in the first current limiting region 130, a dual protection role can be played for the circuit, and the safety performance of a large cylindrical battery can be improved.

[0034] Optionally, a low melting point metal such as tin may be provided in the second current limiting region 210. When an extreme situation such as a short circuit occurs in the circuit, the current in the circuit rapidly increases. As the current increases, the temperature of the circuit rises. When the temperature rises until the melting of the low melting point metal occurs, the alloying process starts, the resistance of the alloy region increases, the temperature in the second current limiting region 210 rises rapidly, the low melting point metal is melted within a few milliseconds, the current is interrupted, and the circuit is protected. The low melting point metal may be fixed to the second current limiting region 210 by a welding method, may be installed in the second current limiting region 210 by other methods, or may be installed according to actual needs. By providing the second through hole 211 and the low melting point metal in the second current limiting region 210, a dual protection role can be played for the circuit, and the safety performance of the large cylindrical battery can be improved.

[0035] Exemplarily, in another embodiment, the thickness of the first current limiting region 130 may be reduced so that the thickness of the first current limiting region 130 is smaller than the thickness of other parts of the conductive unit 100, that is, the cross-sectional area of the first current limiting region 130 may be made smaller than the cross-sectional area of other parts of the conductive unit 100. When an extreme situation such as a short circuit occurs in the circuit, since the cross-sectional area of the first current limiting region 130 is relatively small, it is melted due to the concentration of thermal stress, cuts off the current circuit, and plays a role in protecting the cell and the circuit. Of course, the thickness of the second current limiting region 210 may be reduced so that the thickness of the second current limiting region 210 is smaller than the thickness of the connector 200, that is, the cross-sectional area of the second current limiting region 210 may be made smaller than the cross-sectional area of the connector 200. When an extreme situation such as a short circuit occurs in the circuit, since the cross-sectional area of the second current limiting region 210 is relatively small, it is melted due to the concentration of thermal stress, cuts off the current circuit, and plays 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 installed according to the needs of fusing.

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

[0037] Optionally, as shown in FIGS. 2 and 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 on the convex portion of the convex structure. On one side, by providing the first current limiting region 130 on the convex portion, the fusing space of the first current limiting region 130 can be increased, the first current limiting region can be fused faster, and when the first current limiting region 130 fuses, damage to the large cylindrical battery caused by the high temperature generated can be prevented. On the other side, the positive and negative electrodes of the large cylindrical battery have a certain height difference, and during the use of the battery module, there is a slight relative rattling between the plurality of large cylindrical batteries. However, the conductive unit 100 is usually connected to the positive and negative electrodes of the large cylindrical battery by welding. Along with the rattling of the large cylindrical battery, in order to stretch or compress the large cylindrical battery connection piece, by providing the conductive unit 100 in a convex structure, a certain buffer space can be provided for the large cylindrical battery connection piece, avoiding breakage of the large cylindrical battery connection piece, and improving the operating reliability of the large cylindrical battery connection piece. Optionally, the convex structure is a "ji" - shaped structure. In another embodiment, the conductive unit 100 may be a Z - shaped structure, and the first current limiting region 130 may be provided on the inclined portion of the Z - shaped structure. In other embodiments, a corrugated structure may be provided on the conductive unit 100, and the first current limiting region 130 may be provided on the corrugated structure, and it may be selected according to actual needs.

[0038] As an option, in one embodiment, the material of the conductive unit 100 can be copper. Copper has excellent electrical conductivity, relatively high thermal conductivity, and corrosion resistance. In other embodiments, other conductive metals may be used and can be selected according to actual needs.

[0039] Exemplarily, in a large cylindrical battery, the positive and negative electrodes are located on the same side, and the positive electrode is a cylindrical protrusion located in the center, with the negative electrode surrounding the protrusion. Therefore, an arcuate notch that matches the positive electrode post of the large cylindrical battery can be provided in the negative electrode connection region 120. Such a structure can increase the connection area between the negative electrode connection region 120 and the negative electrode of the large cylindrical battery, enhance the connection reliability between the negative electrode connection region 120 and the negative electrode of the large cylindrical battery, and improve the operating reliability of the large cylindrical battery connection piece.

[0040] Exemplarily, the positive electrode connection region 110 may include an arcuate portion and may be installed such that the outer edge of the arcuate portion partially overlaps the outer edge of the positive electrode post of the large cylindrical battery. On one side, it facilitates the pre-positioning of the positive electrode connection region 110 by the positive electrode post of the large cylindrical battery and can reduce the difficulty for workers during welding. On the other side, when ensuring that the connection area between the positive electrode post of the large cylindrical battery and the positive electrode connection region 110 is maximized, the size of the positive electrode connection region 110 can be reduced to save materials and reduce costs.

[0041] A first current limiting region 130 and a second current limiting region 210 are provided, and a first through hole 131 is formed in the first current limiting region 130, and a second through hole 211 is formed in the second current limiting region 210, so that 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 are melted due to the concentration of thermal stress, and can quickly cut between large cylindrical batteries, timely cut off the entire battery circuit, play a role in protecting the large cylindrical battery, reduce the loss caused by thermal runaway, save costs, and can quickly find out the problematic large cylindrical battery, which is beneficial to later maintenance and replacement.

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

[0043] Exemplarily, in one embodiment, a plurality of large cylindrical batteries form a plurality of column groups, and the large cylindrical batteries in adjacent column groups are installed offset from each other. Accordingly, the adjacent conductive units 100 are installed offset from each other, thereby saving assembly space, reducing the size of the battery module, and reducing costs.

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

Claims

1. A large cylindrical battery connection piece used in a large cylindrical battery with positive and negative electrodes located on the same side and comprising a plurality of conductive units (100), wherein the conductive unit (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). When the temperature in the circuit is too high, the first current limiting region (130) fuses, and adjacent conductive units (100) are electrically connected via a connector (200). A large cylindrical battery connection piece.

2. The connector (200) is provided with a second current limiting region (210). When the temperature in the circuit is too high, the second current limiting region (210) fuses. The large cylindrical battery connection piece according to claim 1.

3. A first through hole (131) is formed in the first current limiting region (130), and a second through hole (211) is formed in the second current limiting region (210). The large cylindrical battery connection piece according to claim 2.

4. A plurality of the first through holes (131) are provided, and the plurality of first through holes (131) are spaced along the width direction of the conductive unit (100). The large cylindrical battery connection piece according to claim 3.

5. A low melting point metal is provided in at least one of the first current limiting region (130) and the second current limiting region (210). The large cylindrical battery connection piece according to claim 3.

6. The large cylindrical battery connection piece satisfies at least one of the following: The thickness of the first current limiting region (130) is smaller than the thickness of the conductive unit (100); The thickness of the second current limiting region (210) is smaller than the thickness of the connector (200). The large cylindrical battery connection piece according to claim 2.

7. The thickness of the first current limiting region (130) is 0.8 mm to 1.6 mm. The large cylindrical battery connection piece according to claim 6.

8. The conductive unit (100) has a convex structure, and the convex portion of the convex structure serves as the first current limiting region (130). The large cylindrical battery connection piece according to claim 1.

9. The conductive unit (100) has a Z-shaped structure, and the inclined portion of the Z-shaped structure serves as the first current limiting region (130). The large cylindrical battery connection piece according to claim 1.

10. The large cylindrical battery connection piece according to claim 1, wherein a waveform structure is provided in the conductive unit (100), and the first current limiting region (130) is provided in the waveform structure.

11. The large cylindrical battery connection piece according to claim 1, wherein the negative electrode connection region (120) includes an arcuate notch that matches the positive electrode post of the large cylindrical battery.

12. The large cylindrical battery connection piece according to claim 1, wherein the positive electrode connection region (110) includes an arcuate portion, and an outer edge of the arcuate portion can partially overlap an outer edge of the positive electrode post of the large cylindrical battery.

13. A battery module comprising a plurality of large cylindrical batteries with positive and negative electrodes located on the same side, and the large cylindrical battery connection piece according to any one of claims 1 to 12.

14. The battery module according to claim 13, wherein the plurality of large cylindrical batteries form a plurality of column groups, the large cylindrical batteries in adjacent column groups are offset from each other, and the adjacent conductive units (100) are offset from each other.

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

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