A power failure protection connector, a single cell, and a battery module

Abstract

This invention provides a power failure protection connector, a single battery cell, and a battery module, including a tab connection portion and a terminal connection portion, the tab connection portion being connected to the terminal connection portion; a fusing zone is formed at the junction of the tab connection portion and the terminal connection portion, the fusing zone including a first fusing segment, a fusing opening, and a second fusing segment, the fusing opening being parallel hexagonal in shape, the fusing opening including a first diagonal, the length direction of the first diagonal being consistent with the extension direction of the fusing zone, the first fusing segment extending from one end of the first diagonal to one edge of the fusing zone, and the second fusing segment extending from the other end of the first diagonal to the other edge of the fusing zone; the fusing opening of this invention is parallel hexagonal, the first fusing segment, the first diagonal, and the second fusing segment are located on the same straight line, compared with power failure protection connectors having strip-shaped or rectangular fusing openings, under the same overcurrent area, its fusing time is shorter.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a power failure protection connector, a single cell, and a battery module. Background Technology

[0002] With the increasing maturity of battery technology, power batteries are widely used in electric vehicles, leading to increasingly stringent requirements for their performance and safety. Power batteries are susceptible to risks such as thermal runaway. When an abnormal situation such as a short circuit occurs inside the battery, the internal gas pressure increases. If the high-temperature fumes are not promptly released, more serious safety accidents such as battery explosions may occur. To address this, existing technologies incorporate explosion-proof valves on the casing, which release the high-temperature fumes from the battery upon rupture.

[0003] However, explosion-proof valves are usually installed directly on the surface of the casing, and components such as connecting plates inside the battery between the electrode group and the casing can obstruct the flow of gas, affecting the smoothness of exhaust. Furthermore, in the event of thermal runaway, the battery is usually connected to the circuit. If the connection to the circuit cannot be disconnected in time, it may cause a short circuit damage to the entire circuit, further increasing the loss.

[0004] In existing battery modules, the tabs of individual battery cells are connected to the terminals via connecting tabs. When a battery cell is energized, excessive current may occur. Current technology addresses this by incorporating a fuse on the connecting tab, which melts when the current becomes too high. However, the current fuse is strip-shaped, and its melting time often exceeds 30 seconds. In the event of thermal runaway in a single battery cell, this prolonged melting time can easily lead to further thermal runaway, which can then spread to other battery cells, causing serious damage. Therefore, overcoming these technical problems and defects is a key issue that needs to be addressed. Summary of the Invention

[0005] To address the problem that existing connectors have excessively long melting times and cannot effectively protect individual battery cells, this invention provides a power-off protection connector, individual battery cell, and battery module.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] The present invention provides a power failure protection connector, including a tab connection portion and a post connection portion, wherein the tab connection portion is connected to the post connection portion; a fusible region is formed at the junction of the tab connection portion and the post connection portion, the fusible region including a first fusible segment, a fusible opening and a second fusible segment, the fusible opening being parallel hexagonal in shape, the fusible opening including a first diagonal, the length direction of the first diagonal being consistent with the extension direction of the fusible region, the first fusible segment extending from one end of the first diagonal to one edge of the fusible region, and the second fusible segment extending from the other end of the first diagonal to the other edge of the fusible region.

[0008] Optionally, the length of the first diagonal is H, and the length of the fused zone is H1, wherein H and H1 satisfy the relationship: 1 / 3 ≤ H / H1 ≤ 3 / 5.

[0009] Optionally, the fuse opening is formed by a first side, a second side, a third side, a fourth side, a fifth side, and a sixth side connected end to end. The first side and the second side are located on both sides of one end of the first diagonal, and the fourth side and the fifth side are located on both sides of the other end of the first diagonal. The length of the first side is equal to the length of the second side.

[0010] Optionally, the included angle formed between the first side and the second side is angle A, and the angle of angle A is 60°-120°.

[0011] Optionally, the electrode connection portion is provided with an electrode welding area, the first fusion segment is located on the side of the fusion port away from the electrode welding area, and the second fusion segment is located on the side of the fusion port close to the electrode welding area; the length of the first fusion segment is L1, the length of the second fusion segment is L2, and L1 and L2 satisfy the relationship: 1≤L1 / L2≤2.

[0012] Optionally, the distance between the third side and the sixth side is W, and the value of W ranges from 5 to 11 mm.

[0013] Optionally, the electrode connection portion includes a first electrode connection portion and a second electrode connection portion, and the fusible region includes a first fusible region and a second fusible region, wherein the first fusible region is located between the electrode post connection portion and the first electrode connection portion, and the second fusible region is located between the electrode post connection portion and the second electrode connection portion.

[0014] Optionally, the power failure protection connecting piece has a first plane, which is parallel to the thickness direction of the power failure protection connecting piece; the first electrode connecting part and the second electrode connecting part are respectively located on both sides of the first plane, the electrode connecting part is symmetrically arranged with respect to the first plane, and the first fuse area and the second fuse area are symmetrically arranged with respect to the first plane.

[0015] Another aspect of the present invention provides a single-cell battery, including a housing, a cell assembly, and a cover assembly; the cell assembly is disposed in an inner cavity formed by the housing and the cover assembly; the cell assembly is provided with a positive electrode tab, the cover assembly is provided with a positive electrode post, and the battery also includes the aforementioned power failure protection connecting piece, wherein the electrode tab connecting portion of the power failure protection connecting piece is connected to the positive electrode tab, and the electrode post connecting portion of the power failure protection connecting piece is connected to the positive electrode post, and the positive electrode tab and the positive electrode post are respectively located on both sides of the power failure protection connecting piece.

[0016] Optionally, the battery cell assembly includes multiple battery cells, and the positive tabs of the multiple battery cells are connected to the tab connection portion.

[0017] In another aspect, the present invention provides a battery module comprising the aforementioned single battery cell.

[0018] According to the power-off protection connector provided by the present invention, a fusing zone is formed at the junction of the tab connection and the post connection, and a fusing port is provided on the fusing zone. Due to the formation of the fusing port, the resistance around the fusing port is greater, and fusing is more likely to occur at the first fusing segment and the second fusing segment. When an overcurrent occurs (such as a short circuit), the first fusing segment and the second fusing segment on both sides of the fusing port fuse, and the tab connection and the post connection will be separated from each other and form an open circuit, thereby achieving the fusing protection effect. The shape of the fusing port of the present invention is set as a parallel hexagon, and the length direction of the first diagonal of the fusing port is consistent with the extension direction of the fusing zone. The first fusing segment extends from one end of the first diagonal to one edge of the fusing zone, and the second fusing segment extends from the other end of the first diagonal to the other edge of the fusing zone. At this time, the first fusing segment, the first diagonal and the second fusing segment are located on the same straight line. Compared with the power-off protection connector with a strip-shaped fusing port or a rectangular fusing port, its fusing time is shorter when the overcurrent area is the same. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an existing power failure protection connection piece;

[0020] Figure 2 This is a schematic diagram illustrating the power failure protection connection piece provided in an embodiment of the present invention;

[0021] Figure 3This is a schematic diagram of the structure of a power failure protection connecting piece provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of a single battery provided in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the power failure protection connecting piece, cell assembly, and cover plate assembly in a single battery cell provided in an embodiment of the present invention before cell assembly. Figure 1 ;

[0024] Figure 6 yes Figure 5 Structural diagram from another perspective Figure 2 ;

[0025] The reference numerals in the accompanying drawings are as follows:

[0026] 100 - Power failure protection connecting piece; 11 - Pole post connection part; 111 - Pole post welding area; 112 - First plane; 12 - Pole tab connection part; 121 - First pole tab connection part; 122 - Second pole tab connection part; 13 - Avoidance notch; 131 - Arc segment; 132 - Straight segment; 14 - Fuse zone; 141 - First fuse zone; 142 - Second fuse zone; 143 - First fuse segment; 144 - Second fuse segment 15-Fuse break; 151-First fuse break; 152-Second fuse break; 153-First diagonal; 154-First side; 155-Second side; 156-Third side; 157-Fourth side; 158-Fifth side; 159-Sixth side; 200-Single cell; 21-Casing; 22-Cell assembly; 221-Positive tab; 222-Cell; 23-Cover assembly; 231-Positive terminal. Detailed Implementation

[0027] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] In the description of this invention, it should be understood that the terms "side," "inner," "outer," etc., indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] like Figures 2-3 As shown, in one embodiment, the present invention provides a power failure protection connector 100, including a tab connection portion 12 and a post connection portion 11, wherein the tab connection portion 12 is connected to the post connection portion 11; a fusing region 14 is formed at the junction of the tab connection portion 12 and the post connection portion 11, the fusing region 14 includes a first fusing segment 143, a fusing opening 15 and a second fusing segment 144, the fusing opening 15 is parallel hexagonal in shape, the fusing opening 15 includes a first diagonal 153, the length direction of the first diagonal 153 is consistent with the extension direction of the fusing region 14, the first fusing segment 143 extends from one end of the first diagonal 153 to one edge of the fusing region 14, and the second fusing segment 144 extends from the other end of the first diagonal 153 to the other edge of the fusing region 14.

[0031] Specifically, for the sake of simplicity in the following description, the first fuse segment 143 and the second fuse segment 144 will be collectively referred to as fuse segments.

[0032] Specifically, a fusing zone 14 is formed at the junction of the tab connection 12 and the post connection 11. A fusing port 15 is provided on the fusing zone 14. Due to the formation of the fusing port 15, the resistance around the fusing port 15 is greater, and fusing is more likely to occur at the first fusing segment 143 and the second fusing segment 144. When an overcurrent occurs (such as a short circuit), the first fusing segment 143 and the second fusing segment 144 on both sides of the fusing port 15 will fuse. The tab connection 12 and the post connection 11 will be separated from each other and form an open circuit, thereby achieving the fusing protection effect.

[0033] like Figure 1 As shown, the existing fuse 15 is strip-shaped, and its fusing time is greater than 35s when the current is 3200A and the current is constant.

[0034] like Figure 2-3As shown, the shape of the fuse opening 15 of the present invention is set as a parallel hexagon. The length direction of the first diagonal 153 of the fuse opening 15 is consistent with the extension direction of the fuse area 14. The first fuse segment 143 extends from one end of the first diagonal 153 to one edge of the fuse area 14, and the second fuse segment 144 extends from the other end of the first diagonal 153 to the other edge of the fuse area 14. At this time, the first fuse segment 143, the first diagonal 153 and the second fuse segment 144 are located on the same straight line. Compared with the power failure protection connecting piece 100 with strip fuse opening 15 or rectangular fuse opening 15, its melting time is shorter when the overcurrent area is the same.

[0035] like Figures 2-3 As shown, in one embodiment, the length of the first diagonal 153 is H, and the length of the fused region 14 is H1. H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5.

[0036] Specifically, the length of the fuse zone 14 can be designed according to the battery capacity rate performance. When the difference between H1 and H is equal, when the position of the first diagonal 153 of the fuse port 15 coincides with the area of ​​the fuse zone 14, the overcurrent capacity is relatively good, the heat generated during overcurrent accumulates in a shorter time, and therefore the melting speed is faster.

[0037] In a preferred embodiment, the location of the first diagonal 153 of the fuse opening 15 coincides with the location of the fuse area 14, and when the fuse opening 15 is symmetrically arranged about the first diagonal 153, the current carrying capacity is relatively better, the heat generated during the current carrying process accumulates in the shortest time, and therefore the melting speed is the fastest.

[0038] When H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5, the current flowing through the fuse zone 14 is greater than or equal to the fusing current. The fuse zone 14 will quickly fuse accordingly, causing the connection between the tab connection 12 and the terminal connection 11 to break, thus preventing fire inside the single cell 200. When the current flowing through the fuse zone 14 is less than the fusing current, it means that the tab connection 12 and the terminal connection 11 are normally energized. The fuse segment will not be too short due to the fuse opening 15 being too large. This avoids the single cell 200 temperature rising when the current is normal, which would affect the service life of the single cell 200, or even cause the fuse to break when the current is normal, affecting the normal operation of the single cell 200.

[0039] like Figures 2-3As shown, in one embodiment, the fuse opening 15 is formed by a first side 154, a second side 155, a third side 156, a fourth side 157, a fifth side 158, and a sixth side 159 connected end to end. The first side 154 and the second side 155 are located on both sides of one end of the first diagonal 153, and the fourth side 157 and the fifth side 158 are located on both sides of the other end of the first diagonal 153. The length of the first side 154 is equal to the length of the second side 155.

[0040] Specifically, the length of the first side 154 is equal to the length of the second side 155, and the length of the fourth side 157 is equal to the length of the fifth side 158; the third side 156 and the sixth side 159 are set in parallel. At this time, the fuse opening 15 is symmetrically set about the first diagonal 153. Under the condition of the same flow area, the heat generated during the flow is concentrated in the shortest time, and its fuse time is shorter.

[0041] like Figures 2-3 As shown, in one embodiment, the included angle formed between the first side 154 and the second side 155 is angle A, and the angle of angle A is 60°-120°.

[0042] Specifically, the angle of angle A is any one value or a range of any two values ​​from 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115° or 120°; in a preferred embodiment, the angle of angle A is 90°.

[0043] When the angle of angle A is 60°-120°, the area of ​​the fuse opening 15 is moderate, the melting time of the fuse segment is short, and the fuse area 1414 will quickly melt, causing the connection between the tab connection 1212 and the terminal connection 1111 to break, thus preventing fire inside the single cell 200; when the angle of angle A is less than 60°, the melting time of the fuse segment is longer; when the angle of angle A is greater than 120°, the melting time is longer.

[0044] like Figures 2-3 As shown, in one embodiment, the electrode connection portion 11 is provided with an electrode welding area 111, the first fusion segment 143 is located on the side of the fusion port 15 away from the electrode welding area 111, and the second fusion segment 144 is located on the side of the fusion port 15 close to the electrode welding area 111; the length of the first fusion segment 143 is L1, the length of the second fusion segment 144 is L2, and L1 and L2 satisfy the relationship: 1≤L1 / L2≤2.

[0045] Specifically, the ratio of the length of the first fuse segment 143 to the length of the second fuse segment 144 is any one value or a range of any two values ​​from 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2; in a preferred embodiment, the ratio of the length of the first fuse segment 143 to the length of the second fuse segment 144 is 1.5.

[0046] When the ratio of the length of the first fusing segment 143 to the length of the second fusing segment 144 is less than 1, the fusing time is relatively long; when the ratio of the length of the first fusing segment 143 to the length of the second fusing segment 144 is greater than 2, the fusing time is relatively long, the strength of the power failure protection connecting piece 100 becomes weak and easily deformed, affecting the welding of the electrode welding area 111 and the electrode, resulting in poor welding reliability.

[0047] like Figures 2-3 As shown, in one embodiment, the distance between the third side 156 and the sixth side 159 is W, and the value of W ranges from 5 to 11 mm.

[0048] Specifically, the value of W is any one point value or any two points value in the range of 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or 11mm. Within this range, when the overcurrent area is constant and the current is 3200A, the fusing time of the fusing zone 14 is less than 30s.

[0049] In a preferred embodiment, the value of W ranges from 9 to 11 mm.

[0050] like Figures 2-3 As shown, in one embodiment, the tab connection portion 12 includes a first tab connection portion 121 and a second tab connection portion 122, and the fusible region 14 includes a first fusible region 141 and a second fusible region 142. The first fusible region 141 is located between the pole post connection portion 11 and the first tab connection portion 121, and the second fusible region 142 is located between the pole post connection portion 11 and the second tab connection portion 122.

[0051] Specifically, to increase capacity, a single battery cell 200 typically includes multiple cells 222, a first tab connection portion 121, and a second tab connection portion 122. The tabs of some cells 222 are connected to the first tab connection portion 121 (e.g., by welding), and the tabs of some cells 222 are connected to the second tab connection portion 122 (e.g., by welding). This helps to reduce the length of the tabs of the cells 222 and facilitates the welding of the tabs to the tab connection portion 12. Specifically, the first tab connection 121 and the second tab connection 122 can be welded to the tabs of the corresponding cells 222 respectively. When a fire occurs inside the single cell 200, the first fuse section 143 and the second fuse section 144 on both sides of the first fuse zone 141 will melt and break. The first tab connection 121 and the second tab connection 122 will be separated from the terminal connection 11 and form an open circuit, thereby achieving the fuse protection effect, preventing the single cell 200 from catching fire, and preventing the fire in one single cell 200 in the battery module from spreading to other single cells 200.

[0052] like Figures 2-3 As shown, in one embodiment, the power failure protection connecting piece 100 has a first plane 112, which is parallel to the thickness direction of the power failure protection connecting piece 100; the first electrode connecting portion 121 and the second electrode connecting portion 122 are respectively located on both sides of the first plane 112, the pole connecting portion 11 is symmetrically arranged with respect to the first plane 112, and the first fusible region 141 and the second fusible region 142 are symmetrically arranged about the first plane 112.

[0053] The fuse opening 15 on the first fuse zone 141 is the first fuse opening 151, and the fuse opening 15 on the second fuse zone 142 is the second fuse opening 152. The first fuse zone 141 and the second fuse zone 142 are symmetrically arranged about the first plane 112, so that the first fuse opening 151 and the second fuse opening 152 are also symmetrically arranged about the first plane 112. This facilitates the processing of the power failure protection connecting piece 100 and the connection between the power failure protection connecting piece 100 and the tabs and terminals of the single battery cell 200, while also ensuring the consistency of the fusing time of the first fuse zone 141 and the second fuse zone 142.

[0054] Specifically, the pole connection part 11 is provided with a pole welding area 111, which is circular and the center of the pole welding area 111 is located on the first plane 112.

[0055] like Figures 2-3 As shown, in one embodiment, it also includes a clearance notch 13 for avoiding the injection hole. The clearance notch 13 is directly opposite the injection hole. At least part of the clearance notch 13 is constructed as an arc-shaped notch with a radius larger than the size of the injection hole, so as to improve the stability of the cell 222 during the electrolyte filling process. Specifically, the arc-shaped notch is located on the tab connection portion 12 and the post connection portion 11.

[0056] Specifically, the clearance notch 13 is located between the first electrode tab connection portion 121, the electrode post connection portion 11, and the second electrode tab connection portion 122. The clearance notch 13 includes an arc-shaped segment 131 and two straight segments 132. The arc-shaped segment 131 is disposed on the electrode post connection portion 11 and is recessed toward the electrode post connection portion 11. The two straight segments 132 are respectively disposed at both ends of the arc-shaped segment 131, and the two straight segments 132 coincide with the sides of the first electrode tab connection portion 121 and the second electrode tab connection portion 122 that are close to each other. The two ends of the arc-shaped segment 131 are connected to two straight segments 132 respectively, forming a "U" shape. The first tab connecting part 121, the pole connecting part 11, and the second tab connecting part 122 together define the clearance notch 13. The first tab connecting part 121 and the second tab connecting part 122 are provided with straight segments 132, and the pole connecting part 11 is provided with arc-shaped segments 131. The first tab connecting part 121 and the second tab connecting part 122 can also be constructed as straight lines or curves. The two ends of the arc-shaped segment 131 are connected to one end of the straight segment 132 respectively, so that the clearance notch 13 forms a complete notch structure. The straight segments 132 of the two tab connecting parts 12 are parallel to each other and spaced apart to separate them from the injection hole and prevent the injection hole from contacting the tab connecting part 12.

[0057] like Figures 4-6 As shown, in one embodiment, another aspect of the present invention provides a single-cell battery 200, including a housing 21, a cell 222 assembly 22, and a cover plate assembly 23; the cell 222 assembly 22 is disposed in the inner cavity formed by the housing 21 and the cover plate assembly 23; the cell 222 assembly 22 is provided with a positive electrode tab 221, and the cover plate assembly 23 is provided with a positive electrode post 231; the single-cell battery 200 also includes the aforementioned power-off protection connecting piece 100, the tab connecting portion 12 of the power-off protection connecting piece 100 is connected to the positive electrode tab 221, and the electrode post connecting portion 11 of the power-off protection connecting piece 100 is connected to the positive electrode post 231, the positive electrode tab 221 and the positive electrode post 231 are respectively located on both sides of the power-off protection connecting piece 100, and in the figure, the positive electrode tab 221 is located on the lower side of the power-off protection connecting piece 100, and the positive electrode post 231 is located on the upper side of the power-off protection connecting piece 100.

[0058] Specifically, the power failure protection connecting piece 100 is constructed as a thin metal sheet, such as an aluminum sheet.

[0059] The power-off protection connector 100 connects to the battery cell 222 assembly 22. Because the power-off protection connector 100 has a fuse opening 15, which is a parallelogram, the first diagonal 153 of the fuse opening 15 extends along one edge of the fuse area 14 towards the other edge of the fuse area 14. The fuse opening 15 is symmetrically arranged about the first diagonal 153. The first fuse segment 143 and the second fuse segment 144 are located between the two opposite vertices of the fuse opening 15 and the two sides of the fuse area 14, respectively. At this time, the first fuse segment 143, the first diagonal 153, and the second fuse segment 144 are on the same straight line. Compared to a rectangle, with the same overcurrent area, its melting time is shorter. In the event of an overcurrent (such as a short circuit), the power-off protection connector 100 can provide melting protection at the fuse segment, thereby preventing internal fires in the individual battery cell 200.

[0060] This application does not impose any particular restrictions on the shape of the single cell 200, which can be cylindrical, square or other arbitrary shapes.

[0061] like Figures 4-6 As shown, in one embodiment, the battery cell 222 assembly 22 includes a plurality of battery cells 222, and the positive tabs 221 of the plurality of battery cells 222 are connected to the tab connection portion 12.

[0062] Specifically, the positive tabs 221 of some cells 222 are connected to the first tab connection portion 121 (e.g., by welding), and the positive tabs 221 of the remaining cells 222 are connected to the second tab connection portion 122 (e.g., by welding). Compared to connecting the positive tabs 221 of all cells 222 to the same tab connection portion 12, this is more conducive to reducing the tab length of the cells 222 and facilitating the welding of the positive tabs 221 to the tab connection portion 12.

[0063] Preferably, the single battery cell 200 has an even number (e.g., 2, 4, and 6) cells 222, with the positive tab 221 of half of the cells 222 connected to the first tab connection portion 121, and the positive tab 221 of the other half of the cells 222 connected to the second tab connection portion 122.

[0064] In another aspect, the present invention provides a battery module, including the aforementioned single cell 200.

[0065] The battery module of this application contains multiple individual battery cells 200, effectively expanding the capacity and application range of the battery module. Those skilled in the art can select an appropriate number based on the application and capacity of the battery module. Furthermore, within each individual battery cell 200, one or more cells 222 can be connected via a power-off protection connector 100. In the event of overcurrent (such as a short circuit), the power-off protection connector 100 can provide fuse protection at the fuse point, thereby preventing fire within the individual battery cell 200. In the case of multiple individual battery cells 200, this prevents the fire from spreading to other individual battery cells 200, causing serious damage, and improves the safety of the battery module operation.

[0066] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0067] Table 1. Design parameters and test results of an embodiment of a power failure protection connecting piece:

[0068] Table 1

[0069]

[0070]

[0071] Table 2. Comparative examples of the design and test results of various parameters for a power failure protection connecting piece:

[0072] Table 2

[0073]

[0074] Example 1

[0075] This embodiment provides a power failure protection connector, including a tab connection, a post connection, and a fuse opening. The fuse opening is parallelogram-shaped, with a fuse area length of 23.5 mm, a first fuse segment length of 6 mm, a second fuse segment length of 6 mm, a first symmetrical interior angle A of 120°, a first diagonal length of 11.5 mm, and a distance of 11 mm between the third and sixth sides of the fuse opening.

[0076] Examples 2-17

[0077] Examples 2-17 illustrate a power failure protection connecting piece disclosed in this invention, including most of the operating steps in Example 1, with the following differences:

[0078] The lengths of the fusing zone, the lengths of the first fusing line, the lengths of the second fusing line, the degree measure of the first symmetrical interior angle A, the length of the first diagonal of the fusing opening, and the distance between the third and sixth sides of the fusing opening used in Examples 2 to 17 are shown in Table 1.

[0079] Comparative Examples 1-2

[0080] Comparative Examples 1-2 are used to illustrate the power failure protection connecting piece disclosed in this invention, including most of the operating steps in Example 1, with the following differences:

[0081] The lengths of the fusing zone, the first fusing line, the second fusing line, the length of the fusing opening, and the width of the fusing opening used in Comparative Examples 1-2 are shown in Table 2.

[0082] Furthermore, the power failure protection connecting pieces of Examples 1-17 and Comparative Examples 1-2 are identical in material, thickness, and outer contour.

[0083] Performance testing:

[0084] The battery modules prepared from the power failure protection connectors of Examples 1-17 and Comparative Examples 1-2 and individual cells were subjected to power failure protection connector fusing tests:

[0085] Test methods and steps:

[0086] a. Adjust the resistance of the test device between the center position of the short-circuit test device and the center position of the connection between the positive terminal of the short-circuit test device and the negative terminal of the single cell to 0.8–1.0 mΩ, and record the test device resistance.

[0087] Set resistor;

[0088] b. Connect the individual battery cell that has completed initial charging to the short-circuit test device;

[0089] c. Connect the voltage and temperature sampling lines of the short-circuit test device to the individual battery cell;

[0090] d. Measure the contact resistance from the center point of the positive and negative terminals of each individual cell to the positive and negative terminals of the short-circuit test device. Adjust the contact resistance between the short-circuit test device and the positive and negative terminals of each individual cell to be less than or equal to 0.1 mΩ. Record the contact resistance and simultaneously calculate the external circuit resistance (resistance of the test device + positive terminal contact resistance + ...

[0091] (Negative electrode contact resistance);

[0092] e. Start the test apparatus to form a current loop between the positive and negative electrodes of the individual cell. Maintain the current for 10 minutes, then disconnect the current loop and observe for 1 hour. Record the current, time, voltage, and temperature; including recording test phenomena such as:

[0093] Expansion, leakage, smoke, fire, explosion, shell rupture and location of rupture;

[0094] f. Record the melting time of the power failure protection connector. If there is no fire, explosion, or leakage in the individual battery cells, and the performance of the individual battery cells meets the requirements of GB36276-2023, the short circuit test is considered to have passed.

[0095] As can be seen from the test results in Tables 1 and 2, Examples 1-17 use parallel hexagonal fuses, Comparative Example 1 uses rectangular fuses, and Comparative Example 2 uses strip fuses.

[0096] When the thickness of the power failure protection connecting piece is consistent, the current-passing area of ​​the power failure protection connecting pieces in Examples 1-13 and Comparative Examples 1-2 is the same; the current-passing area of ​​the power failure protection connecting piece in Examples 14-15 is greater than that of the power failure protection connecting piece in Examples 1-13, and the current-passing area of ​​the power failure protection connecting piece in Example 14 is greater than that of the power failure protection connecting piece in Example 14; the current-passing area of ​​the power failure protection connecting piece in Examples 16-17 is less than that of the power failure protection connecting piece in Examples 1-13, and the current-passing area of ​​the power failure protection connecting piece in Example 16 is greater than that of the power failure protection connecting piece in Example 17.

[0097] In Examples 1-5, the length of the fusing zone is 23.5 mm, the length of the first diagonal of the fusing opening is 11.5 mm, and the distance between the third and sixth sides of the fusing opening is 11 mm. When the ratio of the length of the first fusing segment to the length of the second fusing segment is between 1 and 2, the fusing time of the fusing segment is less than 25 s. When the ratio of the length of the first fusing segment to the length of the second fusing segment is 1.2, the fusing time of the fusing segment is the shortest, which is 21 s. When the ratio of the length of the first fusing segment to the length of the second fusing segment is less than 1 or greater than 2, the fusing time of the fusing segment is greater than or equal to 25 s and less than 30 s.

[0098] Therefore, the length of the first fuse segment is L1, and the length of the second fuse segment is L2. When L1 and L2 satisfy the relationship: 1≤L1 / L2≤2, the fuse breaking time is short and can meet the safety standards.

[0099] In Examples 2 and 6-9, the length of the fusion zone is 23.5 mm, the length of the first diagonal of the fusion fracture is 11.5 mm, the length of the first fusion segment is 6.55 mm, the length of the second fusion segment is 5.45 mm, and the distance between the third and sixth sides is 11 mm.

[0100] When the degree of the first symmetrical interior angle A is between 30° and 150°, the fusing time of the fused segment first decreases and then increases. When the degree of the first symmetrical interior angle A is between 60° and 120°, the fusing time of the fused segment is less than 25s. When the degree of the first symmetrical interior angle A is 30° or 150°, the fusing time of the fused segment is greater than 25s.

[0101] Therefore, the angle formed between the first side and the second side is angle A. When the angle of angle A is 60°-120°, the area of ​​the fuse break is suitable, and the fuse break time of the fuse segment is short, which can meet the safety use standard.

[0102] In Examples 2 and 10-13, the length of the fusing zone is 23.5 mm, the length of the first diagonal of the fusing opening is 11.5 mm, the length of the first fusing segment is 6.55 mm, and the length of the second fusing segment is 5.45 mm. When the distance between the third and sixth sides is between 4 and 11 mm, the fusing time of the fusing segment gradually decreases. When the distance between the third and sixth sides is between 4 and 11 mm, the fusing time of the fusing segment is less than 25 seconds. When the distance between the third and sixth sides is 12 mm, its fusing time is the same as that when the distance between the third and sixth sides is 9 mm. However, when the distance between the third and sixth sides is 12 mm, it will affect the welding of the electrode welding area and the electrode, resulting in poor welding reliability.

[0103] Therefore, the distance between the third and sixth sides is W. When the value of W is in the range of 4-11mm, the melting time is short and can meet the safety standards.

[0104] In Example 2 and Examples 14-17, the length of the fusing zone is 23.5 mm, and the distance between the third and sixth sides of the fusing point is 11 mm; the ratio of the length of the first fusing segment to the length of the second fusing segment is 1.2.

[0105] In Example 2, the ratio of the length H of the first diagonal to the length H1 of the fused zone is 0.49, and the fused time of the fused segment is 21s, which is less than 20s.

[0106] In Example 14, the ratio of the length H of the first diagonal to the length H1 of the fusing zone is 0.3, and the fusing time of the fusing segment is 40s, which is greater than 35s, indicating a relatively long fusing time.

[0107] In Example 15, the ratio of the length H of the first diagonal to the length H1 of the fusing zone is 0.33, and the fusing time of the fusing segment is 35s. The fusing time is equal to 35s, which meets the safety use standard.

[0108] In Example 16, the ratio of the length H of the first diagonal to the length H1 of the fused zone is 0.60, and the fused time of the fused segment is 15s, which is less than 20s.

[0109] In Example 17, the ratio of the length H of the first diagonal to the length H1 of the fuse zone is 0.65, and the fuse breaking time of the fuse segment is 13s. Although the fuse breaking time is much less than 35s, the length of the first diagonal is too large, resulting in a fuse segment that is too short. An excessively short fuse segment will cause the temperature of the individual battery to rise when the current is normal, thereby affecting the service life of the individual battery and even causing fuse breaking when the current is normal, affecting the normal operation of the individual battery.

[0110] Therefore, the length of the first diagonal is H, and the length of the fusing zone is H1. When H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5, the current carrying capacity of the fusing port is relatively good, the fusing time is short, and the safety use standard can be met.

[0111] Comparative Example 1 uses a rectangular fuse, while Comparative Example 2 uses a strip fuse. When the overcurrent area of ​​the power failure protection connecting piece is the same for Comparative Example 1, Comparative Example 2 and Experimental Example 2, the fusing time of the fuse segment of Comparative Example 1 and Comparative Example 2 is greater than 25s.

[0112] In summary, this invention achieves its goal by setting the fuse opening to a parallelepiped shape and satisfying the following conditions:

[0113] The length of the first fuse segment is L1, and the length of the second fuse segment is L2. When L1 and L2 satisfy the relationship: 1 ≤ L1 / L2 ≤ 2...

[0114] The distance between the third side and the sixth side is W, and the value of W is in the range of 4-11mm;

[0115] The length H of the first diagonal and the length H1 of the fuse zone satisfy the following relationship: 1 / 3H1≤H≤3 / 5H1;

[0116] The power-off protection connector of this invention has a melting time of less than 30 seconds when the current is 3200A, which meets the safety standard. This is because when an overcurrent occurs (such as a short circuit), the overcurrent capacity of the melting zone of the power-off protection connector of this invention is relatively good, and the heat generated during the overcurrent accumulates in a shorter time, so the melting speed is faster. This can prevent fire from occurring inside a single cell. In the case of multiple cells, it can prevent the fire from spreading to other cells and causing serious damage. If any of the above conditions are not met, the melting time will be too long.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power failure protection connecting piece, characterized in that: The device includes a tab connection portion and a post connection portion, the tab connection portion being connected to the post connection portion. A fusing zone is formed at the junction of the tab connection portion and the post connection portion. The fusing zone includes a first fusing segment, a fusing opening, and a second fusing segment. The fusing opening is parallelogram-shaped and includes a first diagonal. The length direction of the first diagonal is consistent with the extension direction of the fusing zone. The first fusing segment extends from one end of the first diagonal to one edge of the fusing zone. The second fusing segment extends from the first diagonal... The other end extends to the other edge of the fusion zone; the length of the first diagonal is H, the length of the fusion zone is H1, and H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5; the pole connection is provided with a pole welding area, the first fusion segment is located on the side of the fusion port away from the pole welding area, and the second fusion segment is located on the side of the fusion port close to the pole welding area; the length of the first fusion segment is L1, the length of the second fusion segment is L2, and L1 and L2 satisfy the relationship: 1≤L1 / L2≤2.

2. The power failure protection connecting piece according to claim 1, characterized in that: The fuse opening is formed by a first side, a second side, a third side, a fourth side, a fifth side, and a sixth side connected end to end. The first side and the second side are located on both sides of one end of the first diagonal, and the fourth side and the fifth side are located on both sides of the other end of the first diagonal. The length of the first side is equal to the length of the second side.

3. The power failure protection connecting piece according to claim 2, characterized in that: The angle formed between the first side and the second side is called angle A, and the angle of angle A is 60°-120°.

4. The power failure protection connecting piece according to claim 2, characterized in that: The distance between the third side and the sixth side is W, and the value of W ranges from 5 to 11 mm.

5. The power failure protection connecting piece according to claim 1, characterized in that: The electrode connection portion includes a first electrode connection portion and a second electrode connection portion, and the fusion zone includes a first fusion zone and a second fusion zone. The first fusion zone is located between the electrode post connection portion and the first electrode connection portion, and the second fusion zone is located between the electrode post connection portion and the second electrode connection portion.

6. The power failure protection connecting piece according to claim 5, characterized in that: The power failure protection connecting piece has a first plane, which is parallel to the thickness direction of the power failure protection connecting piece; the first electrode connecting part and the second electrode connecting part are respectively located on both sides of the first plane, the electrode connecting part is symmetrically arranged with respect to the first plane, and the first fuse area and the second fuse area are symmetrically arranged with respect to the first plane.

7. A single-cell battery, comprising a casing, a cell assembly, and a cover assembly; the cell assembly is disposed within an inner cavity formed by the casing and the cover assembly; the cell assembly has a positive electrode tab, and the cover assembly has a positive electrode post, characterized in that: It also includes a power failure protection connecting piece according to any one of claims 1-6, wherein the tab connecting portion of the power failure protection connecting piece is connected to the positive tab, the post connecting portion of the power failure protection connecting piece is connected to the positive post, and the positive tab and the positive post are respectively located on both sides of the power failure protection connecting piece.

8. A single-cell battery according to claim 7, characterized in that: The battery cell assembly includes multiple battery cells, and the positive electrode tabs of the multiple battery cells are connected to the electrode tab connection portion.

9. A battery module, characterized in that: Includes the single-cell battery as described in claim 7 or 8.

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