A power-off protection tab, single battery and battery module

Abstract

The application provides a power-off protection connecting piece, a single battery and a battery module, which comprise a tab connecting part and a pole connecting part, a fuse area is formed at a connecting joint position of the tab connecting part and the pole connecting part, the fuse area comprises a first fuse section, a fuse opening and a second fuse section, the fuse opening is in a rhombus shape, the fuse opening comprises a first diagonal line and a second diagonal line, the length direction of the first diagonal line is consistent with the extension direction of the fuse area, the first fuse section extends from one end of the first diagonal line to one end edge of the fuse area, and the second fuse section extends from the other end of the first diagonal line to the other end edge of the fuse area; the fuse opening of the application is in a rhombus shape, the first fuse section, the first diagonal line and the second fuse section are located on the same straight line, compared with a rectangle, the fuse area has a shorter fuse time under the condition of the same overcurrent area; and the application avoids the occurrence of fire spreading from the single battery to other single batteries and causes serious loss.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a power-off protection connecting piece, a single battery and a battery module. BACKGROUND

[0002] With the increasing maturity of battery technology, power batteries are widely used in electric vehicles, and the use performance and safety of power batteries are increasingly required. Power batteries have risks such as thermal runaway. When abnormal conditions such as short circuit occur inside the battery, the gas pressure inside the battery increases, and if the high-temperature flue gas inside the battery is not discharged in time, more serious safety accidents such as battery explosion may occur. In view of the above situation, the prior art sets an explosion-proof valve on the shell, and discharges the high-temperature flue gas in the battery through the explosion of the explosion-proof valve.

[0003] However, the explosion-proof valve is usually directly arranged on the surface of the shell, and the components such as the power-off protection connecting piece arranged between the pole group and the shell inside the battery will hinder the flow of gas to some extent, affecting the smoothness of the exhaust, and when thermal runaway occurs, the battery is usually connected to the circuit, and if the connection between the battery cell and the circuit cannot be disconnected in time, it may cause short circuit damage to the entire circuit, further increasing the loss.

[0004] The existing battery module single battery pole lug is connected to the pole by the power-off protection connecting piece. When the single battery is powered on, the current may be too large. In the prior art, a fuse opening is arranged on the power-off protection connecting piece, and when the current is too large, the fuse section at the fuse opening melts. However, the current fuse opening is in the form of a strip, and its melting time is usually greater than 35s. When the single battery experiences thermal runaway, the melting time of the fuse section at the fuse opening is too long, which may cause thermal runaway and spread to other single batteries, causing serious loss. Therefore, how to overcome the above technical problems and defects has become a key problem to be solved. SUMMARY

[0005] In view of the problem that the existing power-off protection connecting piece has a long melting time and cannot effectively protect the single battery, the present application provides a power-off protection connecting piece, a single battery and a battery module.

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

[0007] The application provides a power-off protection connecting piece, which comprises a tab connecting part and a pole connecting part, the tab connecting part is connected with the pole connecting part, a fuse area is formed at the connecting joint position of the tab connecting part and the pole connecting part, the fuse area comprises a first fuse section, a fuse opening and a second fuse section, the fuse opening is in a rhombus shape, the fuse opening comprises a first diagonal line and a second diagonal line, the length direction of the first diagonal line is consistent with the extension direction of the fuse area, the first fuse section extends from one end of the first diagonal line to one end edge of the fuse area, and the second fuse section extends from the other end of the first diagonal line to the other end edge of the fuse area.

[0008] Optionally, the fuse opening is in a square shape.

[0009] Optionally, the length of the first diagonal line is H, the length of the fuse area is H1, and the H and the H1 satisfy the relationship formula: 1 / 3≤H / H1≤3 / 5.

[0010] Optionally, a pole welding area is arranged on the pole connecting part, the first fuse section is located on the side of the fuse opening away from the pole welding area, the second fuse section is located on the side of the fuse opening close to the pole welding area, the length of the first fuse section is L1, the length of the second fuse section is L2, and the L1 and the L2 satisfy the relationship formula: 1≤L1 / L2≤2.

[0011] Optionally, the length of the second diagonal line is W, and the value range of the W is 4-11 mm.

[0012] Optionally, the tab connecting part comprises a first tab connecting part and a second tab connecting part, the fuse area comprises a first fuse area and a second fuse area, the first fuse area is located between the pole connecting part and the first tab connecting part, and the second fuse area is located between the pole connecting part and the second tab connecting part.

[0013] Optionally, the power-off protection connecting piece has a first plane, the first plane is parallel to the thickness direction of the power-off protection connecting piece, the first tab connecting part and the second tab connecting part are located on the two sides of the first plane respectively, the pole connecting part is symmetrically arranged relative to the first plane, and the first fuse area and the second fuse area are symmetrically arranged relative to the first plane.

[0014] Optionally, two top corners on the first diagonal line of the fuse opening are arranged as chamfered corners or rounded corners, and two top corners on the second diagonal line of the fuse opening are arranged as chamfered corners or rounded corners.

[0015] Another aspect of the present application provides a single battery, comprising a shell, an electric core assembly and a cover plate assembly; the electric core assembly is arranged in an inner cavity formed by the shell and the cover plate assembly; a positive electrode lug is arranged on the electric core assembly, a positive electrode column is arranged on the cover plate assembly, and the single battery further comprises the power-off protection connecting piece, the lug connecting part of the power-off protection connecting piece is connected with the positive electrode lug, the column connecting part of the power-off protection connecting piece is connected with the positive electrode column, and the positive electrode lug and the positive electrode column are respectively located on two sides of the power-off protection connecting piece.

[0016] Optionally, the electric core assembly comprises a plurality of electric cores, and the positive electrode lug of each electric core is connected with the lug connecting part.

[0017] Still another aspect of the present application provides a battery module comprising the single battery.

[0018] According to the power-off protection connecting piece provided by the present application, the fuse area is formed at the connection interface between the lug connecting part and the column connecting part, and the fuse hole is arranged on the fuse area. Due to the formation of the fuse hole, the resistance around the fuse hole is larger, and the fuse is more likely to occur at the first fuse section and the second fuse section. When overcurrent occurs (such as short circuit), the first fuse section and the second fuse section on both sides of the fuse hole are fused, and the lug connecting part and the column connecting part are spaced from each other and form an open circuit, thereby realizing the fuse protection effect. The shape of the fuse hole is set as a rhombus. When overcurrent occurs (such as short circuit), the fuse protection can be realized at the fuse section by the power-off protection connecting piece, and thus the fire inside the single battery can be avoided. In the case of multiple single batteries, the fire can be prevented from spreading to other single batteries, thereby avoiding serious loss. The length direction of the first diagonal line of the fuse hole is consistent with the extension direction of the fuse area, and the fuse hole is symmetrically arranged about the first diagonal line. The first fuse section extends from one end of the first diagonal line to one end edge of the fuse area, and the second fuse section extends from the other end of the first diagonal line to the other end edge of the fuse area. At this time, the first fuse section, the first diagonal line and the second fuse section are located on the same straight line. Compared with the power-off protection connecting piece with a strip-shaped fuse hole or a rectangular fuse hole, the fuse time is shorter under the condition of the same overcurrent area. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic view of the existing power-off protection connecting piece;

[0020] Figure 2 is a labeled schematic view of the power-off protection connecting piece provided by an embodiment of the present application;

[0021] Figure 3 is a structural schematic view of the power-off protection connecting piece provided by an embodiment of the present application;

[0022] Figure 4 is a structural schematic diagram of a single battery provided by an embodiment of the present application;

[0023] Figure 5 is a structural schematic diagram of a single battery provided by an embodiment of the present application Figure 1 ;

[0024] Figure 6 is Figure 5 a structural schematic diagram from another perspective Figure 2 ;

[0025] The reference signs in the drawings of the specification are as follows:

[0026] 100 - a power-off protection connecting piece; 11 - a pole connecting part; 111 - a pole welding area; 112 - a first plane; 12 - a tab connecting part; 121 - a first tab connecting part; 122 - a second tab connecting part; 13 - an avoiding notch; 131 - an arc segment; 132 - a straight line segment; 14 - a fuse area; 141 - a first fuse area; 142 - a second fuse area; 143 - a first fuse segment; 144 - a second fuse segment; 15 - a fuse opening; 151 - a first fuse opening; 152 - a second fuse opening; 153 - a first diagonal line; 154 - a second diagonal line; 200 - a single battery; 21 - a shell; 22 - a cell assembly; 221 - a positive tab; 222 - a cell; 23 - a cover plate assembly; 231 - a positive pole. DETAILED DESCRIPTION

[0027] In order to make the technical problems solved by the present application, the technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0028] In the description of the present application, it should be understood that the terms "side surface", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0029] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal connection of two elements. For those skilled in the art, the specific meaning of the above-mentioned term in the present application can be understood according to the specific circumstances.

[0030] As shown in Figures 2-3 In an embodiment, a power-off protection connecting piece 100 includes a tab connecting part 12 and a pole connecting part 11, the tab connecting part 12 is connected with the pole connecting part 11; a melting area 14 is formed at the connecting boundary position of the tab connecting part 12 and the pole connecting part 11, the melting area 14 includes a first melting section 143, a melting opening 15 and a second melting section 144, the melting opening 15 is in the shape of a rhombus, the melting opening 15 includes a first diagonal line 153 and a second diagonal line 154, the length direction of the first diagonal line 153 is consistent with the extension direction of the melting area 14, the first melting section 143 extends from one end of the first diagonal line 153 to one end edge of the melting area 14, and the second melting section 144 extends from the other end of the first diagonal line 153 to the other end edge of the melting area 14.

[0031] Specifically, for the sake of simplifying the subsequent description, the first melting section 143 and the second melting section 144 are collectively referred to as melting sections.

[0032] Specifically, the melting area 14 is formed at the connecting boundary position of the tab connecting part 12 and the pole connecting part 11, and the melting opening 15 is arranged on the melting area 14. Due to the formation of the melting opening 15, the resistance around the melting opening 15 is larger, and the melting is more likely to occur at the first melting section 143 and the second melting section 144. When overcurrent occurs (such as short circuit), the first melting section 143 and the second melting section 144 on both sides of the melting opening 15 melt, and the tab connecting part 12 and the pole connecting part 11 are spaced apart and form an open circuit, thereby achieving the effect of melting protection.

[0033] As shown in Figure 1 The shape of the existing melting opening 15 is strip-shaped, the overcurrent area is constant, and the melting time is greater than 35s when the current is 3200A;

[0034] As shown in Figures 2-3As shown, the shape of the fuse opening 15 is set as a rhombus, the length direction of the first diagonal line 153 of the fuse opening 15 is consistent with the extension direction of the fuse area 14, and the fuse opening 15 is symmetrically arranged about the first diagonal line 153; the first fuse section 143 extends from one end of the first diagonal line 153 to one end edge of the fuse area 14, and the second fuse section 144 extends from the other end of the first diagonal line 153 to the other end edge of the fuse area 14, at this time, the first fuse section 143, the first diagonal line 153 and the second fuse section 144 are located on the same straight line, compared with the power-off protection connecting piece 100 with a strip-shaped fuse opening 15 or a rectangular fuse opening 15, in the case of the same overcurrent area, the fuse time is shorter.

[0035] As shown in the drawings, Figures 2-3 In an embodiment, the shape of the fuse opening 15 is a square.

[0036] The shape of the fuse opening 15 is a square, compared with a rhombus with an inner angle of 90°, in the case of the same overcurrent area, the heat generated during overcurrent is collected in the shortest time, and the fuse time is shorter.

[0037] As shown in the drawings, Figures 2-3 In an embodiment, the length of the first diagonal line 153 is H, the length of the fuse area 14 is H1, and H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5.

[0038] Specifically, the length of the fuse area 14 can be designed according to the battery capacity rate performance, in the case of equal H1-H difference, when the position of the first diagonal line 153 of the fuse opening 15 coincides with the area of the fuse area 14, the overcurrent capacity is relatively good, the heat generated during overcurrent is collected in a shorter time, and thus the fuse speed is faster.

[0039] In a preferred embodiment, the position of the first diagonal line 153 of the fuse opening 15 coincides with the area of the fuse area 14, and when one of the inner angles of the fuse opening 15 is 90°, the overcurrent capacity is relatively better, the heat generated during overcurrent is collected in the shortest time, and thus the fuse speed is the fastest.

[0040] When H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5, and the current flowing through the fusing area 14 is greater than or equal to the fusing current, the fusing area 14 will quickly fuse accordingly, so that the connection between the tab connecting part 12 and the pole connecting part 11 is disconnected, avoiding the occurrence of fire inside the single battery; when the current flowing through the fusing area 14 is less than the fusing current, it can be indicated that the tab connecting part 12 and the pole connecting part 11 are normally powered, and the excessively short fusing section will not cause the single battery 200 to have high temperature rise under normal current, thereby affecting the service life of the single battery 200, or even causing fusing phenomenon under normal current, affecting the normal work of the single battery 200.

[0041] As shown in Figures 2-3 In an embodiment, the pole connecting part 11 is provided with a pole welding area 111, the first fusing section 143 is located on the side of the fusing opening 15 away from the pole welding area 111, the second fusing section 144 is located on the side of the fusing opening 15 close to the pole welding area 111, and the length of the first fusing section 143 is greater than the length of the second fusing section 144; the length of the first fusing section 143 is L1, the length of the second fusing section 144 is L2, and L1 and L2 satisfy the relationship: 1≤L1 / L2≤2.

[0042] Specifically, the length ratio of the first fusing section 143 to the second fusing section 144 is any one value or a range value composed of any two values in the range of 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 length ratio of the first fusing section 143 to the second fusing section 144 is 1.5.

[0043] When the length ratio of the first fusing section 143 to the second fusing section 144 is less than 1, the fusing time is longer; when the length ratio of the first fusing section 143 to the second fusing section 144 is greater than 2, the fusing time is longer, the strength of the power-off protection connecting piece is weak and easy to deform, affecting the welding of the pole welding area 111 and the pole, and resulting in poor welding reliability.

[0044] As shown in Figures 2-3 In an embodiment, the length of the second diagonal line 154 is W, and the value range of W is 4-11mm.

[0045] Specifically, the value range of W is any one value or a range value composed of any two values in the range of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or 11mm, and within this range, when the overcurrent area is constant and the current is 3200A, the fusing time of the fusing area 14 is less than 30s.

[0046] In a preferred embodiment, W ranges from 9 to 11 mm.

[0047] As shown in the drawings, Figures 2-3 In an embodiment, the tab connecting part 12 includes a first tab connecting part 121 and a second tab connecting part 122, and the fuse area 14 includes a first fuse area 141 and a second fuse area 142. The first fuse area 141 is located between the pole connecting part 11 and the first tab connecting part 121, and the second fuse area 142 is located between the pole connecting part 11 and the second tab connecting part 122.

[0048] Specifically, to increase the capacity, a plurality of battery cells 222 are usually arranged in the single battery 200, the first tab connecting part 121 and the second tab connecting part 122 are arranged, the tabs of part of the battery cells 222 are connected (such as welded) to the first tab connecting part 121, and the tabs of part of the battery cells 222 are connected (such as welded) to the second tab connecting part 122, which is conducive to reducing the length of the tabs of the battery cells 222 and facilitating the welding of the tabs and the tab connecting part 12. Specifically, the first tab connecting part 121 and the second tab connecting part 122 can be welded to the tabs of the corresponding battery cells 222, respectively. When a fire occurs inside the single battery 200, the first fuse section 143 and the second fuse section 144 on both sides of the first fuse area 141 are fused, the first tab connecting part 121 and the second tab connecting part 122 are spaced apart from the pole connecting part 11 and form a circuit, thereby achieving the effect of fuse protection, avoiding the single battery from catching fire, and avoiding the fire of one single battery 200 spreading to other single batteries 200 in the battery module.

[0049] As shown in the drawings, Figures 2-3 In an embodiment, the power-off protection connecting sheet 100 has a first plane 112 parallel to the thickness direction of the power-off protection connecting sheet 100. The first tab connecting part 121 and the second tab connecting part 122 are respectively located on both sides of the first plane 112, the pole connecting part 11 is symmetrically arranged relative to the first plane 112, the fuse opening 15 on the first fuse area 141 is a first fuse opening 151, the fuse opening 15 on the second fuse area 142 is a second fuse opening 152, and the first fuse area 141 and the second fuse area 142 are symmetrically arranged relative to the first plane 112, so that the first fuse opening 151 and the second fuse opening 152 are also symmetrically arranged relative to the first plane 112. This facilitates the processing of the power-off protection connecting sheet 100, facilitates the connection of the power-off protection connecting sheet 100 with the tabs and the pole of the single battery 200, and ensures the consistency of the fuse time of the first fuse area 141 and the second fuse area 142.

[0050] Specifically, the pole connecting part 11 is provided with a pole welding area 111, the pole welding area 111 is circular, and the center of the pole welding area 111 is located on the first plane 112.

[0051] As Figures 2-3 shown in the drawings, in an embodiment, a relief gap 13 for avoiding the liquid injection hole is further included, the relief gap 13 is opposite to the liquid injection hole, at least part of the relief gap 13 is configured as an arc-shaped gap and the radius is greater than the size of the liquid injection hole, so as to improve the stability of the battery cell during the electrolyte filling process. Specifically, the arc-shaped gap is located on the tab connecting part 12 and the pole connecting part 11.

[0052] Specifically, the relief gap 13 is located between the first tab connecting part 121, the pole connecting part 11 and the second tab connecting part 122; the relief gap 13 includes an arc-shaped section 131 and two straight sections 132, the arc-shaped section 131 is provided on the pole connecting part 11 and is recessed towards the direction of the pole connecting part 11, the two straight sections 132 are respectively provided at the two ends of the arc-shaped section 131, and the two straight sections 132 respectively coincide with the mutually close sides of the first tab connecting part 121 and the second tab connecting part 122. The two ends of the arc-shaped section 131 are respectively connected with the two straight sections 132 to form a "U" shape, the first tab connecting part 121, the pole connecting part 11 and the second tab connecting part 122 jointly define the relief gap 13, the straight sections 132 are provided on the first tab connecting part 121 and the second tab connecting part 122, and the arc-shaped section 131 is provided on the pole connecting part 11, while the first tab connecting part 121 and the second tab connecting part 122 can also be configured as straight lines or curves, the two ends of the arc-shaped section 131 are respectively connected with one end of the straight section 132, so that the relief gap 13 forms a complete gap structure. The straight sections 132 of the two tab connecting parts 12 are parallel to and spaced apart from each other, so as to be separated from the liquid injection hole and avoid contact between the liquid injection hole and the tab connecting part 12.

[0053] As Figures 2-3 shown in the drawings, in an embodiment, the two top corners on the first diagonal line 153 of the fuse opening 15 are configured as chamfered corners or rounded corners; the two top corners on the second diagonal line 154 of the fuse opening 15 are configured as chamfered corners or rounded corners.

[0054] Specifically, the two top corners on the first diagonal line 153 are configured as chamfered corners or rounded corners, based on the manufacturing process, the mold has a longer service life and the product quality is better after chamfering, which facilitates the demolding of the power-off protection connecting piece 100 when the power-off protection connecting piece 100 is manufactured.

[0055] The two top corners on the second diagonal line 154 are configured as chamfered corners or rounded corners, since one end of the second diagonal line 154 is close to the pole welding area of the pole connecting part 11, enough welding position is left for the pole welding area 111 of the pole connecting part 11, which does not affect the welding process of the pole welding area 111 and the pole; moreover, it is convenient for the demolding of the power-off protection connecting piece 100 when the power-off protection connecting piece 100 is manufactured.

[0056] As Figures 4-6As shown, in one embodiment, another aspect of the present invention provides a single battery 200, including a shell 21, a battery cell assembly 22 and a cover assembly 23; the battery cell assembly 22 is arranged in an inner cavity enclosed by the shell 21 and the cover assembly 23; a positive electrode ear 221 is provided on the battery cell assembly 22, and a positive electrode post 231 is provided on the cover assembly 23; the single battery 200 also includes the above-mentioned power-off protection connecting piece 100, the electrode ear connecting portion 12 of the power-off protection connecting piece 100 is connected to the positive electrode ear 221, and the electrode post connecting portion 11 of the power-off protection connecting piece 100 is connected to the positive electrode post 231, and the positive electrode ear 221 and the positive electrode post 231 are respectively located on both sides of the power-off protection connecting piece 100. Figure 4 In the embodiment, the positive electrode tab 221 is located at the lower side of the power-off protection connecting piece 100 , and the positive electrode posts 231 are respectively located at the upper side of the power-off protection connecting piece 100 .

[0057] Specifically, the power-off protection connecting piece 100 is constructed as a metal sheet, such as an aluminum sheet.

[0058] The power-off protection connector 100 connects to the battery cell assembly 22. Because the power-off protection connector 100 is provided with a diamond-shaped fuse 15, a first diagonal line 153 of the fuse 15 extends from one edge of the fuse region 14 toward the other edge of the fuse region 14. The fuse 15 is symmetrically arranged about the first diagonal line 153. The first fuse section 143 and the second fuse section 144 are located between the two opposite corners of the fuse 15 and the two edges of the fuse region 14, respectively. In this case, the first fuse section 143, the first diagonal line 153, and the second fuse section 144 are located on the same straight line. Compared to a rectangular circuit, the fuse section has a shorter blowing time when the flow area is the same. In the event of an overcurrent (such as a short circuit), the power-off protection connector 100 can provide fuse protection at the fuse section, thereby preventing fires within the battery cells 200.

[0059] The present application has no particular limitation on the shape of the single battery 200 , which may be cylindrical, square, or any other shape.

[0060] like Figures 4-6 As shown, in one embodiment, the battery cell 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 connecting portion 12 .

[0061] Specifically, the positive tabs 221 of some battery cells are connected to the first tab connection portion 121 (such as welding), and the positive tabs 221 of the remaining battery cells are connected to the second tab connection portion 122 (such as welding). Compared with the positive tabs 221 of all battery cells being connected to the same tab connection portion 12, this is more conducive to reducing the tab length of the battery cell and facilitating the welding of the positive tabs and the tab connections.

[0062] Preferably, the single battery 200 has an even number (such as 2, 4, and 6, etc.) of the battery cells 222, and half of the battery cells 222 are connected with the first tab connecting part 121, and the other half of the battery cells 222 are connected with the second tab connecting part 122.

[0063] In still another aspect of the present application, a battery module is provided, which comprises the single battery 200 described above.

[0064] The battery module of the present application contains a plurality of single batteries 200, which effectively expands the capacity of the battery module and expands the application range of the battery module. Those skilled in the art can select an appropriate number according to the application and capacity of the battery module. Moreover, one or more battery cells 222 can be connected inside the single battery 200 through the power-off protection connecting sheet 100. The power-off protection connecting sheet 100 of the present application can perform fuse protection at the fuse section of the power-off protection connecting sheet 100 when overcurrent occurs (such as short circuit), thereby avoiding fire inside the single battery 200. In the case of multiple single batteries 200, the fire can be prevented from spreading to other single batteries 200, thereby avoiding serious loss and improving the safety of the battery module during operation.

[0065] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present application is more thorough and complete, and the scope of the present application is fully conveyed to those skilled in the art.

[0066] Table 1: Design and test results of each parameter of an embodiment of a power-off protection connecting sheet

[0067] Table 1

[0068]

[0069] Table 2: Design and test results of each parameter of a comparative example of a power-off protection connecting sheet

[0070] Table 2

[0071]

[0072] Example 1

[0073] The present embodiment provides a power-off protection connecting sheet, which comprises a tab connecting part, a post connecting part, and a fuse opening. The shape of the fuse opening is a rhombus, the length of the fuse section is 23.5 mm, the length of the first fuse section is 6 mm, the length of the second fuse section is 6 mm, the length of the first diagonal of the fuse opening is 11.5 mm, and the length of the second diagonal of the fuse opening is 11 mm.

[0074] Examples 2-13

[0075] Examples 2-13 for illustrating a power-off protection tab disclosed in the present application, including most of the operating steps in Example 1, the difference is that:

[0076] The length of the melting zone, the length of the first melting line, the length of the second melting line, the length of the first diagonal line of the melting port, and the length of the second diagonal line of the melting port used in Examples 2-13 are shown in Table 1.

[0077] Comparative Example 1-2

[0078] Comparative Example 1-2 for comparative illustration of a power-off protection tab disclosed in the present application, including most of the operating steps in Example 1, the difference is that:

[0079] The length of the melting zone, the length of the first melting line, the length of the second melting line, the length of the first diagonal line of the melting port, and the length of the second diagonal line of the melting port used in Comparative Example 1-2 are shown in Table 2.

[0080] In addition, the material, thickness, and outer contour of the power-off protection tabs of Examples 1-13 and Comparative Example 1-2 are the same.

[0081] Performance test:

[0082] The power-off protection tabs of Examples 1-13 and Comparative Example 1-2 and the battery modules prepared from single batteries were subjected to power-off protection tab melting tests:

[0083] Test method and steps:

[0084] a. Adjust the test device resistance between the center position of the short circuit test device and the positive electrode connection of the single battery to the center position of the short circuit test device and the negative electrode connection of the single battery to 0.8-1.0 mΩ, and record the test device resistance;

[0085] b. Connect the single battery that has completed the initialization charging to the short circuit test device;

[0086] c. Connect the voltage and temperature sampling lines of the short circuit test device to the single battery;

[0087] d. Measure the positive and negative electrode center points of the single battery to the positive and negative electrode contact resistance of the short circuit test device, respectively, and adjust the contact resistance of the short circuit test device and the single battery positive and negative electrode connection state to be less than or equal to 0.1 mΩ, record the contact resistance, and calculate the external line resistance (test device resistance + positive electrode contact resistance + negative electrode contact resistance) at the same time;

[0088] e. Record the voltage and temperature of the single battery at the time of the test;

[0089] f. Record the time when the single battery voltage drops to 0V;

[0090] e. Start the test device, form a current loop between the positive and negative electrodes of the single battery, the current is maintained for 10 min, the current loop is disconnected, and the current, time, voltage, and temperature are observed for 1 h, and the test phenomena such as:

[0091] expansion, liquid leakage, smoking, fire, explosion, shell rupture, and rupture position;

[0092] f. Record the melting time of the power-off protection connecting piece, and there is no fire, explosion, and liquid leakage phenomenon in the single battery, and the performance of the single battery meets the requirements of GB36276-2023, that is, the short circuit test is passed.

[0093] As can be seen from the test results in Tables 1 and 2, Examples 1-13 use a rhombus-shaped melting opening, Comparative Example 1 uses a rectangular melting opening, and Comparative Example 2 uses a strip-shaped melting opening.

[0094] When the thickness of the power-off protection connecting piece is consistent, the overcurrent area of the power-off protection connecting pieces of Examples 1-9 and Comparative Examples 1-2 is the same; the overcurrent area of the power-off protection connecting pieces of Examples 10-11 is greater than that of the power-off protection connecting piece of Example 1-9, the overcurrent area of the power-off protection connecting piece of Example 10 is greater than that of the power-off protection connecting piece of Example 11; the overcurrent area of the power-off protection connecting pieces of Examples 12-13 is less than that of the power-off protection connecting piece of Example 1-9, and the overcurrent area of the power-off protection connecting piece of Example 12 is greater than that of the power-off protection connecting piece of Example 13.

[0095] In Examples 1-5, the length of the melting zone is 23.5 mm, the length of the first diagonal of the melting opening is 11.5 mm, and the length of the second diagonal of the melting opening is 11 mm; when the ratio of the length of the first melting section to the length of the second melting section is between 1-2, the melting time of the melting section is less than 25s, and when the ratio of the length of the first melting section to the length of the second melting section is 1.2, the melting time of the melting section is 19s, which is less than 20s; when the ratio of the length of the first melting section to the length of the second melting section is less than 1 or greater than 2, the melting time of the melting section is greater than or equal to 25s and less than 30s.

[0096] The length of the first melting section is L1, and the length of the second melting section is L2. When L1 and L2 satisfy the relationship: 1≤L1 / L2≤2, the melting time is shorter, and the safety standard can be met.

[0097] In Embodiment 2 and Embodiments 6-9, the length of the fusing area is 23.5 mm, the length of the first diagonal line of the fusing opening is 11.5 mm, the length of the first fusing section is 6.55 mm, the length of the second fusing section is 5.45 mm, the fusing time of the fusing section gradually decreases when the length of the second diagonal line ranges from 4 mm to 11 mm, the fusing time of the fusing section is less than 25 s when the length of the second diagonal line ranges from 4 mm to 11 mm, the fusing time of the fusing section is the same when the length of the second diagonal line is 12 mm as when the length of the second diagonal line is 11 mm, and the welding between the welding area of the pole and the pole is affected when the length of the second diagonal line is 12 mm, resulting in poor welding reliability.

[0098] Therefore, when the length of the second diagonal line is W, the fusing time is shorter when the value of W ranges from 4 mm to 11 mm, and the safety use standard can be achieved.

[0099] In Embodiment 2 and Embodiments 10-13, the length of the fusing area is 23.5 mm, the length of the second diagonal line of the fusing opening is 11 mm, and the ratio of the length of the first fusing section to the length of the second fusing section is 1.2.

[0100] In Embodiment 2, the ratio of the length H of the first diagonal line to the length H1 of the fusing area is 0.49, and the fusing time of the fusing section is 19 s, which is less than 20 s.

[0101] In Embodiment 10, the ratio of the length H of the first diagonal line to the length H1 of the fusing area is 0.3, the fusing time of the fusing section is 38 s, the fusing time is greater than 35 s, and the fusing time is longer.

[0102] In Embodiment 11, the ratio of the length H of the first diagonal line to the length H1 of the fusing area is 0.33, the fusing time of the fusing section is 33 s, and the fusing time is less than 35 s, which can achieve the safety use standard.

[0103] In Embodiment 12, the ratio of the length H of the first diagonal line to the length H1 of the fusing area is 0.60, and the fusing time of the fusing section is 13 s, which is less than 20 s.

[0104] In Embodiment 13, the ratio of the length H of the first diagonal line to the length H1 of the fusing area is 0.65, the fusing time of the fusing section is 11 s, although the fusing time is much less than 35 s, but the length of the first diagonal line is too large, resulting in a too short fusing section, which can cause the temperature of the single battery to rise when the current is normal, thereby affecting the service life of the battery, and even the fusing phenomenon occurs when the current is normal, which affects the normal work of the single battery.

[0105] Therefore, the length of the first diagonal is H, the length of the melting area is H1, when H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5, the overcurrent capacity of the melting port is relatively good, the melting time is relatively short, and the safety use standard can be reached.

[0106] The overcurrent area of the power-off protection connecting piece of the experimental example 2 is the same as that of the comparative example 1 and the comparative example 2, the melting time of the melting section of the comparative example 1 and the comparative example 2 is greater than 25s.

[0107] Therefore, the length of the first diagonal is H, the length of the melting area is H1, when H and H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5, the overcurrent capacity of the melting port is relatively good, the melting time is relatively short, and the safety use standard can be reached.

[0108] The length of the first melting section is L1, the length of the second melting section is L2, when L1 and L2 satisfy the relationship: 1≤L1 / L2≤2,

[0109] The length of the second diagonal is W, when the value range of W is 4-11mm;

[0110] The length of the first diagonal is H, and the length of the melting area is H1, when H and H1 satisfy the relationship: 1 / 3H1≤H≤3 / 5H1;

[0111] The melting time of the power-off protection connecting piece of the present application is less than 30s when the current is 3200A, and the safety use standard can be reached, because the overcurrent capacity of the melting area of the power-off protection connecting piece of the present application is relatively good when overcurrent occurs (such as short circuit), the heat generated during overcurrent is collected for a short time, so the melting speed is relatively fast, and then the internal fire of the single battery can be avoided, in the case of multiple single batteries, the fire spreading to other single batteries can be avoided, and serious loss can be avoided; when any of the above conditions is not satisfied, the melting time will be too long.

[0112] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A disconnect protection tab, characterized by: The tab connecting part and the pole connecting part are connected, and a fuse area is formed at the connecting joint of the tab connecting part and the pole connecting part, the fuse area comprises a first fuse section, a fuse port and a second fuse section, the fuse port is in a rhombus shape, the fuse port comprises a first diagonal line and a second diagonal line, the length direction of the first diagonal line is consistent with the extension direction of the fuse area, the first fuse section extends from one end of the first diagonal line to one end edge of the fuse area, the second fuse section extends from the other end of the first diagonal line to the other end edge of the fuse area, the length of the first diagonal line is H, the length of the fuse area is H1, the H and the H1 satisfy the relationship: 1 / 3≤H / H1≤3 / 5, the pole welding area is arranged on the pole connecting part, the first fuse section is located on the side of the fuse port away from the pole welding area, the second fuse section is located on the side of the fuse port close to the pole welding area, the length of the first fuse section is L1, the length of the second fuse section is L2, the L1 and the L2 satisfy the relationship: 1≤L1 / L2≤2.

2. The de-energized protective tab of claim 1, wherein: The shape of the fuse port is a square.

3. The de-energized protective tab of claim 1, wherein: The length of the second diagonal line is W, and the value range of W is 4-11mm.

4. The de-energized protective tab of claim 1, wherein: The tab connecting part comprises a first tab connecting part and a second tab connecting part, and the fuse area comprises a first fuse area and a second fuse area, the first fuse area is located between the pole connecting part and the first tab connecting part, and the second fuse area is located between the pole connecting part and the second tab connecting part.

5. The de-energization protection tab of claim 4, wherein: The power-off protection connecting sheet has a first plane parallel to the thickness direction of the power-off protection connecting sheet, the first tab connecting part and the second tab connecting part are located on both sides of the first plane, the pole connecting part is symmetrically arranged relative to the first plane, and the first fuse area and the second fuse area are symmetrically arranged relative to the first plane.

6. The de-energizing protection tab of claim 1, wherein: The two top corners on the first diagonal line of the fuse port are provided as cut corners or rounded corners, and the two top corners on the second diagonal line of the fuse port are provided as cut corners or rounded corners.

7. A single battery, comprising a shell, an electrode assembly and a cover plate assembly; the electrode assembly is arranged in an inner cavity formed by the shell and the cover plate assembly; the electrode assembly is provided with a positive electrode tab, and the cover plate assembly is provided with a positive electrode post, characterized in that: The power-off protection connecting sheet of any one of claims 1-6 is further included, the tab connecting part of the power-off protection connecting sheet is connected with the positive tab, the pole connecting part of the power-off protection connecting sheet is connected with the positive pole, and the positive tab and the positive pole are located on both sides of the power-off protection connecting sheet respectively.

8. A single cell according to claim 7, wherein: The electric core assembly comprises a plurality of electric cores, and the positive tabs of the plurality of electric cores are connected with the tab connecting part.

9. A battery module, characterized by: The single battery of claim 7 or 8 is further included.

Images