Connecting piece and battery

Abstract

The present invention relates to the field of battery technology, and discloses a connecting piece and a battery, wherein the connecting piece comprises: a connecting piece body, one side of which is electrically connected to a pole group; a connecting portion, which is formed by extending a part of the structure of the connecting piece body to a side away from the pole group, and the connecting portion is electrically connected to a pole column; a convex rib, which is constructed on the connecting piece body and protrudes from the upper surface of the connecting piece body, the convex rib surrounds the connecting portion, the strength of the convex rib is less than the strength of the connecting piece body, and the convex rib is suitable for breaking when the gas pressure in the battery reaches a preset value, so that the pole column and the pole group are disconnected electrically; the thickness of the connecting piece body is H1, and the thickness of the convex rib is H2, wherein 0.1≤H2 / H1≤0.8. The convex rib of the present invention breaks in time when the gas pressure in the battery reaches a preset value, and an exhaust channel is formed on the connecting piece body, and the connecting portion and the pole column are ejected as a whole, which solves the problem of gas flow obstruction inside the battery and the inability to cut off the circuit in time.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a connecting sheet and a battery. Background Art

[0002] As battery technology matures, power batteries are widely used in electric vehicles, and the requirements for the performance and safety of power batteries are increasing. Power batteries have risks such as thermal runaway. When an abnormal situation such as a short circuit occurs inside the battery, the gas pressure inside the battery increases. 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, in the prior art, an explosion-proof valve is set on the shell to discharge 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 set on the surface of the shell, and components such as the connecting piece set between the electrode group and the shell inside the battery will cause certain obstruction to the flow of gas, affecting the smoothness of exhaust. In addition, when thermal runaway occurs, the battery is usually connected to the circuit. If the connection with the circuit cannot be disconnected in time, it may cause short-circuit damage to the entire circuit, further increasing the loss. Summary of the invention

[0004] In view of this, the present invention provides a connecting piece and a battery to solve the problem that the gas flow inside the battery is blocked and the circuit cannot be cut off in time when the explosion-proof valve needs to be opened.

[0005] In the first aspect, the present invention provides a connecting piece, comprising: a connecting piece body, one side of which is electrically connected to a pole group; a connecting portion, which is formed by extending a part of the structure of the connecting piece body to a side away from the pole group, and the connecting portion is electrically connected to a pole; a convex rib, which is constructed on the connecting piece body and protrudes from the upper surface of the connecting piece body, the convex rib surrounds the connecting portion, the strength of the convex rib is less than the strength of the connecting piece body, and the convex rib is suitable for breaking when the air pressure in the battery reaches a preset value to disconnect the pole group from the pole; the thickness of the connecting piece body is H1, and the thickness of the convex rib is H2, wherein 0.1≤H2 / H1≤0.8.

[0006] By constructing a convex rib protruding from the upper surface of the connecting piece body on the connecting piece body, and the strength of the convex rib is smaller than that of the connecting piece body, when the gas pressure in the battery reaches a certain value, the weaker convex rib breaks first, and the connecting part surrounded by the convex rib falls off from the connecting piece body. After the solid part falls off, an exhaust channel is formed on the connecting piece body. The exhaust channel conducts the high-temperature flue gas in the pole group area on one side of the connecting piece to the other side of the connecting piece, thereby increasing the ventilation area of ​​the connecting piece and avoiding the connecting piece from obstructing the gas flow. Moreover, since the connecting part is connected to the pole, the exhaust channel formed after the convex rib breaks faces the pole. Therefore, under the action of the gas pressure in the battery, the connecting part and the pole connected to the connecting part can be integrated under the action of the gas pressure. The body pops open and detaches from the battery, thereby improving the unobstructed exhaust of the battery to the outside and preventing the battery from exploding. After the pole detaches from the battery, the connection between the battery and the external circuit can be cut off in time, thereby avoiding short-circuit damage to the entire circuit and improving safety. At the same time, by setting the ratio of the thickness of the convex rib to the thickness of the connecting piece body to 0.1-0.8, the thickness of the convex rib is less than the thickness of the connecting piece body, so that the setting requirement that the strength of the convex rib is less than the strength of the connecting piece body can be achieved. The value range of 0.1-0.8 can prevent the convex rib from breaking prematurely when the air pressure in the battery does not reach the preset value, and can ensure that the convex rib breaks in time when the air pressure in the battery reaches the preset value. Moreover, the convex rib has a simple structure and is easy to process.

[0007] In an optional implementation, the distance that the convex rib is higher than the upper surface of the connecting piece body is H3, wherein 1.2≤H3 / H1≤5. This facilitates the processing and forming of the convex rib and maintains sufficient strength.

[0008] In an optional embodiment, the convex rib is in the form of a circular ring, and the outer diameter of the circular ring is in the range of 12 mm to 20 mm. The flow capacity between the connecting piece and the pole and the pole group can be balanced, ensuring both the flow capacity between the connecting piece and the pole and the flow capacity between the connecting piece and the pole group, thereby maximizing the performance of the battery.

[0009] In an optional embodiment, the convex rib is integrally formed with the connecting piece body. The convex rib and the connecting piece body are integrally stamped, and the molding process is simple, the preparation process is easy to control, the structure is stable, and the cost is low.

[0010] In an optional embodiment, the edge of the connecting piece body is provided with a plurality of reinforcing ribs at intervals, and the reinforcing ribs protrude from the surface of the connecting piece body, which can not only strengthen the strength of the connecting piece, but also be used to engage with the structure above the connecting piece to prevent the connecting piece from rotating, and have a good limiting effect.

[0011] In a second aspect, the present invention further provides a battery, comprising: a shell; a pole group, placed in the shell; a pole assembly, installed at one end of the shell, the pole assembly is insulated and connected to the shell, and an explosion-proof fracture position is constructed on the shell around the pole assembly; the above-mentioned connecting piece, the connecting piece is arranged between the pole in the pole assembly and the pole group, one side of the connecting piece is electrically connected to the pole group and the other side is electrically connected to the pole. By setting one side of the connecting piece to be electrically connected to the pole group and the other side to be electrically connected to the pole, the pole and the pole group can be electrically connected through the connecting piece. When the convex rib on the connecting piece breaks when the air pressure in the battery reaches a preset value, the gas acts on the pole through the exhaust channel formed on the connecting piece, so that the pole is easily lifted up by the airflow, and the explosion-proof fracture position surrounding the pole on the shell can be disconnected when the air pressure in the battery reaches a preset value, ensuring that the area surrounded by the explosion-proof fracture position can be bounced open as a whole, that is, ensuring that the pole assembly is completely separated from the battery, thereby increasing the exhaust area and ensuring that the battery and the external circuit are disconnected, so as to prevent the problem of battery explosion caused by the spread of thermal runaway and improve safety performance.

[0012] In an optional embodiment, the distance between the upper surface of the convex rib and the inner surface of the upper end of the shell is L, where L>1.2mm; and / or, a protrusion protruding from the upper surface of the shell is constructed around the pole on the shell, and the explosion-proof fracture position is set on the protrusion. By setting the distance between the upper surface of the convex rib and the inner surface of the upper end of the shell to be greater than the minimum creepage distance, the insulation between the connecting piece and the shell can be effectively guaranteed, and the safety of the battery can be further guaranteed; the protrusion protrudes from the upper surface of the shell, providing a limit for the pole, ensuring the stability of the assembly, and the explosion-proof fracture position is not on the same surface as the upper surface of the shell. If an injection hole is provided on the upper surface of the shell, it can be ensured that the explosion-proof fracture position and the injection hole are separated, avoiding contamination of the explosion-proof fracture position during injection and causing breakdown and leakage, and ensuring that the explosion-proof valve can be opened in time, thereby ensuring the safety of the battery.

[0013] In an optional embodiment, the battery further comprises: a support member, the support member is arranged between the shell and the connecting piece, one side of the support member is in contact with the connecting piece and the other side is in contact with the shell, the support member is provided with a plurality of exhaust holes, and the plurality of exhaust holes correspond to the explosion-proof rupture position; a clearance hole is constructed at a position corresponding to the pole assembly on the support member, and the clearance hole passes through the connecting portion and the pole assembly. The support member plays a supporting role of connecting the upper and lower parts, the upper end of the support member contacts the inner surface of the shell through the upper support surface, and the lower end of the support member contacts the pole group, so that the pole group and the shell are more integrated, and at the same time, the upper end surface of the pole group and the upper end surface of the shell can be ensured to be parallel; the support member is an insulating member, which can not only play the role of supporting the connecting piece and the shell, but also ensure the insulation between the connecting piece and the shell; the support member is provided with exhaust holes corresponding to the explosion-proof rupture position, so that when the battery has problems such as thermal runaway, the internal pressure of the battery can be quickly transmitted to the position corresponding to the explosion-proof rupture position through the exhaust holes, so as to quickly open the explosion-proof valve to release pressure and improve the safety of the battery.

[0014] In an optional embodiment, the convex rib on the connecting piece extends into between the support and the pole assembly, and there is a first gap between the convex rib and the support, and there is a second gap between the convex rib and the pole assembly, wherein the size of the first gap and the second gap are both greater than 0.3 mm. This avoids interference between the convex rib and the support or the pole assembly during the installation of the connecting piece, facilitates the installation of the connecting piece, and avoids the support and the pole assembly from squeezing the convex rib due to too small a gap, thereby avoiding damage to the convex rib due to squeezing, and ensuring that the convex rib can be opened when the air pressure in the battery reaches a preset value.

[0015] In an optional embodiment, the pole is a positive pole, the positive pole is electrically connected to the positive pole of the pole group through the connecting sheet, the end of the shell away from the positive pole is an open end, and the battery further comprises: a negative pole cover, the negative pole cover is arranged at the open end of the shell to close the shell, the negative pole cover is electrically connected to the negative pole of the pole group, and an injection hole is arranged on the negative pole cover. By arranging the injection hole on the negative pole cover away from one end of the positive pole, it is ensured that the injection hole is separated from the positive pole, that is, the injection hole and the explosion-proof rupture position are far away from each other, effectively ensuring that the electrolyte will not splash to the explosion-proof rupture position when injecting liquid into the battery through the injection hole, ensuring that the explosion-proof rupture position is not contaminated, thereby ensuring the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a connecting piece according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A top view of the connecting piece shown;

[0019] Figure 3 for Figure 2 Sectional view in the AA direction;

[0020] Figure 4 for Figure 3 A is a partial enlarged schematic diagram;

[0021] Figure 5 A schematic diagram of the structure of a battery according to an embodiment of the present invention;

[0022] Figure 6 for Figure 5 A top view of the battery shown;

[0023] Figure 7 for Figure 6 Cross-sectional view in the BB direction;

[0024] Figure 8 for Figure 7 A partial enlarged schematic diagram of B in the middle;

[0025] Fig. 9 for Figure 7 A partial enlarged schematic diagram of C in the middle;

[0026] Fig.10 It is a schematic structural diagram of a housing according to an embodiment of the present invention;

[0027] Fig.11 for Fig.10 a top view of the housing;

[0028] Fig.12 for Fig.11 Cross-sectional view in CC direction;

[0029] Fig.13 for Fig.12 A partial enlarged schematic diagram of D in the middle;

[0030] Fig.14 It is a structural schematic diagram of a support member according to an embodiment of the present invention;

[0031] Fig.15 for Fig.14 A structural schematic diagram of the support member shown in another perspective;

[0032] Fig.16 for Fig.14 a top view of the support member shown;

[0033] Fig.17 for Fig.16 Cross-sectional view in the middle DD direction;

[0034] Fig.18 A schematic structural diagram of a negative electrode cover plate according to an embodiment of the present invention;

[0035] Fig.19 for Fig.18 A cross-sectional view of the negative electrode cover is shown.

[0036] Description of reference numerals:

[0037] 1. Shell; 101. Explosion-proof fracture position; 102. Raised part; 103. Mounting hole; 2. Pole group; 3. Connecting piece; 301. Connecting piece body; 302. Connecting part; 303. Convex rib; 305. Reinforcing rib; 4. Support member; 401. Exhaust hole; 402. Support member body; 403. Make way hole; 404. First supporting rib; 405. Second supporting rib; 4051. First positioning groove; 406. Third supporting rib; 4061. Second positioning groove; 407. Fourth supporting rib; 5. Pole; 6. Negative electrode cover; 601. Liquid injection hole; 602. Pole group welding area; 603. Concave area; 604. Liquid injection area; 605. Welding part; 7. Sealing cover; 8. Insulating seal. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0039] Combine the following Figures 1 to 19 , describing an embodiment of the present invention.

[0040] According to an embodiment of the present invention, on the one hand, Figures 1 to 4 As shown, a connecting piece is provided, which mainly includes: a connecting piece body 301, a connecting portion 302 and a convex rib 303.

[0041] Specifically, one side of the connecting piece body 301 is electrically connected to the pole group 2; the connecting portion 302 is formed by extending a part of the structure of the connecting piece body 301 to a side away from the pole group 2, and the connecting portion 302 is electrically connected to the pole 5; the convex rib 303 is constructed on the connecting piece body 301 and protrudes from the upper surface of the connecting piece body 301, the convex rib 303 surrounds the connecting portion 302, and the strength of the convex rib 303 is less than the strength of the connecting piece body 301. The convex rib 303 is suitable for breaking when the air pressure in the battery reaches a preset value, so as to disconnect the pole group from the pole 5; the thickness of the connecting piece body 301 is H1, and the thickness of the convex rib 303 is H2, wherein 0.1≤H2 / H1≤0.8. The thickness refers to the thickness along Figure 3 The arrow in the middle points to the dimension in the "up and down" direction.

[0042] In this embodiment, a convex rib 303 protruding from the upper surface of the connecting piece body 301 is constructed on the connecting piece body 301, and the strength of the convex rib 303 is less than that of the connecting piece body 301. When the gas pressure in the battery reaches a certain value, the weaker convex rib 303 breaks first, and the connecting portion 302 surrounded by the convex rib 303 falls off from the connecting piece body 301. After the solid part falls off, an exhaust channel is formed on the connecting piece body 301. The exhaust channel conducts the high-temperature flue gas in the electrode group 2 area on one side of the connecting piece 3 to the other side of the connecting piece, thereby increasing the ventilation area of ​​the connecting piece 3 and preventing the connecting piece 3 from obstructing the gas flow. In addition, since the connecting portion 302 is connected to the pole 5, the exhaust channel formed after the convex rib 303 breaks is opposite to the pole 5. Under the action of the gas pressure in the battery, the connecting portion 302 and the pole 5 connected to the connecting portion 302 can be in the gas. Under the action of the body pressure, the convex rib 303 bounces open as a whole and detaches from the battery, thereby improving the smoothness of the battery's exhaust to the outside and preventing the battery from exploding. After the pole 5 detaches from the battery, the pole group is electrically disconnected from the pole 5, and the connection between the battery and the external circuit can be cut off in time, thereby avoiding short-circuit damage to the entire circuit and improving safety. At the same time, by setting the ratio of the thickness of the convex rib 303 to the thickness of the connecting piece body 301 to be in the range of 0.1-0.8, the thickness of the convex rib 303 is less than the thickness of the connecting piece body 301, and the setting requirement that the strength of the convex rib 303 is less than the strength of the connecting piece body 301 can be achieved. The value range of 0.1-0.8 can prevent the convex rib 303 from breaking prematurely when the air pressure in the battery does not reach the preset value, and can ensure that the convex rib 303 breaks in time when the air pressure in the battery reaches the preset value. Moreover, the convex rib 303 has a simple structure and is easy to process.

[0043] It should be noted that the convex rib 303 and the connecting piece body 301 are made of the same material. By setting the thickness H2 of the convex rib 303 to be smaller than the thickness H1 of the connecting piece body 301, it can be ensured that the strength of the convex rib 303 is smaller than the strength of the connecting piece body 301. Furthermore, if the ratio of the thickness H2 of the convex rib 303 to the thickness H1 of the connecting piece body 301 is less than 0.1, the thickness of the convex rib 303 is too small, the manufacturing difficulty is large, the cost is high, the overall structural stability of the connecting piece 3 is poor, the convex rib 303 does not have sufficient strength, and the convex rib 303 will break prematurely before the air pressure in the battery reaches the preset value that requires opening the explosion-proof valve, causing unnecessary losses. If the thickness H2 of the convex rib 303 is If the ratio of the thickness H1 of the convex rib 303 to the thickness of the connecting piece body 301 is greater than 0.8, the thickness of the convex rib 303 is too large, and correspondingly, the strength of the convex rib 303 is too large. When the air pressure in the battery reaches the preset value that requires opening the explosion-proof valve, the convex rib 303 cannot break in time, affecting the exhaust effect, causing the gas inside the battery to not be discharged in time, and then causing dangerous accidents such as battery explosion. Therefore, when the ratio of the thickness of the convex rib 303 to the thickness of the connecting piece body 301 is set within the range of 0.1-0.8, it can not only avoid the convex rib 303 from breaking prematurely when the air pressure in the battery does not reach the preset value, but also ensure that the convex rib 303 breaks in time when the air pressure in the battery reaches the preset value, thereby ensuring the exhaust effect.

[0044] It should be noted that the preset value is a predetermined air pressure value to prevent the battery from exploding, specifically 1.8±0.3Mpa, that is, when the air pressure inside the battery reaches the preset value, the convex rib 303 breaks, the explosion-proof valve on the shell 1 opens, and the battery exhausts to the outside; the connecting piece 3 is a component in the battery, located between the pole group 2 and the shell 1, and the poles 5 on the pole group 2 and the shell 1 are respectively located on the upper and lower sides of the connecting piece 3. The connecting piece 3 is made of metal, preferably aluminum, to achieve electrical connection between the pole 5 and the pole group 2; the convex rib 303 surrounds the connecting portion 302, and the connecting portion 302 is electrically connected to the pole 5. Therefore, when the convex rib 303 breaks, the gas ejected through the exhaust channel formed after the break directly acts on the pole 5, and the force is relatively large, which facilitates the ejection of the pole 5 out of the battery. Among them, the upper part refers to Figure 7 The arrow in the middle points to the direction of "up", and the arrow in the middle points to the direction of "down". Figure 7 The arrow in the middle points to the “down” direction.

[0045] Preferably, the convex rib 303 is annular, and the annular continuity is good. When the gas pressure in the battery reaches a preset value, it can ensure that the circle surrounding the connecting portion 302 is broken as a whole, so as to facilitate exhaust, and the processing is convenient and the structure is stable. It can be understood that as an alternative embodiment, the convex rib 303 can also be set as a surrounding structure composed of multiple continuous convex parts, which can also ensure that the circle surrounding the connecting portion 302 is broken as a whole, so as to ensure the timeliness of exhaust.

[0046] Preferably, the connecting portion 302 is welded to the pole 5 , and the connecting piece body 301 is welded to the pole group 2 . The welding method is stable and reliable and can ensure electrical connection.

[0047] In one embodiment, the convex rib 303 is integrally formed with the connecting piece body 301. The convex rib 303 and the connecting piece body 301 are integrally stamped and formed, and the forming process is simple, the preparation process is easy to control, the structural stability is good, and the cost is low. Specifically, the cross-section of the convex rib 303 and the connecting piece body 301 connected thereto is roughly in the shape of a "J".

[0048] In one embodiment, the distance between the convex rib 303 and the upper surface of the connecting piece body 301 is H3, wherein 1.2≤H3 / H1≤5. Figure 3 , Figure 4 As shown, the dimension H3 of the convex rib 303 that is higher than the upper surface of the connecting piece body 301 is 1.2-5 times the thickness H1 of the connecting piece body 301. If H3 is less than 1.2 times H1, the height of the convex rib 303 is too small, the product is not easy to form, and there is a rebound phenomenon after forming, and the size is unstable; if H3 is greater than 5 times H1, the height of the convex rib 303 is too large, occupying more space between the electrode group 2 and the shell 1, and the volume utilization rate is reduced, which is not conducive to reducing the overall volume of the battery. Therefore, the ratio of the distance H3 of the convex rib 303 above the upper surface of the connecting piece body 301 to the thickness H1 of the connecting piece body 301 is set between 1.2-5, which is convenient for the processing and forming of the convex rib 303 and maintains sufficient strength. Preferably, the dimension H3 of the convex rib 303 that is higher than the upper surface of the connecting piece body 301 is 2.8 times the thickness H1 of the connecting piece body 301. Among them, the upper surface refers to Figure 3 The surface in the "up" direction indicated by the arrow.

[0049] In one embodiment, the convex rib 303 surrounds the connecting portion 302 in a circular ring, and the outer diameter of the circular ring ranges from 12 mm to 20 mm. The connecting portion 302 surrounded by the convex rib 303 is used to be electrically connected to the pole 5 to achieve electrical connection between the pole 5 and the connecting piece 3. If the outer diameter of the ring is less than 12 mm, the outer diameter of the ring is too small, which will make the size of the connecting portion 302 too small, thereby affecting the connection area between the pole 5 and the connecting piece, resulting in insufficient current flow capacity between the pole 5 and the connecting piece 3, affecting the battery performance; the portion of the connecting piece 3 located outside the ring is used to be electrically connected to the pole group 2. If the outer diameter of the ring is greater than 20 mm, the outer diameter of the ring is too large, then the area of ​​the connecting piece 3 connected to the pole group 2 is too small, resulting in insufficient current flow capacity between the pole group 2 and the connecting piece 3, affecting the battery performance. Therefore, setting the outer diameter of the ring between 12 mm and 20 mm can balance the current flow capacity between the connecting piece 3 and the pole 5 and the pole group 2, respectively, which can ensure the current flow capacity between the connecting piece 3 and the pole 5, and the current flow capacity between the connecting piece 3 and the pole group 2, thereby maximizing the performance of the battery. Preferably, the outer diameter of the ring is 14 mm.

[0050] In addition, in other embodiments, the convex rib 303 may also be an elliptical ring, a polygonal ring, etc.

[0051] In one embodiment, a plurality of reinforcing ribs 305 are arranged at intervals on the edge of the connecting piece body 301. The reinforcing ribs 305 protrude from the surface of the connecting piece body 301, which can not only strengthen the strength of the connecting piece 3, but also be used to engage with the structure above the connecting piece 3 to prevent the connecting piece 3 from rotating, and have a good limiting effect. Figure 3 The direction of the "upward" indicated by the middle arrow protrudes from the upper surface of the connecting piece body 301, which is the same as the protruding direction of the connecting portion 302. The upward protruding dimension of the reinforcing rib 305 is smaller than the upward protruding dimension of the connecting portion 302, so as to reduce the portion of the connecting piece 3 other than the connecting portion 302 along the Figure 3 The size in the "up and down" direction indicated by the middle arrow is reduced, thereby compressing the battery height and improving the battery energy density. Preferably, the number of reinforcing ribs 305 is three, and the three reinforcing ribs 305 are arranged around the edge of the connecting piece body 301 at equal intervals.

[0052] According to an embodiment of the present invention, on the other hand, Figures 5 to 19 As shown, a battery is also provided, comprising: a housing 1, an electrode group 2, a pole assembly and the above-mentioned connecting piece 3.

[0053] Specifically, the pole group 2 is placed in the shell 1; the pole assembly is installed at one end of the shell 1, the pole assembly is insulated and connected to the shell 1, and an explosion-proof rupture position 101 is constructed around the pole assembly on the shell 1; the connecting piece 3 is arranged between the pole 5 in the pole assembly and the pole group 2, one side of the connecting piece 3 is electrically connected to the pole group 2 and the other side is electrically connected to the pole 5.

[0054] In this embodiment, one side of the connecting piece 3 is electrically connected to the pole group 2 and the other side is electrically connected to the pole 5, so that the pole 5 is electrically connected to the pole group 2 through the connecting piece 3. When the convex rib 303 on the connecting piece 3 breaks when the air pressure in the battery reaches a preset value, the gas acts on the pole 5 through the exhaust channel formed on the connecting piece 3, so that the pole 5 is easily lifted up by the airflow, and the explosion-proof fracture position 101 constructed around the pole 5 on the shell 1 can be disconnected when the air pressure in the battery reaches a preset value, ensuring that the area surrounded by the explosion-proof fracture position 101 can be bounced open as a whole, that is, ensuring that the pole assembly is completely separated from the battery, thereby increasing the exhaust area and ensuring that the battery and the external circuit are disconnected, so as to prevent the problem of battery explosion caused by the spread of thermal runaway and improve safety performance.

[0055] It should be noted that the explosion-proof rupture position 101 constitutes an explosion-proof valve, and the strength of the explosion-proof rupture position 101 is less than the strength of other areas on the shell 1. When the gas pressure in the battery reaches a preset value, the explosion-proof rupture position 101 breaks, and the explosion-proof valve opens to discharge the gas inside the battery to prevent the battery from exploding due to excessive internal gas pressure; one side of the connecting piece 3 refers to the side along the Figure 7 The side of the "downward" direction indicated by the middle arrow, and the other side of the connecting piece 3 refers to the side along Figure 7 The side in the direction indicated by the arrow.

[0056] Preferably, the pole 5 is mounted on the upper end of the housing 1, wherein the upper end refers to the Figure 7 The end in the direction indicated by the arrow.

[0057] Preferably, the explosion-proof rupture position 101 is a circle surrounding the pole 5, which has a large exhaust area and is easy to process. It can be understood that as an alternative embodiment, the explosion-proof rupture position 101 can also be an ellipse, a racetrack, or other shapes.

[0058] Specifically, further combining Figure 6 As shown, a recessed portion is constructed on one side of the pole 5 facing the inside of the shell 1, and the shape of the recessed portion is the same as the outer shape of the connecting portion 302, and the size of the recessed portion is slightly larger than the connecting portion 302, so that the connecting portion 302 can be inserted into the recessed portion. After the connecting portion 302 is assembled with the recessed portion, the connecting portion 302 is fixedly connected to the pole 5 by laser penetration welding from the top of the pole 5.

[0059] Specifically, the pole assembly includes a pole 5 and an insulating seal 8, the insulating seal 8 is wrapped around the pole 5, and the insulating seal 8 is arranged between the pole 5 and the housing 1. The housing 1 is provided with a mounting hole 103, and the pole 5 is wrapped by the insulating seal 8 and clamped in the mounting hole 103, so that the pole 5 is insulated and sealed to the housing 1. The insulating seal 8 can not only realize the insulating connection between the pole 5 and the housing 1, but also improve the sealing of the battery. Moreover, the insulating seal 8 combines sealing and insulation in one structural part, which is different from the current separate functions of sealing and insulation. It not only improves the sealing and insulation performance, but also greatly saves the battery cost and improves the competitiveness of the product.

[0060] In one embodiment, a protrusion 102 protruding from the upper surface of the shell 1 is constructed around the pole 5 on the shell 1, and the explosion-proof rupture position 101 is arranged on the protrusion 102. The protrusion 102 protrudes from the upper surface of the shell 1, providing a limit for the insulating seal 8 to ensure the stability of the assembly, and the explosion-proof rupture position 101 is not on the same surface as the upper surface of the shell 1. If a liquid injection hole is provided on the upper surface of the shell 1, the explosion-proof rupture position 101 and the liquid injection hole can be separated to avoid contamination of the explosion-proof rupture position 101 during liquid injection, resulting in breakdown and leakage, and ensuring that the explosion-proof valve can be opened in time, thereby ensuring the safety of the battery. Among them, the upper surface refers to the area along the Figure 6 , Fig.11 The surface in the "up" direction indicated by the arrow.

[0061] In one embodiment, further combining Figure 7 , Figure 8 As shown, the distance between the upper surface of the convex rib 303 and the inner surface of the upper end of the shell 1 is L, where L>1.2mm. A certain distance is left between the convex rib 303 and the inner surface of the shell 1 to avoid direct contact between the connecting piece 3 and the shell 1. 1.2mm is the minimum creepage distance between components. By setting the distance L between the upper surface of the convex rib 303 and the inner surface of the upper end of the shell 1 to be greater than the minimum creepage distance, the insulation between the connecting piece 3 and the shell 1 can be effectively guaranteed, further ensuring the safety of the battery. The upper surface refers to the distance along the Figure 7 The arrow in the middle points to the surface in the direction of "up"; the upper end refers to the surface along the Figure 7 The inner surface at the end in the “upper” direction indicated by the middle arrow refers to the surface facing the inner side of the housing 1 .

[0062] In one embodiment, the battery further includes: a support member 4, the support member 4 is arranged between the shell 1 and the connecting plate 3, one side of the support member 4 abuts against the connecting plate 3 and the other side abuts against the shell 1, and a plurality of exhaust holes 401 are arranged on the support member 4, and the plurality of exhaust holes 401 correspond to the explosion-proof fracture positions 101; a clearance hole 403 is constructed at a position on the support member 4 corresponding to the pole assembly, and the clearance hole 403 passes through the connecting portion 302 and the pole assembly. The support member 4 plays a supporting role of connecting the upper and lower parts. The upper end of the support member 4 contacts the inner surface of the shell 1 through the upper supporting surface, and the lower end of the support member 4 contacts the pole group 2, so that the pole group 2 and the shell 1 are more integrated, and at the same time, the upper end surface of the pole group 2 and the upper end surface of the shell 1 can be ensured to be parallel; the support member 4 is an insulating member, which can not only play the role of supporting the connecting piece 3 and the shell 1, but also ensure the insulation between the connecting piece 3 and the shell 1; the support member 4 is provided with an exhaust hole 401 corresponding to the explosion-proof fracture position 101 to ensure that when the battery has problems such as thermal runaway, the internal pressure of the battery can be quickly transmitted to the position corresponding to the explosion-proof fracture position 101 through the exhaust hole 401, so as to quickly open the explosion-proof valve to release pressure, thereby improving the safety of the battery, wherein the upper end refers to the exhaust hole 401 along the explosion-proof fracture position 101. Figure 7 , Fig.17 The arrow in the middle points to the "up" end, and the lower end refers to the Figure 7 , Fig.17 It should be noted that the shape of the support member 4 is adapted to the cross-sectional shape of the housing 1. Specifically, when the battery is a cylindrical battery, the cross-sectional shape of the housing 1 is circular, and correspondingly, the support member 4 is circular; the support member 4 can be made of insulating materials such as fluororubber, PFA, TPU and TPV.

[0063] In one embodiment, the convex rib 303 extends between the support member 4 and the pole assembly, and there is a first gap between the convex rib 303 and the support member 4, and there is a second gap between the convex rib 303 and the pole assembly, wherein the size of the first gap and the second gap are both greater than 0.3 mm. Specifically, the pole assembly is located in the clearance hole 403 of the support member 4, and the convex rib 303 is located between the inner wall of the clearance hole 403 and the pole assembly. An assembly gap greater than 0.3 mm is reserved between the convex rib 303 and the support member 4 and between the convex rib 303 and the pole assembly, so as to avoid interference between the convex rib 303 and the support member 4 or the pole assembly during the installation of the connecting piece 3, facilitate the installation of the connecting piece 3, and avoid the support member 4 and the pole assembly from squeezing the convex rib 303 due to too small a gap, thereby avoiding damage to the convex rib 303 due to squeezing, and ensuring that the convex rib 303 can be opened when the air pressure in the battery reaches a preset value. The inner wall of the clearance hole 403 refers to the side wall of the clearance hole 403 facing the pole assembly.

[0064] In one embodiment, the total area of ​​the plurality of vents 401 is S3, the explosion-proof fracture position 101 is an explosion-proof notch, and the area of ​​the explosion-proof notch is S4, wherein S3>5*S4. The total area of ​​the plurality of vents 401 is the total area on the support member 4 through which gas can pass, and the plurality of vents 401 are directly opposite to the explosion-proof notch. If the total area of ​​the vents 401 is too small, it is difficult to ensure that the explosion-proof notch can be broken in time. By setting the total area of ​​the plurality of vents 401 to be greater than 5 times the area of ​​the explosion-proof notch, it can be ensured that a sufficient amount of gas can pass through the vents 401 to impact the explosion-proof notch, and provide sufficient impact force to the explosion-proof notch, so as to break the explosion-proof notch and improve the safety of the battery. The explosion-proof notch can be obtained by die-cutting; it can be understood that, as an alternative embodiment, the explosion-proof fracture position 101 can also be a thinning area formed by stamping, which can also ensure that the strength of this area is less than the strength of other areas on the shell 1.

[0065] In one embodiment, the support member 4 mainly includes a support member body 402 and a first support rib 404. Specifically, a clearance hole 403 is constructed at a position on the support member body 402 corresponding to the pole 5; the first support rib 404 is formed by extending downward from the edge of the support member body 402, and the first support rib 404 extends into the gap between the side wall of the shell 1 and the pole group 2 to position the pole group 2. The clearance hole 403 opened on the support member body 402 provides a clearance space for the connecting part 302 to achieve the connection between the connecting plate 3 and the pole 5, and the space utilization is reasonable; and there is a certain gap between the pole group 2 and the shell 1, and the first support rib 404 extends between the pole group 2 and the shell 1, which plays a role in positioning and fixing the pole group 2, and can ensure the axial center symmetry of the pole group 2 and the shell 1, thereby improving the overall stability of the battery. Among them, the lower part refers to Figure 7 , Fig.17 The arrow in the middle points to the direction of "down".

[0066] In one embodiment, the support member 4 also includes: at least one internal support rib, which is formed by extending downward from a part of the structure on the lower surface of the support member body 402, and the internal support rib is in contact with the upper surface of the connecting piece 3. It should be noted that the first support rib 404 is formed by extending downward from the edge of the support member body 402, forming a ring or other closed shape consistent with the edge of the support member body 402, and the internal support rib is located on the inner side of the first support rib 404 in the radial direction. The lower end of the support member 4 is in contact with the connecting piece 3 through the internal support rib, which has a good fixing effect and can prevent the connecting piece 3 from moving in the up and down directions inside the battery, thereby increasing the stability of the structure, and the structural form of the support rib can reduce the weight of the support member 4, thereby improving the overall energy density of the battery. Among them, the lower refers to Figure 7 , Fig.17 The middle arrow points to the direction of "down", and the up arrow points to the direction of Figure 7 , Fig.17 The arrow in the middle points to the direction “up”.

[0067] In one embodiment, the lower end face of the first support rib 404 is 0.5mm-1.0mm longer than the lower end face of the internal support rib. The lower end face of the internal support rib abuts against the upper end face of the connecting piece 3, and the lower end face of the first support rib 404 is 0.5mm-1.0mm lower than the upper end face of the connecting piece 3 to ensure that the first support rib 404 can extend into the gap between the pole group 2 and the shell 1. If the difference between the lower end face of the first support rib 404 and the lower end face of the internal support rib is less than 0.5mm, the size is too small and difficult to process, which will increase the manufacturing cost. If the difference between the lower end face of the first support rib 404 and the lower end face of the internal support rib is greater than 1.0mm, the size is too large, which will increase the weight and reduce the precision, and will also affect the space utilization. Therefore, setting the lower end face of the first support rib 404 to be 0.5mm-1.0mm longer than the lower end face of the internal support rib will not affect the difficulty of processing, but also avoid excessive weight and ensure processing accuracy. Preferably, the lower end surface of the first support rib 404 is 0.8 mm longer than the lower end surface of the inner support rib.

[0068] In one embodiment, the thickness of the support member 4 is 1.8±0.03 mm, wherein the thickness of the support member 4 refers to the distance between the upper end surface of the support member 4 and the lower end surface of the first support rib 404. The thickness of the support member 4 needs to be as thin as possible to reduce the distance between the inner surface of the shell 1 and the upper surface of the connecting sheet 3, improve the space utilization, and improve the overall energy density of the battery, but at the same time, the support strength of the support member 4 itself needs to be ensured. By setting the thickness of the support member 4 to 1.8±0.03 mm, the strength of the support member 4 itself can be ensured, and space can be saved and space utilization can be improved.

[0069] In one embodiment, the internal support ribs include: a second support rib 405, a third support rib 406 and a fourth support rib 407. Specifically, the second support rib 405 is arranged on the inner side of the first support rib 404, and a first positioning groove 4051 is configured on the second support rib 405, and the first positioning groove 4051 matches with the reinforcing rib 305 on the connecting piece body 301; the third support rib 406 is arranged on the inner side of the second support rib 405 and is located on the outer side of the exhaust hole 401, and a second positioning groove 4061 is configured on the third support rib 406, and the second positioning groove 4061 corresponds to the first positioning groove 4051 and matches with the reinforcing rib 305; the fourth support rib 407 is arranged on the inner side of the third support rib 406 and is located on the inner side of the exhaust hole 401, and the fourth support rib 407 surrounds the clearance hole 403. Among them, the inner side refers to the direction pointing to the center along the radial direction of the cross section of the battery. The arrangement of multiple support ribs in concentric rings can further increase the strength of the support member 4 and reduce the weight of the support member 4 at the same time. Among them, the second support rib 405, the third support rib 406 and the fourth support rib 407 are in zero-gap contact with the connecting piece 3. When the explosion-proof valve is opened, the internal support ribs press the connecting piece body 301, so that the connecting piece 3 breaks at the position of the convex rib 303, and the connecting part 302 and other parts after the break fly out of the clearance hole 403, so as to bounce open together with the pole 5, so as to ensure that the exhaust channel of the battery is unobstructed; and the first positioning groove 4051 on the second support rib 405 and the second positioning groove 4061 on the third support rib 406 are both matched with the reinforcing rib 305, and the positioning groove is clamped with the reinforcing rib 305 to achieve relative fixation of the support member 4 and the connecting piece 3, with good positioning effect and stable connection, which effectively avoids relative shaking between structural parts, thereby ensuring the stability of the overall structure.

[0070] Specifically, the convex rib 303 is located between the fourth supporting rib 407 and the insulating seal 8 of the pole assembly.

[0071] In one embodiment, the pole 5 is a positive pole, which is electrically connected to the positive pole of the pole group 2 through the connecting piece 3, and the end of the shell 1 away from the positive pole is an open end, and the battery further includes: a negative pole cover plate 6, which is arranged at the open end of the shell 1 to close the shell 1, and the negative pole cover plate 6 is electrically connected to the negative pole of the pole group 2, and a liquid injection hole 601 is arranged on the negative pole cover plate 6. It should be noted that when the pole 5 is a positive pole, the connecting piece 3 is a positive pole connecting piece; the negative pole cover plate 6 is electrically connected to the negative pole of the pole group 2, and the negative pole cover plate 6 is connected to an external circuit or other batteries as the negative pole connection end of the battery. By setting the injection hole 601 on the negative electrode cover plate 6 away from one end of the positive electrode column, the injection hole 601 is ensured to be separated from the positive electrode column, that is, the injection hole 601 and the explosion-proof rupture position 101 are far away from each other, which effectively ensures that the electrolyte will not splash onto the explosion-proof rupture position 101 when the battery is injected through the injection hole 601, and ensures that the explosion-proof rupture position 101 is not contaminated, avoiding the risk of explosion-proof notches being contaminated by electrolyte and causing breakdown and leakage, thereby ensuring the safety of the battery and ensuring that the explosion-proof valve can be opened in time.

[0072] It can be understood that, as an alternative embodiment, the injection hole 601 can also be set at the same end of the shell 1 as the explosion-proof rupture position 101. In this case, the explosion-proof rupture position 101 needs to be protected. For example, the above-mentioned setting of the explosion-proof rupture position 101 on the raised portion 102 protruding from the upper surface of the shell 1 can also prevent the explosion-proof rupture position 101 from being contaminated.

[0073] In one embodiment, the battery is a cylindrical battery, the pole 5 is a positive pole, the connecting piece 3 is a positive connecting piece, the connecting piece 3 is circular, the positive pole is connected to the positive pole of the pole group 2 through the positive connecting piece, and the negative pole cover plate 6 located at one end of the shell 1 away from the positive pole is connected to the negative pole of the pole group 2. In addition, in other embodiments, the battery is not limited to cylindrical batteries, but can also be a square battery, etc. The shape of the connecting piece 3 is adapted to the shape of the battery shell, and the shell 1 is constructed so that only one end with the pole 5 is an open end. The pole 5 can include both the positive pole and the negative pole, and insulation between the positive pole and the negative pole must be ensured. The positive pole is connected to the positive pole of the pole group 2, and the negative pole is connected to the negative pole of the pole group 2. The positive pole and the negative pole can be provided with explosion-proof rupture positions 101 in the circumference to increase the exhaust area.

[0074] In one embodiment, the negative electrode cover plate 6 includes a pole group welding area 602 and a recessed area 603. The pole group welding area 602 is arranged around the recessed area 603. The recessed area 603 is recessed downward relative to the pole group welding area 602. The pole group welding area 602 is welded to the pole group 2. The electrical connection between the negative electrode cover plate 6 and the pole group 2 is achieved by welding the pole group welding area 602 to the pole group 2. Compared with the traditional method of connecting the negative pole and the negative pole column of the pole group 2 through a negative pole sheet connecting piece, the use of the negative pole connecting piece is eliminated, the number of structural parts is reduced, the welding process is reduced, and the product production cost is saved; the pole group welding area 602 is a plane that protrudes upward relative to the recessed area 603. The setting of the recessed area 603 increases the overall strength of the negative electrode cover plate 6, and is conducive to ensuring the flatness of the pole group welding area 602, and ensuring the fit between the pole group welding area 602 and the pole group 2, thereby ensuring the welding effect. The following refers to Figure 7 The middle arrow points to the direction of "down"; up refers to Figure 7 , Fig.19 The arrow in the middle points to the direction “up”.

[0075] Preferably, the electrode group welding area 602 is connected to the electrode group 2 by laser penetration welding. After the negative electrode cover plate 6 is buckled on the shell 1, the welding connection between the negative electrode cover plate 6 and the electrode group 2 can be achieved by directly operating from the side of the negative electrode cover plate 6 facing the outside of the battery. The technology is mature, the operation is convenient, and the connection after welding is stable. It can also optimize the assembly process, improve the manufacturability of the product, and improve the product yield.

[0076] In one embodiment, the negative electrode cover plate 6 further includes: a liquid injection area 604, which is upwardly protruding relative to the recessed area 603 and flush with the upper surface of the electrode group welding area 602, and the recessed area 603 is arranged around the liquid injection area 604, and a liquid injection hole 601 is arranged on the liquid injection area 604. Figure 7 , Fig.19 The arrow in the middle indicates the direction of "upward"; the concave area 603 surrounding the injection area 604 means that the concave area 603 is located outside the injection area 604 in the radial direction. By providing the injection area 604 that protrudes upward relative to the concave area 603, a position is provided for the setting of the injection hole 601, and the injection is convenient, and the electrolyte can be prevented from flowing onto the surface of the negative electrode cover plate 6 other than the injection area 604 during the injection process, thereby preventing the outflowing electrolyte from corroding the negative electrode cover plate 6.

[0077] In one embodiment, the negative electrode cover plate 6 includes: a welding portion 605, which is formed by extending downward from the edge of the negative electrode cover plate 6, and the welding portion 605 abuts against the inner wall of the shell 1 and is welded to the shell 1. Figure 7 , Fig.19The welding part 605 is adapted to the shape of the shell 1. By welding the welding part 605 to the shell 1, the connection between the negative electrode cover plate 6 and the shell 1 is realized. The operation is convenient and the connection is stable. Figure 7 The “up and down” direction indicated by the middle arrow has a certain dimension, which can ensure the stability of the assembly of the negative electrode cover plate 6 and the shell 1.

[0078] In one embodiment, the battery further includes: a sealing cover plate 7, which is detachably disposed at the injection hole 601 on the negative electrode cover plate 6. When the battery needs to be injected, the sealing cover plate 7 is opened to inject liquid into the battery from the injection hole 601; when the battery is injected, the sealing cover plate 7 is installed to close the injection hole 601 to prevent the electrolyte in the battery from flowing out, with good sealing performance and convenient use.

[0079] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: case; A pole group is placed in the housing; A pole assembly is mounted at one end of the housing, the pole assembly is insulated and connected to the housing, and an explosion-proof rupture position is constructed on the housing around the pole assembly; the explosion-proof rupture position is suitable for disconnecting when the gas pressure in the battery reaches a preset value; A connecting piece, the connecting piece is arranged between the pole in the pole assembly and the pole group; The connecting piece comprises: A connecting piece body, one side of which is electrically connected to the electrode group; A connecting portion, formed by extending a part of the connecting piece body toward a side away from the pole group, and connected to the pole; a convex rib, constructed on the connecting piece body and protruding from the upper surface of the connecting piece body, the convex rib surrounding the connecting portion, the strength of the convex rib being less than the strength of the connecting piece body, and the convex rib being adapted to break when the gas pressure in the battery reaches a preset value, so that the connecting portion and the pole connected to the connecting portion are separated from the battery under the action of the gas pressure; The thickness of the connecting piece body is H1, and the thickness of the convex rib is H2, wherein 0.1≤H2 / H1≤0.8; The distance that the convex rib is higher than the upper surface of the connecting piece body is H3, wherein 1.2≤H3 / H1≤5; The convex rib is in the form of a circular ring, and the outer diameter of the circular ring ranges from 12 mm to 20 mm; The convex rib is integrally formed with the connecting piece body; The battery further includes: a support member, the support member is arranged between the shell and the connecting piece, one side of the support member abuts against the connecting piece and the other side abuts against the shell, the support member is provided with a plurality of exhaust holes, and the plurality of exhaust holes correspond to the explosion-proof fracture positions; a clearance hole is constructed at a position on the support member corresponding to the pole assembly, and the connection portion and the pole assembly pass through the clearance hole.

2. The battery according to claim 1, characterized in that A plurality of reinforcing ribs are arranged at intervals on the edge of the connecting piece body, and the reinforcing ribs protrude from the surface of the connecting piece body.

3. The battery according to claim 1, characterized in that The distance between the upper surface of the convex rib and the inner surface of the upper end of the shell is L, where L>1.2mm; And / or, a protrusion protruding from an upper surface of the shell is constructed on the shell around the pole, and the explosion-proof fracture point is arranged on the protrusion.

4. The battery according to claim 1, characterized in that The convex rib on the connecting plate extends between the support member and the pole assembly, a first gap is formed between the convex rib and the support member, and a second gap is formed between the convex rib and the pole assembly, wherein the sizes of the first gap and the second gap are both greater than 0.3 mm.

5. The battery according to claim 1, characterized in that The electrode column is a positive electrode column, and the positive electrode column is electrically connected to the positive electrode of the electrode group through the connecting sheet. The end of the shell away from the positive electrode column is an open end. The battery also includes: a negative electrode cover plate, which is arranged at the open end of the shell to close the shell. The negative electrode cover plate is electrically connected to the negative electrode of the electrode group, and an injection hole is arranged on the negative electrode cover plate.

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