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 arranged on a side of the connecting piece body away from the pole group, the connecting portion protruding from the surface of the connecting piece body, and the connecting portion is suitable for electrically connecting to a pole; a plurality of vents, which are arranged on the connecting piece body at intervals around the connecting portion, the ring formed by the plurality of vents corresponds to the pole, and the connecting piece body between two adjacent vents forms a connecting rib, which is suitable for breaking when the gas pressure in the battery reaches a preset value, so that the pole is disconnected from the pole group. When the gas pressure in the battery of the present invention reaches a certain value, the weaker connecting rib breaks first, and the connecting portion and the pole are bounced open as a whole under the action of the gas pressure, thereby improving the patency of the exhaust gas and timely cutting off the connection between the battery and the external circuit.

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 during thermal runaway.

[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 arranged on a side of the connecting piece body away from the pole group, the connecting portion protruding from the surface of the connecting piece body, and the connecting portion is suitable for being electrically connected to a pole; a plurality of vents, which are arranged on the connecting piece body at intervals around the connecting portion, the ring formed by the plurality of vents corresponding to the pole, the connecting piece body between two adjacent vents forming a connecting rib, the connecting rib being suitable for breaking when the air pressure in the battery reaches a preset value, so as to disconnect the pole from the pole group.

[0006] By arranging a plurality of spaced vent holes on the connecting piece body, and the plurality of vent holes form a ring, a connecting rib is formed between each two adjacent vent holes, and the strength of the connecting rib is less than the strength of the connecting piece body. When the gas pressure in the battery reaches a certain value, the weaker connecting rib breaks first, and then the connecting part located in the middle of the ring formed by the plurality of vent holes falls off from the connecting piece body, thereby increasing the ventilation area of ​​the connecting piece and avoiding the connecting piece from obstructing the gas flow. Moreover, since the ring formed by the plurality of vent holes corresponds to the pole, under the action of the gas pressure in the battery, the connecting part and the pole connected to the connecting part can be bounced open as a whole under the action of the gas pressure and detached from the battery, thereby improving the smoothness of the exhaust and preventing the battery from exploding. Moreover, 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.

[0007] In an optional embodiment, the distance between the centers of two adjacent vent holes ranges from 0.8 mm to 1.2 mm, which can ensure the strength of the connecting sheet 3 and ensure that the connecting rib 304 breaks in time when the air pressure in the battery reaches a preset value, thereby ensuring the safety of the battery.

[0008] In an optional embodiment, the connecting portion is cylindrical, the diameter of the cylinder is D1, the diameter of the ring formed by the plurality of vents is D2, wherein 1.25≤D2 / D1≤2.75, which can ensure the exhaust effect without affecting the flow capacity between the electrode group 2 and the connecting sheet 3, thereby ensuring the battery performance;

[0009] And / or, the diameter of the ring formed by the plurality of vent holes is in the range of 3.5 mm to 16 mm, which can ensure the flow capacity between the connecting piece 3 and the pole 5, and the flow capacity between the connecting piece 3 and the pole group 2, thereby maximizing the performance of the battery.

[0010] In an optional embodiment, the thickness of the connecting piece body is 0.4 mm, which can ensure the welding effect and product strength, and meet the product's current capacity.

[0011] In a second aspect, the present invention further provides a battery, comprising: a shell; a pole group, placed in the shell; a pole, installed at one end of the shell, the pole being insulated and connected to the shell, and an explosion-proof fracture position being constructed on the shell around the pole; the above-mentioned connecting piece, the connecting piece is arranged between the pole 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, and at least part of the structure of one end of the pole close to the connecting piece is located within the range of a circular ring formed by a plurality of ventilation holes on the connecting piece. By arranging one side of the connecting piece to be electrically connected to the electrode group and the other side to be electrically connected to the pole, the pole is electrically connected to the pole group through the connecting piece, and then the battery can be connected to an external circuit or other batteries through the pole. By arranging at least a part of the area of ​​the pole to correspond to the vent hole, the gas passing through the vent hole can directly act on the pole, so that the pole can be pushed up when the gas pressure in the battery is too high, and the explosion-proof fracture position surrounding the pole on the shell is disconnected when the gas pressure in the battery is too high, which can ensure that the area surrounded by the explosion-proof fracture position can be bounced open as a whole, that is, the pole is ensured to be completely separated from the battery, thereby increasing the exhaust area and ensuring that the battery is disconnected from the external circuit, 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 battery further includes: a support member, wherein the support member is disposed between the shell and the connecting plate, one side of the support member abuts against the connecting plate 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; and / or a raised portion protruding from the upper surface of the shell is constructed around the pole on the shell, and the explosion-proof fracture position is provided on the raised portion. 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 supporting surface, and the lower end 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 an exhaust hole corresponding to the explosion-proof fracture position 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 through the exhaust hole, so as to quickly open the explosion-proof valve to relieve pressure and improve the safety of the battery; the raised portion protrudes from the upper surface of the shell, provides a limit for the pole column, ensures the stability of assembly, and the explosion-proof fracture position and the upper surface of the shell are not on the same surface. If a liquid injection hole is provided on the upper surface of the shell, it can be ensured that the explosion-proof fracture position and the liquid injection hole are separated to avoid contamination of the explosion-proof fracture position during liquid injection, resulting in breakdown and leakage, and ensure that the explosion-proof valve can be opened in time, thereby ensuring the safety of the battery.

[0013] In an optional embodiment, the total area of ​​the plurality of vents is S3, the explosion-proof fracture site is an explosion-proof notch, the explosion-proof notch is annular and the area of ​​the notch is S4, wherein S3>5*S4. This ensures that a sufficient amount of gas can pass through the vents 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.

[0014] In an optional embodiment, the support member includes: a support member body, a clearance hole is constructed at a position on the support member body corresponding to the pole, and the clearance hole passes through the connecting portion and the pole; and / or a first support rib is formed by extending downward from the edge of the support member body, and the first support rib extends into the gap between the side wall of the shell and the connecting piece to position the connecting piece and the pole group. The clearance hole provided on the support member body provides clearance space for the connecting portion to achieve the connection between the connecting piece and the pole, and the space is reasonably used; there is a certain gap between the pole group and the shell, and the first support rib extends between the side wall of the shell and the connecting piece, and further extends between the pole group and the shell, which plays a role in positioning and fixing the connecting piece and the pole group, which can ensure the axial center symmetry of the pole group and the shell, and improve the overall stability of the battery.

[0015] In an optional embodiment, the support member further includes: at least one internal support rib, the internal support rib is formed by extending downward from a part of the structure on the lower surface of the support member body, and the internal support rib abuts against the upper surface of the connecting piece. The lower end of the support member abuts against the connecting piece through the internal support rib, which has a good fixing effect and can prevent the connecting piece from moving in the vertical direction inside the battery, thereby increasing the stability of the structure. In addition, the structural form of the support rib can reduce the weight of the support member, thereby increasing the overall energy density of the battery.

[0016] In an optional embodiment, the internal support rib includes: a second support rib, which is arranged on the inner side of the first support rib, and the second support rib is provided with a first positioning groove, and the first positioning groove cooperates with the reinforcing rib on the connecting plate body; and / or, a third support rib, which is arranged on the inner side of the second support rib and located on the outer side of the exhaust hole, and the third support rib is provided with a second positioning groove, and the second positioning groove corresponds to the first positioning groove and cooperates with the reinforcing rib; and / or, a fourth support rib, which is arranged on the inner side of the third support rib and located on the inner side of the exhaust hole, and the fourth support rib surrounds the clearance hole. The arrangement of multiple support ribs in the form of concentric rings can further increase the strength of the support member and reduce the weight of the support member at the same time. The second support rib, the third support rib and the fourth support rib are in zero-gap contact with the connecting piece. When the explosion-proof valve is opened, the internal support ribs press the connecting piece body, so that the connecting piece breaks at the position of the connecting ribs. The broken connecting parts fly out of the clearance hole and thus pop open with the pole, ensuring that the exhaust channel of the battery is unobstructed. In addition, the first positioning groove on the second support rib and the second positioning groove on the third support rib are both matched with the reinforcing ribs, and the positioning grooves are clamped with the reinforcing ribs to achieve the clamping connection between the support member and the connecting piece. The positioning effect is good and the connection is stable, which effectively avoids relative shaking between the structural parts, thereby ensuring the stability of the overall structure.

[0017] In an optional embodiment, the lower end surface of the first support rib is 0.5mm-1.0mm longer than the lower end surface of the internal support rib, and / or the thickness of the support member is 1.8±0.03mm, which can ensure the strength of the support member itself and save space, thereby improving space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] Figure 1 A schematic diagram of the structure of a connecting piece according to an embodiment of the present invention;

[0020] Figure 2 for Figure 1 A top view of the connecting piece shown;

[0021] Figure 3 for Figure 2 Sectional view in the AA direction;

[0022] Figure 4 A schematic diagram of the structure of a battery according to an embodiment of the present invention;

[0023] Figure 5 for Figure 4 A top view of the battery shown;

[0024] Figure 6 for Figure 5 Cross-sectional view in the BB direction;

[0025] Figure 7 for Figure 6 A is a partial enlarged schematic diagram;

[0026] Figure 8 for Figure 6 A partial enlarged schematic diagram of B in the middle;

[0027] Fig. 9 It is a schematic structural diagram of a housing according to an embodiment of the present invention;

[0028] Fig.10 for Fig. 9 a top view of the housing;

[0029] Fig.11 for Fig.10 Cross-sectional view in CC direction;

[0030] Fig.12 for Fig.11 A partial enlarged schematic diagram of C in the middle;

[0031] Fig.13 It is a structural schematic diagram of a support member according to an embodiment of the present invention;

[0032] Fig.14 for Fig.13 A structural schematic diagram of the support member shown in another perspective;

[0033] Fig.15 for Fig.13 a top view of the support member shown;

[0034] Fig.16 for Fig.15 Cross-sectional view in the middle DD direction;

[0035] Fig.17 A schematic structural diagram of a negative electrode cover plate according to an embodiment of the present invention;

[0036] Fig.18 for Fig.17 A cross-sectional view of the negative electrode cover is shown.

[0037] Description of reference numerals:

[0038] 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. Vent hole; 304. Connecting 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

[0039] 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.

[0040] Combine the following Figures 1 to 18 , describing an embodiment of the present invention.

[0041] According to an embodiment of the present invention, on one hand, a connecting sheet is provided, which mainly includes: a connecting sheet body 301 , a connecting portion 302 and a plurality of vent holes 303 .

[0042] Specifically, one side of the connecting piece body 301 is suitable for being electrically connected to the electrode group 2; the connecting portion 302 is arranged on the side of the connecting piece body 301 away from the electrode group 2, the connecting portion 302 protrudes from the surface of the connecting piece body 301, and the connecting portion 302 is electrically connected to the pole 5; a plurality of vents 303 are arranged on the connecting piece body 301 at intervals around the connecting portion 302, and the ring surrounded by the plurality of vents 303 corresponds to the pole 5, and the connecting piece body 301 between two adjacent vents 303 forms a connecting rib 304, and the connecting rib 304 is suitable for breaking when the air pressure in the battery reaches a preset value, so as to disconnect the pole 5 from the pole group.

[0043] In this embodiment, a plurality of spaced vent holes 303 are provided on the connecting piece body 301, and the plurality of vent holes 303 form a ring, and a connecting rib 304 is formed between each two adjacent vent holes 303, and the strength of the connecting rib 304 is less than the strength of the connecting piece body 301. When the air pressure in the battery reaches a certain value, the weaker connecting rib 304 breaks first, and the connecting portion 302 located in the middle of the ring formed by the plurality of vent holes 303 falls off from the connecting piece body 301, thereby increasing the ventilation area of ​​the connecting piece 3 and preventing the connecting piece 3 from damaging the battery. The gas flow is hindered, and because the ring surrounded by the plurality of vents 303 corresponds 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 bounced open as a whole under the action of the gas pressure and detached from the battery, thereby improving the smoothness of the exhaust and preventing the battery from exploding. After the pole 5 is detached from the battery, the electrical connection between the pole 5 and the pole group can be cut off in time, thereby cutting off the connection between the battery and the external circuit, thereby avoiding short-circuit damage to the entire circuit and improving safety.

[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; 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, and the connecting piece 3 is made of metal to achieve electrical connection between the pole 5 and the pole group 2; the ring surrounded by the plurality of vents 303 corresponds to the pole 5, which means that the ring is located below the pole 5, and the gas flowing upward through the vents 303 is directly facing the pole 5. Therefore, when the connecting rib 304 breaks, the gas ejected through the ring area directly acts on the pole 5, and the force is relatively large, so as to eject the pole 5 out of the battery. Preferably, the range of the ring surrounded by the plurality of vents 303 is suitable for covering the edge of the pole 5 close to one end of the connecting piece body 301, wherein the upper portion refers to Figure 6 The arrow in the middle points to the direction of "up", and the arrow in the middle points to the direction of "down". Figure 6 The arrow in the middle points to the “down” direction.

[0045] 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.

[0046] In one embodiment, the distance between two adjacent vent holes 303 ranges from 0.8 mm to 1.2 mm, that is, the circumferential dimension of each connecting rib 304 along the circle surrounded by the vent holes 303 ranges from 0.8 mm to 1.2 mm. The connecting rib 304 formed between two adjacent vent holes 303 is small in size and strength. The connecting rib 304 plays a connecting role in the normal state of the battery, and is disconnected when the air pressure in the battery is too high. If the distance between the two adjacent vent holes 303 is less than 0.8mm, the size of the connecting rib 304 along the circumferential direction of the ring is too small, which makes the product strength weak, which is not conducive to the stability of the battery product structure and is not easy to process; if the distance between the two adjacent vent holes 303 of the connecting rib 304 is greater than 1.2mm, the size of the connecting rib 304 along the circumferential direction of the ring is too large, which will make the connecting rib 304 difficult to break, affecting the opening effect of the explosion-proof valve and the safety performance of the battery. Therefore, when the distance between the two adjacent vent holes 303 is within the range of 0.8mm-1.2mm, it can not only ensure the strength of the connecting sheet 3, but also ensure that the connecting rib 304 breaks in time when the air pressure in the battery reaches the preset value, thereby ensuring the safety of the battery. Preferably, the distance between the two adjacent vent holes 303 is 1mm.

[0047] In one embodiment, the connecting portion 302 is cylindrical, the diameter of the cylinder is D1, and the diameter of the ring formed by the plurality of vent holes 303 is D2, wherein 1.25≤D2 / D1≤2.75. It should be noted that the diameter of the ring is a range value, the minimum value in the range of the diameter of the ring is the minimum value of the diameter of the inner ring, and the maximum value in the range of the diameter of the ring is the maximum value of the diameter of the outer ring. The ring formed by the plurality of vents 303 and the connecting portion 302 are both located on the connecting piece 3. If the ratio of the diameter D2 of the ring to the diameter of the connecting portion 302 is less than 1.25, the diameter of the ring is too small. Correspondingly, the area of ​​the vent 303 is small, the ventilation area is small, and the exhaust effect is affected. If the ratio of the diameter D2 of the ring to the diameter of the connecting portion 302 is greater than 2.75, the diameter of the ring is too large, that is, the area occupied by the ring on the connecting piece 3 is large, and correspondingly, the area of ​​the connecting piece body 301 is small, which affects the flow capacity of the electrode group 2 and the connecting piece 3. Therefore, the ratio of the diameter of the ring to the diameter of the connecting portion 302 is designed to be between 1.25-2.75, which can ensure the exhaust effect without affecting the flow capacity between the electrode group 2 and the connecting piece 3, thereby ensuring the battery performance.

[0048] In one embodiment, the diameter of the ring surrounded by the plurality of vents 303 is 3.5mm-16mm. The connecting portion 302 located in the middle of the ring is used to electrically connect with the pole 5 to realize the electrical connection between the pole 5 and the connecting piece 3. If the diameter of the ring is less than 3.5mm, the diameter of the ring is too small, which will make the connecting portion 302 too small, affecting the flow capacity of the pole 5 and the connecting piece 3; the portion outside the ring on the connecting piece 3 is used to electrically connect with the pole group 2. If the diameter of the ring is greater than 16mm, the diameter of the ring is too large, and the area of ​​the connecting piece body 301 is too small, affecting the flow capacity of the pole group 2 and the connecting piece 3. Therefore, setting the diameter of the ring to 3.5mm-16mm can balance the flow capacity between the connecting piece 3 and the pole 5 and the pole group 2, respectively, which can ensure the flow capacity between the connecting piece 3 and the pole 5, and the flow capacity between the connecting piece 3 and the pole group 2, thereby maximizing the performance of the battery.

[0049] In one embodiment, the thickness of the connecting piece body 301 is 0.4 mm, wherein the thickness refers to the thickness of the connecting piece body 301. Figure 3 The dimension in the "up and down" direction indicated by the arrow in the figure. The connecting piece 3 is located between the battery shell 1 and the electrode group 2, and is welded to the electrode column 5 and the electrode group 2 respectively, which plays the role of electrically connecting the electrode column 5 and the electrode group 2, and also plays the role of support. The thickness of the connecting piece body 301 is set to 0.4mm, which can not only ensure the welding effect and product strength, but also meet the product's current capacity.

[0050] 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 indicated by the middle arrow "up" is the same as the protrusion direction of the connecting portion 302, and the upward protrusion of the reinforcing rib 305 is smaller than the upward protrusion 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.

[0051] According to an embodiment of the present invention, on the other hand, a battery is provided, which mainly includes: a housing 1, an electrode group 2, an electrode column 5 and the above-mentioned connecting piece 3.

[0052] Specifically, the pole group 2 is placed in the shell 1; the pole 5 is installed at one end of the shell 1, the pole 5 is insulated and connected to the shell 1, and an explosion-proof fracture position 101 is constructed around the pole 5 on the shell 1; the connecting piece 3 is arranged between the pole 5 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, and at least part of the structure of one end of the pole 5 close to the connecting piece 3 is located within the range of the circular ring formed by a plurality of vents 303 on the connecting piece 3.

[0053] In this embodiment, by setting one side of the connecting piece 3 to be electrically connected to the electrode group 2 and the other side to be electrically connected to the pole 5, the pole 5 is electrically connected to the pole group 2 through the connecting piece 3, and then the battery can be connected to an external circuit or other batteries through the pole 5. By setting at least a partial area of ​​the pole 5 to correspond to the vent 303, the gas passing through the vent 303 can directly act on the pole 5, so that the pole 5 is easily pushed up when the gas pressure in the battery is too high, and the explosion-proof rupture position 101 constructed around the pole 5 on the shell 1 is disconnected when the gas pressure in the battery is too high, which can ensure that the area surrounded by the explosion-proof rupture position 101 can be bounced open as a whole, that is, the pole 5 is completely separated from the battery, thereby increasing the exhaust area and ensuring that the battery is disconnected from the external circuit, so as to prevent the problem of battery explosion caused by the spread of thermal runaway and improve safety performance.

[0054] 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 first, 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 Figure 6 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 6 The side in the direction indicated by the arrow.

[0055] Preferably, the pole 5 is mounted on the upper end of the housing 1, wherein the upper end refers to the Figure 6 The end in the direction indicated by the arrow.

[0056] 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.

[0057] 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, at this time, the negative pole of the battery is located at the end of the shell 1 away from the positive pole and connected to the negative pole of the pole group 2. It can be understood that as a replaceable embodiment, 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, the pole 5 can include both positive poles and negative poles, the positive poles and the negative poles can be arranged on the same end face of the shell 1 or on two opposite end faces, and insulation between the positive poles and the negative poles must be ensured, the positive poles are connected to the positive pole of the pole group 2, and the negative poles are connected to the negative pole of the pole group 2, and the positive poles and the negative poles can be provided with explosion-proof rupture positions 101 in the circumference to increase the exhaust area.

[0058] In one embodiment, the battery further includes: an insulating seal 8, which is arranged between the pole 5 and the shell 1 to make the pole 5 and the shell 1 insulated and sealed connection. The insulating seal 8 can not only realize the insulating connection between the pole 5 and the shell 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. Specifically, a mounting hole 103 is opened on the shell 1, and the pole 5 and the insulating seal 8 are clamped in the mounting hole 103. The insulating seal 8 is wrapped around the circumference of the pole 5, so as to realize the sealed connection between the pole 5 and the shell 1.

[0059] In one embodiment, the battery further includes: a support member 4, the support member 4 is arranged between the shell 1 and the connecting piece 3, one side of the support member 4 is in contact with the connecting piece 3 and the other side is in contact with 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 rupture position 101. 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 contacts the pole group 2, so that the pole group 2 and the shell 1 are more integrated, and at the same time, it can also ensure that the upper end surface of the pole group 2 is parallel to the upper end surface of the shell 1; 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 exhaust holes 401 corresponding to the explosion-proof rupture position 101 are arranged on the support member 4, so as 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 rupture position 101 through the exhaust holes 401, so as to quickly open the explosion-proof valve to release pressure and improve the safety of the battery. Among them, the upper end refers to the part along the Figure 6 , Fig.16 The arrow in the middle points to the "up" end, and the lower end refers to the Figure 6 , Fig.16It 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.

[0060] In one embodiment, the total area of ​​the plurality of exhaust holes 401 is S3, the explosion-proof fracture position 101 is an explosion-proof notch, the explosion-proof notch is annular and the area of ​​the notch is S4, wherein S3>5*S4. It should be noted that the explosion-proof notch is a narrow ring around the pole 5 on the surface of the shell 1, and the area occupied by the ring is the area of ​​the explosion-proof notch. The total area of ​​the plurality of exhaust holes 401 is the total area on the support 4 through which gas can pass, and the plurality of exhaust holes 401 are directly opposite to the explosion-proof notch. If the total area of ​​the exhaust holes 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 exhaust holes 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 exhaust holes 401 to impact the explosion-proof notch, and provide sufficient impact force to the explosion-proof notch to break the explosion-proof notch, thereby improving the safety of the battery. Among them, 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.

[0061] 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 fracture position 101 is set on the protrusion 102. The protrusion 102 protrudes from the upper surface of the shell 1, and the explosion-proof fracture position 101 is not on the same surface as the upper surface of the shell 1. Therefore, when a liquid injection hole is set on the upper surface of the shell 1, it can be ensured that the explosion-proof fracture position 101 and the liquid injection hole are separated, avoiding contamination of the explosion-proof fracture position during injection and causing breakdown and leakage, 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 upper surface of the shell 1. Figure 6 , Fig.11 The surface in the "up" direction indicated by the arrow.

[0062] In one embodiment, the support member 4 mainly includes a support member body 402. A clearance hole 403 is configured at a position on the support member body 402 corresponding to the pole 5, and the clearance hole 403 passes through the connecting portion 302 and the pole 5. The clearance hole 403 opened on the support member body 402 provides clearance space for the connecting portion 302 to achieve the connection between the connecting piece 3 and the pole 5, and the space utilization is reasonable.

[0063] In one embodiment, the support member 4 further includes: a first support rib 404, which 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 connecting piece 3 to position the connecting piece 3 and the electrode group 2. There is a certain gap between the electrode group 2 and the shell 1, and the first support rib 404 extends between the side wall of the shell 1 and the connecting piece 3, and further extends between the electrode group 2 and the shell 1, which plays a role in positioning and fixing the connecting piece 3 and the electrode group 2, and can ensure that the electrode group 2 and the shell 1 are axially symmetrical, thereby improving the overall stability of the battery.

[0064] 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 6 The middle arrow points to the direction of "down", and the up arrow points to the direction of Figure 6 The arrow in the middle points to the direction “up”.

[0065] 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, reduce the precision, and affect the space utilization. Preferably, the lower end face of the first support rib 404 is 0.8mm longer than the lower end face of the internal support rib, which will not affect the difficulty of processing, but also avoid excessive weight and ensure processing accuracy.

[0066] 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.

[0067] In one embodiment, the internal support ribs include: a second support rib 405, which 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 cooperates with the reinforcing rib 305 on the connecting piece body 301. The internal support ribs also include: a third support rib 406, which is arranged on the inner side of the second support rib 405 and 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 cooperates with the reinforcing rib 305. The internal support ribs also include: a fourth support rib 407, which is arranged on the inner side of the third support rib 406 and located on the inner side of the exhaust hole 401, and the fourth support rib 407 surrounds the clearance hole 403. The inner side refers to the inner side 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 connecting rib 304, and the broken connecting part 302 and other parts 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 realize the clamping 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.

[0068] In one embodiment, the battery further includes: a liquid injection hole 601, which is arranged at one end of the battery away from the explosion-proof rupture position 101. The liquid injection hole 601 and the explosion-proof rupture position 101 are separately arranged at opposite ends of the shell 1, which can prevent the liquid from splashing onto the explosion-proof rupture position 101 during liquid injection and contaminating the explosion-proof rupture position 101, thereby preventing the explosion-proof rupture position 101 from being penetrated and leaking due to contamination, and ensuring that the explosion-proof valve can be opened in time. It can be understood that, as an alternative embodiment, the liquid injection hole 601 can also be arranged 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 explosion-proof rupture position 101 is arranged on the raised portion 102 protruding from the upper surface of the shell 1, which can also prevent the explosion-proof rupture position 101 from being contaminated.

[0069] 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 end of the shell 1 away from the positive pole 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 the 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 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 arranged around the electrode column 5 are far away from each other, which effectively ensures that the electrolyte will not splash to the explosion-proof rupture position 101 when the electrolyte is injected into the battery through the injection hole 601, and ensures that the explosion-proof rupture position 101 is not contaminated, thereby ensuring the safety of the battery.

[0070] 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 cost is saved. By setting the pole group welding area 602 as a plane protruding 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 6 The middle arrow points to the direction of "down"; up is Figure 6 , Fig.18The arrow in the middle points to the direction “up”.

[0071] 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.

[0072] 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 6 , Fig.18 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 setting the injection area 604 that bulges 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.

[0073] In one embodiment, the negative electrode cover plate 6 further includes: a welding portion 605, which is formed by extending downward from the edge of the electrode group welding area 602, and the welding portion 605 abuts against the inner wall of the shell 1 and is welded to the shell 1, wherein the lower part refers to Figure 6 , Fig.18 The 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 6 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.

[0074] 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.

[0075] 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 connecting sheet, characterized in that: include: A connecting piece body, one side of which is electrically connected to the electrode group; A connecting portion, arranged on a side of the connecting piece body away from the pole group, the connecting portion protruding from the surface of the connecting piece body, and the connecting portion being suitable for being electrically connected to the pole; A plurality of vent holes are arranged on the connecting piece body at intervals around the connecting portion, the ring formed by the vent holes corresponds to the pole, the connecting piece body between two adjacent vent holes forms a connecting rib, the strength of the connecting rib is less than the strength of the connecting piece body, the connecting rib is suitable for breaking when the gas pressure in the battery reaches a preset value, the connecting portion and the pole connected to the connecting portion are integrally ejected under the action of the gas pressure and detached from the battery, so that the pole is disconnected from the pole group electrically; The connecting portion is cylindrical, the diameter of the cylinder is D1, and the diameter of the ring surrounded by the plurality of vent holes is D2, wherein 1.25≤D2 / D1≤2.

75.

2. The connecting piece according to claim 1, characterized in that: The distance between the centers of two adjacent vent holes ranges from 0.8 mm to 1.2 mm; And / or, the diameter of the ring formed by the plurality of ventilation holes ranges from 3.5 mm to 16 mm.

3. The connecting piece according to claim 1 or 2, characterized in that: The thickness of the connecting piece body is 0.4 mm.

4. A battery, characterized in that: include: case; A pole group is placed in the housing; A pole is mounted at one end of the shell, the pole is insulated and connected to the shell, and an explosion-proof fracture position is constructed on the shell around the pole; The connecting piece according to any one of claims 1 to 3, wherein the connecting piece is arranged between the pole 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, and at least part of the structure of one end of the pole close to the connecting piece is located within the range of a circular ring formed by a plurality of vents on the connecting piece.

5. The battery according to claim 4, characterized in that The battery further includes: a support member, the support member is arranged between the shell and the connecting sheet, one side of the support member abuts against the connecting sheet and the other side abuts against the shell, and the support member is provided with a plurality of exhaust holes, and the plurality of exhaust holes correspond to the explosion-proof fracture positions; 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.

6. The battery according to claim 5, characterized in that The total area of ​​the exhaust holes is S3, the explosion-proof fracture site is an explosion-proof notch, the explosion-proof notch is annular and the area of ​​the annular notch is S4, wherein S3>5*S4.

7. The battery according to claim 5, characterized in that The support member comprises: A support body, wherein a clearance hole is configured at a position of the support body corresponding to the pole, and the connection portion and the pole pass through the clearance hole; And / or, a first support rib is formed by extending downward from the edge of the support member body, and the first support rib extends into the gap between the side wall of the shell and the connecting plate to position the connecting plate and the pole group.

8. The battery according to claim 7, characterized in that The support member further includes: at least one internal support rib, which is formed by extending downward from a portion of the structure on the lower surface of the support member body, and the internal support rib is in contact with the upper surface of the connecting piece.

9. The battery according to claim 8, characterized in that The internal support ribs include: A second supporting rib is arranged on the inner side of the first supporting rib, a first positioning groove is configured on the second supporting rib, and the first positioning groove matches with the reinforcing rib on the connecting piece body; And / or, a third supporting rib is arranged on the inner side of the second supporting rib and located on the outer side of the exhaust hole, and a second positioning groove is constructed on the third supporting rib, and the second positioning groove corresponds to the first positioning groove and cooperates with the reinforcing rib.

10. The battery according to claim 9, characterized in that The internal support ribs also include: The fourth supporting rib is arranged on the inner side of the third supporting rib and located on the inner side of the exhaust hole, and the fourth supporting rib surrounds the clearance hole.

11. The battery according to claim 8, characterized in that The lower end surface of the first supporting rib is 0.5 mm-1.0 mm longer than the lower end surface of the internal supporting rib; And / or, the thickness of the support member is 1.8±0.03 mm.

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