Collecting plate and battery

Abstract

The utility model provides a collector plate and a battery. The collector plate comprises a body part and at least one power-off protection part, the body part comprises a first connecting part and a second connecting part, and the first connecting part and the second connecting part are spaced to form an isolation space; the power-off protection part is arranged in the isolation space and connected with the first connecting part and the second connecting part, the power-off protection part comprises a first connecting section and a second connecting section which are connected in sequence, the thickness of the second connecting section is smaller than that of the first connecting section, and / or the thickness of the first connecting section is smaller than that of the second connecting section. And the width of the second connecting section is smaller than that of the first connecting section. The lithium ion battery aims to solve the problems that an existing lithium ion battery is low in safety coefficient and prone to thermal runaway.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly relates to a current collector plate and a battery. Background Art

[0002] During the use of a battery, when it suffers from abnormal states such as high-temperature burning, heavy object impact, puncture, short circuit, overcharge, etc., safety accidents such as fire and explosion are likely to occur, which is directly related to the reliability, service life, capacity of the battery, and the personal safety of the user.

[0003] In the related art, when the battery lacks a power-off function and an uncontrollable temperature change occurs inside the battery, the battery system generates gas violently, the internal pressure of the battery case increases, and when the pressure reaches a certain value, the components inside the battery are in a high-pressure state for a long time, which will be damaged and broken, easily leading to internal short circuit of the battery, and thus phenomena such as thermal runaway occur, and the safety factor is relatively low. Summary of the Utility Model

[0004] Embodiments of the present application provide a current collector plate and a battery, aiming to solve the problem that the existing lithium-ion battery has a relatively low safety factor and is prone to thermal runaway.

[0005] In a first aspect, embodiments of the present application provide a current collector plate, and the current collector plate includes:

[0006] A body part, including a first connection part and a second connection part, with a space formed between the first connection part and the second connection part to form an isolation space; and,

[0007] At least one power-off protection part, arranged in the isolation space, and the first connection part and the second connection part are connected through the power-off protection part. The power-off protection part includes a first connection segment and a second connection segment connected in sequence, wherein the thickness of the second connection segment is less than the thickness of the first connection segment, and / or the width of the second connection segment is less than the width of the first connection segment.

[0008] In one embodiment, the thickness of the body part is T1, where 0.1 mm ≤ T1 ≤ 0.8 mm.

[0009] In one embodiment, the thickness of the second connection segment is T2, where T2 = T1 - Z0, 0.05 mm ≤ Z0 ≤ 0.4 mm, and T2 = aT1, a is a fifth coefficient, 0.25 ≤ a ≤ 0.7, and T1 > Z0.

[0010] In one embodiment, the second connection part is arranged to be connected to the core. Define the diameter of the core as S1, define the width of the second connection segment as Q1, and define the diameter of the current collector plate as s, where s < S1 and Q1 < (S1 / 2).

[0011] In one embodiment, the impact force received when the second connecting section is disconnected is defined as F 300 , the fracture strength of the material of the current collecting plate is σ 300 , the number of the power-off protection parts is n 300 , the thickness of the main body part is T1, where Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 , 0.25 ≤ z ≤ 0.75, z is the first coefficient, σ 300 ≥ 60 MPa.

[0012] In one embodiment, the power-off protection part further includes a third connecting section. The second connecting section is connected between the first connecting section and the third connecting section. The thickness of the third connecting section is greater than that of the second connecting section. The third connecting section, the second connecting section and the first connecting section enclose a groove.

[0013] In one embodiment, the first connecting section has a first side close to the second connecting section, and the third connecting section has a second side close to the first connecting section. The shortest distance between the first side and the center line of the first connecting part is defined as Q2, and the shortest distance between the second side and the center line of the first connecting part is defined as Q3. Wherein, Q3 > Q2, Q3 = (2Q2 + Z1) / 2, 1 ≤ Z1 ≤ 4 mm, 6 mm ≤ 2Q2 ≤ 10 mm.

[0014] In one embodiment, the thickness of the first connecting section is greater than or equal to that of the third connecting section. One of the first connecting section and the third connecting section is connected to the first connecting part, and the other is connected to the second connecting part.

[0015] In one embodiment, the second connecting part is arranged to be connected to the core. The diameter of the core is defined as S1, the width of the first connecting section is defined as Q4, the width of the third connecting section is defined as Q5, and the width of the second connecting section is defined as Q1. Wherein, Q4 < (S1 / 2), Q5 < (S1 / 2), 1.1Q1 ≤ Q4 ≤ 1.5Q1, 1.1Q1 ≤ Q5 ≤ 1.5Q1.

[0016] In one embodiment, the second connecting part is arranged to be connected to the core. The diameter of the core is defined as S1. The second connecting part has a third side away from the first connecting part and a fourth side close to the first connecting part. The shortest distance between the third side and the center line of the first connecting part is S2, and the shortest distance between the fourth side and the center line of the first connecting part is S3. Wherein, 2S2 < S1, S3 ≥ 1 mm, 17.5 mm ≤ S1 ≤ 45 mm.

[0017] In one embodiment, S2 = (S1 - 2Z2) / 2, 2Z2 < S1, 4 mm ≤ Z2 ≤ 10 mm, S3 = S2 - Z3, Z3 < S2, 2 mm ≤ Z3 ≤ 5 mm.

[0018] In one embodiment, the first connecting portion is arranged to be connected to the pole column. The pole column is formed with a first hole, and the diameter of the first hole is defined as S4. The first connecting portion has a fifth side close to the second connecting portion, and the shortest distance from the fifth side to the center line of the first connecting portion is S5. A through hole is formed in the first connecting portion, and the first hole and the through hole are correspondingly communicated. The through hole has a sixth side, and the shortest distance from the sixth side to the center line of the first connecting portion is S6. Wherein, S5 = S6 + Z4, 1.5 mm ≤ Z4 ≤ 3.5 mm, S6 = (Z5 + S4) / 2, 0.5 mm ≤ Z5 ≤ 1.5 mm.

[0019] In one embodiment, the number of the power-off protection portions is multiple;

[0020] The isolation space includes a plurality of avoidance through grooves, and each avoidance through groove is located between two adjacent power-off protection portions.

[0021] In one embodiment, the avoidance through groove includes two first grooves and two second grooves. Each first groove is connected to the corresponding second groove. Each second connecting section is located between the two first grooves of two adjacent avoidance through grooves, and each first connecting section is located between the two second grooves of two adjacent avoidance through grooves.

[0022] In one embodiment, the second groove extends along the length direction of the first connecting section, the first groove is an arc groove, and the center of the arc groove is concentric with the center of the first connecting portion;

[0023] The avoidance through groove further includes a connecting groove, and the connecting groove extends along a part of the outer circumference of the first connecting portion and communicates with the corresponding two second grooves, and is located on the side of the two second grooves away from the two first grooves.

[0024] In one embodiment, the diameter of the core is defined as S1. The second connecting portion has a seventh side away from the first connecting portion, and the shortest distance from the seventh side to the center line of the first connecting portion is S7. Wherein, S7 = (S1 - 2Z6) / 2, 0.6 mm ≤ Z6 ≤ 2.5 mm.

[0025] In one embodiment, the thickness of the main body portion is defined as T1, the width of the second connecting section is defined as Q1, the first groove has a ninth side away from the first connecting portion and a tenth side close to the first connecting portion, the shortest distance from the ninth side to the center line of the first connecting portion is S9, and the shortest distance from the tenth side to the center line of the first connecting portion is S 10 , where S9 > S 10 , S9 = S7 - Z7Q1, 1.1 ≤ Z7 ≤ 2.5, S 10 = S9 - Z8T1, 1.1 ≤ Z8 ≤ 2.5, Z7 is the third coefficient and Z8 is the fourth coefficient.

[0026] In one embodiment, the first connecting portion has an outer side close to the second connecting portion. The side with the shortest distance from the center line of the first connecting portion among the sides of the outer side is defined as the fifth side, and the shortest distance from the fifth side to the center line of the first connecting portion is defined as S5. The connecting groove has an eighth side away from the first connecting portion, and the shortest distance from the eighth side to the center line of the first connecting portion is S8. Among them, S7 > S8, S8 = S5 + Z9, 2 mm ≤ Z9 ≤ 8 mm.

[0027] In a second aspect, an embodiment of the present application provides a battery, including the current collector plate described above.

[0028] In one embodiment, the battery further includes a cover plate assembly, a wound core, and a housing with at least one end open. The cover plate assembly includes a pole post. The housing has a receiving cavity. The wound core and the current collector plate are both located in the receiving cavity. The cover plate assembly is disposed at the opening. The first connecting portion of the current collector plate is connected to the pole post, and the second connecting portion is connected to the wound core.

[0029] In one embodiment, the cover plate assembly further includes a cover plate, a seal, and an insulating member. The pole post passes through the cover plate; the seal is sleeved outside the pole post and is located between the pole post and the cover plate; the insulating member is disposed below the cover plate; the current collector plate is disposed below the insulating member.

[0030] In one embodiment, the pole post is formed with a first hole, and a through hole is formed on the first connecting portion. The first hole and the through hole are correspondingly communicated.

[0031] The beneficial effects of the embodiments of the present application:

[0032] In the technical solution of this application, the body part includes a first connection part and a second connection part. The first connection part can be connected to the pole column, and the second connection part can be connected to the winding core. A power-off protection part is arranged on the current collector plate. The main purpose is to disconnect the connection between the pole column and the winding core when an out-of-control situation occurs inside the battery, so that the entire battery is powered off and short-circuit phenomena are avoided. Specifically, when the pressure inside the battery reaches a certain value, under the action of the internal air pressure (i.e., impact force), the power-off protection part deforms upward and breaks, so that the first connection part and the second connection part are disconnected. Disconnecting the connection between the first connection part and the second connection part further disconnects the electrical connection between the pole column and the winding core, thus ensuring that the battery will not have short-circuit phenomena and improving the safety performance of the battery. The power-off protection part includes a first connection section and a second connection section. It is defined that the current-carrying cross-sectional area of the second connection section is smaller than that of the first connection section, that is, the thickness of the second connection section is smaller than that of the first connection section, and / or it is defined that the width of the second connection section is smaller than that of the first connection section. By reducing the thickness and / or width of the second connection section, the power-off protection part breaks at the second connection section, further improving the safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 is a schematic structural diagram of an embodiment of the battery provided by this application;

[0035] Figure 2 is a schematic structural diagram of an embodiment of the cooperation between the cover plate assembly and the current collector plate provided by this application;

[0036] Figure 3 is a schematic structural diagram of another embodiment of the cooperation between the cover plate assembly and the current collector plate provided by this application;

[0037] Figure 4 is a schematic structural diagram of the current collector plate provided by an embodiment of this application;

[0038] Figure 5 is Figure 4 a cross-sectional view of the current collector plate;

[0039] Figure 6 is Figure 4 an enlarged schematic view of V in;

[0040] Figure 7 isFigure 5 Schematic enlarged view of W

[0041] Figure 8 Schematic structural view of a current collector tray provided by another embodiment of the present application

[0042] Figure 9 is Figure 8 Cross-sectional view of the current collector tray in

[0043] Figure 10 is Figure 8 Schematic enlarged view of X in

[0044] Explanation of reference numerals in the drawings

[0045]

[0046] Specific embodiments

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the drawings; and "inner" and "outer" refer to the outline of the device.

[0048] In the related art, when the battery lacks a power-off function and an uncontrollable temperature change occurs inside the battery, the battery system generates gas violently, the internal pressure of the battery case increases, and when the pressure reaches a certain value, the components inside the battery are in a high-pressure state for a long time, which will cause damage and fracture, easily leading to internal short circuit of the battery, and thus phenomena such as thermal runaway occur, with a low safety factor.

[0049] In view of this, the present application proposes a battery 1000 Figures 1 to 3 Schematic structural view of an embodiment of the battery 1000 provided by the present application, please refer to Figure 1, the battery 1000 includes a current collector plate 300. When the impact force inside the battery 1000 reaches a specific condition, the current collector plate 300 can break and cut off the power, with a high safety factor, avoiding the short - circuit phenomenon of the battery 1000. The battery 1000 further includes a cover plate assembly, a wound core 800, and a housing 900 with at least one open end. The cover plate assembly includes a terminal post 400. The housing 900 has a receiving cavity. The wound core 800 and the current collector plate 300 are both located in the receiving cavity. The cover plate assembly is disposed at the opening. The first connection portion 301 of the current collector plate 300 is connected to the terminal post 400, and the second connection portion 302 is connected to the wound core 800.

[0050] Please refer to Figure 2 , Figure 2 is a schematic diagram of the cooperation between the cover plate assembly and the current collector plate 300 provided by an embodiment of the present application. Among them, Figure 2 the power - off protection portion 303 in the current collector plate 300 in [] is one. Specifically, please continue to refer to Figure 2 , the cover plate assembly includes a terminal post 400, a seal 500, a cover plate 600, and an insulating member 700. The terminal post 400 passes through the cover plate 600. The seal 500 is sleeved outside the terminal post 400, and the seal 500 is located between the cover plate 600 and the terminal post 400. One end of the seal 500 close to the current collector plate 300 is turned outwards to form a first flanging 601. The first flanging 601 is located between the cover plate 600 and the current collector plate 300. The insulating member 700 is disposed below the cover plate 600, and the insulating member 700 is connected to the first flanging 601 of the seal 500; the current collector plate 300 is disposed below the insulating member 700 or below the seal 500, and the first connection portion 301 of the current collector plate 300 is welded to the terminal post 400.

[0051] Please refer to Figure 3 , Figure 3 is a schematic diagram of the cooperation between the cover plate assembly and the current collector plate 300 provided by another embodiment of the present application. Among them, Figure 3 the power - off protection portion 303 in the current collector plate 300 in [] is four. Specifically, please continue to refer to Figure 3 , the cover plate assembly includes a terminal post 400, a seal 500, a cover plate 600, and an insulating member 700. The terminal post 400 passes through the cover plate 600. The seal 500 is sleeved outside the terminal post 400, and the seal 500 is located between the cover plate 600 and the terminal post 400; the insulating member 700 is disposed below the cover plate 600, the current collector plate 300 is disposed below the insulating member 700, and the first connection portion 301 of the current collector plate 300 is welded to the terminal post 400.

[0052] Figures 4 to 10 Schematic structural diagrams of some embodiments of the current collector plate 300 provided for this application; the current collector plate 300 will be described in detail below with reference to the main drawings.

[0053] The current collector plate 300 includes a body portion 309 and at least one power-off protection portion 303. Please refer to Figure 4 and Figure 5 , the current collector plate 300 includes one power-off protection portion 303. The body portion 309 includes a first connection portion 301 and a second connection portion 302. An isolation space 308 is formed by an interval between the first connection portion 301 and the second connection portion 302; the power-off protection portion 303 is disposed in the isolation space 308 and is respectively connected to the first connection portion 301 and the second connection portion 302. The power-off protection portion 303 includes a first connection segment 304 and a second connection segment 305 that are sequentially connected. The thickness of the second connection segment 305 is less than the thickness of the first connection segment 304, and / or the width of the second connection segment 305 is less than the width of the first connection segment 304.

[0054] In some embodiments, the first connection portion 301 is arranged to be connected to the pole 400. The second connection portion 302 surrounds the outside of the first connection portion 301. An isolation space 308 is formed by an interval between the second connection portion 302 and the first connection portion 301; the second connection portion 302 is arranged to be connected to the core 800.

[0055] It should be noted that the power-off protection portion 303 is provided on the current collector plate 300. When a runaway occurs inside the battery 1000, the main function of the power-off protection portion 303 is to be broken by impact, so as to disconnect the connection between the pole 400 and the core 800, causing the entire battery 1000 to lose power and avoiding a short-circuit phenomenon; specifically, when the pressure inside the battery 1000 reaches a certain value, under the action of the internal air pressure (i.e., impact force), the power-off protection portion 303 deforms upward and breaks, so that the first connection portion 301 and the second connection portion 302 are disconnected, and further the pole 400 and the core 800 are disconnected from the electrical connection, thereby ensuring that the battery 1000 does not have a short-circuit phenomenon and improving the safety performance of the battery 1000.

[0056] The power-off protection part 303 includes a first connection section 304 and a second connection section 305. Among them, the cross-sectional area for current passing of the second connection section 305 is smaller than that of the first connection section 304. Further, the thickness of the second connection section 305 is smaller than that of the first connection section 304, and / or the width of the second connection section 305 is smaller than that of the first connection section 304. By reducing the thickness and / or width of the second connection section 305, the second connection section 305 of the power-off protection part 303 can be made to break preferentially, improving the safety performance.

[0057] It should be noted that condition one is defined as limiting the thickness of the second connection section 305 to be smaller than that of the first connection section 304, and condition two is defined as limiting the width of the second connection section 305 to be smaller than that of the first connection section 304. In actual application, condition one and condition two can be selected according to the actual situation, that is, either one can be selected for use, or both can be selected for use simultaneously.

[0058] Specifically, the specific connection method between the first connection section 304 and the second connection section 305 is not limited and is selected according to the actual layout situation. For example, in one embodiment, the first connection section 304 is connected to the first connection part 301, and the second connection section 305 is connected to the second connection part 302; in another embodiment, the first connection section 304 is connected to the second connection part 302, and the second connection section 305 is connected to the first connection part 301.

[0059] Specifically, in this embodiment, please refer to Figure 2 and Figure 4 Considering that the sealing member 500 and the insulating member 700 are provided above the current collecting plate 300, in order to avoid interference between the current collecting plate 300 and the sealing member 500 and the insulating member 700, the thickness of the second connection section 305 is smaller than that of the first connection section 304. The first connection section 304 is connected to the first connection part 301, and the second connection section 305 is connected to the second connection part 302. In this way, the thickness of the second connection section 305 is smaller and the occupied space is also smaller, and interference with the sealing member 500 and the insulating member 700 can be avoided.

[0060] More specifically, the breaking mode of the power-off protection part 303 can be that when the air pressure of the gas in the cavity of the battery 1000 reaches a certain value, an impact force impacts the power-off protection part 303 to break it, or when the temperature in the battery 1000 reaches a certain value, the power-off protection part 303 melts at high temperature.

[0061] Further, in this embodiment, the second connecting section 305 is broken by air pressure. To meet the connection strength, the fracture strength of the material of the second connecting section 305 is greater than or equal to 60 MPa. Specifically, in this embodiment, when the air pressure in the cavity of the battery 1000 reaches a certain value, the cavity of the battery 1000 can no longer accommodate more gas. At this time, the force generated by the gas in the cavity of the battery 1000 pushes the second connecting section 305 to deform away from the winding core 800. Thus, the second connecting section 305 will break and disconnect from the first connecting section 304, thereby achieving power-off protection.

[0062] It should be noted that the current collector plate 300 provided in this embodiment is integrally formed, that is, the first connecting portion 301, the second connecting portion 302, the first connecting section 304 and the second connecting section 305 are integrally formed. Therefore, the materials of the first connecting portion 301, the second connecting portion 302, the first connecting section 304 and the second connecting section 305 are the same. That is, if the material of the second connecting section 305 is described hereinafter, it means that the materials of the first connecting section 304, the first connecting portion 301 and the second connecting portion 302 are the same as those of the second connecting section 305. For example, when the material of the second connecting section 305 is copper, it means that the materials of the first connecting section 304, the first connecting portion 301 and the second connecting portion 302 are all copper. Similarly, since the first connecting portion 301, the second connecting portion 302, the first connecting section 304 and the second connecting section 305 are integrally formed, the fracture strengths of the materials of the first connecting portion 301, the second connecting portion 302, the first connecting section 304 and the second connecting section 305 are also the same. For example, when the fracture strength of the material of the second connecting section 305 is described hereinafter as being between 60 MPa and 140 MPa, it means that the fracture strengths of the materials of the first connecting section 304, the first connecting portion 301 and the second connecting portion 302 are also between 60 MPa and 140 MPa, that is, the fracture strength of the entire current collector plate 300 is between 60 MPa and 140 MPa.

[0063] Further, the material of the second connecting section 305 is not limited as long as it is a metal that can conduct electricity. For example, the material of the second connecting section 305 can be copper, iron, aluminum, stainless steel, silver, aluminum alloy, etc.

[0064] Since the material fracture strengths of different materials are different, as a preferred embodiment, the material of the second connecting section 305 is preferably aluminum or copper. Specifically, in one embodiment, when the material fracture strength of the second connecting section 305 is between 60 MPa and 140 MPa, the material of the second connecting section 305 is aluminum; or, in another embodiment, when the material fracture strength of the second connecting section 305 is between 160 MPa and 300 MPa, the material of the second connecting section 305 is copper. It should be noted that the above range of material fracture strength is not a limiting condition for material selection, but a relatively preferred choice within the above range of material fracture strength. For example, when the material fracture strength of the second connecting section 305 exceeds 140 MPa and the material of the second connecting section 305 is aluminum, the second connecting section 305 may also break; similarly, when the material fracture strength of the second connecting section 305 exceeds 300 MPa and the material of the second connecting section 305 is copper, the second connecting section 305 may also break.

[0065] Furthermore, it should be noted that metals have different hardness states, and at the same thickness and different hardness states, the material fracture strengths of metals are also different. For example, when the material of the second connecting section 305 is aluminum and the thickness of the second connecting section 305 is 0.3 mm, the material fracture strength of aluminum in the one-quarter hardness state is different from that of aluminum in the two-quarter hardness state.

[0066] Specifically, please refer to Figure 4 and Figure 7 , define the thickness of the body portion 309 as T1. When T1 is greater than 0.8 mm, the thickness of the body portion 309 is too thick, and the volume occupied by the entire current collector plate 300 increases, which will cause the overall size of the battery 1000 to increase; when T1 is less than 0.1 mm, the thickness of the body portion 309 is relatively thin and the strength is insufficient, and it is easy to break during the welding process. Therefore, in this embodiment, T1 satisfies the following condition: 0.1 mm ≤ T1 ≤ 0.8 mm. Within the above range, the body portion 309 will neither cause the overall size of the battery 1000 to be too large due to its thickness nor be easily broken due to its thinness.

[0067] Even further, please continue to refer to Figure 3 and Figure 7, define the thickness of the second connecting section 305 as T2, where T2 satisfies the following conditions: T2 = T1 - Z0, and the value range of Z0 is 0.05 mm to 0.4 mm, and T1 > Z0. If the thickness of the second connecting section 305 is too large, the impact force required for the second connecting section 305 to break will be greater. When the air pressure value in the cavity of the battery 1000 is too large, it cannot be released in time, and the battery 1000 will explode, causing danger. Therefore, the thickness of the second connecting section 305 should not be too thick, generally controlled to be 0.05 to 0.4 mm smaller than the thickness of the body portion 309. At the same time, T2 also needs to satisfy the following conditions: T2 = aT1, where a is the fifth coefficient and 0.25 ≤ a ≤ 0.7. It should be noted that when a is less than 0.25, the thickness of the second connecting section 305 is too thin to work properly. When a is greater than 0.7, the thickness of the second connecting section 305 is relatively thick, and it is easy for the second connecting section 305 not to break, resulting in thermal runaway of the battery 1000. Specifically, for example, if the thickness T1 of the body portion 309 is 0.5 mm and Z0 is 0.2 mm, by calculating with the formula T2 = T1 - Z0, T2 is 0.3 mm. At this time, T1 is 0.5 mm, T2 is 0.3 mm, and T2 / T1 = 0.6, that is, a is 0.6, which satisfies 0.25 ≤ a ≤ 0.7. Therefore, the final value of T2 is 0.3 mm.

[0068] It should be noted that the second connecting portion 302 is connected to the winding core 800. Define the diameter of the winding core 800 as S1, define the width of the second connecting section 305 as Q1, and define the diameter of the current collecting plate as s. Among them, s < S1 and Q1 < (S1 / 2). If s is greater than S1 and Q1 is greater than (S1 / 2), it will cause the size of the entire current collecting plate 300 to be larger than the size of the battery 1000, that is, the edge of the current collecting plate 300 extends beyond the edge of the housing 900 of the battery 1000.

[0069] Please refer to Figure 5 and Figure 6 , in order to ensure that the second connecting section 305 can break smoothly, the impact force received by the second connecting section 305 needs to be greater than the breaking force of the current collecting plate 300. Among them, define the impact force received when the second connecting section 305 breaks as F 300 , the breaking force of the current collecting plate 300 is mainly related to the material breaking strength of the current collecting plate 300; the impact force F received when the second connecting section 305 breaks 300 , is mainly related to the opening tension of the explosion-proof valve on the cover plate assembly. The opening tension of the explosion-proof valve is determined according to the opening pressure of the explosion-proof valve and its area. Specifically, in this embodiment, define the opening pressure of the explosion-proof valve as P 300 , there is a notch a on the explosion-proof valve, and the radius of the notch a is R300 When the second connection segment 305 breaks, the impact force F 300 = πR 300 2 P 300 ; Define the fracture strength of the material of the current collecting plate 300 (or the second connection segment 305) as σ 300 , Define the number of the power-off protection parts 303 as n 300 , Define the thickness of the main body part as T1, and define the width of the second connection segment 305 as Q1. Wherein, Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 , z is the first coefficient and 0.25 ≤ z ≤ 0.75, P 300 ranges from 1.4 MPa to 2.1 MPa, and R 300 ranges from 12 mm to 20 mm. More specifically, for example, when the opening pressure P 300 of the explosion-proof valve is 1.7 MPa, the radius R 300 of the notch a on the explosion-proof valve is 16 mm, the material of the current collecting plate 300 is aluminum, the fracture strength σ 300 of the material of the second connection segment 305 is 100 MPa, the thickness T1 of the main body part 309 is 0.5 mm, the number n 300 of the power-off protection parts 303 is 1, the first coefficient z is 0.5, according to the formula Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 It is calculated that the width Q1 of the second connection segment 305 ≤ 13.67 mm. Considering the convenience of processing and production, the cost of mold development and accuracy and other issues, the result of Q1 generally takes 13 mm.

[0070] Please refer to Figure 4 and Figure 5 , In order to avoid the phenomenon that the second connection segment 305 overlaps with the second connection part 302 when breaking, the power-off protection part 303 further includes a third connection segment 306. It should be noted that the second connection segment 305 is connected between the first connection segment 304 and the third connection segment 306. In one embodiment, the first connection segment 304 is connected to the first connection part 301, the third connection segment 306 is connected to the second connection part 302, and the first connection segment 304 and the third connection segment 306 are connected through the second connection segment 305. In another embodiment, the first connection segment 304 is connected to the second connection part 302, the third connection segment 306 is connected to the first connection part 301, and the first connection segment 304 and the third connection segment 306 are connected through the second connection segment 305.

[0071] Further, the thickness of the third connecting section 306 is not limited. Considering the fracture situation, the thickness of the third connecting section 306 is greater than the thickness of the second connecting section 305.

[0072] Further, please continue to refer to Figure 1 、 Figure 2 、 Figure 5 and Figure 7 . Generally, components such as a seal 500 and an insulator 700 are installed on the current collector plate 300. To avoid interference with the insulator 700 and the seal 500, the third connecting section 306, the second connecting section 305, and the first connecting section 304 enclose a groove 307. More specifically, since the thickness of the second connecting section 305 is less than the thicknesses of the first connecting section 304 and the third connecting section 306, the groove 307 is a stepped groove. In this embodiment, the main function of the groove 307 is to avoid components such as the seal 500 and the insulator 700. At the same time, the groove 307 also reduces the weight of the current collector plate 300, making the current collector plate 300 lighter.

[0073] It should be noted that the position of the second connecting section 305 also affects the fracture. Specifically, the specific position of the second connecting section 305 can be determined according to the length of the second connecting section 305, the distance from the second connecting section 305 to the first connecting portion 301, and the distance from the second connecting section 305 to the second connecting portion 302. Please refer to 6 and Figure 7, the first connecting section 304 has a first side 314 close to the second connecting section 305, and the third connecting section 306 has a second side 315 close to the first connecting section 304. Define the shortest distance between the first side 314 and the center line of the first connecting portion 301 as Q2, and the shortest distance between the second side 315 and the center line of the first connecting portion 301 as Q3. In this embodiment, the main function of the shortest distances Q2 and Q3 is to define the position of the second connecting section 305. When setting the position of the second connecting section 305, the main consideration is to avoid the height of the flanging of the terminal post 400 (a second flanging is formed by the inner bending of the terminal post 400, and the second flanging has a certain height). Therefore, the magnitudes of the shortest distances Q2 and Q3 are mainly affected by the position and dimensions of the terminal post 400. Specifically, the following conditions need to be satisfied first: Q3 > Q2; secondly, when the above conditions are met, the shortest distance Q2 satisfies the following condition: 6 mm ≤ 2Q2 ≤ 10 mm; at the same time, the shortest distance Q3 satisfies the condition: Q3 = (2Q2 + Z1) / 2, and the value range of Z1 is 1 - 4 mm. It should be noted that in the above formula, Z1 is the length of the second connecting section 305. More specifically, in one embodiment, the shortest distance Q2 between the first side 314 and the center line of the first connecting portion 301 is 5 mm. According to the formula Q3 = (2Q2 + Z1) / 2, when Z1 is 4 mm and Q2 is 5 mm, the distance Q3 between the second side 315 and the center line of the first connecting portion 301 is 7 mm, and the length of the second connecting section 305 is 2 mm. Therefore, when the lengths from both ends of the second connecting section 305 to the center line of the first connecting portion 301 are known and the length of the second connecting section 305 is also known, the position of the second connecting section 305 can also be determined.

[0074] Please refer to Figure 5 , Figure 6 and Figure 7 , the thickness of the third connecting section 306 is not limited as long as it does not interfere with components such as the insulating part 700. Specifically, in this embodiment, it is defined that the thickness of the first connecting section 304 is equal to the thickness of the third connecting section 306; further, in order to prevent the first connecting section 304 from breaking along with the second connecting section 305 during the fracture process, the thickness of the first connecting section 304 is set to be greater than the thickness of the second connecting section 305, and the thickness of the first connecting section 304 is less than the thickness of the first connecting portion 301, and the thickness of the third connecting section 306 is less than the thickness of the second connecting portion 302. In some other embodiments, the thickness of the first connecting section 304 can also be set to be greater than the thickness of the third connecting section 306.

[0075] Further, please continue to refer to Figure 6 and Figure 7 , define the width of the first connecting section 304 as Q4, where Q4 satisfies the following condition: 1.1Q1 ≤ Q4 ≤ 1.5Q1; define the width of the third connecting section 306 as Q5, where Q5 satisfies the following condition: 1.1Q1 ≤ Q5 ≤ 1.5Q1. It should be noted that on the premise that Q4 and Q5 satisfy the above conditions, the following conditions also need to be met: (2Q4) < S1, (2Q5) < S1, otherwise, the size of the current collecting plate 300 will exceed the size of the outer shell 900. Specifically, the values of Q4 and Q5 are mainly affected by the value of Q1 and the size of the core 800. According to the size of the core 800, a suitable second coefficient is selected. Specifically, the second coefficient is 1.1 to 1.5 to ensure that the size of the current collecting plate 300 does not exceed the size of the core 800. For example, in an embodiment, when the width Q1 of the second connecting section 305 is 13 mm and the value of S1 is 44.7 mm, at this time, the value range of Q4 is 14.3 mm to 19.5 mm, and the value range of Q5 is 14.3 mm to 19.5 mm. In another embodiment, when the width Q1 of the second connecting section 305 is 6 mm, the value of S1 is 17.5 mm, and when the second coefficient is 1.5, the calculated value of 1.5Q1 is 9 mm. Due to the limitation of (2Q4) < S1 and (2Q5) < S1, the calculated Q4 and Q5 at this time have exceeded the size of the core 800, so the radius value of the core 800, that is, (17.5 / 2) mm, can be used as the maximum limit. Optionally, the value range of Q4 is 6.6 mm to 8.7 mm, and the value range of Q5 is 6.6 mm to 8.7 mm. By setting 1.1Q1 ≤ Q4 ≤ 1.5Q1 and 1.1Q1 ≤ Q5 ≤ 1.5Q1, while ensuring the strength of the current collecting plate 300, when the battery 1000 is out of control internally, the power-off protection part can also break at a specific position, such as the position where the second connecting section 305 is located, to improve the safety performance of the battery 1000.

[0076] Please continue to refer to Figure 6 and Figure 7, the second connecting portion 302 is connected to the core 800, and the size of the second connecting portion 302 is mainly affected by the core 800; specifically, in this embodiment, the diameter of the core 800 is defined as S1, the second connecting portion 302 has a third side 316 away from the first connecting portion 301 and a fourth side 317 close to the first connecting portion 301, the shortest distance from the third side 316 to the center line of the first connecting portion 301 is defined as S2, and the shortest distance from the fourth side 317 to the center line of the first connecting portion 301 is defined as S3; further, if the size of S2 is too small, the size of the second connecting portion 302 is too small, resulting in difficulty in welding the second connecting portion 302 to the core 800. If the size of S2 is too large, the weight of the second connecting portion 302 will increase, resulting in a lighter weight in the middle of the current collector plate 300 and a heavier weight in the outer ring portion of the current collector plate 300, making the overall current collector plate 300 in an unbalanced state and easily causing offset misalignment. Therefore, S2 satisfies the following condition: S2 = (S1 - 2Z2) / 2, and the value range of Z2 is 4 to 10 mm; if the size of S3 is too small, the distance between the first connecting portion 301 and the second connecting portion 302 will be too small, which will interfere with the welding of the tabs in the inner circle of the current collector plate 300. If the size of S3 is too large, the distance between the first connecting portion 301 and the second connecting portion 302 will be too far, and the structure will not be compact. Therefore, S3 satisfies the following condition: S3 = S2 - Z3, and the value range of Z3 is 2 to 5 mm; furthermore, the length of the second connecting portion 302 (this length specifically refers to the distance in the radial direction of the current collector plate 300) can be obtained through S2 and S3, and the length of the second connecting portion 302 is S2 - S3. In this embodiment, the value range of the diameter S1 of the core 800 is 17.5 mm to 45 mm, and 2S2 < S1, S3 ≥ 1 mm.

[0077] Specifically, taking the diameter S1 of the core 800 as 44.7 mm as an example, the value relationship between S1, S2, and S3 is explained. The calculation process of S2 is as follows: When S1 is 44.7 mm and Z2 is 4 mm, according to the formula S2 = (S1 - 2Z2) / 2, the calculated result is 18.35 mm. The calculation process of S3 is as follows: When the value of S2 is 18.35 mm and the value of Z3 is 2 mm, according to the formula S3 = S2 - Z3, the calculated result is 16.35 mm. According to the results of S2 and S3, the length of the second connecting portion 302 can be obtained as 2 mm. It should be noted that in the actual production process of the product, considering issues such as production and processing convenience, mold development cost, and accuracy, the values of S2 and S3 will be rounded in the actual production process, and the specific values can be selected according to the actual situation.

[0078] Please continue to refer to Figure 5 、 Figure 6 and Figure 7 wherein the first connecting portion 301 is connected to the pole 400, so the dimensions during the welding of the first connecting portion 301 and the pole 400 need to be considered. In some embodiments, a through hole 324 is formed on the first connecting portion 301, and the pole 400 is formed with a first hole, and the first hole is correspondingly communicated with the through hole 324 to serve as a liquid-down channel when the battery 1000 is filled with liquid. Therefore, the size of the through hole 324 is mainly related to the size of the first hole on the pole 400; specifically, the diameter of the first hole is defined as S4, the first connecting portion 301 has a fifth side 318 close to the second connecting portion 302, and the shortest distance from the fifth side 318 to the center line of the first connecting portion 301 is defined as S5; a through hole 324 is formed on the first connecting portion 301, the first hole corresponds to the through hole 324, the through hole 324 has a sixth side 319, and the shortest distance from the sixth side 319 to the center line of the first connecting portion 301 is S6. Among them, S5 satisfies the following condition S5 = S6 + Z4, and the value range of Z4 is 1.5 to 3.5 mm; the shortest distance from the sixth side 319 to the center line of the first connecting portion 301 is S6, and S6 satisfies the following condition S6 = (Z5 + S4) / 2, the value range of Z5 is 0.5 to 1.5 mm, and the value range of S4 is 1 mm to 4 mm; in this embodiment, by limiting the sizes of S5 and S6, the length of the first connecting portion 301 (this length specifically refers to the distance in the radial direction of the current collector plate 300) can be obtained. For example, in one embodiment, the value of S4 is 3 mm, the value of Z5 is 1 mm, and the calculation result according to the formula S6 = (Z5 + S4) / 2 is 2 mm; the value of S6 is 2 mm, the value of Z4 is 2 mm, and the calculation result according to the formula S5 = S6 + Z4 is 4 mm, that is, the shortest distance S5 from the fifth side 318 to the center line of the first connecting portion 301 is 4 mm, and the shortest distance S6 from the sixth side 319 to the center line of the first connecting portion 301 is 2 mm, then the length of the first connecting portion 301 is S5 - S6 = 2 mm.

[0079] In some embodiments, the first connecting portion 301 is annular, and the second connecting portion 302 is annular.

[0080] In another embodiment, please refer to Figure 8 and Figure 9, the number of the power-off protection parts 303 is multiple. For example, the number of the power-off protection parts 303 is two, three, four, five, six, etc.; the multiple power-off protection parts 303 are arranged at intervals, and the isolation space 308 includes multiple avoidance through grooves 310, and each avoidance through groove 310 is located between two adjacent power-off protection parts 303. Since there are multiple power-off protection parts 303, the first connection part 301 and the second connection part 302 are connected by multiple power-off protection parts 303, and the connection is more stable, so that the structure of the current collecting plate 300 is more stable, and there is no risk of breakage during the installation process.

[0081] Please continue to refer to Figure 8 , the avoidance through groove 310 includes two first grooves 311 and two second grooves 312, each first groove 311 is connected to the corresponding second groove 312, each second connection section 305 is located between the two first grooves 311 of two adjacent avoidance through grooves 310, and each first connection section 304 is located between the two second grooves 312 of two adjacent avoidance through grooves 310. Specifically, the width of the second connection section 305 is defined by the two first grooves 311, and the width of the first connection section 304 is defined by the two second grooves 312.

[0082] Furthermore, the second groove 312 extends along the length direction of the first connection section 304, the first groove 311 is an arc groove, and the center of the arc groove is concentric with the center of the first connection part 301; with such a setting, the shapes of the first connection section 304 and the second connection section 305 can be defined by the first groove 311 and the second groove 312.

[0083] Even further, the avoidance through groove 310 further includes a connection groove 313, the connection groove 313 communicates with two corresponding second grooves 312, and is located on the side of the two second grooves 312 away from the two first grooves 311. The connection groove 313 communicates with the second groove 312, so that only the first connection part 301 and the second connection part 302 can be connected by multiple power-off protection parts 303.

[0084] Please refer to Figure 8 , Figure 9 and Figure 10 , define the impact force received when the second connection section 305 is disconnected as F 300 , in order to ensure that the second connection section 305 can be broken smoothly, F 300 needs to be greater than the breaking force of the current collecting plate 300, and the breaking force of the current collecting plate 300 is mainly related to the material breaking strength of the current collecting plate 300; the impact force F received when the second connection section 305 is broken300 , which is mainly related to the opening tensile force of the explosion-proof valve. The opening tensile force of the explosion-proof valve is determined according to the opening pressure and the area of the explosion-proof valve. Specifically, in this embodiment, the opening pressure of the explosion-proof valve is defined as P 300 , a notch a is provided on the explosion-proof valve, and the radius of the notch a is R 300 , then the pressure F received when the second connecting section 305 breaks 300 =πR 300 2 P 300 , the fracture strength of the material of the current collector plate 300 is defined as σ 300 , the number of the power-off protection parts 303 is defined as n 300 , the width of the second connecting section 305 is defined as Q1, where Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 , z is the first coefficient and 0.25 ≤ z ≤ 0.75, and the value of P 300 ranges from 1.4 MPa to 2.1 MPa, and the value of R 300 ranges from 12 mm to 20 mm. More specifically, for example, when the opening pressure P 300 of the explosion-proof valve is 1.7 MPa, the radius R 300 of the notch a on the explosion-proof valve is 16 mm, the material of the current collector plate 300 is aluminum, the fracture strength σ 300 of the material of the second connecting section 305 is 100 MPa, the thickness T1 of the main body part 309 is 0.5 mm, and the number n 300 of the power-off protection parts 303 is 4, and when the first coefficient z is 0.5, according to the formula Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 , it is calculated that the width Q1 of the second connecting section 305 ≤ 3.42 mm. It can be understood that in the actual production process of the product, considering issues such as the convenience of production and processing, the cost of mold development, and precision, the result of Q1 is usually taken as 3 mm.

[0085] It should be noted that when the current collector plate 300 deviates during the welding positioning process, the current collector plate 300 may exceed the outer contour of the core 800, resulting in the current collector plate 300 piercing the insulating member 700 and then contacting the outer shell 900 (such as a steel shell), thus posing a risk of short circuit. To avoid the above problems, the dimensions of the second connecting portion 302 need to be defined. Specifically, define the diameter of the core 800 as S1, the second connecting portion 302 has a seventh side 320 away from the first connecting portion 301, and define the shortest distance from the seventh side 320 to the center line of the first connecting portion 301 as S7. Among them, S7 satisfies the following condition: S7 = (S1 - 2Z6) / 2, and the value range of Z6 is 0.6 - 2.5 mm, which is convenient for calculating the dimensions of the second connecting portion 302; the first connecting portion 301 has an outer side close to the second connecting portion 302, define the side with the shortest distance from the center line of the first connecting portion 301 among the sides of the outer side as the fifth side 318, and define the shortest distance from the fifth side 318 to the center line of the first connecting portion 301 as S5. The connecting groove 313 has an eighth side 321 away from the first connecting portion 301, and the shortest distance from the eighth side 321 to the center line of the first connecting portion 301 is S8. Among them, S8 satisfies the following condition: S7 > S8, S8 = S5 + Z9, and the value range of Z9 is 2 - 8 mm. More specifically, in this embodiment, when the diameter S1 of the core 800 takes a value of 44.7 mm, the value of Z6 takes 2.5 mm, the value of Z9 takes 2 mm, and the value of S5 takes 4 mm, the result calculated according to the formula S7 = (S1 - 2Z6) / 2 is 19.85 mm, and the result calculated according to the formula S8 = S5 + Z9 is 6 mm. Therefore, S8 is 6 mm. According to the results of S7 and S8, the length of the second connecting portion 302 can be obtained as 13.85 mm (this length specifically refers to the distance in the radial direction of the current collector plate 300). It should be noted that during the actual production process of the product, considering issues such as the convenience of production and processing, the cost of mold development, and precision, the value of S7 will be rounded in the actual production process, and the specific value can be selected according to the actual situation.

[0086] Further, please continue to refer to Figure 8 、 Figure 9 and Figure 10, define the thickness of the body portion 309 as T1, the width of the second connection segment 305 as Q1. The first groove 311 has a ninth side 322 away from the first connection portion 301 and a tenth side 323 close to the first connection portion 301. Define the shortest distance from the ninth side 322 to the center line of the first connection portion 301 as S9, and define the shortest distance from the tenth side 323 to the center line of the first connection portion 301 as S 10 , S9 satisfies the following condition: S9 > S 10 , S9 = S7 - Z7Q1, where the value range of Z7 is 1.1 to 2.5; S 10 satisfies the following condition S 10 = S9 - Z8T1, where the value range of Z8 is 1.1 to 2.5, Z7 is the third coefficient, and Z8 is the fourth coefficient. In this embodiment, according to the above calculations, the value of S7 is 19.85 mm. When the value of Z7 is 2.5, the value of Q1 is 3 mm, the value of Z8 is 2, and the value of T1 is 0.5 mm, the result calculated according to the formula S9 = S7 - Z7Q1 is 12.35 mm, and according to the formula S 10 = S9 - Z8T1, the calculated result is 11.35 mm; the shortest distance S9 from the ninth side 322 to the center line of the first connection portion 301 is 12.35 mm, and the shortest distance S 10 from the tenth side 323 to the center line of the first connection portion 301 is 11.35 mm. The length of the second connection segment 305 is 1 mm (this length specifically refers to the distance in the radial direction of the current collector plate 300). It should be noted that during the actual production process of the product, considering issues such as the convenience of production and processing, the cost of mold development, and accuracy, the values of S9 and S 10 will be rounded in the actual production process, and the specific values can be selected according to the actual situation.

[0087] The following specifically describes the data of each embodiment (it should be understood that the data of the following embodiments are only used to explain the present application and are not used to limit the present application):

[0088] Embodiment 1

[0089] The diameter S1 of the core is 44.7 mm; the diameter S4 of the first hole on the pole is 3 mm; the material of the current collector plate is aluminum, and the power-off protection part is set to one. The specific dimensions of the current collector plate are as follows:

[0090] The thickness T1 of the body portion is 0.5 mm;

[0091] The thickness T2 of the second connection segment is 0.15 mm (where the value of z0 is 0.35 mm and the value of a is 0.3);

[0092] The width Q1 of the second connecting section is 12 mm (where Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 ,F 300 =πR 300 2 P 300 ,R 300 =16 mm,P 300 =1.6 MPa,z=0.47,σ 300 =100 MPa,n 300 =1);

[0093] The distance Q2 from the first side to the center line of the first connecting part is 5 mm;

[0094] The distance Q3 from the second side to the center line of the first connecting part is 7 mm;

[0095] The width Q4 of the first connecting section is 18 mm;

[0096] The width Q5 of the third connecting section is 18 mm;

[0097] The shortest distance S2 from the third side to the center line of the first connecting part is 18.35 mm;

[0098] The shortest distance S3 from the fourth side to the center line of the first connecting part is 16.35 mm;

[0099] The shortest distance S5 from the fifth side to the center line of the first connecting part is 4 mm;

[0100] The shortest distance S6 from the sixth side to the center line of the first connecting part is 2 mm.

[0101] It should be noted that the setting methods and specific structures of Examples 2-26 and Comparative Examples 1-14 are the same as those of Example 1, only the specific parameters are different. The setting methods and specific structures of Examples 2-26 and Comparative Examples 1-14 can be referred to Example 1, and will not be elaborated here one by one; the specific parameters of Examples 2-26 and Comparative Examples 1-14 are shown in Table 1-4.

[0102] Table 1 Examples 2-7, Comparative Examples 1-4

[0103] B2 B3 B4 B5 B6 B7 D1 D2 D3 D4 Material Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum <![CDATA[T1]]> 0.8 0.5 0.5 0.8 0.5 0.8 0.85 0.9 0.1 0.8 <![CDATA[T2]]> 0.56 0.2 0.125 0.4 0.25 0.55 0.035 0.8 0.07 0.3 <![CDATA[z0]]> 0.24 0.3 0.375 0.4 0.25 0.25 0.815 0.1 0.03 0.5 a 0.7 0.4 0.25 0.5 0.5 0.6875 0.041 0.889 0.7 0.375 <![CDATA[Q1]]> 12 12 12 12 12 12 12 12 12 12 <![CDATA[Q4]]> 18 18 18 18 18 18 18 18 18 18 <![CDATA[Q5]]> 18 18 18 18 18 18 18 18 18 18 <![CDATA[S2]]> 18.35 18.35 18.35 18.35 18.35 18.35 18.35 18.35 18.35 18.35 <![CDATA[S3]]> 16.35 16.35 16.35 16.35 16.35 16.35 16.35 16.35 16.35 16.35 <![CDATA[2Q3]]> 14 14 14 14 14 14 14 14 14 14 <![CDATA[2Q2]]> 10 10 10 10 10 10 10 10 10 10 <![CDATA[S5]]> 4 4 4 4 4 4 4 4 4 4 <![CDATA[S6]]> 2 2 2 2 2 2 2 2 2 2

[0104] Note: In the above table, B represents an example, D represents a comparative example, that is, B2 represents Example 2, D1 represents Comparative Example 1, and so on.

[0105] Table 2 Examples 8-17, Comparative Examples 5-6

[0106]

[0107] Note: In the above table, B represents the example, D represents the comparative example, that is, B8 represents Example 8, D5 represents Comparative Example 5, and so on.

[0108] Table 3 Examples 18 - 26

[0109]

[0110]

[0111] Note: In the above table, B represents the example, that is, B18 represents Example 18, and so on.

[0112] Table 4 Comparative Examples 7 - 14

[0113] D7 D8 D9 D10 D11 D12 D13 D14 Material Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum T1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 T2 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Q1 12 12 12 12 12 12 12 12 Q4 15 15 15 15 15 15 15 15 <![CDATA[Q5]]> 15 15 15 15 15 15 15 15 S2 18.35 18.35 18.35 18.35 18.35 18.35 18.35 18.35 S3 16.35 16.35 16.35 16.35 16.35 16.35 16.35 16.35 2Q3 6 12 9 15 11 16 6.5 11.5 2Q2 5 11 5 11 6 11 6 11 S5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 S6 1 1 1 1 1 1 1 1

[0114] Note: In the above table, D represents the comparative example, that is, D7 represents Comparative Example 7, and so on.

[0115] Example 27

[0116] The diameter S1 of the core is 44.7 mm; the diameter S4 of the first hole on the terminal post is 3 mm; the material of the current collector plate is copper, and there are four power-off protection parts. The specific dimensions of the current collector plate are as follows:

[0117] The thickness T1 of the main body part is 0.5 mm;

[0118] The thickness T2 of the second connection section is 0.15 mm (where the value of z0 is 0.35 mm and the value of a is 0.3);

[0119] The width Q1 of the second connection section is 3 mm (where Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 , F 300 = πR 300 2 P 300 , R 300 = 16 mm, P 300 = 1.6 MPa, z = 0.47, σ 300 = 100 MPa, n 300 = 4);

[0120] The width Q4 of the first connection section is 4.5 mm;

[0121] The shortest distance S5 from the fifth side to the center line of the first connection part is 4 mm;

[0122] The shortest distance S6 from the sixth side to the center line of the first connecting portion is 2 mm;

[0123] The shortest distance S7 from the seventh side to the center line of the first connecting portion is 19.85 mm;

[0124] The shortest distance S8 from the eighth side to the center line of the first connecting portion is 6 mm;

[0125] The shortest distance S9 from the ninth side to the center line of the first connecting portion is 12.35 mm;

[0126] The shortest distance S from the tenth side to the center line of the first connecting portion 10 is 11.35 mm.

[0127] It should be noted that the setting methods and specific structures of Examples 28 - 40 and Comparative Examples 15 - 18 are the same as those of Example 27, only the specific parameters are different. For the setting methods and specific structures of Examples 28 - 40 and Comparative Examples 15 - 18, reference can be made to Example 27, and they will not be elaborated here one by one; the specific parameters of Examples 28 - 40 and Comparative Examples 15 - 18 are shown in Tables 5 and 6.

[0128] Table 5 Examples 28 - 37, Comparative Examples 15 - 16

[0129]

[0130]

[0131] Note: In the above table, B represents an example, and D represents a comparative example. That is, B28 represents Example 28, D15 represents Comparative Example 15, and so on.

[0132] Table 6 Examples 38 - 40, Comparative Examples 17 - 18

[0133] <![CDATA[Q1]]> Material <![CDATA[T1]]> <![CDATA[T2]]> <![CDATA[Q4]]> <![CDATA[S7]]> <![CDATA[S9]]> <![CDATA[S 10 > <![CDATA[S8]]> <![CDATA[S5]]> <![CDATA[S6 <!-- 15 -->]]> B38 3 Aluminum 0.5 0.15 4.5 19.85 16.55 16 6 4 2 B39 3 Aluminum 0.5 0.15 4.5 15 10.5 9.7 6 4 2 B40 3 Aluminum 0.5 0.15 4.5 12 8.7 8 6 4 2 D17 3 Aluminum 0.5 0.15 4.5 20 19 17 6 4 2 D18 3 Aluminum 0.5 0.15 4.5 8.15 4.5 4.2 2.8 2.5 1

[0134] Note: In Table 6, B represents an example, and D represents a comparative example. That is, B38 represents Example 38, D17 represents Comparative Example 17, and so on. Among them, the value of S1 in B38 is 44.7 mm, the value of S1 in B39 is 35 mm, the value of S1 in B40 is 29 mm, the value of S1 in D17 is 44.7 mm, and the value of S1 in D18 is 21.3 mm.

[0135] Experimental verification

[0136] Examples 1 - 40 and Comparative Examples 1 - 18 were actually installed, and their performance was tested after installation:

[0137] 1. Test on the internal resistance of the current collector plate: The test is carried out according to the records in "SJ / T 10690-1996 General Specification for Digital DC Micro-Resistance Measuring Instruments". Among them, the minimum measurement resolution is 0.01 mΩ, the voltage is 1 mV, and the test position is the resistance value from the welding area between the current collector plate and the core to the welding area between the steel shell and the current collector plate after the core is welded. The test results are shown in Table 7. It should be noted that an internal resistance between 0.50 and 3.00 mΩ indicates compliance with the process requirements;

[0138] 2. Short-circuit test: The test is carried out according to the external short-circuit test method of the battery recorded in 6.2.4 of GB31458.

[0139] When the battery shows a thermal runaway phenomenon, the battery cover plate is impacted and opened to release pressure, and the power-off protection part set on the current collector plate can also break under the action of the impact force. Therefore, the battery may have the following situations: the current collector plate disconnects and powers off, the current collector plate is short-circuited after disconnection and reconnection, or other situations that cause the battery to short-circuit. When the current collector plate disconnects and powers off and the battery does not have a short-circuit situation, it indicates that the battery meets the process requirements.

[0140] The batteries assembled with the current collector plates prepared according to the data of Examples 1-40 and the batteries assembled with the current collector plates prepared according to the data of Comparative Examples 1-18 are placed in the same environment, and air pressure is applied to the batteries in each example through the internal pressurization device inside the battery. Record the power-off situation of the current collector plate and conduct a short-circuit test on the battery. The specific test results are shown in Table 7.

[0141] Table 7 Test Results

[0142]

[0143]

[0144]

[0145] 3. Actual impact force test: By simulating the thermal runaway of the battery, an internal pressure pressurization device is set inside the battery, and the verification test of the parallel group is realized by controlling the acceleration rate of the internal pressure of the battery. Among them, it should be noted that the valve opening value of the cover plate is determined by the cover plate process. Specifically, the opening pressure of the explosion-proof valve is between 1.4 and 2.1 MPa. When the actual impact force range is between 1.4 and 2.1 MPa and the second connection section disconnects within the above range, it proves that the current collector plate is qualified. The specific test situation is as follows:

[0146] Four groups of batteries are provided. Each group of batteries includes batteries assembled with current collectors prepared according to the data of Examples 1-40, and batteries assembled with current collectors prepared according to the data of Comparative Examples 1-18. Place the first group of batteries in the same environment, apply air pressure to 1.0 MPa (the air pressure under normal use conditions) through the internal pressure pressurizing device inside the battery, and detect whether the second connection section is disconnected; place the second group of batteries in the same environment, apply air pressure to 1.6 MPa through the internal pressure pressurizing device inside the battery, and detect whether the second connection section is disconnected; place the third group of batteries in the same environment, apply air pressure to 1.7 MPa through the internal pressure pressurizing device inside the battery, and detect whether the second connection section is disconnected; place the fourth group of batteries in the same environment, apply air pressure to 1.8 MPa through the internal pressure pressurizing device inside the battery, and detect whether the second connection section is disconnected; the test results are shown in Table 8.

[0147] Table 8 Test Results

[0148]

[0149]

[0150]

[0151] Conclusion

[0152] 1. From Examples 1-7 and Comparative Examples 1-4, it can be concluded that:

[0153] For the batteries provided in Examples 1-7, in the internal resistance test, the internal resistance values are all between 0.50 and 3.00 mΩ, and the internal resistance meets the requirements; during the short-circuit test, no short circuit occurs, meeting the short-circuit test requirements; during the impact test, at an air pressure of 1.0 MPa, the second connection section does not break, meeting the normal use requirements, and at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section disconnects normally, meeting the impact test requirements.

[0154] For the battery provided in Comparative Example 1, during the impact test, at an air pressure of 1.0 MPa, the second connection section breaks and cannot be used normally.

[0155] For the battery provided in Comparative Example 2, during the impact test, at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section does not break, not meeting the impact test requirements.

[0156] For the battery provided in Comparative Example 3, during the short-circuit test, it is in a short-circuit state, not meeting the short-circuit test requirements.

[0157] For the battery provided in Comparative Example 4, in the internal resistance test, the resistance value exceeds 3.00 mΩ, not meeting the internal resistance test requirements.

[0158] 2. It can be concluded from Examples 8 - 17 and Comparative Examples 5 - 6 that:

[0159] For the batteries provided in Examples 8 - 17, during the internal resistance test, the internal resistance values are all between 0.50 and 3.00 mΩ, meeting the requirements; during the short - circuit test, no short - circuit occurred, meeting the short - circuit test requirements; during the impact force test, at a gas pressure of 1.0 MPa, the second connection section did not break, meeting the normal use requirements, and at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section disconnected normally, meeting the impact force test requirements.

[0160] For the battery provided in Comparative Example 5, during the impact force test, at a gas pressure of 1.0 MPa, the second connection section broke and could not be used normally.

[0161] For the battery provided in Comparative Example 6, during the impact force test, at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section did not break, not meeting the impact force test requirements.

[0162] 3. It can be concluded from Examples 18 - 26 and Comparative Examples 7 - 14 that:

[0163] For the batteries provided in Examples 18 - 26, during the internal resistance test, the internal resistance values are all between 0.50 and 3.00 mΩ, meeting the requirements; during the short - circuit test, no short - circuit occurred, meeting the short - circuit test requirements; during the impact force test, at a gas pressure of 1.0 MPa, the second connection section did not break, meeting the normal use requirements, and at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section disconnected normally, meeting the impact force test requirements.

[0164] For the batteries provided in Comparative Examples 7 and 8, during the impact force test, at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section did not break, not meeting the impact force test requirements.

[0165] For the batteries provided in Comparative Examples 9 - 14, during the short - circuit test, they were all in a short - circuit state, not meeting the short - circuit test requirements.

[0166] 4. It can be concluded from Examples 27 - 37 and Comparative Examples 15 - 16 that:

[0167] The batteries provided in Examples 27 - 37 have internal resistance values between 0.50 and 3.00 mΩ during the internal resistance test, and the internal resistance meets the requirements; during the short - circuit test, no short - circuit occurs, meeting the short - circuit test requirements; during the impact test, at a gas pressure of 1.0 MPa, the second connection section does not break, meeting the normal use requirements, and at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section disconnects normally, meeting the impact test requirements.

[0168] For the battery provided in Comparative Example 15, during the impact test, at a gas pressure of 1.0 MPa, the second connection section breaks and cannot be used normally.

[0169] For the battery provided in Comparative Example 16, during the impact test, at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section does not break, not meeting the impact test requirements.

[0170] 5. It can be concluded from Examples 38 - 40 and Comparative Examples 17 - 18 that:

[0171] The batteries provided in Examples 38 - 40 have internal resistance values between 0.50 and 3.00 mΩ during the internal resistance test, and the internal resistance meets the requirements; during the short - circuit test, no short - circuit occurs, meeting the short - circuit test requirements; during the impact test, at a gas pressure of 1.0 MPa, the second connection section does not break, meeting the normal use requirements, and at gas pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connection section disconnects normally, meeting the impact test requirements.

[0172] For the batteries provided in Comparative Examples 17 - 18, during the short - circuit test, they are all in a short - circuit state, not meeting the short - circuit test requirements.

[0173] In summary, the current - collecting plates provided in Examples 1 - 40 have a small internal resistance value and less energy consumption. During the impact test, they all break normally. When the internal pressure value of the battery is abnormal, the current - collecting plate can break, disconnecting the connection between the pole column and the winding core, causing the entire battery to power off, with a high safety factor and the ability to avoid thermal runaway.

[0174] The above has introduced the embodiments of the present application in detail. Specific examples are used in this article to elaborate on the principle and implementation method of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, based on the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A current collection tray, characterized in that, The current collecting disk includes: A main body part including a first connecting part and a second connecting part, with a separation space formed between the first connecting part and the second connecting part; and, At least one power-off protection part disposed in the separation space, and the first connecting part and the second connecting part are connected through the power-off protection part. The power-off protection part includes a first connecting section and a second connecting section connected in sequence. Among them, the thickness of the second connecting section is less than that of the first connecting section, and / or the width of the second connecting section is less than that of the first connecting section.

2. The current collector tray according to claim 1, characterized in that, The thickness of the main body part is T1, where 0.1mm ≤ T1 ≤ 0.8mm.

3. The current collector tray according to claim 2, characterized in that, The thickness of the second connecting section is T2, where T2 = T1 - Z0, 0.05mm ≤ Z0 ≤ 0.4mm, and T2 = aT1, a is the fifth coefficient, 0.25 ≤ a ≤ 0.7, and T1 > Z0.

4. The current collector plate according to claim 1, characterized in that, The second connecting part is arranged to be connected to the core. Define the diameter of the core as S1, the width of the second connecting section as Q1, and the diameter of the current collecting disk as s. Among them, s < S1, and Q1 < (S1 / 2).

5. The current collector tray according to claim 4, characterized in that, Define the impact force received when the second connection segment is disconnected as F 300 , the fracture strength of the material of the current collecting plate is σ 300 , the number of the power-off protection parts is n 300 , the thickness of the main body part is T1, where Q1 ≤ [(zF 300 ) / (σ 300 T1)] / n 300 , 0.25 ≤ z ≤ 0.75, z is the first coefficient, σ 300 ≥ 60 MPa.

6. The current collector tray according to any one of claims 1-5, characterized in that, The power-off protection part further includes a third connecting section. The second connecting section is connected between the first connecting section and the third connecting section. The thickness of the third connecting section is greater than that of the second connecting section. The third connecting section, the second connecting section, and the first connecting section enclose a groove.

7. The current collector tray according to claim 6, characterized in that The first connecting section has a first side close to the second connecting section, and the third connecting section has a second side close to the first connecting section. Define the shortest distance between the first side and the center line of the first connecting part as Q2, and the shortest distance between the second side and the center line of the first connecting part as Q3. Among them, Q3 > Q2, Q3 = (2Q2 + Z1) / 2, 1 ≤ Z1 ≤ 4mm, 6mm ≤ 2Q2 ≤ 10mm.

8. The current collector plate according to claim 6, characterized in that, The thickness of the first connecting section is greater than or equal to that of the third connecting section. One of the first connecting section and the third connecting section is connected to the first connecting part, and the other is connected to the second connecting part.

9. The current collector plate according to claim 6, wherein, The second connecting part is arranged to be connected to the core. Define the diameter of the core as S1, the width of the first connecting section as Q4, the width of the third connecting section as Q5, and the width of the second connecting section as Q1. Among them, Q4 < (S1 / 2), Q5 < (S1 / 2), 1.1Q1 ≤ Q4 ≤ 1.5Q1, 1.1Q1 ≤ Q5 ≤ 1.5Q1.

10. The current collector tray according to claim 7 or 8 or 9, characterized in that The second connecting part is arranged to be connected to the core. Define the diameter of the core as S1. The second connecting part has a third side far from the first connecting part and a fourth side close to the first connecting part. The shortest distance from the third side to the center line of the first connecting part is S2, and the shortest distance from the fourth side to the center line of the first connecting part is S3. Among them, 2S2 < S1, S3 ≥ 1mm, 17.5mm ≤ S1 ≤ 45mm.

11. The current collector tray according to claim 10, characterized in that S2 = (S1 - 2Z2) / 2, 2Z2 < S1, 4mm ≤ Z2 ≤ 10mm, S3 = S2 - Z3, Z3 < S2, 2mm ≤ Z3 ≤ 5mm.

12. The current collecting plate according to any one of claims 1-5, characterized in that, The first connecting part is arranged to be connected to the pole column. The pole column is formed with a first hole, and the diameter of the first hole is defined as S4. The first connecting part has a fifth side close to the second connecting part. The shortest distance from the fifth side to the center line of the first connecting part is S5. A through hole is formed on the first connecting part. The first hole and the through hole are correspondingly communicated. The through hole has a sixth side. The shortest distance from the sixth side to the center line of the first connecting part is S6. Among them, S5 = S6 + Z4, 1.5mm ≤ Z4 ≤ 3.5mm, S6 = (Z5 + S4) / 2, 0.5mm ≤ Z5 ≤ 1.5mm.

13. The current collector tray according to any one of claims 1-5, characterized in that, The number of the power-off protection parts is multiple; The isolation space includes a plurality of avoidance through grooves, and each avoidance through groove is located between two adjacent power-off protection parts.

14. The current collector plate according to claim 13, characterized in that, The avoidance through groove includes two first grooves and two second grooves. Each first groove is connected to the corresponding second groove. Each second connecting section is located between the two first grooves of two adjacent avoidance through grooves. Each first connecting section is located between the two second grooves of two adjacent avoidance through grooves.

15. The current collector tray according to claim 14, characterized in that, The second groove extends along the length direction of the first connecting section. The first groove is an arc groove, and the center of the arc groove is concentric with the center of the first connecting part; The avoidance through groove further includes a connecting groove, and the connecting groove extends along a part of the outer circumference of the first connecting part and communicates with two corresponding second grooves, and is located on the side of the two second grooves away from the two first grooves.

16. The current collector tray according to claim 15, characterized in that, Define the diameter of the core as S1. The second connecting part has a seventh side far from the first connecting part. The shortest distance from the seventh side to the center line of the first connecting part is S7. Among them, S7 = (S1 - 2Z6) / 2, 0.6mm ≤ Z6 ≤ 2.5mm.

17. The current collector tray according to claim 16, wherein Define the thickness of the main body part as T1, the width of the second connecting section as Q1. The first groove has a ninth side away from the first connecting part and a tenth side close to the first connecting part. The shortest distance from the ninth side to the center line of the first connecting part is S9, and the shortest distance from the tenth side to the center line of the first connecting part is S 10 , where S9 > S 10 , S9 = S7 - Z7Q1, 1.1 ≤ Z7 ≤ 2.5, S 10 = S9 - Z8T1, 1.1 ≤ Z8 ≤ 2.5, Z7 is the third coefficient, and Z8 is the fourth coefficient.

18. The current collector tray according to claim 16, characterized in that, The first connecting part has an outer side close to the second connecting part. Define the side with the shortest distance to the center line of the first connecting part among the sides of the outer side as the fifth side. Define the shortest distance from the fifth side to the center line of the first connecting part as S5. The connecting groove has an eighth side far from the first connecting part. The shortest distance from the eighth side to the center line of the first connecting part is S8. Among them, S7 > S8, S8 = S5 + Z9, 2mm ≤ Z9 ≤ 8mm.

19. A battery, characterized in that, Including: The current collector plate according to any one of claims 1-18.

20. The battery according to claim 19, wherein, The battery further includes a cover plate assembly, a core, and a housing with at least one end open. The cover plate assembly includes a pole column. The housing has an accommodation cavity. The core and the current collector plate are both located in the accommodation cavity. The cover plate assembly is arranged at the opening. The first connecting part of the current collector plate is connected to the pole column, and the second connecting part is connected to the core.

21. The battery according to claim 20, wherein The cover plate assembly further includes a cover plate, a seal, and an insulator. The pole post passes through the cover plate. The seal is sleeved outside the pole post and is located between the pole post and the cover plate. The insulator is disposed below the cover plate. The current collector plate is disposed below the insulator.

22. The battery according to claim 20, wherein, The pole post is formed with a first hole, and a through hole is formed on the first connecting portion. The first hole and the through hole are correspondingly communicated.

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