Current collecting disc and battery

Abstract

A current collecting disc (300) and a battery (1000). The current collecting disc (300) comprises a body part (309) and at least one power-off protection part (303). The body part (309) comprises a first connection part (301) and a second connection part (302), the first connection part (301) and the second connection part (302) being spaced apart from each other to form an isolation space (308). The power-off protection part (303) is arranged in the isolation space (308), the first connection part (301) and the second connection part (302) being connected to each other by means of the power-off protection part (303). The power-off protection part (303) comprises, successively connected to each other, a first connection section (304) and a second connection section (305), the thickness of the second connection section (305) being less than the thickness of the first connection section (304), and / or the width of the second connection section (305) being less than the width of the first connection section (304).

Description

Collector plates and batteries

[0001] This application claims priority to the Chinese patent application with application number 202410391387.1 filed with the Chinese Patent Office on March 31, 2024, and priority to the Chinese patent application with application number 202411030929.9 filed with the Chinese Patent Office on July 29, 2024. The entire contents of the above applications are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a current collecting plate and a battery. Background Art

[0003] When the battery is subjected to abnormal conditions such as high temperature burns, heavy object impact, puncture, short circuit, overcharge, etc. during use, it is prone to safety accidents such as fire and explosion, which is directly related to the battery's reliability, service life, capacity and the personal safety of the user.

[0004] In related technologies, when the battery lacks a power-off function and uncontrollable temperature changes occur inside the battery, the battery system produces gas violently and the pressure inside the battery shell increases. 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 an internal short circuit in the battery, thereby causing thermal runaway and other phenomena, and the safety factor is low. SUMMARY OF THE INVENTION

[0005] This application aims to solve the problem that existing lithium-ion batteries have a low safety factor and are prone to thermal runaway.

[0006] In a first aspect, the present application provides a current collecting tray. The current collecting tray comprises:

[0007] a main body, comprising a first connecting portion and a second connecting portion, wherein the first connecting portion and the second connecting portion are spaced apart to form an isolation space; and

[0008] At least one power-off protection part is arranged in the isolation 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, wherein the thickness of the second connecting section is smaller than the thickness of the first connecting section, and / or the width of the second connecting section is smaller than the width of the first connecting section.

[0009] In a second aspect, the present application further provides a battery. The battery includes a current collecting plate, which includes:

[0010] a main body, comprising a first connecting portion and a second connecting portion, wherein the first connecting portion and the second connecting portion are spaced apart to form an isolation space; and

[0011] At least one power-off protection part is arranged in the isolation 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, wherein the thickness of the second connecting section is smaller than the thickness of the first connecting section, and / or the width of the second connecting section is smaller than the width of the first connecting section. Beneficial effects

[0012] In the technical solution of this application, the main body includes a first connecting portion and a second connecting portion. The first connecting portion can be connected to the terminal post, and the second connecting portion can be connected to the winding core. A power-off protection portion is provided on the current collecting disk. Its main purpose is to disconnect the terminal post and the winding core in the event of a battery outage, thereby disconnecting the entire battery and preventing a short circuit. Specifically, when the pressure inside the battery reaches a certain value, the internal gas pressure (i.e., impact force) causes the power-off protection portion to deform upward and break, disconnecting the first and second connecting portions. Disconnecting the first and second connecting portions further disconnects the terminal post and the winding core, thereby preventing a short circuit and improving battery safety. The power-off protection portion includes a first connecting segment and a second connecting segment. The flow cross-sectional area of ​​the second connecting segment is defined as smaller than the flow cross-sectional area of ​​the first connecting segment. That is, the thickness of the second connecting segment is smaller than the thickness of the first connecting segment, and / or the width of the second connecting segment is defined as smaller than the width of the first connecting segment. By reducing the thickness and / or width of the second connecting segment, the power-off protection portion breaks at the second connecting segment, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG1 is a schematic structural diagram of some implementations of the battery provided in this application.

[0014] FIG2 is a schematic structural diagram of some implementations of the cover plate assembly and the current collecting plate provided in the present application.

[0015] FIG3 is a schematic structural diagram of some other implementations of the cover plate assembly and the current collecting plate provided in the present application.

[0016] FIG4 is a schematic structural diagram of a current collecting plate provided by some implementations of the present application.

[0017] FIG5 is a cross-sectional view of the current collecting plate in FIG4 .

[0018] FIG6 is an enlarged schematic diagram of V in FIG4 .

[0019] FIG7 is an enlarged schematic diagram of W in FIG5 .

[0020] FIG8 is a schematic structural diagram of a current collecting plate provided in some other implementations of the present application.

[0021] FIG9 is a cross-sectional view of the current collecting plate in FIG8 .

[0022] FIG10 is an enlarged schematic diagram of X in FIG8 .

[0023] Description of reference numerals:

[0024] 300, current collecting plate; 301, first connecting portion; 302, second connecting portion; 303, power-off protection portion; 304, first connecting section; 305, second connecting section; 306, third connecting section; 307, groove; 308, isolation space; 309, main body; 310, avoidance slot; 311, first slot; 312, second slot; 313, connecting slot; 314. First side; 315. Second side; 316. Third side; 317. Fourth side; 318. Fifth side; 319. Sixth side; 320. Seventh side; 321. Eighth side; 322. Ninth side; 323. Tenth side; 324. Through hole; a. Notch; 400. Pole; 500. Seal; 600. Cover; 601. First flange; 700. Insulator; 800. Winding core; 900. Housing; 1000. Battery. Modes for Carrying Out the Invention

[0025] In related technologies, when the battery lacks a power-off function and uncontrollable temperature changes occur inside the battery, the battery system produces gas violently and the pressure inside the battery shell increases. When the pressure reaches a certain value, the components inside the battery are in a high-voltage state for a long time, which may cause damage and fracture, easily leading to an internal short circuit in the battery, resulting in thermal runaway and other phenomena, and the safety factor is low.

[0026] In view of this, the present application proposes a battery 1000. Figures 1 to 3 are schematic structural diagrams of an embodiment of the battery 1000 provided by the present application. Referring to Figure 1, the battery 1000 includes a current collecting tray 300. When the impact force inside the battery 1000 reaches a specific condition, the current collecting tray 300 can break and cut off the power, which has a high safety factor and prevents short circuits in the battery 1000. The battery 1000 also includes a cover assembly, a winding core 800, and a shell 900 with at least one end open. The cover assembly includes a pole 400. The shell 900 has a receiving cavity. The winding core 800 and the current collecting tray 300 are both located in the receiving cavity. The cover assembly is disposed at the opening. The first connecting portion 301 of the current collecting tray 300 is connected to the pole 400, and the second connecting portion 302 is connected to the winding core 800.

[0027] This application also provides a current collecting tray 100. Please refer to Figure 2, which is a schematic diagram illustrating the cooperation between a cover plate assembly and a current collecting tray 300 according to one embodiment of this application. In particular, the current collecting tray 300 in Figure 2 has a single power-off protection portion 303. Please refer to Figure 3, which is a schematic diagram illustrating the cooperation between a cover plate assembly and a current collecting tray 300 according to another embodiment of this application. In particular, the current collecting tray 300 in Figure 3 has multiple power-off protection portions 303.

[0028] Specifically, please continue to refer to Figure 2. The cover plate assembly includes a pole 400, a seal 500, a cover plate 600 and an insulating member 700. The pole 400 is inserted into the cover plate 600. The seal 500 is sleeved on the outside of the pole 400, and the seal 500 is located between the cover plate 600 and the pole 400. The end of the seal 500 close to the collecting plate 300 is folded outward to form a first flange 601. The first flange 601 is located between the cover plate 600 and the collecting plate 300. The insulating member 700 is arranged below the cover plate 600 and is connected to the first flange 601 of the seal 500; the collecting plate 300 is arranged below the insulating member 700 or below the seal 500, and the first connecting portion 301 of the collecting plate 300 is welded to the pole 400.

[0029] Please refer to Figure 3, which is a schematic diagram of the cooperation between the cover plate assembly and the current collecting plate 300 provided in another embodiment of the present application, wherein the current collecting plate 300 in Figure 3 has four power-off protection parts 303. Specifically, please continue to refer to Figure 3, the cover plate assembly includes a pole 400, a seal 500, a cover plate 600, and an insulating member 700. The pole 400 is inserted into the cover plate 600, and the seal 500 is sleeved on the outside of the pole 400, and the seal 500 is located between the cover plate 600 and the pole 400; the insulating member 700 is disposed below the cover plate 600, and the current collecting plate 300 is disposed below the insulating member 700. The first connecting portion 301 of the current collecting plate 300 is welded to the pole 400.

[0030] 4 to 10 are schematic structural diagrams of some embodiments of the current collecting plate 300 provided in the present application; the current collecting plate 300 will be described in detail below in conjunction with the main drawings.

[0031] The current collecting tray 300 includes a main body 309 and at least one power-off protection portion 303. Referring to Figures 4 and 5 , the current collecting tray 300 includes a power-off protection portion 303. The main body 309 includes a first connecting portion 301 and a second connecting portion 302, with the first connecting portion 301 and the second connecting portion 302 separated to form an isolation space 308. The power-off protection portion 303 is disposed within the isolation space 308 and is connected to the first connecting portion 301 and the second connecting portion 302, respectively. The power-off protection portion 303 includes a first connecting segment 304 and a second connecting segment 305, which are sequentially connected. The thickness of the second connecting segment 305 is less than that of the first connecting segment 304, and / or the width of the second connecting segment 305 is less than that of the first connecting segment 304.

[0032] In some embodiments, the first connection portion 301 is configured to be connected to the pole 400, the second connection portion 302 surrounds the outside of the first connection portion 301, and an isolation space 308 is formed between the second connection portion 302 and the first connection portion 301; the second connection portion 302 is configured to be connected to the winding core 800.

[0033] It should be noted that a power-off protection part 303 is provided on the collecting disk 300. When a loss of control occurs inside the battery 1000, the main function of the power-off protection part 303 is to be broken by being broken, thereby disconnecting the connection between the pole 400 and the winding core 800, so that the entire battery 1000 is powered off and a short circuit is avoided. Specifically, when the pressure inside the battery 1000 reaches a certain value, under the action of the internal air pressure (i.e., the impact force), the power-off protection part 303 deforms upward and breaks, so that the first connection part 301 and the second connection part 302 are disconnected, and then the pole 400 and the winding core 800 are disconnected electrically, thereby ensuring that the battery 1000 will not short-circuit and improving the safety performance of the battery 1000.

[0034] The power-off protection portion 303 includes a first connecting segment 304 and a second connecting segment 305. The second connecting segment 305 has a smaller cross-sectional area than the first connecting segment 304. The thickness of the second connecting segment 305 is smaller than that of the first connecting segment 304, and / or the width of the second connecting segment 305 is smaller than that of the first connecting segment 304. Reducing the thickness and / or width of the second connecting segment 305 allows the second connecting segment 305 of the power-off protection portion 303 to break first, thereby improving safety.

[0035] It should be noted that condition one specifies that the thickness of the second connecting segment 305 must be less than the thickness of the first connecting segment 304, and condition two specifies that the width of the second connecting segment 305 must be less than the width of the first connecting segment 304. In practical applications, condition one and condition two can be selected based on actual circumstances, i.e., one or both can be used. In this embodiment, to improve the safety of the battery 1000, the second connecting segment 305 and the first connecting segment 304 meet both conditions one and two.

[0036] Specifically, the specific connection method of the first connecting section 304 and the second connecting section 305 is not limited and can be selected according to the actual layout. For example, in one embodiment, the first connecting section 304 is connected to the first connecting portion 301, and the second connecting section 305 is connected to the second connecting portion 302; in another embodiment, the first connecting section 304 is connected to the second connecting portion 302, and the second connecting section 305 is connected to the first connecting portion 301.

[0037] Specifically, in this embodiment, referring to Figures 2 and 4, considering that a seal 500 and an insulating member 700 are provided above the collecting plate 300, in order to avoid interference between the collecting plate 300 and the seal 500 and the insulating member 700, the thickness of the second connecting segment 305 is less than the thickness of the first connecting segment 304, the first connecting segment 304 is connected to the first connecting portion 301, and the second connecting segment 305 is connected to the second connecting portion 302. In this way, the thickness of the second connecting segment 305 is smaller, and the space occupied is also smaller, which can avoid interference with the seal 500 and the insulating member 700.

[0038] More specifically, the power-off protection part 303 may be broken when the gas pressure in the cavity of the battery 1000 reaches a certain value, generating an impact force to impact the power-off protection part 303, causing it to break; or the power-off protection part 303 may be melted at high temperature when the temperature inside the battery 1000 reaches a certain value.

[0039] In this embodiment, the second connecting segment 305 is broken by gas pressure. In order to meet the connection strength, the material fracture strength of the second connecting segment 305 is greater than or equal to 60MPa. Specifically, in this embodiment, when the gas 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 segment 305 to deform in the direction away from the winding core 800. As a result, the second connecting segment 305 will break and disconnect from the first connecting segment 304, thereby achieving power-off protection.

[0040] It should be noted that the current collecting 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 first connecting portion 301, the second connecting portion 302, the first connecting section 304, and the second connecting section 305 are all made of the same material. That is, when the material of the second connecting section 305 is described below, it means that the material of the first connecting section 304, the first connecting portion 301, and the second connecting section 302 are all made of the same material as the second connecting section 305. For example, if the material of the second connecting section 305 is copper, it means that the material of the first connecting section 304, the first connecting portion 301, and the second connecting section 302 are all copper. Similarly, since the first connecting part 301, the second connecting part 302, the first connecting section 304 and the second connecting section 305 are integrally formed, the material fracture strengths of the first connecting part 301, the second connecting part 302, the first connecting section 304 and the second connecting section 305 are also the same. For example, when the material fracture strength of the second connecting section 305 is described as being between 60 MPa and 140 MPa below, it means that the material fracture strengths of the first connecting section 304, the first connecting part 301 and the second connecting section 302 are also between 60 MPa and 140 MPa, that is, the material fracture strength of the entire collecting plate 300 is between 60 MPa and 140 MPa.

[0041] In some embodiments, the material of the second connecting segment 305 is not limited, as long as it is a metal that can achieve conductivity. For example, the material of the second connecting segment 305 can be copper, iron, aluminum, stainless steel, silver, aluminum alloy, etc.

[0042] Because different materials have different fracture strengths, in some embodiments, the second connecting segment 305 is made of aluminum or copper. Specifically, in one embodiment, when the fracture strength of the second connecting segment 305 is between 60 MPa and 140 MPa, the second connecting segment 305 is made of aluminum. Alternatively, in another embodiment, when the fracture strength of the second connecting segment 305 is between 160 MPa and 300 MPa, the second connecting segment 305 is made of copper. It should be noted that the range of fracture strength is not a limiting condition for material selection, but rather a reference for material selection. For example, if the fracture strength of the second connecting segment 305 exceeds 140 MPa and the second connecting segment 305 is made of aluminum, the second connecting segment 305 may also break. Similarly, if the fracture strength of the second connecting segment 305 exceeds 300 MPa and the second connecting segment 305 is made of copper, the second connecting segment 305 may also break.

[0043] It should be noted that metals have different hardness states. At the same thickness and different hardness states, the material fracture strength of the metal is 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.

[0044] Specifically, please refer to FIGS. 4 and 7. The thickness of the body portion 309 is 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 conditions: 0.1 mm ≤ T1 ≤ 0.8 mm. 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.

[0045] Please continue to refer to FIGS. 3 and 7. The thickness of the second connecting section 305 is T2, where T2 satisfies the following condition 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, and it is generally controlled to be 0.05 to 0.4 mm smaller than the thickness of the body portion 309. Specifically, for example, if the thickness T1 of the body portion 309 is 0.5 mm and Z0 is 0.2 mm, then the thickness T2 of the second connecting section 305 is 0.3 mm.

[0046] It should be noted that the second connecting portion 302 is connected to the core 800. The diameter of the core 800 is S1, the width of the second connecting section 305 is Q1, and the diameter of the current collector plate is 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 collector plate 300 to be larger than the size of the battery 1000, that is, the edge of the current collector plate 300 extends beyond the edge of the housing 900 of the battery 1000.

[0047] Please refer to FIGS. 5 and 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 collector plate 300. Among them, the impact force received when the second connecting section 305 breaks is F 300 , the breaking force of the current collector plate 300 is mainly related to the material fracture strength of the current collector plate 300; the impact force F received when the second connecting section 305 breaks 300, which is mainly related to the opening tension of the explosion-proof valve on the cover 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, the opening pressure of the explosion-proof valve is P 300 , there is a notch a on the explosion-proof valve, and the radius of the notch a is R 300 , the impact force F received when the second connecting section 305 breaks 300 =πR 300 2 P 300 The material fracture strength of the collecting plate 300 (or the second connecting section 305) is σ 300 , the number of power-off protection units 303 is n 300 The thickness of the main body is T1, and the width of the second connecting section 305 is Q1, wherein Q1≤[(zF 300 ) / (σ 300 T1)] / n 300 , z is the first coefficient and 0.25≤z≤0.75, P 300 The value of R is 1.4MPa~2.1MPa, 300 The value of is 12mm~20mm. More specifically, for example, when the explosion-proof valve opening pressure P 300 is 1.7MPa, the radius R of the notch a on the explosion-proof valve 300 is 16 mm, the material of the collecting plate 300 is aluminum, and the material breaking strength σ of the second connecting section 305 is 300 is 100 MPa, the thickness T1 of the main body 309 is 0.5 mm, and the number of the power-off protection parts 303 is n. 300 is 1, the first coefficient z is 0.5, according to the formula Q1≤[(zF 300 ) / (σ 300 T1)] / n 300 Calculation shows that the width Q1 of the second connecting section 305 is ≤13.67 mm. Considering the convenience of processing and production, the cost of mold development, and precision, Q1 is generally taken as 13 mm.

[0048] Referring to Figures 4 and 5 , to prevent the second connecting segment 305 from overlapping the second connecting portion 302 when broken, the power-off protection portion 303 further includes a third connecting segment 306. It should be noted that the second connecting segment 305 is connected between the first connecting segment 304 and the third connecting segment 306. In one embodiment, the first connecting segment 304 is connected to the first connecting portion 301, the third connecting segment 306 is connected to the second connecting portion 302, and the first and third connecting segments 304, 306 are connected via the second connecting segment 305. In another embodiment, the first connecting segment 304 is connected to the second connecting portion 302, the third connecting segment 306 is connected to the first connecting portion 301, and the first and third connecting segments 304, 306 are connected via the second connecting segment 305.

[0049] In some embodiments, the thickness of the third connecting segment 306 is not limited. Considering the fracture situation, the thickness of the third connecting segment 306 is greater than the thickness of the second connecting segment 305 .

[0050] In some embodiments, please continue to refer to Figures 1, 2, 5 and 7. Components such as a seal 500 and an insulating component 700 are generally installed on the collecting plate 300. In order to avoid interference with the insulating component 700 and the seal 500, the third connecting segment 306, the second connecting segment 305 and the first connecting segment 304 are enclosed into a groove 307. More specifically, since the thickness of the second connecting segment 305 is less than the thickness of the first connecting segment 304 and the third connecting segment 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 insulating component 700. At the same time, the groove 307 also reduces the weight of the collecting plate 300, making the collecting plate 300 more lightweight.

[0051] It should be noted that the position of the second connecting segment 305 also affects the fracture. Specifically, the specific position of the second connecting segment 305 can be determined based on the length of the second connecting segment 305, the distance from the second connecting segment 305 to the first connecting portion 301, and the distance from the second connecting segment 305 to the second connecting portion 302. Referring to Figures 6 and 7, the first connecting segment 304 has a first side 314 adjacent to the second connecting segment 305, and the third connecting segment 306 has a second side 315 adjacent to the first connecting segment 304. The shortest distance between the first side 314 and the centerline of the first connecting portion 301 is Q2, and the shortest distance between the second side 315 and the centerline of the first connecting portion 301 is Q3. In this embodiment, the minimum distances Q2 and Q3 primarily define the position of the second connecting segment 305. When determining the position of the second connecting segment 305, the primary consideration is the need to accommodate the height of the flange of the terminal 400 (the inner bend of the terminal 400 forms the second flange, which has a certain height). Therefore, the minimum distances Q2 and Q3 are primarily influenced by the position and size of the terminal 400. Specifically, the following conditions must be met: Q3 > Q2. Secondly, when the size conditions are met, the minimum distance Q2 satisfies the following condition: 6 mm ≤ 2Q2 ≤ 10 mm. Furthermore, the minimum distance Q3 satisfies the following condition: Q3 = (2Q2 + Z1) / 2, with the value of Z1 ranging from 1 to 4 mm. It should be noted that Z1 in the formula is the length of the second connecting segment 305. More specifically, in one embodiment, the shortest distance Q2 between the first side 314 and the centerline of the first connecting portion 301 is 5 mm. According to the formula Q3 = (2Q2 + Z1) / 2, if Z1 is 4 mm and Q2 is 5 mm, then the distance Q3 between the second side 315 and the centerline of the first connecting portion 301 is 7 mm, and the length of the second connecting segment 305 is 2 mm. Therefore, if the lengths from both ends of the second connecting segment 305 to the centerline of the first connecting portion 301 are known, and the length of the second connecting segment 305 is also known, the position of the second connecting segment 305 can also be determined.

[0052] Referring to Figures 5, 6, and 7, the thickness of the third connecting segment 306 is not limited, as long as it does not interfere with components such as the insulating member 700. Specifically, in this embodiment, the thickness of the first connecting segment 304 is equal to the thickness of the third connecting segment 306. Specifically, to prevent the first connecting segment 304 from breaking along with the second connecting segment 305 during the breaking process, the thickness of the first connecting segment 304 is set to be greater than the thickness of the second connecting segment 305, and the thickness of the first connecting segment 304 is set to be less than the thickness of the first connecting portion 301, and the thickness of the third connecting segment 306 is set to be less than the thickness of the second connecting portion 302. In other embodiments, the thickness of the first connecting segment 304 may also be set to be greater than the thickness of the third connecting segment 306.

[0053] Please continue to refer to FIGS. 6 and 7. The width of the first connecting segment 304 is Q4, where Q4 satisfies the following condition: 1.1Q1 ≤ Q4 ≤ 1.5Q1; the width of the third connecting segment 306 is 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 proportional condition, the following conditions need to be satisfied: (2Q4) < S1, (2Q5) < S1. Otherwise, the size of the current collector 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 collector plate 300 does not exceed the size of the core 800. For example, in an embodiment, when the value of the width Q1 of the second connecting segment 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 value of the width Q1 of the second connecting segment 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. Therefore, 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 collector plate 300, when the inside of the battery 1000 gets out of control, the power-off protection part can also break at a specific position, such as the position where the second connecting segment 305 is located, to improve the safety performance of the battery 1000.

[0054] 6 and 7 , the second connection portion 302 is connected to the winding core 800, and the size of the second connection portion 302 is mainly affected by the winding core 800. Specifically, in this embodiment, the diameter of the winding core 800 is S1, and the second connection portion 302 has a third side 316 away from the first connection portion 301 and a fourth side 317 close to the first connection portion 301. The shortest distance from the third side 316 to the center line of the first connection portion 301 is S2, and the shortest distance from the fourth side 317 to the center line of the first connection portion 301 is S3. Specifically, if the size of S2 is too small, the size of the second connection portion 302 is too small, resulting in difficulty in welding the second connection portion 302 to the winding core 800. If the size of S2 is too large, the weight of the second connection portion 302 will increase, resulting in the middle part of the collecting plate 300 being lighter and the outer ring part of the collecting plate 300 being heavier, so that the collecting plate 300 as a whole is in an unbalanced state, which is prone to displacement and misalignment. Therefore, S2 satisfies the following conditions: S2=(S1-2Z2) / 2, and the value range of Z2 is 4~10mm; if the size of S3 is too small, the distance between the first connection part 301 and the second connection part 302 will be too small, which will interfere with the welding of the tabs on the inner ring of the collecting disk 300. If the size of S3 is too large, the distance between the first connection part 301 and the second connection part 302 will be too far, and the structure will not be compact. Therefore, S3 satisfies the following conditions: S3=S2-Z3, and the value range of Z3 is 2~5mm; more specifically, the length of the second connection part 302 (this length specifically refers to the distance in the radial direction of the collecting disk 300) can be obtained by S2 and S3, and the length of the second connection part 302 is S2-S3. In this embodiment, the diameter S1 of the winding core 800 ranges from 17.5mm to 45mm, and 2S2 <S1,S3≥1mm。

[0055] Specifically, taking the diameter S1 of the core 800 as 44.7mm as an example, the relationship between the values ​​of S1, S2 and S3 is explained. The calculation process of S2 is as follows: when S1 is 44.7mm and Z2 is 4mm, the result calculated according to the formula S2=(S1-2Z2) / 2 is 18.35mm. The calculation process of S3 is as follows: when the value of S2 is 18.35mm and the value of Z3 is 2mm, the result calculated according to the formula S3=S2-Z3 is 16.35mm. According to the results of S2 and S3, it can be concluded that the length of the second connecting part 302 is 2mm. It should be noted that in the actual production process of the product, considering the convenience of production and processing, mold development cost and precision, 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.

[0056] Continuing with Figures 5, 6, and 7, the first connecting portion 301 is connected to the terminal 400, so the dimensions of the first connecting portion 301 and the terminal 400 when welded need to be considered. In some embodiments, a through hole 324 is formed on the first connecting portion 301, and a first hole is formed on the terminal 400. The first hole is connected to the through hole 324 to serve as a liquid discharge channel during liquid injection into the battery 1000. Therefore, the dimensions of the through hole 324 are primarily related to the dimensions of the first hole on the terminal 400. Specifically, the diameter of the first hole is S4. The first connecting portion 301 has a fifth side 318 proximal to the second connecting portion 302, and the shortest distance from the fifth side 318 to the centerline of the first connecting portion 301 is S5. The first connecting portion 301 has a through hole 324 formed thereon, the first hole corresponding to the through hole 324, and the through hole 324 has a sixth side 319. The shortest distance from the sixth side 319 to the centerline 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 1.5~3.5mm; the shortest distance from the sixth side 319 to the center line of the first connection part 301 is S6, and S6 satisfies the following condition S6=(Z5+S4) / 2, the value range of Z5 is 0.5~1.5mm, and the value range of S4 is 1mm~4mm; in this embodiment, the length of the first connection part 301 can be obtained by limiting the dimensions of S5 and S6 (the length specifically refers to the distance in the radial direction of the collecting plate 300). For example, in one embodiment, the value of S4 is 3 mm, the value of Z5 is 1 mm, and the result calculated 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 result calculated 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.

[0057] In some embodiments, the first connection portion 301 is annular, and the second connection portion 302 is annular.

[0058] In another embodiment, referring to Figures 8 and 9 , there are multiple power-off protection portions 303, for example, two, three, four, five, or six power-off protection portions 303; the multiple power-off protection portions 303 are spaced apart, and the isolation space 308 includes multiple avoidance slots 310, each of which is located between two adjacent power-off protection portions 303. The multiple power-off protection portions 303 connect the first connecting portion 301 and the second connecting portion 302 via the multiple power-off protection portions 303, making the connection more stable and, in turn, making the structure of the current collecting tray 300 more stable, and eliminating the risk of breakage during installation.

[0059] Continuing with FIG8 , the avoidance slot 310 includes two first slots 311 and two second slots 312. Each first slot 311 is connected to a corresponding second slot 312. Each second connecting segment 305 is located between the two first slots 311 of two adjacent avoidance slots 310, and each first connecting segment 304 is located between the two second slots 312 of two adjacent avoidance slots 310. Specifically, the width of the second connecting segment 305 is defined by the two first slots 311, and the width of the first connecting segment 304 is defined by the two second slots 312.

[0060] In some embodiments, the second groove 312 extends along the length direction of the first connecting segment 304, and the first groove 311 is an arc-shaped groove, and the center of the arc-shaped groove is concentric with the center of the first connecting portion 301; in this way, the shapes of the first connecting segment 304 and the second connecting segment 305 can be defined by the first groove 311 and the second groove 312.

[0061] In some embodiments, the avoidance slot 310 further includes a connecting slot 313, which communicates with the corresponding two second slots 312 and is located on a side of the two second slots 312 away from the two first slots 311. The connecting slot 313 communicates with the second slots 312, thereby allowing the first connection portion 301 and the second connection portion 302 to be connected only through the multiple power-off protection portions 303.

[0062] Please refer to Figures 8, 9 and 10. The impact force received by the second connecting section 305 when it is disconnected is F 300 In order to ensure that the second connecting section 305 can be broken smoothly, F 300 The breaking force of the collecting plate 300 needs to be greater than that of the collecting plate 300. The breaking force of the collecting plate 300 is mainly related to the breaking strength of the material of the collecting plate 300. The impact force F 300 , which is mainly related to the opening tension of the explosion-proof valve. 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, the opening pressure of the explosion-proof valve is P 300 , there is a notch a on the explosion-proof valve, and the radius of the notch a is R 300 , then the pressure F applied to the second connecting section 305 when it breaks is 300 =πR 300 2 P 300 , the material fracture strength of the collecting plate 300 is σ 300 , the number of power-off protection units 303 is n 300 , the width of the second connecting section 305 is Q1, wherein Q1≤[(zF 300 ) / (σ 300 T1)] / n 300 , z is the first coefficient and 0.25≤z≤0.75, P300 The value of R is 1.4MPa~2.1MPa, 300 The value of is 12mm~20mm. More specifically, for example, when the explosion-proof valve opening pressure P 300 is 1.7MPa, the radius R of the notch a on the explosion-proof valve 300 The material of the collecting plate 300 is aluminum, and the material breaking strength σ of the second connecting section 305 is 300 is 100 MPa, the thickness T1 of the main body 309 is 0.5 mm, and the number of the power-off protection parts 303 is n. 300 When the first coefficient z is 0.5, according to the formula Q1≤[(zF 300 ) / (σ 300 T1)] / n 300 Calculation shows that the width Q1 of the second connecting section 305 is ≤ 3.42 mm. It is understandable that in the actual production process of the product, considering the convenience of production and processing, the cost of mold development, and precision, the result of Q1 is usually taken as 3 mm.

[0063] It should be noted that when the collecting disc 300 deviates during the welding positioning process, the collecting disc 300 may exceed the outer contour of the winding core 800, causing the collecting disc 300 to pierce the insulating member 700 and contact the outer shell 900 (such as a steel shell), thereby causing a risk of short circuit. In order to avoid the problem of short circuit, it is necessary to limit the size of the second connection part 302. Specifically, the diameter of the winding core 800 is S1, the second connection part 302 has a seventh side 320 away from the first connection part 301, and the shortest distance from the seventh side 320 to the center line of the first connection part 301 is S7, wherein S7 satisfies the following conditions: S7=(S1-2Z6) / 2, and the value range of Z6 is 0.6~2.5mm, which is convenient for calculating the size of the second connection part 302; the first connection part 301 has an outer side surface close to the second connection part 302, and the outer side surface The side with the shortest distance from the center line of the first connecting part 301 among the side surfaces is the fifth side 318, and the shortest distance from the fifth side 318 to the center line of the first connecting part 301 is S5. The connecting groove 313 has an eighth side 321 away from the first connecting part 301, and the shortest distance from the eighth side 321 to the center line of the first connecting part 301 is S8, wherein S8 satisfies the following conditions: S7>S8, S8=S5+Z9, and the value range of Z9 is 2~8mm. More specifically, in this embodiment, when the diameter S1 of the winding core 800 is 44.7 mm, Z6 is 2.5 mm, Z9 is 2 mm, and S5 is 4 mm, the result calculated using the formula S7 = (S1 - 2Z6) / 2 is 19.85 mm. The result calculated using the formula S8 = S5 + Z9 is 6 mm, so S8 is 6 mm. Based on the results of S7 and S8, the length of the second connecting portion 302 is 13.85 mm (this length specifically refers to the radial distance of the collecting plate 300). It should be noted that in actual production, the value of S7 is rounded to the nearest integer to consider factors such as production and processing convenience, mold development costs, and precision. The specific value should be selected based on actual conditions.

[0064] Continuing to refer to FIG8, FIG9 and FIG10, the thickness of the main body 309 is T1, the width of the second connecting section 305 is Q1, the first groove 311 has a ninth side 322 away from the first connecting portion 301, and a tenth side 323 close to the first connecting portion 301. The shortest distance from the ninth side 322 to the center line of the first connecting portion 301 is S9, and the shortest distance from the tenth side 323 to the center line of the first connecting portion 301 is S 10 , S9 satisfies the following conditions, S9>S 10 , S9=S7-Z7Q1, the value range of Z7 is 1.1~2.5; S 10 Satisfy the following conditions S 10=S9-Z8T1, the value range of Z8 is 1.1~2.5, Z7 is the third coefficient, and Z8 is the fourth coefficient. In this embodiment, according to the calculation, the value of S7 is 19.85mm. When the value of Z7 is 2.5, the value of Q1 is 3mm, the value of Z8 is 2, and the value of T1 is 0.5mm, the result calculated according to the formula S9=S7-Z7Q1 is 12.35mm. According to the formula S 10 = S9-Z8T1 calculated result is 11.35mm; the shortest distance S9 from the ninth side 322 to the center line of the first connecting portion 301 is 12.35mm, the shortest distance S from the tenth side 323 to the center line of the first connecting portion 301 is 10 The length of the second connecting section 305 is 11.35mm, and the length of the second connecting section 305 is 1mm (the length specifically refers to the distance in the radial direction of the collecting plate 300). It should be noted that in the actual production process of the product, considering the convenience of production and processing, mold development cost and precision, etc., the S9 and S 10 The specific value can be selected according to the actual situation.

[0065] 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):

[0066] Example 1

[0067] The diameter S1 of the winding core is 44.7 mm; the diameter S4 of the first hole on the pole is 3 mm; the collecting disc is made of aluminum, and there is one power-off protection unit. The specific dimensions of the collecting disc are as follows:

[0068] The thickness T1 of the main body is 0.5 mm;

[0069] The thickness T2 of the second connecting section is 0.15 mm;

[0070] 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 =16mm, P 300 =1.6MPa,z=0.47,σ 300 =100MPa, n 300 =1);

[0071] The distance Q2 between the first side and the center line of the first connecting portion is 5 mm;

[0072] The distance Q3 between the second side and the center line of the first connecting portion is 7 mm;

[0073] The width Q4 of the first connecting section is 18 mm;

[0074] The width Q5 of the third connecting section is 18 mm;

[0075] The shortest distance S2 from the third side to the center line of the first connecting portion is 18.35 mm;

[0076] The shortest distance S3 from the fourth side to the center line of the first connecting portion is 16.35 mm;

[0077] The shortest distance S5 from the fifth side to the center line of the first connecting portion is 4 mm;

[0078] The shortest distance S6 from the sixth side to the center line of the first connecting portion is 2 mm.

[0079] 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, except that 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 described one by one here; the specific parameters of Examples 2-26 and Comparative Examples 1-14 are shown in Table 1-4.

[0080] Table 1 Examples 2-7, Comparative Examples 1-4

[0081] B2B3B4B5B6B7D1D2D3D4MaterialAluminumAluminumAluminumAluminumAluminumAluminumAluminumT10.80.50.50.80.50.80.850.90.10.8T20.750.450.10.40.250.550.0350.80.070.3T1-T20.050.050.40.40.250.250.8150.10.030.5Q112121212121212121212Q41818181818181818181818Q51 8181818181818181818S218.3518.3518.3518.3518.3518.3518.3518.3518.3518.35S316.3516.3516.3516.3516. 3516.3516.3516.3516.3516.352Q3141414141414141414142Q210101010101010101010S54444444444S62222222222

[0082] Note: In Table 1, B represents an embodiment, and D represents a comparative example, that is, B2 represents embodiment 2, D1 represents comparative example 1, and so on.

[0083] Table 2 Examples 8-17, Comparative Examples 5-6

[0084] B8B9B10B11B12B13B14B15B16B17D5D6z0.470.360.260.60.60.750.60.60.290.7 30.20.8F300128616881367136713671688136713671367136716881688σ300100100 60140160300100100100100100100100T10.50.50.50.50.50.50.40.80.50.50.50.5Q1121212111082010820627MaterialAluminumAluminumAluminumAluminumCopperAluminumAluminumAluminumAluminumT20.150.150.150.150.150.150.150.40 .150.150.150.15Q418181816.5151222151222930Q518181816.515122215122293 0S218.3518.3518.3518.3518.3518.3518.3518.3518.3518.3518.3518.35S316.3 516.3516.3516.3516.3516.3516.3516.3516.3516.3516.3516.352Q31414141414 141414141414142Q2101010101010101010101010S5444444444444S6222222222222

[0085] Note: In Table 2, B represents an embodiment, and D represents a comparative example, i.e., B8 represents embodiment 8, D5 represents comparative example 5, and so on.

[0086] Table 3 Examples 18-26

[0087] B18B19B20B21B22B23B24B25B26MaterialAluminumAluminumAluminumAluminumAluminumAluminumAluminumT10.50.50.50.50.50.50.50.50.5T20.10.10.10.10.10.10.10.10.10.1Q1121212121212121212Q4151515151515151515Q5151515151515151515S218.351 8.3518.3518.3518.3518.3518.3518.3518.35S316.3516.3516.3516.3516.3516.3516.3516.351 6.352Q379111012148.512.510.52Q2681068106108S52.52.52.52.52.52.52.52.52.5S6111111111

[0088] Note: In Table 3, B represents an embodiment, i.e., B18 represents embodiment 18, and so on.

[0089] Table 4 Comparative Examples 7-14

[0090] D7D8D9D10D11D12D13D14MaterialAluminumAluminumAluminumAluminumAluminumAluminumT10.50.50.50.50.50.50.50.5T20.10.10.10.10.10.10.10.10.1Q11212121212121212Q41515151515151515Q51515151515151515S218.3518 .3518.3518.3518.3518.3518.3518.35S316.3516.3516.3516.3516.3516.3516.3516. 352Q361291511166.511.52Q2511511611611S52.52.52.52.52.52.52.52.5S611111111

[0091] Note: In Table 4, D represents comparative example, i.e. D7 represents comparative example 7, and so on.

[0092] Example 27

[0093] The diameter S1 of the winding core is 44.7 mm; the diameter S4 of the first hole on the pole is 3 mm; the material of the collecting plate is copper, and there are four power-off protection parts. The specific dimensions of the collecting plate are as follows:

[0094] The thickness T1 of the main body is 0.5 mm;

[0095] The thickness T2 of the second connecting section is 0.15 mm;

[0096] The width Q1 of the second connecting section is 3 mm (where Q1≤[(zF 300 ) / (σ 300 T1)] / n 300 , F 300 =πR 300 2 P 300 , R 300 =16mm, P 300 =1.6MPa,z=0.47,σ 300 =100MPa, n 300 =4);

[0097] The width Q4 of the first connecting section is 4.5 mm;

[0098] The shortest distance S5 from the fifth side to the center line of the first connecting portion is 4 mm;

[0099] The shortest distance S6 from the sixth side to the center line of the first connecting portion is 2 mm;

[0100] The shortest distance S7 from the seventh side to the center line of the first connecting portion is 19.85 mm;

[0101] The shortest distance S8 from the eighth side to the center line of the first connecting portion is 6 mm;

[0102] The shortest distance S9 from the ninth side to the center line of the first connecting portion is 12.35 mm;

[0103] The shortest distance S from the tenth side to the center line of the first connecting portion 10 It is 11.35mm.

[0104] 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, except that the specific parameters are different. The setting methods and specific structures of Examples 28-40 and Comparative Examples 15-18 can be referred to Example 27, and will not be described one by one here; the specific parameters of Examples 28-40 and Comparative Examples 15-18 are shown in Tables 5 and 6.

[0105] Table 5 Examples 28-37, Comparative Examples 15-16

[0106] B28B29B30B31B32B33B34B35B36B37D15D16z0.470.360.260.60.60.750.60.60.2 90.730.20.8F300128616881367136713671688136713671367136716881688σ3001 0010060140160300100100100100100100100T10.50.50.50.50.50.50.40.80.50.50.50.5Q13332.72.5252.5251.56.75MaterialAluminumAluminumAluminumAluminumCopperCopperAluminumAluminumAluminumAluminumAluminumT20.10.10.10.10.10.10.10.10. 40.10.10.10.1Q44.54.54.543.735.53.735.527.5S719.8519.8519.8519.8519. 8519.8519.8519.8519.8519.8519.8519.85S912.3512.3512.3512.3512.3512.3 512.3512.3512.3512.3512.3512.35S1011.3511.3511.3511.3511.3511.3511.3 511.3511.3511.3511.3511.35S8666666666666S5444444444444S6222222222222

[0107] Note: In Table 5, B represents an embodiment, and D represents a comparative example, that is, B28 represents embodiment 28, D15 represents comparative example 15, and so on.

[0108] Table 6 Examples 38-40, Comparative Examples 17-18

[0109] Q1 Material T1T2Q4S7S9S10S8S5S6B383 Aluminum 0.50.14.519.8516.5516642B393 Aluminum 0.50.14.51510.59.7642B403 Aluminum 0.50.14.5128.78642D173 Aluminum 0.50.14.5201917642D183 Aluminum 0.50.14.58.154.54.22.82.51

[0110] Note: In Table 6, B represents an embodiment and D represents a comparative example, that is, B38 represents embodiment 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.

[0111] Experimental verification

[0112] Examples 1 to 40 and comparative examples 1 to 18 were installed, and performance tests were performed on them after installation:

[0113] 1. Collector disc internal resistance test: The test was conducted in accordance with the "SJ / T 10690-1996 General Specification for Digital DC Microresistance Meters", with a minimum measurement resolution of 0.01mΩ and a voltage of 1mV. The test location was the resistance value between the weld area between the collector disc and the core and the weld area between the steel shell and the collector disc after the core was welded. The test results are shown in Table 7. It should be noted that an internal resistance between 0.50 and 3.00mΩ meets the process requirements.

[0114] 2. Short circuit test: Test according to the battery external short circuit test method described in 6.2.4 of GB31458.

[0115] When a battery experiences thermal runaway, the battery cover opens to release pressure due to the impact force. The power-off protection on the current collecting tray can also break under the impact force. Therefore, the battery may be experiencing power outages due to disconnection of the current collecting tray, short circuits caused by overlapping after disconnection of the current collecting tray, or other conditions that may cause battery short circuits. If the current collecting tray is disconnected and the battery does not short-circuit, the battery meets the process requirements.

[0116] Batteries assembled with current collecting trays prepared according to the data from Examples 1-40 and batteries assembled with current collecting trays prepared according to the data from Comparative Examples 1-18 were placed in the same environment. Air pressure was applied to the batteries in each example using an internal pressurizing device. The power failure status of the current collecting trays was recorded, and the batteries were short-circuited. The specific test results are shown in Table 7.

[0117] Table 7 Test results

[0118] Internal resistance (mΩ) Power-off condition of the collector plate B11.31 Power off B22.13 Power off B31.36 Power off B41.40 Power off B52.14 Power off B61.37 Power off B72.14 Power off D12.39 Power off D22.40 Not powered off D30.52 Short circuit D43.14 Power off B81.38 Power off B91.38 Power off B101.38 Power off B1 11.39 Power off B122.19 Power off B132.19 Power off B141.37 Power off B151.39 Power off B161.35 Power off B171.36 Power off D51.42 Power off D61.37 Not powered off B181.40 Power off B191.37 Power off B201.38 Power off B211.38 Power off B221.38 Power off B231.44 Power off Power B241.44 Power off B251.44 Power off B261.41 Power off D71.37 Power on D81.37 Power off D91.39 Short circuit D101.39 Short circuit D111.40 Short circuit D121.40 Short circuit D131.37 Short circuit D141.37 Short circuit B271.41 Power off B281.41 Power off B291.11 Power off B301. 11 power off, B311.11 power off, B321.11 power off, B331.11 power off, B341.08 power off, B351.11 power off, B361.39 power off, B371.32 power off, D151.11 power off, D161.11 not power off, B381.35 power off, B391.39 power off, B401.33 power off, D171.11 short circuit, D181.21 short circuit

[0119] 3. Actual impact force test: By simulating battery thermal runaway, an internal pressure device is installed inside the battery, and the battery internal pressure acceleration rate is controlled to achieve parallel group verification testing. It should be noted that the 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 connecting section is disconnected within the range of 1.4 to 2.1 MPa, it proves that the collector plate is qualified. The specific test results are as follows:

[0120] Four battery groups were provided, each comprising batteries assembled with current collecting trays prepared according to the data of Examples 1-40, and batteries assembled with current collecting trays prepared according to the data of Comparative Examples 1-18. The first battery group was placed in the same environment, and an internal pressure-applying device within the battery applied an air pressure of 1.0 MPa (the air pressure under normal use) to test whether the second connecting segment was disconnected. The second battery group was placed in the same environment, and an internal pressure-applying device within the battery applied an air pressure of 1.6 MPa to test whether the second connecting segment was disconnected. The third battery group was placed in the same environment, and an internal pressure-applying device within the battery applied an air pressure of 1.7 MPa to test whether the second connecting segment was disconnected. The fourth battery group was placed in the same environment, and an internal pressure-applying device within the battery applied an air pressure of 1.8 MPa to test whether the second connecting segment was disconnected. The test results are shown in Table 8.

[0121] Table 8 Test results

[0122]

[0123] in conclusion

[0124] 1. From Examples 1-7 and Comparative Examples 1-4, it can be concluded that:

[0125] The batteries provided in Examples 1-7 had internal resistance values ​​between 0.50 and 3.00 mΩ in the internal resistance test, meeting the internal resistance requirements. No short circuits occurred during the short-circuit test, meeting the short-circuit test requirements. During the impact force test, at an air pressure of 1.0 MPa, the second connecting section did not break, meeting normal usage requirements. At air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connecting section disconnected normally, meeting the impact force test requirements.

[0126] In the battery provided in Comparative Example 1, during the impact force test, the second connecting section broke under an air pressure of 1.0 MPa and could not be used normally.

[0127] For the battery provided in Comparative Example 2, during the impact force test, the second connecting section did not break at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, thus failing to meet the impact force test requirements.

[0128] The battery provided in Comparative Example 3 was in a short-circuit state during the short-circuit test and did not meet the short-circuit test requirements.

[0129] The battery provided in Comparative Example 4 had a resistance value exceeding 3.00 mΩ in the internal resistance test, which did not meet the internal resistance test requirements.

[0130] 2. From Examples 8-17 and Comparative Examples 5-6, it can be concluded that:

[0131] The batteries provided in Examples 8-17 had internal resistance values ​​between 0.50 and 3.00 mΩ in the internal resistance test, meeting the internal resistance requirements; no short circuit occurred during the short-circuit test, meeting the short-circuit test requirements; during the impact force test, at an air pressure of 1.0 MPa, the second connecting section did not break, meeting normal usage requirements; at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connecting section disconnected normally, meeting the impact force test requirements.

[0132] In the battery provided in Comparative Example 5, during the impact force test, the second connecting section broke under an air pressure of 1.0 MPa and could not be used normally.

[0133] For the battery provided in Comparative Example 6, during the impact force test, the second connecting section did not break at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, thus failing to meet the impact force test requirements.

[0134] 3. From Examples 18-26 and Comparative Examples 7-14, it can be concluded that:

[0135] The batteries provided in Examples 18-26 had internal resistance values ​​between 0.50 and 3.00 mΩ in the internal resistance test, meeting the internal resistance requirements; no short circuit occurred during the short-circuit test, meeting the short-circuit test requirements; during the impact force test, at an air pressure of 1.0 MPa, the second connecting section did not break, meeting normal usage requirements; at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connecting section disconnected normally, meeting the impact force test requirements.

[0136] For the batteries provided in Comparative Examples 7 and 8, during the impact force test, the second connecting section did not break at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, and therefore did not meet the impact force test requirements.

[0137] The batteries provided in Comparative Examples 9-14 were all in a short-circuit state during the short-circuit test and did not meet the short-circuit test requirements.

[0138] 4. From Examples 27-37 and Comparative Examples 15-16, it can be concluded that:

[0139] The batteries provided in Examples 27-37 had internal resistance values ​​between 0.50 and 3.00 mΩ in the internal resistance test, meeting the internal resistance requirements; no short circuit occurred during the short-circuit test, meeting the short-circuit test requirements; during the impact force test, at an air pressure of 1.0 MPa, the second connecting section did not break, meeting normal usage requirements; at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connecting section disconnected normally, meeting the impact force test requirements.

[0140] In the battery provided in Comparative Example 15, during the impact force test, the second connecting section broke under an air pressure of 1.0 MPa and could not be used normally.

[0141] For the battery provided in Comparative Example 16, during the impact force test, the second connecting section did not break at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, and therefore did not meet the impact force test requirements.

[0142] 5. From Examples 38-40 and Comparative Examples 17-18, it can be concluded that:

[0143] The batteries provided in Examples 38-40 had internal resistance values ​​between 0.50 and 3.00 mΩ in the internal resistance test, meeting the internal resistance requirements; no short circuit occurred during the short-circuit test, meeting the short-circuit test requirements; during the impact force test, at an air pressure of 1.0 MPa, the second connecting section did not break, meeting normal usage requirements; at air pressures of 1.6 MPa, 1.7 MPa, and 1.8 MPa, the second connecting section disconnected normally, meeting the impact force test requirements.

[0144] The batteries provided in Comparative Examples 17-18 were all in a short-circuit state during the short-circuit test and did not meet the short-circuit test requirements.

[0145] In summary, the current collecting disk provided in Examples 1-40 has a small internal resistance value and consumes less energy. It breaks normally during the impact force test. When the internal pressure value of the battery is abnormal, the current collecting disk can break, disconnecting the pole and the winding core, so that the entire battery is powered off. It has a high safety factor and can avoid thermal runaway.

Claims

1. A current collecting plate, the current collecting plate (300) comprising: A main body part (309), including a first connecting part (301) and a second connecting part (302), with a separation space (308) formed by the interval between the first connecting part (301) and the second connecting part (302); and, At least one power-off protection part (303), arranged in the separation space (308), and the first connecting part (301) and the second connecting part (302) are connected through the power-off protection part (303), the power-off protection part (303) includes a first connecting segment (304) and a second connecting segment (305) connected in sequence, wherein, the thickness of the second connecting segment (305) is less than the thickness of the first connecting segment (304), and / or, the width of the second connecting segment (305) is less than the width of the first connecting segment (304).

2. The collecting tray according to claim 1, wherein: The thickness of the main body part (309) is T1, 0.1mm ≤ T1 ≤ 0.8mm.

3. The collecting tray according to claim 2, wherein: The thickness of the second connecting segment (305) is T2, T2 = T1 - Z0, 0.05mm ≤ Z0 ≤ 0.4mm, T1 > Z0.

4. The collecting tray according to claim 1, wherein: The second connecting part (302) is arranged to be connected to a core (800), the diameter of the core (800) is S1, the width of the second connecting segment (305) is Q1, the diameter of the current collecting plate (300) is s, s < S1, and Q1 < (S1 / 2).

5. The collecting tray according to claim 4, wherein: The impact force received by the second connecting section (305) when it is disconnected is F 300 The material fracture strength of the collecting plate (300) is σ 300 The number of the power-off protection units (303) is n 300 , the thickness of the main body (309) is T1, Q1≤[(zF 300 ) / (σ 300 T1)] / n 300 , 0.25≤z≤0.75, z is the first coefficient, σ 300 ≥60MPa.

6. The collecting tray according to any one of claims 1 to 5, wherein: The power-off protection part (303) further includes a third connecting segment (306), the second connecting segment (305) is connected between the first connecting segment (304) and the third connecting segment (306), the thickness of the third connecting segment (306) is greater than the thickness of the second connecting segment (305), and the third connecting segment (306), the second connecting segment (305) and the first connecting segment (304) enclose a groove (307).

7. The collecting tray according to claim 6, wherein: The first connecting segment (304) has a first side (314) close to the second connecting segment (305), the third connecting segment (306) has a second side (315) close to the first connecting segment (304), the shortest distance between the first side (314) and the center line of the first connecting part (301) is Q2, the shortest distance between the second side (315) and the center line of the first connecting part (301) is Q3, Q3 > Q2, Q3 = (2Q2 + Z1) / 2, 1 ≤ Z1 ≤ 4mm, 6mm ≤ 2Q2 ≤ 10mm.

8. The collecting tray according to claim 6, wherein: The thickness of the first connecting segment (304) is greater than or equal to the thickness of the third connecting segment (306), one of the first connecting segment (304) and the third connecting segment (306) is connected to the first connecting part (301), and the other is connected to the second connecting part (3)02).

9. The collecting tray according to claim 6, wherein: The second connecting portion (302) is configured to be connected to a winding core (800), the diameter of the winding core (800) is S1, the width of the first connecting section (304) is Q4, the width of the third connecting section (306) is Q5, and the width of the second connecting section (305) is Q1, Q4<(S1 / 2), Q5<(S1 / 2), 1.1Q1≤Q4≤1.5Q1, 1.1Q1≤Q5≤1.5Q1.

10. The collecting tray according to claim 7, 8 or 9, wherein: The second connecting portion (302) is configured to be connected to a winding core (800), the diameter of the winding core (800) is 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 S2, and the shortest distance from the fourth side (317) to the center line of the first connecting portion (301) is S3, 2S2 <S1,S3≥1mm,17.5mm≤S1≤45mm。 11. The collecting tray according to claim 10, wherein: S2=(S1-2Z2) / 2,2Z2 <S1,4mm≤Z2≤10mm,S3=S2-Z3,Z3<S2,2mm≤Z3≤5mm。 12. The collecting tray according to any one of claims 1 to 5, wherein: The first connecting portion (301) is configured to be connected to the pole (400), the pole (400) is formed with a first hole, the diameter of the first hole is S4, the first connecting portion (301) has a fifth side (318) close to the second connecting portion (302), the shortest distance from the fifth side (318) to the center line of the first connecting portion (301) is S5, the first connecting portion (301) is formed with a through hole (324), the first hole is correspondingly connected to the through hole (324), the through hole (324) has a sixth side (319), the shortest distance from the sixth side (319) to the center line of the first connecting portion (301) is S6, S5=S6+Z4, 1.5mm≤Z4≤3.5mm, S6=(Z5+S4) / 2, 0.5mm≤Z5≤1.5mm.

13. The collecting tray according to any one of claims 1 to 5, wherein: There are multiple power-off protection units (303); The isolation space (308) includes a plurality of avoidance slots (310), and each of the avoidance slots (310) is located between two adjacent power-off protection portions (303).

14. The collecting tray according to claim 13, wherein: The avoidance groove (310) comprises two first grooves (311) and two second grooves (312), each of the first grooves (311) is connected to the corresponding second groove (312), each of the second connecting sections (305) is located between the two first grooves (311) of two adjacent avoidance grooves (310), and each of the first connecting sections (304) is located between the two second grooves (312) of two adjacent avoidance grooves (310).

15. The collecting tray according to claim 14, wherein: The second groove (312) is extended along the length direction of the first connecting section (304); the first groove (311) is an arc-shaped groove, and the center of the arc-shaped groove is concentric with the center of the first connecting portion (301); The avoidance groove (310) further includes a connecting groove (313), which extends along a portion of the outer periphery of the first connecting portion (301) and is connected to the corresponding two second grooves (312), and is located on a side of the two second grooves (312) away from the two first grooves (311).

16. The collecting tray according to claim 15, wherein: The diameter of the winding core (800) is S1, the second connecting portion (302) has a seventh side (320) away from the first connecting portion (301), and the shortest distance from the seventh side (320) to the center line of the first connecting portion (301) is S7, S7=(S1-2Z6) / 2, 0.6mm≤Z6≤2.5mm.

17. The collecting tray according to claim 16, wherein: The thickness of the main body (309) is T1, the width of the second connecting section (305) is Q1, the first groove (311) has a ninth side (322) away from the first connecting portion (301), and a tenth side (323) close to the first connecting portion (301), the shortest distance from the ninth side (322) to the center line of the first connecting portion (301) is S9, and the shortest distance from the tenth side (323) to the center line of the first connecting portion (301) is S 10 , 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 collecting tray according to claim 16, wherein: The first connecting portion (301) has an outer side surface close to the second connecting portion (302), and the side of the outer side surface that is shortest to the center line of the first connecting portion (301) is the fifth side surface (318), and the shortest distance from the fifth side surface (318) to the center line of the first connecting portion (301) is S5. The connecting groove (313) has an eighth side surface (321) away from the first connecting portion (301), and the shortest distance from the eighth side surface (321) to the center line of the first connecting portion (301) is S8, S7>S8, S8=S5+Z9, 2mm≤Z9≤8mm.

19. A battery comprising: The collecting tray (100) according to any one of claims 1 to 18.

20. The battery according to claim 19, further comprising a cover assembly, a winding core (800) and a shell (900) with an opening at at least one end, wherein the cover assembly comprises a pole (400), the shell (900) has a receiving cavity, the winding core (800) and the current collecting disk (300) are both located in the receiving cavity, the cover assembly is arranged at the opening, the first connecting portion (301) of the current collecting disk (300) is connected to the pole (400), and the second connecting portion (302) is connected to the winding core (800).

21. The battery according to claim 20, wherein The cover plate assembly further comprises a cover plate (600), a sealing member (500) and an insulating member (700); the pole (400) is provided through the cover plate (600); the sealing member (500) is sleeved on the outside of the pole (400) and is located between the pole (400) and the cover plate (600); the insulating member (700) is provided below the cover plate (600); and the collecting plate (300) is provided below the insulating member (700).

22. The battery according to claim 20, wherein The pole (400) is formed with a first hole, the first connecting portion (301) is formed with a through hole (324), and the first hole is correspondingly connected to the through hole (324).

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