Current collector plate, battery cell, and electric device

Abstract

The application discloses a current collecting plate, a battery cell and an electric device, and belongs to the technical field of battery cells. The current collecting plate comprises a first connecting part used for being connected with a bottom shell, and a second connecting part used for being connected with a winding core. The second connecting part is connected with the first connecting part. The second connecting part is provided with a hollow structure. One side of the second connecting part facing the winding core is provided with a first gas chamber. The hollow structure is in communication with the first gas chamber. When a short circuit occurs inside the battery cell or a thermal runaway of the battery cell occurs, the gas generated inside the battery cell is discharged from the battery cell through the first gas chamber and the hollow structure more quickly. The hollow structure is not easy to hinder the discharge of the gas generated inside the battery cell, so that the explosion risk caused by the violent reaction inside the battery cell due to the untimely pressure relief can be effectively avoided.

Description

Technical Field

[0001] This application relates to the field of battery cell technology, and more particularly to a current collector, a battery cell, and an electrical device. Background Technology

[0002] In related technologies, the current collector of cylindrical battery cells is usually a large circular plate structure, or a structure with only a flat surface for the tab welding area. The opposite sides of the current collector are welded to the core and the bottom shell, respectively. After welding, the current collector, core, and bottom shell are completely attached, which can hinder the depressurization of the battery cell. For example, in the event of thermal runaway of the battery cell, the gas inside the cell is not easy to escape, which can easily lead to untimely depressurization of the battery cell, or even cause violent reactions inside the battery cell, resulting in the risk of explosion. Summary of the Invention

[0003] This application provides a current collector, a battery cell, and an electrical device to at least partially solve the above-mentioned technical problems.

[0004] To achieve the above objectives, according to a first aspect of this application, a collector plate is provided, comprising: a first connecting portion for connecting to a bottom shell; and The second connecting part is used to connect with the winding core. The second connecting part is connected to the first connecting part, and the second connecting part has a hollow structure. The second connecting part has a first air chamber on the side facing the core, and the hollow structure communicates with the first air chamber.

[0005] When a short circuit or thermal runaway occurs inside the battery cell, the gas generated inside the cell is quickly discharged through the first gas chamber and the hollow structure. The hollow structure does not easily obstruct the discharge of gas generated inside the cell, thus effectively avoiding the risk of explosion caused by violent reactions inside the cell due to untimely pressure relief.

[0006] Optionally, the second connecting part is connected to the outer periphery of the first connecting part. The second connecting part includes a first sub-part and a second sub-part connected circumferentially along the collector plate. The first sub-part is used to connect with the core. The second sub-part is provided with the first air chamber on the side facing the core. The hollow structure is provided in the second sub-part.

[0007] The second sub-section is spaced apart from the winding core, which facilitates the entry of gas inside the cell and increases the capacity of the battery for gas.

[0008] Optionally, along the thickness direction of the collector plate, in the direction away from the bottom shell, the distance t3 between the surface of the second sub-part and the surface of the first sub-part satisfies: t3 > t1, where t1 is the thickness of the first sub-part.

[0009] This design allows the first gas chamber to have a suitable volume, enabling it to hold a large amount of gas. When a large amount of gas is generated under thermal runaway conditions, the gas contained in the first gas chamber can be discharged through the perforated structure, increasing the exhaust speed, making depressurization more timely, and reducing the risk of explosion caused by untimely depressurization.

[0010] Optionally, the second sub-part includes a first inner wall, a second inner wall, a third inner wall, and a fourth inner wall connected in sequence. The first inner wall, the second inner wall, the third inner wall, and the fourth inner wall surround and define the hollow structure. Along the radial direction of the collecting plate, the first inner wall is located between the first connecting part and the third inner wall, and the second inner wall and the fourth inner wall are arranged at intervals along the circumference of the collecting plate.

[0011] Optionally, the angle α between the plane containing the second inner wall and the plane containing the fourth inner wall is in the range of 5° ≤ α ≤ 90°. This is more conducive to the release of gas inside the battery cell, and the current collector also has better strength.

[0012] Optionally, along the thickness direction of the collector plate, the projection of the hollow structure onto the bottom shell is fan-shaped; wherein, the first inner wall and the third inner wall are both arc-shaped walls; and the second inner wall and the fourth inner wall are both straight walls.

[0013] Optionally, the range of the diameter R4 of the circle containing the first inner wall is: R4 > R5 + 2 × t1 + 2 × t2; Where R5 is the diameter of the end face of the first connecting part of the collector plate away from the core, t1 is the thickness of the first sub-part, and t2 is the process safety distance between the first connecting part and the hollow structure during forming. When this formula is satisfied, the hollow structure is easier to form, and the first connecting part has better strength.

[0014] Optionally, t1 ≥ 0.1 mm, t2 ≥ 0.2 × t1 mm.

[0015] Optionally, the first connecting portion is provided with a second air chamber on the side facing the winding core, and the second air chamber communicates with the first air chamber.

[0016] The second air chamber is connected to the first air chamber. When the valve is opened, the gas contained in the second air chamber can enter the first air chamber and be released from the opening of the explosion-proof structure of the bottom shell through the hollow structure.

[0017] The second gas chamber can also be used to contain the gas inside the battery cell, allowing for a larger volume of gas to be contained within the cell and thus extending its lifespan. The addition of the second gas chamber also increases the venting space for the battery cell located on the collector side, enhancing its safety.

[0018] According to a second aspect of this application, a battery cell is provided, comprising a bottom shell, a core, and a current collector arranged along the axial direction of the battery cell, the current collector being disposed between the bottom shell and the core.

[0019] Optionally, the battery cell includes an explosion-proof structure disposed on the bottom shell, and along the axial direction of the battery cell, at least a portion of the projection of the explosion-proof structure on the bottom shell is located within the projection of the hollow structure on the bottom shell.

[0020] When the valve is opened, the gas inside the battery cell can be released to the outside of the battery cell through the core winding, hollow structure, and explosion-proof structure, which can release the gas inside the battery cell to the outside of the battery cell more quickly.

[0021] Optionally, the relationship between the diameter R1 of the explosion-proof structure, the outer diameter R2 of the battery cell, and the outer diameter R3 of the hollow structure is as follows: 7 / 5×(R2-R1) <R3<R1.

[0022] Optionally, the relationship between the area S2 of the hollow structure and the area S1 of the explosion-proof structure of the battery cell is: S2 > 2 / 3 × S1.

[0023] In this embodiment of the application, by limiting S2 to 2 / 3 × S1, the gas generated inside the cell is less likely to be blocked by the current collector, the gas flow is smoother, and the pressure can be released more in a timely manner, resulting in a smaller gas pressure inside the cell and greater safety and reliability.

[0024] Optionally, the first connecting part is provided with a second air chamber on the side facing the core, the second air chamber is connected to the first air chamber, and the internal gas production volume of the battery cell is Z, the sum of the volumes of the second air chamber and the first air chamber is Z1, Z1≥0.05Z.

[0025] During the charging and discharging process of the battery cell, gas is generated inside. The second gas chamber and the first gas chamber can accommodate a larger volume of gas, which can prevent the internal pressure from being too high due to gas accumulation, thereby improving the charging and discharging efficiency of the battery cell.

[0026] According to a third aspect of this application, an electrical device is also provided, including the aforementioned current collector or the aforementioned battery cell.

[0027] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0030] Figure 1 This is a schematic cross-sectional view of the battery cell provided in an exemplary embodiment of this disclosure; Figure 2 yes Figure 1 An enlarged schematic diagram of part A in the middle; Figure 3 yes Figure 2 Enlarged schematic diagram of part B in the middle; Figure 4 This is a schematic cross-sectional view of the battery cell with the core removed, provided in an exemplary embodiment of this disclosure. Figure 5 yes Figure 4 An enlarged schematic diagram of section C; Figure 6 This is a schematic diagram of the collector disk from one perspective of an exemplary embodiment of this disclosure; Figure 7 This is a schematic diagram of the collector disk from another perspective in an exemplary embodiment of this disclosure; Figure 8 This is a block diagram of an electrical device provided in an exemplary embodiment of this disclosure.

[0031] Explanation of reference numerals in the attached figures: 1. Collector plate; 10. First connecting part; 101. Second air chamber; 30. Second connecting part; 31. First sub-part; 33. Second sub-part; 331. First air chamber; 333. First inner wall; 334. Second inner wall; 335. Third inner wall; 336. Fourth inner wall; 50. Hollowed-out structure; 2. Battery cell; 21. Base shell; 22. Core; 23. Explosion-proof structure; 3. Electrical equipment. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0033] During battery use, gas is generated inside. To reduce safety risks, an explosion-proof structure is installed. When the internal gas pressure or temperature accumulates to a certain level, the explosion-proof structure will rupture or open, releasing the gas and preventing an explosion. This process can be called valve opening.

[0034] The internal structure of a battery typically consists of a core, a busbar, and a casing. Explosion-proof structures are usually located at the bottom of the casing. When the internal gas pressure or temperature of the battery accumulates to a certain level, the explosion-proof structure at the bottom of the casing will rupture or open, thereby releasing the gas and preventing an explosion.

[0035] In related technologies, the current collector of cylindrical battery cells is usually a large circular plate structure, or a structure with only a flat surface for the tab welding area. The opposite sides of the current collector are welded to the core and the bottom shell, respectively. After welding, the current collector, core, and bottom shell are completely attached, which can hinder the depressurization of the battery cell. For example, in the event of thermal runaway of the battery cell, the gas inside the cell is not easy to escape, which can easily lead to untimely depressurization of the battery cell, or even cause violent reactions inside the battery cell, resulting in the risk of explosion.

[0036] Please combine Figure 1 This application provides a data collection disk 1, please refer to... Figure 2 and Figure 3 The collector plate 1 includes a first connecting part 10 and a second connecting part 30. The first connecting part 10 is used to connect with the bottom shell 21, and the second connecting part 30 is used to connect with the core 22. The first connecting part 10 and the second connecting part 30 are connected. The second connecting part 30 is provided with the hollow structure 50. The second connecting part 30 is provided with a first air chamber 331 on the side facing the core 22. The hollow structure 50 communicates with the first air chamber 331.

[0037] The first connecting part 10 and the second connecting part 30 are connected. The first connecting part 10 of the current collector 1 is connected to the bottom shell 21, which facilitates the transmission of current to the outside through the current collector 1. The second connecting part 30 of the current collector 1 has a first air chamber 331 on the side facing the core 22. The first air chamber 331 can be used to accommodate the gas inside the battery cell 2, so that the battery cell 2 can accommodate a larger volume of gas. This is equivalent to providing a buffer space for the generated gas, which can reduce the risk of excessive pressure caused by gas accumulation in the sealed space, thereby reducing the risk of thermal runaway and allowing the battery cell 2 to have a longer service life. The setting of the first air chamber 331 improves the exhaust space of the battery cell 2 located on the side of the current collector 1, and enhances the safety of the battery cell 2. When a short circuit or thermal runaway occurs inside the battery cell 2, the gas generated inside the battery cell 2 can be quickly discharged from the battery cell 2 through the first air chamber 331 and the hollow structure 50. The hollow structure 50 does not easily obstruct the discharge of gas generated inside the battery cell 2, thus effectively avoiding the risk of explosion caused by violent reaction inside the battery cell 2 due to untimely pressure relief.

[0038] The current collector 1 is applied to the battery cell 2. In some examples, the battery cell 2 can be a cylindrical battery cell 2. The battery cell 2 can serve as an independent energy storage unit of the battery. The battery cell 2 may include the current collector 1, the winding core 22, and the housing. The current collector 1 and the winding core 22 are mounted inside the housing. The opposite sides of the current collector 1 are welded to the housing and the winding core 22, respectively. In some examples, along the axial direction of the battery cell 2, the opposite sides of the current collector 1 are welded to the bottom shell 21 portion of the housing and the tabs of the winding core 22, respectively.

[0039] The outer casing can be made of aluminum, steel, or similar materials. The casing shape can be cylindrical with a hollow interior. In some examples, the casing can be a single-pass casing, meaning it is closed at the bottom and has an opening at the top, where the top opening can be used to assemble the core 22 and the collector plate 1. The casing can include connected side walls and a bottom shell 21, where the bottom shell 21 is specifically the portion of the casing opposite the top opening. The side walls can specifically be cylindrical portions enclosed by the casing.

[0040] The core 22 can be formed by stacking electrodes (positive electrode and negative electrode) and separator through a winding process. In some examples, the core 22 can be formed by winding a composite layer of two separators, positive electrode and negative electrode. During winding, the separator can be pre-wound first using a winding needle, and then the negative electrode and positive electrode can be wound. After winding is completed, the winding needle is removed.

[0041] The core 22 may also include tabs, which can be thin metal conductive sheets drawn out from the positive and negative current collectors inside the core 22, used to conduct the current generated by the core 22 to the pole.

[0042] The function of current collector 1 is to collect current. The tab conducts the current to current collector 1, and the current collector 1 collects the current and then transmits it to the terminal or other cell 2.

[0043] The battery cell 2 may include a bottom shell 21 and a core 22 arranged along the axial direction of the battery cell 2. The current collector 1 is located between the bottom shell 21 and the core 22. That is, along the axial direction of the battery cell 2, the bottom shell 21, the current collector 1, and the core 22 are arranged sequentially. The current collector 1 can be welded to the bottom shell 21 and the core 22 respectively.

[0044] The second connecting part 30 is connected to the outer periphery of the first connecting part 10. The second connecting part 30 includes a first sub-part 31 and a second sub-part 33 connected circumferentially along the collecting plate 1. The first sub-part 31 is used to connect with the core 22. The second sub-part 33 is provided with the first air chamber 331 on the side facing the core 22. The hollow structure 50 is provided on the second sub-part 33.

[0045] Please combine Figure 6 The collector plate 1 includes a first connecting portion 10 and a second connecting portion 30. The second connecting portion 30 can be connected to the outer periphery of the first connecting portion 10. The first connecting portion 10 and the second connecting portion 30 can be manufactured using an integral molding process. In some examples, the collector plate 1 is generally disc-shaped, the first connecting portion 10 is generally disc-shaped, and the second connecting portion 30 is generally annular, connected to the outer periphery of the first connecting portion 10. The arrangement direction of the first connecting portion 10 and the second connecting portion 30 can be radial to the collector plate 1. The first connecting portion 10 is connected to the bottom shell 21; specifically, the first connecting portion 10 can be welded to the bottom shell 21.

[0046] The second connecting portion 30 includes a first sub-part 31 and a second sub-part 33 connected to each other. The first sub-part 31 and the second sub-part 33 can be manufactured using an integral molding process. The first sub-part 31 is used to connect to the winding core 22, and the first sub-part 31 can be welded to the tab of the winding core 22. The second sub-part 33 is spaced apart from the winding core 22, so that the space between the second sub-part 33 and the winding core 22 facilitates the entry of gas inside the cell 2, increasing the gas capacity inside the battery. Both the first sub-part 31 and the second sub-part 33 can be fan-shaped.

[0047] The second sub-part 33 is provided with the hollow structure 50. The hollow structure 50 can be a through hole that penetrates the second sub-part 33 along the thickness direction of the collector plate 1, and the shape of the hollow structure 50 can be fan-shaped.

[0048] When the valve is opened, the hollow structure 50 prevents the manifold 1 from obstructing the gas inside the cell 2, allowing the gas inside the cell 2 to be released more effectively. This effectively avoids the risk of explosion caused by violent reactions inside the cell 2 due to untimely pressure relief, thus improving the safety of the cell 2.

[0049] Specifically, when the valve is opened, the explosion-proof structure 23 of the bottom shell 21 ruptures, creating an opening for gas release at the bottom shell 21. Gas inside the battery cell 2 can be released through the first gas chamber 331, the perforated structure 50, and the opening in the bottom shell 21. In some scenarios, when a short circuit occurs inside the battery cell 2 or thermal runaway occurs, the gas generated inside the battery cell 2 is discharged through the first gas chamber 331, the perforated structure 50, and the opening in the bottom shell 21.

[0050] Along the thickness direction of the collector plate, in the direction away from the bottom shell 21, the distance t3 between the surface of the second sub-part 33 and the surface of the first sub-part 31 satisfies: t3 > t1, where t1 is the thickness of the first sub-part 31.

[0051] Please combine Figure 3 In some embodiments, it is readily understood that the base material is formed into the collector plate 1 through processes such as stamping, and the first sub-part 31 can be regarded as having a thickness approximately equal to that of the base material. In this case, the thickness of the first sub-part 31 can be regarded as the thickness of the base material.

[0052] In some embodiments, along the thickness direction of the collector plate 1, the distance t3 between the surface of the second sub-part 33 facing away from the bottom shell 21 and the surface of the first sub-part 31 facing away from the bottom shell 21 satisfies: t3 > t1, where the above distance can specifically refer to the height difference between the surface of the second sub-part 33 facing away from the bottom shell 21 and the surface of the first sub-part 31 facing away from the bottom shell 21.

[0053] The thickness direction of the current collector 1 is aligned with the axial direction of the battery cell 2. The thickness direction of the current collector 1 can also be referred to as the axial direction of the battery cell 2.

[0054] Please combine Figure 7 When t3 > t1, the first gas chamber 331 has a suitable volume, capable of holding a large amount of gas. When the battery cell 2 experiences an internal short circuit, the gas contained in the first gas chamber 331 can be discharged through the perforated structure 50, increasing the exhaust speed and making pressure relief more timely. This reduces the risk of explosion caused by untimely pressure relief and violent reactions inside the battery cell 2 during an internal short circuit.

[0055] Please combine Figure 6The second sub-part 33 includes a first inner wall 333, a second inner wall 334, a third inner wall 335, and a fourth inner wall 336 connected in sequence. The first inner wall 333, the second inner wall 334, the third inner wall 335, and the fourth inner wall 336 surround and define the hollow structure 50. In some examples, the hollow structure 50 is a fan-shaped through hole punched out at the second sub-part 33. The first inner wall 333, the second inner wall 334, the third inner wall 335, and the fourth inner wall 336 are the four walls of the through hole. Along the radial direction of the collecting plate 1, the first inner wall 333 is located between the first connecting part 10 and the third inner wall 335. In other words, the first inner wall 333 is closer to the first connecting part 10 than the third inner wall 335, and the third inner wall 335 is farther away from the first connecting part 10 than the first inner wall 333. The second inner wall 334 and the fourth inner wall 336 are arranged at intervals along the circumference of the collecting plate 1. The hollow structure 50 is located between the second inner wall 334 and the fourth inner wall 336, and between the first inner wall 333 and the third inner wall 335.

[0056] The angle α between the plane containing the second inner wall 334 and the plane containing the fourth inner wall 336 is in the range of 5°≤α≤90°. When 5°≤α≤90°, it is more conducive to the release of gas inside the cell 2, and at the same time, the current collector also has better strength.

[0057] Specifically, the angle α between the plane containing the second inner wall 334 and the plane containing the fourth inner wall 336 can be: in a second sub-part 33, the angle α between the plane containing the wall surfaces opposite to the second inner wall 334 and the fourth inner wall 336, and the plane containing the wall surfaces opposite to the second inner wall 334.

[0058] The angle α between the second inner wall 334 and the fourth inner wall 336 can specifically be 5°, 15°, 25°, 35°, 45°, 55°, 60°, 65°, 75°, 85°, or 90°. In some examples, the angle α between the plane containing the second inner wall 334 and the plane containing the fourth inner wall 336 can be 60°, which improves the pressure relief effect of the battery cell 2.

[0059] Along the thickness direction of the collecting plate, the projection of the hollow structure 50 onto the bottom shell 21 is fan-shaped; wherein, the first inner wall 333 and the third inner wall 335 are both arc-shaped walls; the second inner wall 334 and the fourth inner wall 336 are both straight walls.

[0060] This configuration allows the perforated structure 50 on the second sub-part 33 to have a large area, enabling more gas to flow through the second sub-part 33 and thus strengthening the gas flow capacity of the manifold 1.

[0061] The value range of the diameter R4 of the circle containing the first inner wall 333 is: R4 > R5 + 2 × t1 + 2 × t2; where R5 is the diameter of the end face of the first connecting part 10 of the collecting plate 1 away from the core 22, t1 is the thickness of the first sub-part 31, and t2 is the process safety distance between the first connecting part 10 and the hollow structure 50 during forming.

[0062] The hollow structure 50 can be a through hole formed in the second sub-part 33 of the second connecting part 30. The through hole is roughly fan-shaped. The outer diameter R3 of the hollow structure 50 is the outer diameter of the fan-shaped through hole. Specifically, the diameter R3 of the circle containing the third inner wall 335 can be the diameter of the circle containing the wall surface of the third inner wall 335 facing the first connecting part 10. The diameter R4 of the circle containing the first inner wall 333 can be the inner diameter of the hollow structure 50. Specifically, the diameter R4 of the circle containing the first inner wall 333 can be the diameter of the circle containing the wall surface of the first inner wall 333 facing the third inner wall 335.

[0063] Please combine Figure 5 The first connecting portion 10 can be in the shape of a disc, and the end face of the first connecting portion 10 away from the core 22 can be circular. Here, R5 is the diameter of the end face of the first connecting portion 10 away from the core 22, and t1 is the thickness of the first sub-part 31, or the thickness of the parent material of the collecting disk 1. It is easily understood that the parent material forms the collecting disk 1 through processes such as stamping, and the first sub-part 31 can be considered to be approximately equal to the thickness t1 of the parent material. Please refer to... Figure 8 In some scenarios, the thickness of the first sub-part 31 of the second connecting part 30 of the collector plate 1 can be regarded as the thickness of the parent material of the collector plate 1. t2 is the process safety distance between the first connecting part 10 and the hollow structure 50 during molding.

[0064] It is readily understood that in these embodiments, the diameter R4 of the circle containing the first inner wall 333 is limited, R4 > R5 + 2 × t1 + 2 × t2. The diameter R4 of the circle containing the first inner wall 333 can be the diameter of the circle containing the wall surface of the first inner wall 333 facing the third inner wall 335. During processing, the first connecting part 10 is obtained by stamping the base material. The first connecting part 10 can be a stamped convex structure with an R-angle, and the thickness of the R-angle can be at least t1. Furthermore, it is readily understood that a safety distance needs to be reserved between the two structural features during the forming process; otherwise, the two structural features will interfere with each other and be difficult to form. t2 is the process safety distance between the first connecting part 10 and the hollow structure 50 during forming. Please refer to... Figure 3 , Figure 3 The diagram roughly illustrates the process safety distance t2 between the first connecting part 10 and the hollow structure 50 during its formation.

[0065] Please combine Figure 2 , Figure 3 If the diameter R4 of the circle containing the first inner wall 333 does not satisfy the formula, problems such as edge collapse during the forming of the hollow structure 50, damage to the thickness at the R-corner of the first connecting part 10, and severe deformation may occur. When the formula is satisfied, the hollow structure 50 is easier to form, and the first connecting part 10 has better strength.

[0066] In some implementations, t1 ≥ 0.1 mm, t2 ≥ 0.2 × t1 mm.

[0067] The thickness t1 of the parent material of the collector plate 1 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm.

[0068] The first connecting part 10 has a second air chamber 101 on the side facing the core 22, and the second air chamber 101 communicates with the first air chamber 331.

[0069] The second air chamber 101 is connected to the first air chamber 331. When the valve is opened, the gas contained in the second air chamber 101 can enter the first air chamber 331 and be released from the opening of the explosion-proof structure 23 of the bottom shell 21 through the hollow structure 50.

[0070] The second gas chamber 101 can also be used to accommodate the gas inside the battery cell 2, thereby allowing the battery cell 2 to hold a larger volume of gas and improving its service life. The second gas chamber 101 increases the exhaust space of the battery cell 2 located on the side of the collector plate 1, enhancing the safety of the battery cell 2.

[0071] This application also provides a battery cell 2, which includes a bottom shell 21, a core 22 and the aforementioned current collector 1 arranged along the axial direction of the battery cell 2, and the current collector 1 is disposed between the bottom shell 21 and the core 22.

[0072] The battery cell 2 includes an explosion-proof structure 23, which is disposed on the bottom shell 21. Along the axial direction of the battery cell 2, at least a portion of the projection of the explosion-proof structure 23 on the bottom shell 21 is located within the projection of the hollow structure 50 on the bottom shell 21.

[0073] The explosion-proof structure 23 can be a grooved explosion-proof structure, which can be formed by scribing grooves on the bottom shell 21. When the valve is opened, the gas inside the battery cell 2 can be released to the outside of the battery cell 2 through the core 22, the hollow structure 50, and the explosion-proof structure 23, which can release the gas inside the battery cell 2 to the outside of the battery cell 2 more quickly.

[0074] Please combine Figure 4 and Figure 5 The relationship between the diameter R1 of the explosion-proof structure 23, the outer diameter R2 of the battery cell 2, and the outer diameter R3 of the hollow structure 50 is as follows: 7 / 5×(R2-R1) <R3<R1.

[0075] In some embodiments, cell 2 is a cylindrical cell 2, and the outer diameter R2 of cell 2 is the outer diameter of the cylindrical cell 2. Please refer to... Figure 6 , Figure 6 This is a cross-section passing through the central axis of cylindrical cell 2, which passes through the center of current collector 1. Figure 5 The diagram shows the outer diameter R2 of cell 2.

[0076] In some embodiments, the explosion-proof structure 23 is a notched explosion-proof structure 23, with notches made on the bottom shell 21. When the pressure inside the battery cell 2 reaches a preset value, it will break through the notches of the explosion-proof structure 23, causing an opening to appear on the bottom shell 21, from which the gas inside the battery cell 2 can escape. The notches can be approximately closed patterns or non-closed patterns. For example, please refer to... Figure 6 When the notch is approximately a closed circle, the diameter R1 of the explosion-proof structure 23 can be the diameter of the circle containing the notch. Specifically, it can be the diameter of the circle containing the center of the notch. When the notch is approximately a non-closed arc, the diameter R1 of the explosion-proof structure 23 can be the diameter of the arc containing the notch. Specifically, it can be the diameter of the arc containing the center of the notch.

[0077] The perforated structure 50 can be a through hole formed in the second sub-part 33 of the second connecting part 30. The through hole is roughly fan-shaped. The outer diameter R3 of the perforated structure 50 is the outer diameter of the fan-shaped through hole. Specifically, the outer diameter R3 of the perforated structure 50 can be the diameter of the circle containing the third inner wall 335, that is, the diameter of the circle containing the wall surface of the third inner wall 335 facing the first connecting part 10. The diameter R4 of the circle containing the first inner wall 333 can be the diameter of the circle containing the wall surface of the first inner wall 333 facing the third inner wall 335, and the diameter R4 of the circle containing the first inner wall 333 is also the inner diameter of the perforated structure 50.

[0078] The relationship between the area S2 of the hollow structure 50 and the area S1 of the explosion-proof structure 23 of the battery cell 2 is: S2 > 2 / 3 × S1.

[0079] When the explosion-proof structure 23 is approximately a circular explosion-proof structure with a diameter of R1, the area of ​​the explosion-proof structure 23 can be: S1 = π (1 / 2R1)².

[0080] Please combine Figure 7 , Figure 7 There are three hollow structures 50 in the middle, and the area S2 of the hollow structure 50 is the sum of the areas of the three hollow structures 50. The area S2 of the hollow structure 50 can be understood as the hollow pressure relief area of ​​the collector plate 1.

[0081] It is easily understood that in related technologies, when a short circuit occurs inside cell 2, the gas generated inside is easily blocked by the current collector, resulting in poor gas flow, untimely pressure relief, and a higher accumulated gas pressure inside the cell, posing a risk of cell explosion. In the embodiment of this application, by limiting S2 to 2 / 3 × S1, the gas generated inside cell 2 is less likely to be blocked by the current collector 1, gas flow is smoother, pressure relief can be carried out more promptly, resulting in a lower accumulated gas pressure inside cell 2 and greater safety and reliability.

[0082] The first connecting part 10 has a second air chamber 101 on the side facing the core 22. The second air chamber 101 is connected to the first air chamber 331. The sum of the internal gas production volume of the battery cell 2, the volume of the second air chamber 101, and the volume of the first air chamber 331 is Z1, where Z1 ≥ 0.05Z. Z1 can be the volume of the air chamber space on one side of the circular manifold.

[0083] During the charging and discharging process of cell 2, gas is generated inside it. The second gas chamber 101 and the first gas chamber 331 can accommodate a larger volume of gas, which can avoid the situation of excessive internal pressure caused by gas accumulation, thereby improving the charging and discharging efficiency of cell 2.

[0084] In some scenarios, cell 2 can specifically be a lithium iron phosphate cell 2 with a capacity of X Ah; each Ah of battery capacity will generate Y standard liters of gas under thermal runaway conditions; therefore, the internal gas generation volume of cell 2 is... The total height H1 of the manifold is within the range of 0.2mm ≤ H1 ≤ 4mm; thus, the volume Z1 of the air chamber space on one side of the circular manifold can be ≥ 0.05Z.

[0085] Please combine Figure 8 The present application also provides an electrical device 3, which includes the above-mentioned collector 1 or the above-mentioned battery cell 2.

[0086] The electrical device 3 possesses all the beneficial effects of the aforementioned collector 1 or the aforementioned battery cell 2, which will not be elaborated upon here. It is understood that the electrical device 3 includes, but is not limited to, electric toys, power tools, electric vehicles, automobiles, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. Automobiles can be gasoline-powered vehicles, natural gas vehicles, and new energy vehicles.

[0087] Since the electrical equipment 3 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0088] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0089] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0090] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0091] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A collector disk (1), characterized in that, include: The first connecting part (10) is used to connect with the bottom shell (21); and The second connecting part (30) is used to connect with the core (22). The second connecting part (30) is connected with the first connecting part (10). The second connecting part (30) is provided with a hollow structure (50). The second connecting part (30) has a first air chamber (331) on the side facing the core (22), and the hollow structure (50) is connected to the first air chamber (331).

2. The collector disk (1) according to claim 1, characterized in that, The second connecting part (30) is connected to the outer periphery of the first connecting part (10). The second connecting part (30) includes a first sub-part (31) and a second sub-part (33) connected circumferentially along the collector plate. The first sub-part (31) is used to connect with the core (22). The second sub-part (33) has a first air chamber (331) on the side facing the core (22). The hollow structure (50) is provided on the second sub-part (33).

3. The collector disk (1) according to claim 2, characterized in that, Along the thickness direction of the collector plate, in the direction away from the bottom shell (21), the distance t3 between the surface of the second sub-part (33) and the surface of the first sub-part (31) satisfies: t3 > t1, where t1 is the thickness of the first sub-part (31).

4. The collector disk (1) according to claim 2, characterized in that, The second sub-part (33) includes a first inner wall (333), a second inner wall (334), a third inner wall (335), and a fourth inner wall (336) connected in sequence. The first inner wall (333), the second inner wall (334), the third inner wall (335), and the fourth inner wall (336) surround and define the hollow structure (50). Along the radial direction of the collecting plate (1), the first inner wall (333) is located between the first connecting part (10) and the third inner wall (335), and the second inner wall (334) and the fourth inner wall (336) are arranged at intervals along the circumference of the collecting plate (1).

5. The collector disk (1) according to claim 4, characterized in that, The angle α between the plane containing the second inner wall (334) and the plane containing the fourth inner wall (336) is in the range of 5°≤α≤90°.

6. The collector disk (1) according to claim 5, characterized in that, Along the thickness direction of the collecting plate, the shape of the projection of the hollow structure (50) on the bottom shell (21) is fan-shaped; wherein, the first inner wall (333) and the third inner wall (335) are both arc-shaped walls; the second inner wall (334) and the fourth inner wall (336) are both flat walls.

7. The collector disk (1) according to claim 4, characterized in that, The range of the diameter R4 of the circle containing the first inner wall (333) is: R4 > R5 + 2 × t1 + 2 × t2; Wherein, R5 is the diameter of the end face of the first connecting part (10) of the collector plate (1) away from the core (22), t1 is the thickness of the first sub-part (31), and t2 is the process safety distance between the first connecting part (10) and the hollow structure (50) during forming.

8. The collector disk (1) according to claim 7, characterized in that, t1≥0.1mm, t2≥0.2×t1mm.

9. The collector disk (1) according to any one of claims 1 to 8, characterized in that, The first connecting part (10) is provided with a second air chamber (101) on the side facing the core (22), and the second air chamber (101) is connected to the first air chamber (331).

10. A battery cell (2), characterized in that, The battery cell (2) includes a bottom shell (21), a core (22) arranged along the axial direction of the battery cell (2) and a current collector (1) as described in any one of claims 1-9, wherein the current collector (1) is disposed between the bottom shell (21) and the core (22).

11. The battery cell (2) according to claim 10, characterized in that, The battery cell (2) includes an explosion-proof structure (23), which is disposed on the bottom shell (21). Along the axial direction of the battery cell (2), at least part of the projection of the explosion-proof structure (23) on the bottom shell (21) is located within the projection of the hollow structure (50) on the bottom shell (21).

12. The battery cell (2) according to claim 11, characterized in that, The relationship between the diameter R1 of the explosion-proof structure (23), the outer diameter R2 of the battery cell (2), and the outer diameter R3 of the hollow structure (50) is as follows: 7 / 5×(R2-R1) <R3<R1.

13. The battery cell (2) according to claim 11, characterized in that, The relationship between the area S2 of the hollow structure (50) and the area S1 of the explosion-proof structure (23) of the battery cell (2) is: S2 > 2 / 3 × S1.

14. The battery cell (2) according to claim 10, characterized in that, The first connecting part (10) is provided with a second air chamber (101) on the side facing the core (22). The second air chamber (101) is connected to the first air chamber (331). The internal gas production volume of the battery cell (2) is Z, and the sum of the volumes of the second air chamber (101) and the first air chamber (331) is Z1, where Z1 ≥ 0.05Z.

15. An electrical appliance (3), characterized in that, Includes the current collector (1) as described in any one of claims 1-9 or the battery cell (2) as described in any one of claims 10-14.

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