Cylindrical battery and electronic device

Abstract

Disclosed in the present application are a cylindrical battery and an electronic device. A housing comprises a first wall portion and a second wall portion that are disposed opposite each other in an axial direction of the cylindrical battery. A first current collector disc is disposed between an electrode assembly and the first wall portion, and a second current collector disc is disposed between the electrode assembly and the second wall portion. The first current collector disc comprises a first portion, a second portion, and a first connection section disposed between the first portion and the second portion. The second current collector disc comprises a third portion, a fourth portion, and a second connection section disposed between the third portion and the fourth portion. When viewed in the axial direction of the cylindrical battery, an included angle α is formed between the first connection section and the second connection section, where 45°≤α≤135°. The risk of a connection failure between the first current collector disc and the electrode assembly and / or the housing and between the second current collector disc and the electrode assembly and / or the housing are reduced, thereby improving the drop resistance of the cylindrical battery.

Description

cylindrical batteries and electronic devices Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cylindrical battery and an electronic device. Background Technology

[0002] With the rapid development of portable electronic devices, electric vehicles and other fields, cylindrical batteries have been widely used due to their high energy density and good stability.

[0003] Cylindrical cells typically consist of a casing, electrode assemblies, and current collectors. The current collectors play a crucial role in conducting electricity and collecting current. Current collectors are usually divided into an upper current collector and a lower current collector. One end of the upper current collector is connected to the electrode assembly, and the other end is connected to the top wall of the casing. One end of the lower current collector is connected to the electrode assembly, and the other end is connected to the bottom wall of the casing. The current collectors are used to conduct the current generated by the electrode assembly to the external circuit. Summary of the Invention

[0004] However, the inventors of this application have discovered that when a cylindrical battery is subjected to a drop impact, the electrode assembly is prone to relative displacement with the casing. During the drop, the upper and lower current collectors are subjected to repeated pulling and squeezing, which can easily cause the electrical connection between the upper current collector and the electrode assembly and / or the top wall to break, as well as the electrical connection between the lower current collector and the electrode assembly and / or the bottom wall to break.

[0005] In view of this, this application provides a cylindrical battery and electronic device, which aims to reduce the problem of easy disconnection of the current collector electrical connection.

[0006] In order to solve its technical problems, the embodiments of this application adopt the following technical solutions:

[0007] In one aspect, this application proposes a cylindrical battery, including a housing, an electrode assembly, a first current collector, and a second current collector. Along the axial direction of the cylindrical battery, the housing includes a first wall and a second wall disposed opposite to each other. The electrode assembly is disposed within the housing. The first current collector is disposed between the electrode assembly and the first wall, and the second current collector is disposed between the electrode assembly and the second wall. The first current collector includes a first portion, a second portion, and a first connection position disposed between the first and second portions. The second portion is folded along the first connection position and is connected to the first portion. The first portion is used for electrical connection with the electrode assembly, and the second portion is used for electrical connection with the first wall. The second current collector includes a third portion, a fourth portion, and a second connection position disposed between the third and fourth portions. The fourth portion is folded along the second connection position and is connected to the third portion. The third portion is used for connection with the electrode assembly, and the fourth portion is used for connection with the second wall. Viewed along the axial direction of the cylindrical battery, the included angle between the first and second connection positions is α, where 45° ≤ α ≤ 135°.

[0008] In the above technical solution, when viewed along the axial direction of the cylindrical battery, the included angle between the first connection position and the second connection position is α, where 45°≤α≤135°. This prevents the cylindrical battery from experiencing simultaneous ground contact and stress at positions A (the end with the first connection portion) or E (the end opposite to the first connection portion) of the first current collector and positions A (the end with the second connection portion) or E (the end opposite to the second connection portion) of the second current collector. This reduces the risk of connection failure between the first current collector and the electrode assembly and / or the housing, as well as the risk of connection failure between the second current collector and the electrode assembly and / or the housing. Furthermore, limiting 45°≤α≤135° reduces the center of gravity of the cylindrical battery from being closer to positions A or E, thereby reducing the stress at positions A or E and improving the drop resistance of the cylindrical battery.

[0009] In some embodiments, 60°≤α≤120° can further reduce the risk of failure in the connection between the first and second current collectors and the electrode assembly and / or the housing. Furthermore, limiting 60°≤α≤120° can further reduce the center of gravity of the cylindrical battery from being close to position A or E, thereby reducing the force on position A or E and further improving the drop resistance of the cylindrical battery.

[0010] In some embodiments, the first current collector further includes a fifth portion, and a second portion is connected between the first portion and the fifth portion, with the second portion connected to the first wall portion via the fifth portion. A third connection point is provided between the fifth portion and the second portion. Viewed axially along the cylindrical cell, the included angle between the first connection point and the third connection point is β, where 45°≤β≤135°. This reduces connection failures between the fifth portion and the first wall portion, as well as connection failures between the first portion and the electrode assembly, improving the impact resistance of the cylindrical cell. Preferably, 60°≤β≤120°.

[0011] In some embodiments, when viewed along the axial direction of the cylindrical battery, the angle between the third connection point and the second connection point is θ, where 45° ≤ θ ≤ 135°. This also reduces the occurrence of maxima and minimizes the simultaneous tearing of the first and second current collectors. Preferably, 60° ≤ θ ≤ 120°.

[0012] In some embodiments, the radius of the first part is R1, and the radius of the second part is R2, where 0 mm ≤ R1 - R2 ≤ 1 mm. By reducing the radius difference between the second and first parts, the current collector structure becomes more stable, better able to withstand the internal pressure of the cylindrical battery and external mechanical impacts, and the stress is more evenly distributed between the first and second parts, reducing stress concentration at the connection and thus reducing the risk of current collector tearing. Furthermore, the smaller radius difference makes the connection between the two parts of the current collector and the electrode assembly and the first wall easier and more reliable, resulting in a larger contact area and improved connection strength. This not only improves the consistency of cylindrical battery production but also reduces the connection resistance between the current collector and the electrode assembly and the first wall, which is beneficial for improving the charge / discharge rate of the cylindrical battery. Moreover, the larger radius of the first part, which connects to the electrode assembly, allows for better adaptation to the shape and size of the electrode assembly, which helps improve the utilization of the internal space of the cylindrical battery, providing more space for active materials and thus increasing the energy density of the cylindrical battery.

[0013] In some embodiments, along the axial direction of the cylindrical battery, the projection of the second outer ring at least partially overlaps with the projection of the first outer ring. When the electrode assembly and the housing undergo relative displacement, the partial overlap of the projections of the first and second outer rings increases the contact area between the first and second parts, forming mutual support, reducing stress concentration, improving the overall deformation resistance of the current collector, and thus reducing tearing of the current collector. Optionally, along the axial direction of the cylindrical battery, the projection of the fourth outer ring at least partially overlaps with the projection of the third outer ring.

[0014] In some embodiments, the cylindrical battery further includes a gasket, with a first portion connected to the inner ring of the gasket, and a first portion and a second portion disposed within the inner ring of the gasket. The gasket is positioned between the electrode assembly and the first wall portion. The gasket can absorb some impact force. When the cylindrical battery is subjected to external impact, such as a drop or collision, the gasket acts as a buffer, reducing the external force transmitted to the current collector, thereby reducing the risk of tearing of the current collector due to instantaneous external force. Furthermore, the gasket can distribute stress concentrated at a point on the current collector over a larger area. When the cylindrical battery is subjected to external force, it can reduce excessive local stress on the current collector, thereby reducing the risk of tearing. Additionally, the gasket, supported between the electrode assembly and the first wall portion of the housing, can limit the relative displacement between the electrode assembly and the bottom of the housing, thereby reducing deformation or tearing of the current collector caused by such displacement.

[0015] In some embodiments, the cylindrical battery further includes a buffer member disposed at the connecting portion and facing the first and second portions. By providing a buffer member at the connecting portion, when the cylindrical battery is subjected to external impact or vibration, the buffer member can absorb part of the impact force, reducing the stress transmitted to the connecting portion and helping to reduce the likelihood of breakage due to stress concentration at the connecting portion. Furthermore, the buffer member allows for a more uniform distribution of stress at the connecting portion, effectively reducing localized stress concentration and improving the overall strength and reliability of the current collector. Simultaneously, the buffer member can fill part of the gap between the first and second portions of the current collector, effectively reducing repeated stress on the connecting portion, improving its fatigue resistance, extending the service life of the current collector, and reducing the risk of cylindrical battery failure. Additionally, when the first and second portions are folded, the buffer member can also withstand some stress, reducing the likelihood of cracks or tears appearing at the connecting portion during folding.

[0016] In some embodiments, the buffer portion is located between the first portion and the second portion, allowing the buffer to fill part of the gap between the first and second portions, reducing tearing of the connection between the first and second portions due to excessive bending. Furthermore, the buffer provides additional protection for the manifold, reducing the impact force transmitted to the manifold and electrode assembly, thus reducing not only tearing of the manifold but also loosening of the electrode assembly due to impact.

[0017] In some embodiments, the thickness of the first part is T1, the thickness of the second part is T2, and the thickness of the connecting part is T3, where T3 < T1 and T3 < T2. By reducing the thickness of the connecting part, it can better adapt to deformation during the folding process, facilitating the uniform transfer of stress from one part to another. Furthermore, reducing the thickness of the connecting part can improve its flexibility, allowing it to better withstand deformation during bending and reducing tearing caused by excessive rigidity.

[0018] In some embodiments, 60% ≤ T3 / T1 ≤ 80% can improve the flexibility of the connecting part while giving it higher strength, which not only facilitates the folding of the first and second parts but also reduces tearing of the connecting part. Based on the same inventive concept, 60% ≤ T3 / T2 ≤ 80% can further improve the flexibility of the connecting part and give it higher strength, which not only facilitates the folding of the first and second parts but also further reduces tearing of the connecting part and gives both the first and second parts higher strength.

[0019] In some embodiments, the material of the first current collector includes at least one selected from copper alloy, copper-nickel alloy, aluminum alloy, titanium alloy, stainless steel, or nickel-chromium alloy. Optionally, the material of the second current collector includes at least one selected from copper alloy, copper-nickel alloy, aluminum alloy, titanium alloy, stainless steel, or nickel-chromium alloy. All of the above materials have high mechanical strength and can withstand the internal pressure of the cylindrical battery and external impact forces, thus reducing tearing of the current collector.

[0020] Secondly, this application also proposes an electronic device including a cylindrical battery as described in any of the embodiments of the first aspect above.

[0021] Additional aspects and advantages of the embodiments of this application will be described, shown, or illustrated in part by way of implementation of the embodiments of this application in the following description. Attached Figure Description

[0022] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0023] Figure 1 is a schematic diagram of the structure of a cylindrical battery according to some embodiments of this application;

[0024] Figure 2 is an exploded schematic diagram of a cylindrical battery according to some embodiments of this application;

[0025] Figure 3 is a cross-sectional schematic diagram of a cylindrical battery according to some embodiments of this application;

[0026] Figure 4 is a schematic diagram of the winding structure of the electrode assembly in some embodiments of this application;

[0027] Figure 5 is a schematic diagram of the unfolded structure of the first data collection disk according to some embodiments of this application;

[0028] Figure 6 is a schematic diagram (top view) of the folded structure of the first collector disk in some embodiments of this application;

[0029] Figure 7 is a schematic diagram (top view) of the folded structure of the second collector disk in some embodiments of this application;

[0030] Figure 8 is a schematic diagram (top view) of the folded structure of the first collector disk in some embodiments of this application;

[0031] Figure 9 is a schematic diagram of the structure in which the first collector disk and the second collector disk overlap along the axial direction in some embodiments of this application;

[0032] Figure 10 is a schematic diagram (front view) of the three-fold structure of the first collector disk in some embodiments of this application;

[0033] Figure 11 is a schematic diagram (top view) of the three-fold structure of the first collector disk in some embodiments of this application.

[0034] Figure 12 is a schematic diagram (top view) of the folded structure of the first collector disk in some embodiments of this application;

[0035] Figure 13 is a schematic diagram (front view) of the folded structure of the first collector disk in some embodiments of this application;

[0036] Figure 14 is a schematic diagram (front view) of the folded structure of the first collector disk in some embodiments of this application;

[0037] Figure 15 is a schematic diagram of the structure of the washer and the first collector plate according to an embodiment of this application;

[0038] Figure 16 is a partial cross-sectional schematic diagram of a cylindrical battery according to some embodiments of this application;

[0039] Figure 17 is a cross-sectional schematic diagram of the gasket and the first collector plate in some embodiments of this application;

[0040] Figure 18 is a schematic diagram (front view) of the folded structure of the first collector disk in some embodiments of this application;

[0041] Figure 19 is a schematic diagram of the structure of the first adhesive layer in some embodiments of this application.

[0042] Explanation of reference numerals in the attached drawings: 100, cylindrical battery; 10, casing; 10a, receiving cavity; 11, first wall portion; 12, second wall portion; 13, main body portion; 14, opening; 20, electrode assembly; 21, positive electrode plate; 22, negative electrode plate; 23, separator; 24, central hole; 30, first current collector; 31, first part; 311, first protrusion; 312, first through hole; 32, second part; 321, second protrusion; 322, second through hole; 33, first connecting part; 331, first connecting position; 35, fifth part; 36, third connecting position; 40, buffer; 50, gasket; 60, first adhesive layer; 70, second current collector; 71, third part; 72, fourth part; 73, second connecting part; 731, second connecting position; X, axial direction. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0044] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0045] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0046] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0047] The technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0048] In a first aspect, this application proposes a cylindrical battery 100. Referring to Figures 1 to 3, the cylindrical battery 100 includes a housing 10, an electrode assembly 20, a first current collector 30, and a second current collector 70. The housing 10 encloses a receiving cavity 10a, and the electrode assembly 20 is disposed in the receiving cavity 10a. Along the axial direction X of the cylindrical battery, the housing 10 includes a first wall portion 11 and a second wall portion 12 disposed opposite to each other. The first current collector 30 is disposed between the first wall portion 11 and the electrode assembly 20, and the second current collector 70 is disposed between the second wall portion 12 and the electrode assembly 20.

[0049] Referring to Figures 2 and 3, the housing 10 is used to house the electrode assembly 20 and the electrolyte (not shown in the figures). The electrolyte permeates the electrode assembly 20 within the housing 10 to induce an electrochemical reaction. The housing 10 may be cylindrical, such as a cylinder, prism, or elliptical cylinder. The housing 10 includes a main body 13, a first wall 11, and a second wall 12. Along the axial direction X of the housing 10, the first wall 11 and the second wall 12 are respectively connected to both ends of the main body 13.

[0050] In some embodiments, the first wall portion 11 is integrally formed with the main body portion 13. For example, the main body portion 13 and the first wall portion 11 are integrally formed by directly extruding metal material using a cold extrusion molding process. During the cold extrusion process, the metal material used to prepare the shell is subjected to triaxial compressive stress, which can improve the utilization rate of the metal material and enhance the overall strength of the shell 10. An opening 14 is provided at one end of the main body portion 13 away from the first wall portion 11. The electrode assembly 20 can be placed into the shell 10 through the opening 14, and then the opening 14 is sealed by the second wall portion 12 to form a closed receiving cavity 10a. In other embodiments, the first wall portion 11 can also be separately formed from the main body portion 13. That is, the main body portion 13 adopts the form of openings 14 at both ends, and a closed receiving cavity 10a can be formed by connecting the first wall portion 11 and the second wall portion 12.

[0051] The casing 10 can be made of conductive metal materials such as aluminum, aluminum alloy, steel, stainless steel, nickel, copper or magnesium alloy, which allows the casing 10 to lead out a certain polarity of the cylindrical battery 100, for example, the casing 10 itself can be used as the positive or negative electrode of the cylindrical battery 100.

[0052] Referring to Figures 3 and 4, the outermost diameter of the electrode assembly 20 is smaller than the inner diameter of the housing 10, which facilitates the placement of the electrode assembly 20 within the housing 10. The electrode assembly 20 includes a positive electrode 21, a negative electrode 22, and a separator 23. The positive electrode 21, the separator 23, and the negative electrode 22 are stacked and wound together. The separator 23 is disposed between the positive electrode 21 and the negative electrode 22 to provide insulation between them.

[0053] Optionally, the negative electrode 22 of the electrode assembly 20 is electrically connected to the first wall portion 11 so that the first wall portion 11 leads out the negative electrode, and the positive electrode 21 of the electrode assembly 20 is electrically connected to the second wall portion 12 so that the second wall portion 12 leads out the positive electrode.

[0054] For example, the negative electrode 22 of the electrode assembly 20 may have a negative electrode empty foil area (not shown in the figure) without a negative electrode material layer, or the negative electrode 22 may be connected to multiple negative electrode tabs (not shown in the figure). The negative electrode empty foil area or the negative electrode tabs are positioned facing the first wall portion 11. By flattening the negative electrode empty foil area or the multiple negative electrode tabs to form a negative electrode flat surface, through-welding can directly connect the first wall portion 11 to the negative electrode flat surface, thereby leading out the negative electrode through the first wall portion 11. The positive electrode of the electrode assembly 20 can be similarly configured. By flattening the positive electrode empty foil area (not shown in the figure) or the multiple positive electrode tabs (not shown in the figure) of the positive electrode 21 to form a positive electrode flat surface, the second wall portion 12 can be electrically connected to the positive electrode flat surface, thereby leading out the positive electrode through the second wall portion 12. In some other embodiments, the second wall portion 12 may also lead out the negative electrode, while the first wall portion 11 leads out the positive electrode.

[0055] Taking the negative electrode led out from the first wall portion 11 as an example, for the first current collector 30 mentioned above, please refer to Figure 3. The first current collector 30 is disposed inside the housing 10. Along the axial direction X of the cylindrical battery 100, the first current collector 30 is electrically connected between the electrode assembly 20 and the first wall portion 11 of the housing 10. For example, by means of welding or conductive adhesive connection, the two sides of the first current collector 30 are electrically connected to the electrode assembly 20 and the first wall portion 11 of the housing 10 respectively, so that the negative electrode is led out from the first wall portion 11.

[0056] The current collector effectively collects the current generated inside the cylindrical battery 100 and conducts it evenly and efficiently to the external circuit, ensuring stable and smooth current output and improving the charging and discharging performance and efficiency of the cylindrical battery 100. For example, in high-discharge-rate applications, the current collector can quickly collect and transmit a large amount of current to meet the high-rate charging and discharging requirements of the cylindrical battery 100. Furthermore, the current collector can be made of highly conductive materials, such as copper or aluminum, which reduces the transmission resistance of current within the cylindrical battery 100 and lowers energy loss. In addition, the current collector provides mechanical support for the electrode assembly 20, increasing the overall structural strength and stability of the cylindrical battery 100. When the cylindrical battery 100 is subjected to external forces such as vibration and impact, the current collector can reduce deformation and damage to the electrode assembly 20. Simultaneously, the current collector provides a more convenient connection point, making the connection between the electrode assembly 20 and the first wall 11 simpler and more reliable.

[0057] In some other embodiments, the housing 10 may include a second collector plate 70, through which the positive electrode plane of the electrode assembly 20 is electrically connected to the second wall portion 12 or the electrode post on the second wall portion 12 to lead out the positive electrode. Alternatively, the first wall portion 11 may also be provided with an electrode post, and the positive electrode plate 21 can be directly electrically connected to the electrode post on the first wall portion 11 through the first collector plate 30.

[0058] Please refer to Figures 5 and 6, where Figure 5 shows the folded structure of the first collector plate 30, and Figure 6 shows the folded structure of the first collector plate 30. The first collector plate 30 includes a first part 31, a second part 32, and a first connecting part 33. The first connecting part 33 connects the first part 31 and the second part 32. The second part 32 is folded together with the first part 31, for example, the second part 32 is folded towards the first part 31 along the first connecting part 33. After folding, a first connecting position 331 is formed at the folded position of the first connecting part 33, that is, the first part 31 is folded together with the second part 32 along the first connecting position 331 of the first connecting part 33. The first part 31 is connected to the electrode assembly 20, and the second part 32 is connected to the first wall part 11.

[0059] The folding design of the first current collector 30 can better adapt to the internal space of the cylindrical battery 100. Through folding, the first current collector 30 can achieve electrical connection with the electrode assembly 20 and the first wall 11 without occupying too much space, while maintaining a certain degree of flexibility to adapt to the volume changes of the cylindrical battery 100 during charging and discharging. For example, when the cylindrical battery 100 is charging and discharging, the electrode plates will expand and contract. The folded first current collector 30 has a certain buffering capacity and can adjust its shape according to the changes in the electrode plates, reducing damage caused by stress concentration.

[0060] Similarly, referring to Figure 7, the second collector plate 70 includes a third part 71, a fourth part 72, and a second connecting part 73. The second connecting part 73 connects the third part 71 and the fourth part 72. The fourth part 72 and the third part 71 are folded together, for example, the fourth part 72 is folded towards the first part 31 along the second connecting part 73. After folding, the folded position of the second connecting part 73 forms a second connecting position 731, that is, the third part 71 is folded along the second connecting position 731 of the second connecting part 73 and the fourth part 72. The third part 71 is connected to the electrode assembly 20, and the fourth part 72 is connected to the second wall part 12.

[0061] In some embodiments, referring to Figures 3, 5, and 6, the first portion 31 is provided with a first through hole 312, and the second portion 32 is provided with a second through hole 322. After the first portion 31 and the second portion 32 are folded, the second through hole 322 at least partially overlaps with the first through hole 312 along the axial direction X of the cylindrical battery 100. The first through hole 312 and the second through hole 322 can serve as electrolyte transport channels, allowing the electrolyte to be directly transported to the electrode assembly 20 through the first through hole 312 and the second through hole 322. This shortens the electrolyte transport path, enabling the electrode assembly 20 to be more quickly and fully wetted by the electrolyte, improving the electrolyte injection efficiency and the electrolyte wetting efficiency. Based on the same inventive concept, the second collector 70 can also be similarly provided with a through hole structure.

[0062] In some other embodiments, the electrode assembly 20 forms a central hole 24 after winding. Along the axial direction X of the cylindrical battery 100, the second through hole 322, the first through hole 312, and the central hole 24 at least partially overlap. Electrolyte can be transported to the central hole 24 through the second through hole 322 and the first through hole 312. The electrolyte can diffuse towards the electrode assembly 20 at the central hole 24, allowing the electrolyte in the central hole 24 to wet the electrode assembly 20 from the inside, while externally free electrolyte wets the electrode assembly 20 from the outside, thus improving the wetting efficiency and electrolyte injection efficiency of the electrode assembly 20. Based on the same inventive concept, the second collector 70 can also be similarly configured to further improve the electrolyte wetting efficiency.

[0063] The inventors of this application have discovered that during the impact of a drop or collision on the cylindrical battery 100, the current collector will generate an instantaneous impact force, and the electrode assembly 20 will undergo relative displacement or have a tendency to do so with the housing 10. This may cause the electrode assembly 20 to pull on the current collector, thereby causing the connection between the current collector and the electrode assembly 20 and / or the housing 10 to fail.

[0064] Taking a drop as an example, as shown in Figure 8, the inventors of this application have discovered that when the drop location is position A or E of the current collector (i.e., the drop direction is perpendicular to the connection position of the current collector), the current collector will be subjected to a large axial tensile force, which may easily lead to the failure of the connection between the current collector and the electrode assembly 20 and / or the housing 10. However, when the drop location is position C or G of the current collector (i.e., the drop direction is parallel to the connection position of the current collector), the axial tensile force is smaller, and the risk of connection failure between the current collector and the electrode assembly 20 and / or the housing 10 is lower. Near position A, there is usually a connection part, which may cause the center of gravity of the cylindrical battery 100 to be closer to position A, potentially resulting in greater force on the portion of the current collector near position A during a drop.

[0065] To mitigate the aforementioned problems, in the embodiments of this application, referring to Figure 9, when viewed along the axial direction X of the cylindrical battery 100, the included angle between the first connection position 331 and the second connection position 731 is α, where 45°≤α≤135°. This prevents the cylindrical battery 100 from experiencing simultaneous ground contact and stress at positions A or E of the first current collector 30 and the second current collector 70, reducing the risk of connection failure between the first current collector 30 and the electrode assembly 20 and / or the housing 10, as well as the risk of connection failure between the second current collector 70 and the electrode assembly 20 and / or the housing 10. Furthermore, limiting 45°≤α≤135° reduces the center of gravity of the cylindrical battery 100 from being closer to positions A or E, thereby reducing the stress at positions A or E and improving the drop resistance of the cylindrical battery 100.

[0066] In some embodiments, 60°≤α≤120° can further reduce the risk of connection failure between the first current collector 30 and the second current collector 70 and the electrode assembly 20 and / or the housing 10. Furthermore, limiting 60°≤α≤120° can further reduce the center of gravity of the cylindrical battery 100 from being closer to position A or E, thereby reducing the force on position A or E and further improving the drop resistance of the cylindrical battery 100.

[0067] In some other embodiments, the first current collector 30 may also adopt a three-fold structure. Referring to Figures 10 and 11, the first current collector 30 further includes a fifth portion 35, and a second portion 32 is connected between the first portion 31 and the fifth portion 35. The second portion 32 is connected to the first wall portion 11 through the fifth portion. A third connection position 36 is provided between the fifth portion 35 and the second portion 32. When viewed along the axial direction X of the cylindrical battery 100, the included angle between the first connection position 331 and the third connection position 36 is β, where 45°≤β≤135°. This can reduce the connection failure between the fifth portion 35 and the first wall portion 11, and also reduce the connection failure between the first portion 31 and the electrode assembly 20, thereby improving the impact resistance of the cylindrical battery. Preferably, 60°≤β≤120°.

[0068] Based on the same inventive concept, when the second current collector 70 has a three-fold structure, it can be configured similarly to the first current collector 30, thereby reducing the connection failure between the second current collector 70 and the electrode assembly 20 and / or the housing 10. Optionally, when viewed along the axial direction X of the cylindrical battery 100, the included angle between the third connection position 36 and the second connection position 731 is θ, 45°≤θ≤135°, which can also reduce the occurrence of maximum values ​​(the A or E position of the first current collector 30 and the A or E position of the second current collector 70 simultaneously touching the ground), and reduce the simultaneous tearing of the first current collector 30 and the second current collector 70. Preferably, 60°≤θ≤120°.

[0069] The inventors of this application have discovered that when the cylindrical battery 100 is subjected to impacts such as drops or collisions, the current collector 30 will generate an instantaneous impact force, and the electrode assembly 20 will undergo relative displacement or have a tendency to do so with the casing 10. This can easily cause stress concentration in the connection part 33, and the connection part 33 is prone to forming obvious geometrical abrupt changes. Such abrupt changes will lead to increased local stress concentration, causing the connection part 33 to bear excessive stress, which in turn can cause the connection part 33 to tear.

[0070] To reduce the risk of tearing in the first connecting portion 33, in this embodiment, referring to Figure 5, the radius of the first part 31 is R1, and the radius of the second part 32 is R2, where |R1-R2|≤1mm. By reducing the radius difference between the second part 32 and the first part 31, the structure of the first current collector 30 becomes more stable, better able to withstand the internal pressure of the cylindrical battery 100 and external mechanical impacts, and the stress is more evenly distributed between the first part 31 and the second part 32, reducing stress concentration in the first connecting portion 33 and thus reducing the risk of tearing in the first current collector 30. Furthermore, the smaller radius difference makes the connection between the two parts of the first current collector 30 and the electrode assembly 20 and the first wall portion 11 easier and more reliable, resulting in a larger contact area and improved connection strength. This not only improves the consistency of the production of the cylindrical battery 100 but also reduces the connection resistance between the first current collector 30 and the electrode assembly 20 and the first wall portion 11, which is beneficial for improving the charge / discharge rate of the cylindrical battery 100.

[0071] The radius of the first part 31 can be the radius of the first part 31 itself, or it can be the radius of the fitted circle, i.e., the equivalent circle, where the first part 31 is located. The second part 32 is similar.

[0072] In some embodiments, 0mm≤R1-R2≤1mm, and the first portion 31, which serves as the part connected to the electrode assembly 20, has a larger radius, allowing it to better accommodate the shape and size of the electrode assembly 20. This helps to improve the utilization of the internal space of the cylindrical battery 100, providing more space for the active material and thus increasing the energy density of the cylindrical battery 100. For example, in a cylindrical battery 100 designed for a compact electronic device, this optimized space utilization can store more energy within a limited volume.

[0073] If the radius of the second part 32 is too large, and when the radius of the second part 32 is greater than the radius of the electrode assembly 20, it will cause an excessive gap between the electrode assembly 20 and the housing 10, which will lead to a loss of energy density in the cylindrical battery 100. Furthermore, the larger radius of the first part 31 increases the contact area with the electrode assembly 20, which can reduce the current transmission resistance between the first current collector 30 and the electrode assembly 20. Lower internal resistance means less energy loss during charging and discharging, thereby increasing the energy density of the cylindrical battery 100.

[0074] In some embodiments, referring to FIG12, along the axial direction X of the cylindrical battery 100, the projection of the outer ring of the second portion 32 at least partially overlaps with the projection of the outer ring of the first portion 31. When the electrode assembly 20 and the housing 10 are relatively displaced, the partial overlap of the projections of the outer ring of the first portion 31 and the outer ring of the second portion 32 increases the contact area between the first portion 31 and the second portion 32, forming mutual support, reducing stress concentration, improving the overall deformation resistance of the first current collector 30, and thus reducing the risk of tearing of the first current collector 30.

[0075] For example, after the first part 31 and the second part 32 are folded, the end of the first part 31 away from the first connecting part 33 and the end of the second part 32 away from the first connecting part 33 will preferentially contact each other. After folding, these two ends can be overlapped, which can better distribute stress. This allows the second part 32 to adopt other irregular structures, and the first part 31 can also adopt a similar irregular structure, which can easily adapt to electrode assemblies 20 with different structures.

[0076] To reduce the risk of tearing at the first connecting portion 33, in embodiments of this application, the cylindrical battery 100 further includes a buffer member 40. Referring to Figure 13, the buffer member 40 is disposed at the first connecting portion 33, and the buffer member 40 faces the first portion 31 and the second portion 32. For example, before the first collector 30 is bent, the buffer member 40 can be disposed at the first connecting portion 33 between the first portion 31 and the second portion 32. By bending the first portion 31 and the second portion 32, the buffer member 40 can be clamped in the first connecting portion 33.

[0077] By providing a buffer 40 at the first connection portion 33, when the cylindrical battery 100 is subjected to external impact or vibration, the buffer 40 can absorb part of the impact force, reducing the stress transmitted to the first connection portion 33 and helping to reduce the risk of breakage due to stress concentration. Furthermore, the buffer 40 allows for a more uniform distribution of stress at the first connection portion 33, effectively reducing localized stress concentration and improving the overall strength and reliability of the first current collector 30. Simultaneously, the buffer 40 can fill part of the gap between the first portion 31 and the second portion 32 of the first current collector 30, effectively reducing repeated stress on the first connection portion 33, improving its fatigue resistance, extending its service life, and reducing the risk of failure of the cylindrical battery 100. Additionally, when the first portion 31 and the second portion 32 are folded, the buffer 40 can also withstand some stress, reducing the likelihood of cracks or tears appearing in the first connection portion 33 during folding.

[0078] In some embodiments, the buffer 40 is partially located between the first portion 31 and the second portion 32, allowing the buffer 40 to fill a portion of the gap between the first portion 31 and the second portion 32, reducing excessive bending between the first portion 31 and the second portion 32 that could lead to tearing of the first connection portion 33. Furthermore, the buffer 40 provides additional protection for the first manifold 30, reducing the impact force transmitted to the first manifold 30 and the electrode assembly 20, thus reducing not only tearing of the first manifold 30 but also loosening of the electrode assembly 20 due to impact.

[0079] Regarding the shape of the buffer member 40, after bending, the first connecting portion 33 will enclose a gap space. Along the direction from the first connecting portion 33 to the first portion 31 and the second portion 32, the height of the gap space (the height along the axial direction X of the cylindrical battery 100) gradually decreases. The buffer member 40 can be configured in a shape similar to the gap space, for example, configured in a shape with a gradually decreasing height, so that it can fully fit the first connecting portion 33, thereby fully absorbing the impact force and dispersing the stress, reducing the risk of tearing of the first connecting portion 33.

[0080] Regarding the material of the buffer 40, in some embodiments, the buffer 40 is at least one of rubber, silicone, hot melt adhesive, or polypropylene.

[0081] Rubber has high elasticity and can deform when subjected to external force, absorbing impact force and thus reducing the stress transmitted to the first connection part 33. In addition, rubber has a certain degree of wear resistance and can maintain its cushioning performance during long-term use.

[0082] The silicone material is soft and can better conform to the surface of the first collector 30, providing a uniform cushioning effect. It can adapt to the first collector 30 of different shapes and sizes, ensuring good contact and cushioning.

[0083] The hot melt adhesive can quickly melt and bond the first connecting part 33 of the first manifold 30 after heating, forming a strong connection. At the same time, the hot melt adhesive can also play a buffering role, reducing the stress at the connection. Furthermore, by controlling the amount of hot melt adhesive and the heating temperature, the thickness and hardness of the buffer 40 can be adjusted to meet different buffering requirements.

[0084] Polypropylene has high strength and toughness, and can withstand certain mechanical stress. It can provide certain support at the first connection 33, reducing the deformation or damage of the first connection 33 due to external force. In addition, polypropylene has good chemical stability and is not easily corroded by the chemical substances inside the cylindrical battery 100, which can extend the service life of the buffer 40.

[0085] In some embodiments, referring to FIG14, a plurality of first protrusions 311 are provided on the surface of the first portion 31 facing the second portion 32. When the first portion 31 and the second portion 32 are folded, the first protrusions 311 can be supported between the first portion 31 and the second portion 32, forming a transport space for electrolyte, which facilitates the wetting of the electrode assembly 20 by the electrode liquid. The first protrusions 311 can also reduce the tearing of the first connecting portion 33 caused by excessive bending of the first portion 31 and the second portion 32, thereby improving the overall strength of the first portion 31.

[0086] In some other embodiments, a plurality of second protrusions 321 may also be provided on the surface of the second part 32 facing the first part 31. The second protrusions 321 support the first part 31 and the second part 32, which can improve the strength of the second part 32 and reduce the tearing of the first connection part 33 caused by excessive bending of the first part 31 and the second part 32.

[0087] Meanwhile, when the first part 31 and the second part 32 are not folded, the first collector plate 30 is in sheet shape, and multiple first collector plates 30 can be stacked. The arrangement of the first protrusion 311 and / or the second protrusion 321 can create a gap space between two adjacent first collector plates 30, which facilitates the removal and placement of the first collector plates 30.

[0088] To reduce the problem of tearing of the first connection portion 33, in the embodiments of this application, please refer to Figures 15 and 16. The cylindrical battery 100 also includes a gasket 50. The first portion 31 and the second portion 32 are disposed in the inner ring of the gasket 50, and the gasket 50 is disposed between the electrode assembly 20 and the first wall portion 11.

[0089] The gasket 50 can absorb some of the impact force. When the cylindrical battery 100 is subjected to external impact, such as a drop or collision, the gasket 50 can act as a buffer, reducing the external force transmitted to the first current collector 30, thereby reducing the risk of tearing of the first current collector 30 due to instantaneous external force. Furthermore, the gasket 50 can distribute the stress concentrated at a certain point on the first current collector 30 to a larger area. When the cylindrical battery 100 is subjected to external force, it can reduce the excessive local stress on the first current collector 30, thus reducing the risk of tearing.

[0090] Furthermore, the gasket 50, supported between the electrode assembly 20 and the first wall 11 of the housing 10, restricts the relative displacement between the electrode assembly 20 and the bottom of the housing 10, thereby reducing deformation or tearing of the first current collector 30 caused by such displacement. When the cylindrical battery 100 is subjected to external force or changes in internal pressure, the electrode assembly 20 and the housing 10 may deform to a certain extent. Without the restriction of the gasket 50, this deformation may be transmitted to the first current collector 30, causing the first current collector 30 to tear. For example, in a high-temperature environment, the material inside the cylindrical battery 100 may expand. The gasket 50 can reduce the squeezing deformation of the first current collector 30 caused by excessive expansion of the electrode assembly 20.

[0091] Regarding the thickness of the gasket 50, the inventors of this application have found that if the thickness of the gasket 50 is too small, it may be difficult to effectively support the electrode assembly 20 and the first wall portion 11, resulting in poor absorption of impact force. On the other hand, if the thickness of the gasket 50 is too large, it occupies a large amount of space, causing a loss of energy density in the cylindrical battery 100.

[0092] In the embodiments of this application, referring to FIG17, along the axial direction X of the cylindrical battery 100, the thickness of the first portion 31 is T1, the thickness of the second portion 32 is T2, and the thickness of the gasket 50 is T, where 0.9(T1+T2)≤T≤1.1(T1+T2). This allows the gasket 50 to effectively support the electrode assembly 20 and the first wall portion 11, fully absorb impact force, reduce stress concentration, thereby reducing tearing of the first current collector 30, and minimizing the impact on the energy density of the cylindrical battery 100.

[0093] Regarding the radius of the washer 50, in the embodiments of this application, the radius of the first part 31 is R1, the radius of the second part 32 is R2, the radius of the electrode assembly 20 is R3, the inner radius of the washer 50 is R4, and the outer radius of the washer 50 is R5, where R2≤R1≤R4<R5<R3. This facilitates a tight fit between the washer 50 and the electrode assembly 20 and the first wall portion 11, thereby reducing stress concentration and reducing the risk of tearing of the first collector plate 30. Similar to the radii of the first part 31 and the second part 32, the radii of the electrode assembly 20, the inner radius of the washer 50, and the outer radius of the washer 50 can be their own radii or the radius of the fitted circle they lie on.

[0094] In some embodiments, the material of the gasket 50 includes at least one of polypropylene (PP), polycarbonate (PC), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyimide (PI), or nylon (PA). These materials provide excellent cushioning, effectively absorbing external impacts and reducing stress transmitted to the first current collector 30. They also possess high strength, providing stable support for the first current collector 30 and reducing its movement or deformation within the cylindrical battery 100. Furthermore, materials such as polypropylene, polyphenylene sulfide, and polyetheretherketone exhibit high corrosion resistance to electrolytes and other chemicals, reducing corrosion of the gasket 50 within the cylindrical battery 100 environment and maintaining its stable performance, thus providing long-term protection for the first current collector 30. In addition, materials such as polycarbonate, polyphenylene sulfide, polyether ether ketone, and polyimide have good high temperature resistance and can maintain stable performance in the high temperature environment during the operation of the cylindrical battery 100, thereby reducing the softening or deformation of the gasket 50 due to high temperature, thus ensuring its support and protection of the first current collector 30.

[0095] The inventors of this application have discovered that after the first part 31 and the second part 32 are folded, the first connecting part 33 may develop cracks. When the cylindrical battery 100 is subjected to impacts such as collisions, the cracks may worsen, or even cause the first connecting part 33 to tear. To reduce this problem, in the embodiments of this application, referring to Figure 17, the thickness of the first part 31 is T1, the thickness of the second part 32 is T2, and the thickness of the first connecting part 33 is T3, where T3 < T1 and T3 < T2. By reducing the thickness of the first connecting part 33, the first connecting part 33 can better adapt to deformation during the folding process, facilitating the uniform transfer of stress from one part to another. Furthermore, reducing the thickness of the first connecting part 33 can improve its flexibility, allowing it to better withstand deformation during bending and reducing the risk of tearing due to excessive rigidity.

[0096] The inventors of this application have discovered that if the thickness of the first connecting portion 33 is too small, although it facilitates the folding of the first part 31 and the second part 32, the tear resistance is weakened, which may cause the first connecting portion 33 to tear during impacts such as collisions to the cylindrical battery 100. On the other hand, if the thickness of the first connecting portion 33 is too large, the rigidity of the first connecting portion 33 will be too large, making it difficult to fold the first current collector 30. During the folding process, cracks may also appear in the first connecting portion 33. During impacts such as collisions to the cylindrical battery 100, the cracks may increase, or even cause the first connecting portion 33 to tear.

[0097] To mitigate this problem, in the embodiments of this application, 60% ≤ T3 / T1 ≤ 80% can improve the flexibility of the first connecting portion 33 while simultaneously giving it higher strength. This not only facilitates the folding of the first part 31 and the second part 32 but also reduces tearing of the first connecting portion 33. Based on the same inventive concept, 60% ≤ T3 / T2 ≤ 80% can be selected, which can further improve the flexibility of the first connecting portion 33 and give it higher strength. This not only facilitates the folding of the first part 31 and the second part 32 but also further reduces tearing of the first connecting portion 33 and gives both the first part 31 and the second part 32 higher strength.

[0098] In some embodiments, referring to FIG18, the cylindrical battery 100 further includes a first adhesive layer 60, which is disposed on the surface of the first connecting portion 33 facing away from the first portion 31 and the second portion 32. For example, after the first portion 31 and the second portion 32 are bent, the first adhesive layer 60 can be attached to the first connecting portion 33. The provision of the first adhesive layer 60 can improve the connection stability between the first portion 31 and the second portion 32, reduce the relative displacement between the first portion 31 and the second portion 32, and disperse some of the shear force on the first connecting portion 33 to the first adhesive layer 60. The first adhesive layer 60 can resist tearing of the first connecting portion 33, thereby improving the stability of the first current collector 30.

[0099] Referring to Figure 19, the first adhesive layer 60 includes a substrate layer 61 and an adhesive layer 62.

[0100] The substrate layer 61 includes polyethylene terephthalate (PET) and / or polyimide (PI). PET has good mechanical properties and chemical resistance, high strength, good toughness, and is not easily broken, which can improve the structural stability of the first adhesive layer 60 and thus reduce tearing of the first manifold 30. Polyimide has high heat resistance, chemical resistance, and mechanical strength, allowing the first adhesive layer 60 to maintain good performance at high temperatures. Its high strength and chemical resistance can effectively protect the first connecting portion 33 of the first manifold 30.

[0101] The adhesive layer 62 includes acrylic resin and / or epoxy resin, etc. Acrylic resin has good adhesion, weather resistance and chemical stability, which can improve the bonding strength between the first adhesive layer 60 and the first connecting part 33. Epoxy resin has high strength, high adhesion and good heat resistance and chemical corrosion resistance. After curing, it can form a strong adhesive layer, which can effectively resist the deformation of the first connecting part 33, thereby reducing the tearing of the first connecting part 33.

[0102] Regarding the material of the first current collector 30, in the embodiments of this application, the material of the first current collector 30 includes at least one of copper alloy, copper-nickel alloy, aluminum alloy, titanium alloy, stainless steel, or nickel-chromium alloy. Copper alloy and copper-nickel alloy have high conductivity, which can reduce the internal resistance of the cylindrical battery 100 and improve the charging and discharging efficiency of the cylindrical battery 100. They also have high strength and corrosion resistance, which can extend the service life of the first current collector 30. Aluminum alloy is lightweight and low in cost, which can reduce the overall weight of the cylindrical battery 100. Titanium alloy and stainless steel have good corrosion resistance and can adapt to the electrolyte environment inside the cylindrical battery 100, which is beneficial to extending the service life of the first current collector 30. Nickel-chromium alloy also has good corrosion resistance, as well as high oxidation resistance and heat resistance. Under high temperature environment, the nickel-chromium alloy first current collector 30 can maintain stable performance and will not affect the normal operation of the cylindrical battery 100 due to oxidation or deformation. All of the above materials have high mechanical strength and can withstand the internal pressure of the cylindrical battery 100 and the external impact force, which can reduce the tearing of the first current collector 30.

[0103] Based on the same inventive concept, the second collector plate 70 can also be configured similarly to the first collector plate 30, for example, by reducing the radius difference between the third part 71 and the fourth part 72, and by setting a washer 50 and a buffer 40, etc.

[0104] Secondly, this application also proposes an electronic device, including the cylindrical battery 100 as described in any embodiment of the first aspect above. The electronic device in this application is not particularly limited and can be any electronic device known in the prior art. For example, electronic devices include, but are not limited to, Bluetooth headsets, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, 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., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0105] Experiment 1: Drop Test of Cylindrical Battery

[0106] Example 1:

[0107] Preparation of the positive electrode sheet:

[0108] The cathode material is lithium cobalt oxide, the cathode conductive agent is acetylene black, and the cathode binder is polyvinylidene fluoride (PVDF, with a weight-average molecular weight of 5×10⁻⁶). 5The materials were mixed at a mass ratio of 94:3:3, and N-methylpyrrolidone (NMP) was added to prepare a positive electrode slurry with a solid content of 75 wt%. The mixture was then stirred uniformly under vacuum. A 10 μm thick aluminum foil was used as the positive electrode current collector. The positive electrode slurry was uniformly coated onto one surface of the current collector, leaving an uncoated area on the foil. The coating weight was 0.135 mg / mm². 2 The cathode material layer is dried at 110°C to obtain a cathode electrode sheet with a single-sided coating. Then, the above steps are repeated on the other surface of the cathode current collector to obtain a cathode electrode sheet with a double-sided coating.

[0109] Preparation of negative electrode sheet:

[0110] Artificial graphite (negative electrode material), conductive carbon black (Super P) (conductive agent), and styrene-butadiene rubber (SBR) (binder) were mixed in a weight ratio of 97.5:1:1.5. Deionized water was then added to prepare a negative electrode slurry with a solid content of 50 wt%, and the mixture was stirred thoroughly. A 6 μm thick copper foil was selected as the negative electrode current collector. The negative electrode slurry was uniformly coated onto one surface of the copper foil, with a coating weight of 0.075 mg / mm². 2 The electrode is dried at 120℃ to obtain a single-sided negative electrode sheet. After completing the above steps, the single-sided coating of the negative electrode sheet is finished. Then, the above steps are repeated on the other surface of the negative electrode sheet to obtain a negative electrode sheet with a double-sided coating of the negative electrode material layer.

[0111] Preparation of the separating membrane:

[0112] A porous polyethylene (PE) film with a thickness of 5 μm was used as the separator.

[0113] Electrolyte preparation:

[0114] In a dry argon atmosphere, ethylene carbonate, methyl ethyl carbonate and diethyl carbonate are mixed in a mass ratio of 30:50:20 to obtain an organic solvent. Then, lithium hexafluorophosphate is added to the organic solvent to dissolve and mix evenly to obtain an electrolyte with a lithium salt concentration of 1.15 mol / L.

[0115] Fabrication of cylindrical solar cells:

[0116] A first and second current collector plate with a thickness of 200 μm are selected. The first current collector plate includes a first part (radius 14 mm), a second part (radius 12 mm), and a first connecting part connecting the first and second parts. The first and second parts are folded together to form a first connecting position in the first connecting part. The second current collector plate includes a third part (radius 14 mm), a fourth part (radius 12 mm), and a second connecting part connecting the third and fourth parts. The third and fourth parts are folded together to form a second connecting position in the second connecting part.

[0117] A 3mm wide aluminum sheet is used as the positive electrode tab, which is welded to the positive electrode plate. A 3mm wide nickel sheet is used as the negative electrode tab, which is welded to the negative electrode plate. The separator, positive electrode plate, separator, and negative electrode plate prepared above are stacked in sequence and wound to obtain an electrode assembly. The electrode assembly is then hot-pressed (pressure 5MPa, temperature 65℃, holding time 10s). The first current collector and the electrode assembly are placed in a cylindrical steel shell (casing). The first part of the first current collector is welded to the negative electrode tab of the electrode assembly, and the second part of the first current collector is welded to the bottom wall (first wall) of the cylindrical steel shell using laser penetration welding to lead out the negative electrode. The third part of the second current collector is welded to the positive electrode tab of the electrode assembly, and the fourth part is welded to the electrode post on the cover plate (second wall) to lead out the positive electrode. Electrolyte is injected, and after vacuum sealing, settling, hot-pressing formation, and shaping processes, a cylindrical battery is obtained. When viewed along the axial direction of the cylindrical battery, the included angle α between the first connection point and the second connection point is 90°.

[0118] The relevant parameters in Examples 2 to 8 and Comparative Examples 1 to 6 are shown in Table 1 below.

[0119] Drop test method: The cylindrical battery was placed in a 25℃ environment and left to stand for 30 minutes. Then, the cylindrical battery was placed in a fixture and dropped from a height of 1.8m above a marble floor, once along both end faces and once along the cylindrical surface, for a total of 20 drops. The drop order was (end faces first, then cylindrical surfaces). After the drops, the battery was left to stand at room temperature for 24 hours. The battery was then disassembled, and the appearance of the first and second current collectors was inspected and photographed. The drop test pass / fail criteria were: the connection between the first current collector and the electrode assembly and the first wall was not broken; the connection between the second current collector and the electrode assembly and the second wall was not broken. Of the 20 cylindrical batteries tested, X batteries failed the test, resulting in a failure rate of X / 20.

[0120] Table 1

[0121] According to Table 1 above, and in conjunction with Examples 1 to 8 and Comparative Examples 1 to 6, the drop failure rate in Examples 1 to 8 is significantly lower than that in Comparative Examples 1 to 6. This is because, when viewed along the axial direction of the cylindrical battery, the angle between the first connection point and the second connection point is α, where 45°≤α≤135°. This prevents the cylindrical battery from experiencing simultaneous ground impact at positions A (the end with the first connection) or E (the end opposite to the first connection) of the first current collector and positions A (the end with the second connection) or E (the end opposite to the second connection) of the second current collector, reducing the risk of connection failure between the first current collector and the electrode assembly and / or the housing, as well as the risk of connection failure between the second current collector and the electrode assembly and / or the housing. Furthermore, limiting the angle to 45°≤α≤135° reduces the center of gravity of the cylindrical battery from being closer to positions A or E, thereby reducing the force on positions A or E and improving the drop resistance of the cylindrical battery. Therefore, in the embodiments of this application, 45°≤α≤135° can be selected.

[0122] In Examples 2 to 7, the drop failure rate is further reduced by limiting the angle to 60°≤α≤120°. This further reduces the center of gravity of the cylindrical battery from being close to position A or E, thereby reducing the force on position A or E and further improving the drop resistance of the cylindrical battery. Therefore, in the embodiments of this application, 60°≤α≤120° is preferred.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A cylindrical battery, comprising a housing, an electrode assembly, a first current collector, and a second current collector, wherein along the axial direction of the cylindrical battery, the housing includes a first wall and a second wall disposed opposite to each other, the electrode assembly is disposed within the housing, the first current collector is disposed between the electrode assembly and the first wall, and the second current collector is disposed between the electrode assembly and the second wall, characterized in that: The first collector includes a first part, a second part, and a first connection position disposed between the first part and the second part. The second part is folded along the first connection position and the first part. The first part is connected to the electrode assembly, and the second part is connected to the first wall portion. The second collector includes a third part, a fourth part, and a second connection position disposed between the third part and the fourth part. The fourth part is folded along the second connection position and the third part. The third part is used to connect with the electrode assembly, and the fourth part is used to connect with the second wall portion. Viewed along the axial direction of the cylindrical battery, the angle between the first connection position and the second connection position is α, where 45°≤α≤135°.

2. The cylindrical battery according to claim 1, characterized in that, 60°≤α≤120°。 3. The cylindrical battery according to claim 1, characterized in that, The first collector plate further includes a fifth part, and the second part is connected between the first part and the fifth part, and the second part is connected to the first wall portion through the fifth part; The fifth part and the second part have a third connection bit; Viewed along the axial direction of the cylindrical battery, the angle between the first connection position and the third connection position is β, where 45°≤β≤135°.

4. The cylindrical battery according to claim 3, characterized in that, 60°≤β≤120°。 5. The cylindrical battery according to claim 3 or 4, characterized in that, Viewed along the axial direction of the cylindrical battery, the angle between the third connection position and the second connection position is θ, where 45°≤θ≤135°.

6. The cylindrical battery according to claim 5, characterized in that, 60°≤θ≤120°.

7. The cylindrical battery according to claim 1, characterized in that, The radius of the first part is R1, and the radius of the second part is R2, where 0mm ≤ R1 - R2 ≤ 1mm.

8. The cylindrical battery according to claim 1 or 2, characterized in that, Along the axial direction of the cylindrical battery: The projection of the second outer ring at least partially overlaps with the projection of the first outer ring; and / or, the projection of the fourth outer ring at least partially overlaps with the projection of the third outer ring.

9. The cylindrical battery according to claim 1, characterized in that, The cylindrical battery also includes a gasket, with the first portion and the second portion disposed on the inner ring of the gasket, and the gasket disposed between the electrode assembly and the first wall portion.

10. The cylindrical battery according to claim 1, characterized in that, The cylindrical battery also includes a buffer member disposed on the connecting portion and facing the first portion and the second portion.

11. The cylindrical battery according to claim 10, characterized in that, The buffer portion is located between the first portion and the second portion.

12. The cylindrical battery according to claim 1, characterized in that, The thickness of the first part is T1, the thickness of the second part is T2, and the thickness of the connecting part is T3, where T3 < T1 and T3 < T2.

13. The cylindrical battery according to claim 10, characterized in that, 60% ≤ T3 / T1 ≤ 80%, 60% ≤ T3 / T2 ≤ 80%.

14. The cylindrical battery according to any one of claims 1 to 11, characterized in that, The material of the first manifold includes at least one of copper alloy, copper-nickel alloy, aluminum alloy, titanium alloy, stainless steel, or nickel-chromium alloy; and / or, The material of the second manifold includes at least one of copper alloy, copper-nickel alloy, aluminum alloy, titanium alloy, stainless steel, or nickel-chromium alloy.

15. An electronic device, characterized in that, Including the cylindrical battery as described in any one of claims 1 to 13.

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