Cylindrical battery and electronic equipment

Abstract

The utility model relates to the technical field of batteries, in particular to a cylindrical battery and electronic equipment. The cylindrical battery comprises a shell, a roll core, a first current collecting disc and a second current collecting disc, the roll core is arranged in the shell and provided with a first tab and a second tab which are oppositely arranged, the first current collecting disc is arranged at the end, close to the first tab, of the shell, and the second current collecting disc is arranged at the end, close to the second tab, of the shell. A first welding spot is arranged between the first current collecting disc and the first tab, the second current collecting disc is arranged at one end, close to the second tab, of the shell, and a second welding spot is arranged between the second current collecting disc and the second tab. Wherein a first overlapping area is arranged between every two adjacent first welding spots, and a second overlapping area is arranged between every two adjacent second welding spots. The electronic equipment comprises the cylindrical battery. The cylindrical battery and the electronic equipment have relatively high use safety.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cylindrical battery and electronic equipment. Background Art

[0002] The current collector and tabs of full-tab cylindrical batteries are welded by laser welding. To ensure the energy density of the cylindrical battery, the tab area is generally thin, making the distance between the laser welding interface and the core very close, resulting in the laser welding energy being easily transferred to the core. If the laser welding energy is too high, it can easily damage the core structure, causing the core to shrink or even burn, affecting the safety of the cylindrical battery. If the laser welding energy is too low, it will reduce the weld strength between the current collector and tabs, making the overall structure of the cylindrical battery unstable, which also affects the safety of the cylindrical battery. Utility Model Content

[0003] The main purpose of the utility model is to propose a cylindrical battery and electronic equipment, aiming to solve the technical problems that when the energy of laser welding is large, it is easy to cause the core to shrink or even burn, and when the energy of laser welding is small, it is easy to cause loose welding between the collecting plate and the tab.

[0004] To achieve the above objectives, the present invention provides a cylindrical battery comprising:

[0005] case;

[0006] A winding core, the winding core being disposed inside the shell, the winding core having a first electrode tab and a second electrode tab disposed opposite to each other;

[0007] a first current collecting disk, the first current collecting disk being arranged at one end of the housing close to the first electrode tab, and a first welding point being arranged between the first current collecting disk and the first electrode tab;

[0008] a second current collecting disk, the second current collecting disk being arranged at one end of the housing close to the second pole tab, and a second welding point being arranged between the second current collecting disk and the second pole tab;

[0009] There is a first overlapping area between two adjacent first welding spots, and there is a second overlapping area between two adjacent second welding spots.

[0010] In some embodiments, the area S1 of the first overlapping region and the area S2 of the first welding point satisfy: 20%≤S1 / S2≤80%; the area S3 of the second overlapping region and the area S4 of the second welding point satisfy: 20%≤S3 / S4≤80%.

[0011] In some embodiments, the total area S5 of the first welding points and the area S6 of the first current collecting plate satisfy: S5 / S6≥50%; the total area S7 of the second welding points and the area S8 of the second current collecting plate satisfy: S7 / S8≥50%.

[0012] In some embodiments, the welding depth D1 of the first welding spot satisfies: D1 ≥ 0.2 mm, and the welding width W1 of the first welding spot satisfies: W1 ≥ 0.1 mm;

[0013] The welding depth D2 of the second welding spot satisfies: D2 ≥ 0.2 mm, and the welding width W2 of the second welding spot satisfies: W2 ≥ 0.1 mm.

[0014] In some embodiments, the winding core has a first central hole pointing from the first tab end to the second tab end, the first current collecting disk has a second central hole, and the second current collecting disk has a third central hole;

[0015] Wherein, the second center hole is aligned with the first center hole, and the third center hole is aligned with the first center hole.

[0016] In some embodiments, the core comprises:

[0017] A first current collector, wherein the first current collector is provided with a first active material coating layer and a first hollow foil area along the width direction of the first current collector, and the first hollow foil area forms the first electrode tab;

[0018] A second current collector, wherein the second current collector is provided with a second active material coating layer and a second hollow foil area along the width direction of the second current collector, and the second hollow foil area forms the second electrode tab;

[0019] a diaphragm disposed between the first current collector and the second current collector;

[0020] The first current collector, the second current collector and the separator are stacked and then wound to form the winding core.

[0021] In some embodiments, along the thickness direction of the first current collector, two sides of the first current collector have the first active material coating layer disposed opposite to each other;

[0022] Along the thickness direction of the second current collector, two sides of the second current collector have the second active material coating layers arranged opposite to each other.

[0023] In some embodiments, the width W3 of the first active material coating layer and the width W4 of the second active material coating layer satisfy the following relationship: 2 mm ≤ W3 - W4 ≤ 5 mm.

[0024] In some embodiments, the first current collector is a negative electrode current collector, the first active material coating layer is a negative electrode active material coating layer, and the first electrode tab is a negative electrode tab;

[0025] The second current collector is a positive electrode current collector, the second active material coating layer is a positive electrode active material coating layer, and the second electrode tab is a positive electrode tab.

[0026] Correspondingly, the present invention also provides an electronic device, which includes the cylindrical battery described in any one of the above embodiments.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] In the technical solution of the present utility model, after the winding core is placed inside the shell, a first current collecting disk is provided at one end of the shell near the first pole tab of the winding core, and the first current collecting disk is welded to the first pole tab through a first welding point. A second current collecting disk is provided at one end of the shell near the second pole tab of the winding core, and the second current collecting disk is welded to the second pole tab through a second welding point. By laser welding the first and second current collecting disks, the winding core can be enclosed in the shell to achieve the encapsulation of the winding core in the shell. At the same time, electronic conduction is formed between the first current collecting disk and the first pole tab, and electronic conduction is formed between the second current collecting disk and the second pole tab to ensure normal charging and discharging of the cylindrical battery.

[0029] When laser welding the first current collecting disc and the first electrode tab, a partially overlapping first weld point is provided between the first current collecting disc and the first electrode tab, that is, a first overlapping area is provided between two adjacent first weld points. With such a structure, since the welding of the first weld points is continuous, when welding the next first weld point, the previous first weld point still has welding heat. By overlapping the two adjacent first weld points, it is beneficial to utilize the residual heat of the previous first weld point to preheat the welding of the next first weld point. Therefore, when welding a series of first weld points, the energy of laser welding can be reduced. This can ensure that the heat of laser welding will not damage the winding core, avoid causing heat shrinkage or burning of the winding core, and ensure the welding strength between the first current collecting disc and the first electrode tab, thereby improving the structural stability of the cylindrical battery and enhancing the safety of the cylindrical battery.

[0030] Similarly, when laser welding the second current collector and the second tab, a partially overlapping second weld point is provided between the second current collector and the second tab, i.e., a second overlapping region exists between two adjacent second weld points. With this structure, since the welding of the second weld points is continuous, the previous second weld point still has welding heat when the next second weld point is welded. By overlapping the two adjacent second weld points, the residual heat of the previous second weld point is utilized to preheat the welding of the next second weld point. Therefore, when welding a series of second weld points, the laser welding energy can be reduced. This ensures that the heat from the laser welding does not damage the winding core, preventing thermal shrinkage or burning of the winding core, while also ensuring the welding strength between the second current collector and the second tab, thereby improving the structural stability of the cylindrical battery and enhancing the safety of the cylindrical battery.

[0031] Electronic devices using the cylindrical battery can ensure safety during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 A schematic diagram of the overall structure of a cylindrical battery provided in one embodiment of the present utility model;

[0034] Figure 2 A schematic structural diagram of a first current collecting plate in a cylindrical battery provided in one embodiment of the present utility model;

[0035] Figure 3 A schematic structural diagram of a second current collecting plate in a cylindrical battery provided in one embodiment of the present utility model;

[0036] Figure 4 A front view of the structure of the first current collector of the cylindrical battery provided in one embodiment of the present invention;

[0037] Figure 5 A side view of the structure of the first current collector of the cylindrical battery provided in one embodiment of the present invention;

[0038] Figure 6 A front view of the structure of the second current collector of the cylindrical battery provided in one embodiment of the present invention;

[0039] Figure 7A side view of the structure of the second current collector of the cylindrical battery core provided by one embodiment of the present invention.

[0040] Description of Figure Numbers:

[0041] 100-housing;

[0042] 200-coil core;

[0043] 210 - first electrode tab; 220 - second electrode tab; 230 - first center hole; 240 - first current collector; 250 - second current collector;

[0044] 241 - first active material coating layer; 242 - first empty foil area;

[0045] 251 - second active material coating layer; 252 - second empty foil area;

[0046] 300-first collecting plate;

[0047] 310-second center hole;

[0048] 400-second collector plate;

[0049] 410 - third center hole;

[0050] 500-first welding point;

[0051] 510-first superposition area;

[0052] 600-second welding point;

[0053] 610-Second overlapping area.

[0054] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0056] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0057] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or", "and / or" or "and / or" appear in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0058] The current collector and tabs of full-tab cylindrical batteries are welded by laser welding. To ensure the energy density of the cylindrical battery, the tab area is generally thin, making the distance between the laser welding interface and the core very close, resulting in the laser welding energy being easily transferred to the core. If the laser welding energy is too high, it can easily damage the core structure, causing the core to shrink or even burn, affecting the safety of the cylindrical battery. If the laser welding energy is too low, it will reduce the weld strength between the current collector and tabs, making the overall structure of the cylindrical battery unstable, which also affects the safety of the cylindrical battery.

[0059] Based on this, in order to solve the technical problem that when the laser welding energy is large, the winding core 200 is likely to shrink or even burn, and when the laser welding energy is small, the welding between the collecting plate and the tab is likely to be weak, refer to Figures 1 to 3 One embodiment of the present invention provides a cylindrical battery, comprising a housing 100, a winding core 200, a first current collecting disc 300, and a second current collecting disc 400. The winding core 200 is disposed within the housing 100. The winding core 200 has a first electrode tab 210 and a second electrode tab 220 disposed opposite each other. The first current collecting disc 300 is disposed at an end of the housing 100 near the first electrode tab 210. A first welding spot 500 is disposed between the first current collecting disc 300 and the first electrode tab 210. The second current collecting disc 400 is disposed at an end of the housing 100 near the second electrode tab 220. A second welding spot 600 is disposed between the second current collecting disc 400 and the second electrode tab 220. A first overlapping region 510 is defined between two adjacent first welding spots 500, and a second overlapping region 610 is defined between two adjacent second welding spots 600.

[0060] Specifically, in this embodiment, after the winding core 200 is placed inside the housing 100, a first current collecting disc 300 is provided at one end of the housing 100 near the first tab 210 of the winding core 200. The first current collecting disc 300 is welded to the first tab 210 via a first weld point 500. A second current collecting disc 400 is provided at one end of the housing 100 near the second tab 220 of the winding core 200. The second current collecting disc 400 is welded to the second tab 220 via a second weld point 600. By laser welding the first current collecting disc 300 and the second current collecting disc 400, the winding core 200 can be enclosed within the housing 100, thereby achieving the encapsulation of the winding core 200 within the housing 100. At the same time, electronic conduction is established between the first current collecting disc 300 and the first tab 210, and between the second current collecting disc 400 and the second tab 220, ensuring normal charging and discharging of the cylindrical battery.

[0061] During laser welding of the first current collecting disc 300 and the first electrode tab 210, partially overlapping first weld spots 500 are provided between the first current collecting disc 300 and the first electrode tab 210, i.e., a first overlapping region 510 is defined between two adjacent first weld spots 500. With this structure, since the welding of the first weld spots 500 is continuous, the previous weld spot 500 still has welding heat when the next first weld spot 500 is welded. By overlapping the two adjacent first weld spots 500, the residual heat of the previous weld spot 500 is utilized to preheat the welding of the next first weld spot 500. Therefore, when welding a series of first weld spots 500, the laser welding energy can be reduced. This ensures that the heat from the laser welding does not damage the winding core 200, preventing thermal shrinkage or burning of the winding core 200, while also ensuring the weld strength between the first current collecting disc 300 and the first electrode tab 210, thereby improving the structural stability and safety of the cylindrical battery.

[0062] Similarly, when laser welding the second current collecting disc 400 and the second tab 220, partially overlapping second welds 600 are provided between the second current collecting disc 400 and the second tab 220, i.e., a second overlapping region 610 is defined between two adjacent second welds 600. With this structure, since the welding of the second welds 600 is continuous, the previous weld 600 still has welding heat when the next second weld 600 is welded. By overlapping the two adjacent second welds 600, the residual heat of the previous weld 600 is utilized to preheat the welding of the next second weld 600. Therefore, when welding a series of second welds 600, the laser welding energy can be reduced. This ensures that the heat from the laser welding does not damage the winding core 200, preventing thermal shrinkage or burning of the winding core 200, while also ensuring the weld strength between the second current collecting disc 400 and the second tab 220, thereby improving the structural stability and safety of the cylindrical battery.

[0063] Furthermore, taking the first and second welding points 500 and 600 as circular welding points as an example, when welding the first current collecting disc 300 and the first electrode tab 210, the center-to-center distance between two adjacent first welding points 500 is less than the sum of the radii of the two first welding points 500, meaning that the two adjacent first welding points 500 will partially overlap. Similarly, when welding the second current collecting disc 400 and the second electrode tab 220, the center-to-center distance between two adjacent second welding points 600 is less than the sum of the radii of the two second welding points 600, meaning that the two adjacent second welding points 600 will partially overlap.

[0064] Of course, it is understandable that the first welding spot 500 and the second welding spot 600 can also be square welding spots, or welding spots of other irregular shapes.

[0065] In some embodiments, reference Figure 2 and Figure 3 The area S1 of the first overlapping region 510 and the area S2 of the first solder joint 500 satisfy the following relationship: 20% ≤ S1 / S2 ≤ 80%; the area S3 of the second overlapping region 610 and the area S4 of the second solder joint 600 satisfy the following relationship: 20% ≤ S3 / S4 ≤ 80%. For example, the values ​​of S1 / S2 can be 30%, 40%, 50%, 75%, 80%, etc., and the values ​​of S3 / S4 can be 30%, 40%, 50%, 75%, 80%, etc.

[0066] Specifically, in this embodiment, if the area of ​​the first overlapping region 510 is set too small, that is, S1 / S2 < 20% (for example, S1 / S2 is 5%, 10%, 15%, etc.), the purpose of preheating the next first weld 500 from the previous weld point 500 cannot be achieved, which can easily lead to a loose weld between the first current collecting plate 300 and the first tab 210, resulting in unstable electronic conduction between the first current collecting plate 300 and the first tab 210, affecting the normal use of the cylindrical battery. If the area of ​​the first overlapping region 510 is set too large, that is, S1 / S2 > 80% (for example, S1 / S2 is 85%, 90%, 95%, etc.), the heat from the laser welding is still relatively concentrated, which can easily cause the core 200 to shrink or even burn, causing damage to the core 200 and affecting the safe use of the cylindrical battery.

[0067] Similarly, if the area of ​​the second overlap region 610 is set too small, that is, S3 / S4 < 20% (for example, S3 / S4 is 5%, 10%, 15%, etc.), the purpose of preheating the next second weld 600 from the previous weld point 600 cannot be achieved, which can easily lead to a loose weld between the second current collecting plate 400 and the second tab 220, making the electronic conduction between the second current collecting plate 400 and the second tab 220 unstable, affecting the normal use of the cylindrical battery. If the area of ​​the second overlap region 610 is set too large, that is, S3 / S4 > 80% (for example, S3 / S4 is 85%, 90%, 95%, etc.), the heat from the laser welding is still relatively concentrated, which can easily cause the core 200 to shrink or even burn, causing damage to the core 200 and affecting the safe use of the cylindrical battery.

[0068] In some embodiments, reference Figure 2 and Figure 3 The total area S5 of the first welding points 500 and the area S6 of the first current collecting tray 300 satisfy: S5 / S6 ≥ 50%. The total area S7 of the second welding points 600 and the area S8 of the second current collecting tray 400 satisfy: S7 / S8 ≥ 50%. For example, the values ​​of S5 / S6 can be 50%, 60%, 70%, 75%, 80%, etc., and the values ​​of S7 / S8 can be 50%, 60%, 70%, 75%, 80%, etc.

[0069] Specifically, in this embodiment, setting the area ratio of the first welding point 500 on the first current collecting disc 300 within the aforementioned range is beneficial for ensuring the weld strength between the first current collecting disc 300 and the first electrode tab 210, and preventing cracking between the first current collecting disc 300 and the first electrode tab 210, or even causing the first current collecting disc 300 to fall off, due to a weak weld between the first current collecting disc 300 and the first electrode tab 210. Similarly, setting the area ratio of the second welding point 600 on the second current collecting disc 400 within the aforementioned range is beneficial for ensuring the weld strength between the second current collecting disc 400 and the second electrode tab 220, and preventing cracking between the second current collecting disc 400 and the second electrode tab 220, or even causing the second current collecting disc 400 to fall off, due to a weak weld between the second current collecting disc 400 and the second electrode tab 220.

[0070] It should be noted that the first current collecting tray 300 and the first tab 210 do not need to be fully welded, that is, the values ​​of S5 / S6 do not need to be 100%. The second current collecting tray 400 and the second tab 220 do not need to be fully welded, that is, the values ​​of S7 / S8 do not need to be 100%. By properly arranging the first weld points 500 and the second weld points 600, a stable connection between the first current collecting tray 300 and the first tab 210, and between the second current collecting tray 400 and the second tab 220 can be ensured. Full welding between the first current collecting tray 300 and the first tab 210, and between the second current collecting tray 400 and the second tab 220, increases the processing cost of the cylindrical battery and increases the probability of damaging the winding core 200 during welding.

[0071] In some embodiments, reference Figure 2 and Figure 3 The welding depth D1 of the first weld 500 satisfies: D1 ≥ 0.2 mm, and the welding width W1 of the first weld 500 satisfies: W1 ≥ 0.1 mm. The welding depth D2 of the second weld 600 satisfies: D2 ≥ 0.2 mm, and the welding width W2 of the second weld 600 satisfies: W2 ≥ 0.1 mm. For example, the value of D1 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc., and the value of W1 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, etc. The value of D2 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc., and the value of W2 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, etc.

[0072] Specifically, in this embodiment, if the penetration depth of the first weld point 500 is set too shallow (for example, the penetration depth of the first weld point 500 is set to 0.05 mm, 0.1 mm, 0.15 mm, etc.), or the weld width of the first weld point 500 is set too narrow (for example, the weld width of the first weld point 500 is set to 0.01 mm, 0.05 mm, 0.08 mm, etc.), it will cause the welding between the first current collecting plate 300 and the first pole ear 210 to be loose, making it easy for the first current collecting plate 300 and the first pole ear 210 to crack, and even making the first current collecting plate 300 easy to fall off. Similarly, if the penetration depth of the second weld 600 is set too shallow (for example, the penetration depth of the second weld 600 is set to 0.05mm, 0.1mm, 0.15mm, etc.), or the weld width of the second weld 600 is set too narrow (for example, the weld width of the second weld 600 is set to 0.01mm, 0.05mm, 0.08mm, etc.), it will cause the welding between the second current collecting plate 400 and the second pole ear 220 to be loose, making it easy for the second current collecting plate 400 and the second pole ear 220 to crack, and even making the second current collecting plate 400 easy to fall off.

[0073] In some embodiments, reference Figures 1 to 3 The winding core 200 has a first center hole 230 pointing from the first electrode tab 210 end to the second electrode tab 220 end, the first current collecting plate 300 has a second center hole 310, and the second current collecting plate 400 has a third center hole 410. The second center hole 310 is aligned with the first center hole 230, and the third center hole 410 is aligned with the first center hole 230.

[0074] Specifically, in this embodiment, the cylindrical battery shell 100 is provided with an injection hole. The injection hole is used to inject electrolyte into the shell 100, so that the core 200 is immersed in the electrolyte, and ions can migrate in the electrolyte, thereby realizing the charging and discharging of the cylindrical battery. To improve the effect of electrolyte infiltration in the core 200, a hollow first center hole 230 is provided inside the core 200. When the electrolyte is injected into the shell 100, the electrolyte will flow into the first center hole 230, and then the electrolyte will gradually diffuse from the first center hole 230 to both sides of the core 200, thereby ensuring that the electrolyte evenly infiltrates the core 200, which is beneficial to improving the effect of electrolyte infiltration in the core 200 and improving the charge and discharge performance of the cylindrical battery.

[0075] Furthermore, since the first current collecting disk 300 is welded to the first pole tab 210, the first current collecting disk 300 is in close contact with the first pole tab 210 end of the core 200. Since the second current collecting disk 400 is welded to the second pole tab 220, the second current collecting disk 400 is in close contact with the second pole tab 220 end of the core 200. The first current collecting disk 300 and the second current collecting disk 400 block both ends of the first center hole 230, resulting in the electrolyte being unable to flow into the first center hole 230, and the electrolyte being unable to diffuse from the first center hole 230 to both sides of the core 200, which may eventually lead to poor electrolyte infiltration in the core 200 and affect the charge and discharge performance of the cylindrical battery. In this embodiment, by providing a second center hole 310 aligned with the first center hole 230 on the first collecting plate 300, and providing a third center hole 410 aligned with the first center hole 230 on the second collecting plate 400, it is beneficial for the electrolyte to flow into the first center hole 230 through the second center hole 310 and the third center hole 410, and then the electrolyte stored in the first center hole 230 will gradually diffuse to both sides of the core 200, which is beneficial to improve the effect of electrolyte infiltration in the core 200 and ensure that the electrolyte can evenly infiltrate the core 200.

[0076] In some embodiments, reference Figures 4 to 7 The winding core 200 includes a first current collector 240, a second current collector 250, and a separator. Along the width direction of the first current collector 240, the first current collector 240 is provided with a first active material coating layer 241 and a first empty foil area 242. The first empty foil area 242 forms the first electrode tab 210. Along the width direction of the second current collector 250, the second current collector 250 is provided with a second active material coating layer 251 and a second empty foil area 252. The second empty foil area 252 forms the second electrode tab 220. The separator is provided between the first current collector 240 and the second current collector 250. The first current collector 240, the second current collector 250, and the separator are stacked and then wound to form the winding core 200.

[0077] Specifically, in this embodiment, the first current collector 240 can be a negative electrode current collector, and the second current collector 250 can be a positive electrode current collector. In this case, the first active material coating layer 241 is a negative electrode active material coating layer, the first electrode tab 210 is a negative electrode tab, the second active material coating layer 251 is a positive electrode active material coating layer, and the second electrode tab 220 is a positive electrode tab. Alternatively, the first current collector 240 can also be a positive electrode current collector, and the second current collector 250 can also be a negative electrode current collector. In this case, the first active material coating layer 241 is a positive electrode active material coating layer, the first electrode tab 210 is a positive electrode tab, the second active material coating layer 251 is a negative electrode active material coating layer, and the second electrode tab 220 is a negative electrode tab.

[0078] Furthermore, there is electronic conduction between the first active material coating layer 241 and the first current collector 240, and there is electronic conduction between the second active material coating layer 251 and the second current collector 250. A diaphragm is provided between the first current collector 240 and the second current collector 250. The diaphragm can prevent the first current collector 240 and the second current collector 250 from directly contacting each other, thereby avoiding a short circuit in the cylindrical battery and ensuring the safety of the cylindrical battery. However, the diaphragm can pass ions (for example, the diaphragm can pass lithium ions), allowing ions to migrate between the first current collector 240 and the second current collector 250, thereby realizing the charge and discharge of the cylindrical battery.

[0079] Furthermore, when the first current collector 240, the second current collector 250 and the diaphragm are stacked, the first empty foil area 242 and the second empty foil area 252 are respectively arranged relative to each other, so that the first empty foil area 242 and the second empty foil area 252 are respectively located on opposite sides of the winding core 200, serving as the first pole tab 210 and the second pole tab 220 of the cylindrical battery.

[0080] Furthermore, in some embodiments, taking the cylindrical battery as a lithium-ion battery as an example, the negative electrode current collector can be made of copper foil, the positive electrode current collector can be made of aluminum foil, the negative electrode active material coating layer can be made of graphite material, and the positive electrode active material coating layer can be made of lithium-rich compound material (for example, the positive electrode active material coating layer can be made of LiFePO4, LiMn2O4 and other materials).

[0081] In some embodiments, reference Figures 4 to 7 Along the thickness direction of the first current collector 240, the first current collector 240 has a first active material coating layer 241 disposed oppositely on both sides. Along the thickness direction of the second current collector 250, the second current collector 250 has a second active material coating layer 251 disposed oppositely on both sides.

[0082] Specifically, in this embodiment, the first active material coating layer 241 is coated on both sides of the first current collector 240, and the second active material coating layer 251 is coated on both sides of the second current collector 250. This can effectively utilize the coating space of the first current collector 240 and the second current collector 250, thereby facilitating the improvement of the energy density of the cylindrical battery.

[0083] In some embodiments, reference Figures 4 to 7 The width W3 of the first active material coating layer 241 and the width W4 of the second active material coating layer 251 satisfy the following relationship: 2 mm ≤ W3 - W4 ≤ 5 mm. For example, the value of W3 - W4 can be 2 mm, 3 mm, 4 mm, 5 mm, etc.

[0084] Specifically, in this embodiment, the first active material coating layer 241 is a negative electrode active material coating layer, and the second active material coating layer 251 is a positive electrode active material coating layer. When the active material coating layers are coated on the current collector, the width of the negative electrode active material coating layer needs to be set slightly wider than the width of the positive electrode active material coating layer to ensure that the ions extracted from the positive electrode active material coating layer can be completely absorbed by the negative electrode active material coating layer when the cylindrical battery is charged. This prevents the formation of lithium dendrites in the negative electrode active material coating layer due to the limited lithium insertion capacity of the negative electrode active material coating layer, which may penetrate the separator and cause direct contact between the first current collector 240 and the second current collector 250, thereby causing an internal short circuit in the cylindrical battery and affecting the safety of the cylindrical battery.

[0085] Furthermore, the difference in coating width between the first active material coating layer 241 and the second active material coating layer 251 is set within the above range. On the one hand, it is avoided that the difference in coating width between the first active material coating layer 241 and the second active material coating layer 251 is too small (for example, the value of W3-W4 is 0.5mm, 1mm, 1.5mm, etc.), which cannot ensure that the deintercalated ions are completely absorbed, so that the cylindrical battery still has the risk of puncturing the diaphragm. On the other hand, it is avoided that the difference in coating width between the first active material coating layer 241 and the second active material coating layer 251 is too large (for example, the value of W3-W4 is 5.5mm, 6mm, 7mm, etc.), which causes the energy density of the cylindrical battery to decrease, resulting in poor battery performance, slow charging speed, and low endurance of the cylindrical battery.

[0086] In some embodiments, the first current collector 240 is a negative electrode current collector, and accordingly, the first active material coating layer 241 is a negative electrode active material coating layer, and the first electrode tab 210 is a negative electrode tab. If the second current collector 250 is a positive electrode current collector, then correspondingly, the second active material coating layer 251 is a positive electrode active material coating layer, and the second electrode tab 220 is a positive electrode tab.

[0087] Correspondingly, another embodiment of the present invention further provides an electronic device, which includes the cylindrical battery in any of the above embodiments. For example, the electronic device can be an electric vehicle, a new energy vehicle, etc.

[0088] Specifically, in this embodiment, the electronic device using the cylindrical battery can ensure safety during operation.

[0089] Thanks to the improvement of the above cylindrical battery, the electronic device of this embodiment has the same technical effects as the above cylindrical battery, which will not be described in detail here.

[0090] It should be noted that other contents of the cylindrical battery and electronic device disclosed in the present utility model can be found in the prior art and will not be described in detail here.

[0091] The above are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the utility model concept, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. Cylindrical battery, characterized in that, include: case; A winding core, the winding core being disposed inside the shell, the winding core having a first electrode tab and a second electrode tab disposed opposite to each other; a first current collecting disk, the first current collecting disk being arranged at one end of the housing close to the first electrode tab, and a first welding point being arranged between the first current collecting disk and the first electrode tab; a second current collecting disk, the second current collecting disk being arranged at one end of the housing close to the second pole tab, and a second welding point being arranged between the second current collecting disk and the second pole tab; There is a first overlapping area between two adjacent first welding spots, and there is a second overlapping area between two adjacent second welding spots.

2. The cylindrical battery according to claim 1, characterized in that: The area S1 of the first overlapping region and the area S2 of the first welding point satisfy: 20%≤S1 / S2≤80%; the area S3 of the second overlapping region and the area S4 of the second welding point satisfy: 20%≤S3 / S4≤80%.

3. The cylindrical battery according to claim 1, characterized in that: The total area S5 of the first welding points and the area S6 of the first current collecting plate satisfy: S5 / S6≥50%; the total area S7 of the second welding points and the area S8 of the second current collecting plate satisfy: S7 / S8≥50%.

4. The cylindrical battery according to claim 1, characterized in that The welding depth D1 of the first welding spot satisfies: D1 ≥ 0.2 mm, and the welding width W1 of the first welding spot satisfies: W1 ≥ 0.1 mm; The welding depth D2 of the second welding spot satisfies: D2 ≥ 0.2 mm, and the welding width W2 of the second welding spot satisfies: W2 ≥ 0.1 mm.

5. The cylindrical battery according to claim 1, characterized in that: The winding core has a first central hole pointing from the first tab end to the second tab end, the first current collecting disk has a second central hole, and the second current collecting disk has a third central hole; Wherein, the second center hole is aligned with the first center hole, and the third center hole is aligned with the first center hole.

6. The cylindrical battery according to claim 1, characterized in that The winding core comprises: A first current collector, wherein the first current collector is provided with a first active material coating layer and a first hollow foil area along the width direction of the first current collector, and the first hollow foil area forms the first electrode tab; A second current collector, wherein the second current collector is provided with a second active material coating layer and a second hollow foil area along the width direction of the second current collector, and the second hollow foil area forms the second electrode tab; a diaphragm disposed between the first current collector and the second current collector; The first current collector, the second current collector and the separator are stacked and then wound to form the winding core.

7. The cylindrical battery according to claim 6, characterized in that: Along the thickness direction of the first current collector, two sides of the first current collector have the first active material coating layer arranged opposite to each other; Along the thickness direction of the second current collector, two sides of the second current collector have the second active material coating layers arranged opposite to each other.

8. The cylindrical battery according to claim 6, characterized in that: The width W3 of the first active material coating layer and the width W4 of the second active material coating layer satisfy the following relationship: 2 mm ≤ W3 − W4 ≤ 5 mm.

9. The cylindrical battery according to any one of claims 6 to 8, characterized in that: The first current collector is a negative electrode current collector, the first active material coating layer is a negative electrode active material coating layer, and the first electrode tab is a negative electrode tab; The second current collector is a positive electrode current collector, the second active material coating layer is a positive electrode active material coating layer, and the second electrode tab is a positive electrode tab.

10. An electronic device, characterized in that A cylindrical battery comprising the cylindrical battery according to any one of claims 1 to 9.

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