Cylindrical battery and electronic device

Abstract

A cylindrical battery, comprising a housing (100), a roll core (200), a first current collector disc (300) and a second current collector disc (400). The roll core (200) is arranged inside the housing (100). The roll core (200) is provided with a first tab (210) and a second tab (220) opposite to each other. The first current collector disc (300) is provided at the end of the housing (100) close to the first tab (210), and first welding points (500) are provided between the first current collector disc (300) and the first tab (210); the second current collector disc (400) is provided at the end of the housing (100) close to the second tab (220), and second welding points (600) are provided between the second current collector disc (400) and the second tab (220). A first overlapping region (510) is provided between two adjacent first welding points (500), and a second overlapping region (610) is provided between two adjacent second welding points (600). By overlapping two adjacent first welding points (500) and overlapping two adjacent second welding points (600), the energy of laser welding can be reduced, thereby ensuring the welding strength while ensuring that the heat of laser welding does not damage the roll core (200), improving the use safety of the cylindrical battery.

Description

Cylindrical battery and electronic device TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a cylindrical battery and an electronic device. BACKGROUND

[0002] The current collector disc and the tab of the winding core of the full-tab cylindrical battery are laser-welded. In order to ensure the energy density of the cylindrical battery, the thickness of the tab area is generally thin, so that the interface of the laser welding and the winding core are very close, which causes the energy of the laser welding to be easily conducted to the winding core. If the energy of the laser welding is large, the winding core structure is easily damaged, which leads to thermal shrinkage or even burning of the winding core, and affects the safety of the cylindrical battery. If the energy of the laser welding is small, the welding strength between the current collector disc and the tab is reduced, which makes the overall structure of the cylindrical battery not firm, and also affects the safety of the cylindrical battery.

[0003] SUMMARY

[0004] The main purpose of the present application is to provide a cylindrical battery and an electronic device, which aims to solve the technical problems that the energy of the laser welding is large and easily leads to thermal shrinkage or even burning of the winding core, and the energy of the laser welding is small and easily leads to the welding between the current collector disc and the tab being not firm.

[0005] To achieve the above-mentioned purpose, the present application provides a cylindrical battery, comprising:

[0006] a shell;

[0007] a winding core, the winding core is arranged in the interior of the shell, and the winding core has a first tab and a second tab arranged oppositely;

[0008] a first current collector disc, the first current collector disc is arranged at one end of the shell close to the first tab, and a first welding point is arranged between the first current collector disc and the first tab;

[0009] a second current collector disc, the second current collector disc is arranged at one end of the shell close to the second tab, and a second welding point is arranged between the second current collector disc and the second tab;

[0010] wherein, the first overlapping area is between two adjacent first welding points, and the second overlapping area is between two adjacent second welding points.

[0011] In some embodiments, the area S1 of the first overlapping area and the area S2 of the first welding point satisfy: 20%≤S1 / S2≤80%; and the area S3 of the second overlapping area and the area S4 of the second welding point satisfy: 20%≤S3 / S4≤80%.

[0012] In some embodiments, a total area S5 of the first welding spot and an area S6 of the first current collector satisfy: S5 / S6≥50%; a total area S7 of the second welding spot and an area S8 of the second current collector satisfy: S7 / S8≥50%.

[0013] In some embodiments, a welding depth D1 of the first welding spot satisfies: D1≥0.2mm, and a welding width W1 of the first welding spot satisfies: W1≥0.1mm.

[0014] A welding depth D2 of the second welding spot satisfies: D2≥0.2mm, and a welding width W2 of the second welding spot satisfies: W2≥0.1mm.

[0015] 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 collector has a second central hole, and the second current collector has a third central hole;

[0016] The second central hole and the first central hole are aligned, and the third central hole and the first central hole are aligned.

[0017] In some embodiments, the winding core comprises:

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

[0019] A second current collector, along a width direction of the second current collector, the second current collector is provided with a second active material coating layer and a second empty foil area, the second empty foil area forms the second tab;

[0020] A separator, the separator is arranged between the first current collector and the second current collector;

[0021] The first current collector, the second current collector and the separator are stacked and wound to form the winding core.

[0022] In some embodiments, along a thickness direction of the first current collector, both sides of the first current collector have the first active material coating layer arranged oppositely;

[0023] Along a thickness direction of the second current collector, both sides of the second current collector have the second active material coating layer arranged oppositely.

[0024] In some embodiments, a width W3 of the first active material coating layer and a width W4 of the second active material coating layer satisfy: 2mm≤W3-W4≤5mm.

[0025] In some embodiments, the first current collector is a negative current collector, the first active material coating layer is a negative active material coating layer, and the first tab is a negative tab.

[0026] The second current collector is a positive current collector, the second active material coating layer is a positive active material coating layer, and the second tab is a positive tab.

[0027] Correspondingly, the application also provides an electronic device comprising the cylindrical battery described in any of the above embodiments.

[0028] Compared with the prior art, the application has the following beneficial effects:

[0029] In the technical solution of the application, after the winding core is placed inside the shell, a first current collecting disc is arranged at one end of the shell close to the first tab of the winding core, and the first current collecting disc is welded to the first tab through a first welding point; a second current collecting disc is arranged at one end of the shell close to the second tab of the winding core, and the second current collecting disc is welded to the second tab through a second welding point. By laser welding the first current collecting disc and the second current collecting disc, the winding core can be enclosed in the shell to realize the packaging of the winding core in the shell. At the same time, electronic conduction is formed between the first current collecting disc and the first tab, and electronic conduction is formed between the second current collecting disc and the second tab to ensure the normal charging and discharging of the cylindrical battery.

[0030] When laser welding the first current collecting disc and the first tab, a first welding point is arranged between the first current collecting disc and the first tab, and the first welding point is locally overlapped, that is, the first welding point has a first overlapping area between two adjacent first welding points. With such a structure, since the welding of the first welding point is continuous, the last first welding point still has welding heat when the next first welding point is welded. By overlapping the two adjacent first welding points, the residual heat of the last first welding point can be utilized to preheat the next first welding point. Therefore, when a series of first welding points are welded, the energy of laser welding can be reduced. This can not only ensure that the heat of laser welding does not damage the winding core and avoid causing thermal shrinkage or scorching of the winding core, but also ensure the welding strength between the first current collecting disc and the first tab, improve the structural stability of the cylindrical battery, and improve the use safety of the cylindrical battery.

[0031] Similarly, when laser welding the second current collecting disc and the second tab, a second welding spot is arranged between the second current collecting disc and the second tab in a partially overlapped manner, that is, the two adjacent second welding spots have a second overlapping area. With such a structure, since the welding of the second welding spot is continuous, when the welding of the next second welding spot is performed, the previous second welding spot still has welding heat, and by arranging the two adjacent second welding spots in an overlapped manner, the residual heat of the previous second welding spot can be utilized to preheat the welding of the next second welding spot, so that when a series of second welding spots are welded, the energy of the laser welding can be reduced, which can not only ensure that the heat of the laser welding does not damage the winding core and avoid causing thermal shrinkage or scorching of the winding core, but also ensure the welding strength between the second current collecting disc and the second tab, improve the structural stability of the cylindrical battery, and improve the use safety of the cylindrical battery.

[0032] The electronic device using the cylindrical battery can ensure safety during operation. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the drawings shown.

[0034] Fig. 1 is a schematic diagram of the overall structure of the cylindrical battery according to an embodiment of the present application;

[0035] Fig. 2 is a schematic diagram of the structure of the first current collecting disc in the cylindrical battery according to an embodiment of the present application;

[0036] Fig. 3 is a schematic diagram of the structure of the second current collecting disc in the cylindrical battery according to an embodiment of the present application;

[0037] Fig. 4 is a front view of the structure of the first current collector of the winding core in the cylindrical battery according to an embodiment of the present application;

[0038] Fig. 5 is a side view of the structure of the first current collector of the winding core in the cylindrical battery according to an embodiment of the present application;

[0039] Fig. 6 is a front view of the structure of the second current collector of the winding core in the cylindrical battery according to an embodiment of the present application;

[0040] Fig. 7 is a side view of the structure of the second current collector of the winding core in the cylindrical battery according to an embodiment of the present application.

[0041] The following items are explained in the order of the numbers: 100: case; 200: core; 210: first tab; 220: second tab; 230: first center hole; 240: first current collector; 250: second current collector; 241: first active material coating layer; 242: first empty foil area; 251: second active material coating layer; 252: second empty foil area; 300: first current collecting disc; 310: second center hole; 400: second current collecting disc; 410: third center hole; 500: first welding spot; 510: first overlapping area; 600: second welding spot; 610: second overlapping area.

[0042] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the present application.

[0044] It should be noted that if the present application has directionality indication (such as up, down, left, right, front, back, etc.) in the embodiments, the directionality indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directionality indication also changes accordingly.

[0045] In addition, if the present application has the description of "first", "second", etc. in the embodiments, the description of "first", "second", etc. is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or", "and / or", or "and / or" appearing throughout the text means that the three parallel schemes include A scheme, or B scheme, or A and B schemes are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope claimed by the present application.

[0046] The laser welding of the current collector plate and the tab of the winding core of the full-tab cylindrical battery is used to ensure the energy density of the cylindrical battery. The thickness of the tab area is generally thin, so that the interface of the laser welding is close to the winding core, which causes the energy of the laser welding to easily conduct to the winding core. If the energy of the laser welding is large, the winding core structure is easily damaged, the winding core is shrunk or even burned, and the use safety of the cylindrical battery is affected. If the energy of the laser welding is small, the welding strength between the current collector plate and the tab is reduced, the overall structure of the cylindrical battery is not firm, and the use safety of the cylindrical battery is also affected.

[0047] To solve the technical problems that the winding core 200 is easily shrunk or even burned when the energy of the laser welding is large, and the welding between the current collector plate and the tab is not firm when the energy of the laser welding is small, referring to FIGS. 1-3, an embodiment of the present application provides a cylindrical battery, which comprises a shell 100, a winding core 200, a first current collector plate 300 and a second current collector plate 400. The winding core 200 is arranged in the interior of the shell 100. The winding core 200 has a first tab 210 and a second tab 220 arranged oppositely. The first current collector plate 300 is arranged at one end of the shell 100 close to the first tab 210. The first current collector plate 300 and the first tab 210 are provided with a first welding point 500. The second current collector plate 400 is arranged at one end of the shell 100 close to the second tab 220. The second current collector plate 400 and the second tab 220 are provided with a second welding point 600. The first welding point 500 and the second welding point 600 are arranged between the first tab 210 and the second tab 220.

[0048] Specifically, in the embodiment, after the winding core 200 is placed in the interior of the shell 100, the first current collector plate 300 is arranged at one end of the shell 100 close to the first tab 210 of the winding core 200, and the first current collector plate 300 is welded to the first tab 210 through the first welding point 500. The second current collector plate 400 is arranged at one end of the shell 100 close to the second tab 220 of the winding core 200, and the second current collector plate 400 is welded to the second tab 220 through the second welding point 600. The first current collector plate 300 and the second current collector plate 400 are laser welded, so as to enclose the winding core 200 in the shell 100, to realize the packaging of the winding core 200 in the shell 100. At the same time, the first current collector plate 300 and the first tab 210 are in electronic conduction, and the second current collector plate 400 and the second tab 220 are in electronic conduction, to ensure the normal charging and discharging of the cylindrical battery.

[0049] When laser welding the first current collecting disc 300 and the first tab 210, the first current collecting disc 300 and the first tab 210 are provided with locally overlapped first welding spots 500, i.e. the first welding spots 500 adjacent to each other have a first overlapping area 510. With such a structure, since the welding of the first welding spots 500 is continuous, when welding the next first welding spot 500, the previous first welding spot 500 still has welding heat, and by overlapping the two first welding spots 500 adjacent to each other, the residual heat of the previous first welding spot 500 can be used to preheat the next first welding spot 500, so when welding a series of first welding spots 500, the energy of laser welding can be reduced, which can not only ensure that the heat of laser welding does not damage the winding core 200 and avoid causing thermal shrinkage or burning of the winding core 200, but also ensure the welding strength between the first current collecting disc 300 and the first tab 210, improve the structural stability of the cylindrical battery, and improve the use safety of the cylindrical battery.

[0050] Similarly, when laser welding the second current collecting disc 400 and the second tab 220, the second current collecting disc 400 and the second tab 220 are provided with locally overlapped second welding spots 600, i.e. the second welding spots 600 adjacent to each other have a second overlapping area 610. With such a structure, since the welding of the second welding spots 600 is continuous, when welding the next second welding spot 600, the previous second welding spot 600 still has welding heat, and by overlapping the two second welding spots 600 adjacent to each other, the residual heat of the previous second welding spot 600 can be used to preheat the next second welding spot 600, so when welding a series of second welding spots 600, the energy of laser welding can be reduced, which can not only ensure that the heat of laser welding does not damage the winding core 200 and avoid causing thermal shrinkage or burning of the winding core 200, but also ensure the welding strength between the second current collecting disc 400 and the second tab 220, improve the structural stability of the cylindrical battery, and improve the use safety of the cylindrical battery.

[0051] Further, taking the first welding spots 500 and the second welding spots 600 as examples, when welding the first current collecting disc 300 and the first tab 210, the center distance between the two first welding spots 500 adjacent to each other is less than the sum of the radii of the two first welding spots 500, i.e. the two first welding spots 500 adjacent to each other will locally overlap together. Similarly, when welding the second current collecting disc 400 and the second tab 220, the center distance between the two second welding spots 600 adjacent to each other is less than the sum of the radii of the two second welding spots 600, i.e. the two second welding spots 600 adjacent to each other will locally overlap together.

[0052] Of course, it can be understood that the first welding spot 500 and the second welding spot 600 can also be square welding spots or other irregularly shaped welding spots.

[0053] In some embodiments, referring to FIGS. 2 and 3, the following conditions are satisfied: 20%≤S1 / S2≤80% between the area S1 of the first overlapping area 510 and the area S2 of the first welding spot 500; and 20%≤S3 / S4≤80% between the area S3 of the second overlapping area 610 and the area S4 of the second welding spot 600. Exemplarily, for example, the value of S1 / S2 can be 30%, 40%, 50%, 75%, 80%, etc., and the value of S3 / S4 can be 30%, 40%, 50%, 75%, 80%, etc.

[0054] Specifically, in the present embodiment, if the area of the first overlapping area 510 is set too small, i.e., S1 / S2<20% (exemplarily, for example, the value of S1 / S2 is 5%, 10%, 15%, etc.), the purpose of preheating the next first welding spot 500 by the previous first welding spot 500 cannot be achieved, which can easily lead to unstable welding between the first current collecting plate 300 and the first tab 210, unstable electronic conduction between the first current collecting plate 300 and the first tab 210, and impact on the normal use of the cylindrical battery. If the area of the first overlapping area 510 is set too large, i.e., S1 / S2>80% (exemplarily, for example, the value of S1 / S2 is 85%, 90%, 95%, etc.), the laser welding heat is still relatively concentrated, which can easily lead to thermal shrinkage or even scorching of the winding core 200, damage to the winding core 200, and impact on the safe use of the cylindrical battery.

[0055] Similarly, if the area of the second overlapping area 610 is set too small, i.e., S3 / S4<20% (exemplarily, for example, the value of S3 / S4 is 5%, 10%, 15%, etc.), the purpose of preheating the next second welding spot 600 by the previous second welding spot 600 cannot be achieved, which can easily lead to unstable welding between the second current collecting plate 400 and the second tab 220, unstable electronic conduction between the second current collecting plate 400 and the second tab 220, and impact on the normal use of the cylindrical battery. If the area of the second overlapping area 610 is set too large, i.e., S3 / S4>80% (exemplarily, for example, the value of S3 / S4 is 85%, 90%, 95%, etc.), the laser welding heat is still relatively concentrated, which can easily lead to thermal shrinkage or even scorching of the winding core 200, damage to the winding core 200, and impact on the safe use of the cylindrical battery.

[0056] In some embodiments, referring to FIG. 2 and FIG. 3, the total area S5 of the first welding spot 500 and the area S6 of the first current collector 300 satisfy: S5 / S6≥50%; the total area S7 of the second welding spot 600 and the area S8 of the second current collector 400 satisfy: S7 / S8≥50%. Exemplarily, for example, S5 / S6 can be 50%, 60%, 70%, 75%, 80%, etc., and S7 / S8 can be 50%, 60%, 70%, 75%, 80%, etc.

[0057] Specifically, in the present embodiment, the area ratio of the first welding spot 500 on the first current collector 300 is set within the above range, which is conducive to ensuring the welding strength between the first current collector 300 and the first tab 210, preventing cracking between the first current collector 300 and the first tab 210 due to poor welding between the first current collector 300 and the first tab 210, and even preventing the first current collector 300 from falling off. Similarly, the area ratio of the second welding spot 600 on the second current collector 400 is set within the above range, which is conducive to ensuring the welding strength between the second current collector 400 and the second tab 220, preventing cracking between the second current collector 400 and the second tab 220 due to poor welding between the second current collector 400 and the second tab 220, and even preventing the second current collector 400 from falling off.

[0058] It should be noted that the first current collector 300 and the first tab 210 do not have to be fully welded, i.e., S5 / S6 does not have to be 100%, and the second current collector 400 and the second tab 220 do not have to be fully welded, i.e., S7 / S8 does not have to be 100%. By reasonably arranging the first welding spot 500 and the second welding spot 600, it is sufficient to ensure the stable connection between the first current collector 300 and the first tab 210, and between the second current collector 400 and the second tab 220. If the first current collector 300 and the first tab 210 are fully welded, and the second current collector 400 and the second tab 220 are fully welded, the processing cost of the cylindrical battery will be increased, and the probability of damaging the jelly-roll 200 during welding will also be increased.

[0059] In some embodiments, referring to FIG. 2 and FIG. 3, the welding depth D1 of the first welding spot 500 satisfies: D1≥0.2mm, and the welding width W1 of the first welding spot 500 satisfies: W1≥0.1mm. The welding depth D2 of the second welding spot 600 satisfies: D2≥0.2mm, and the welding width W2 of the second welding spot 600 satisfies: W2≥0.1mm. For example, the value of D1 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc., and the value of W1 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, etc. The value of D2 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc., and the value of W2 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, etc.

[0060] Specifically, in the present embodiment, if the penetration depth of the first welding spot 500 is set too shallow (for example, the penetration depth of the first welding spot 500 is set to 0.05mm, 0.1mm, 0.15mm, etc.), or the penetration width of the first welding spot 500 is set too narrow (for example, the penetration width of the first welding spot 500 is set to 0.01mm, 0.05mm, 0.08mm, etc.), it will result in that the welding between the first current collector plate 300 and the first tab 210 is not firm, so that the first current collector plate 300 and the first tab 210 are prone to crack, and even the first current collector plate 300 is prone to fall off. Similarly, if the penetration depth of the second welding spot 600 is set too shallow (for example, the penetration depth of the second welding spot 600 is set to 0.05mm, 0.1mm, 0.15mm, etc.), or the penetration width of the second welding spot 600 is set too narrow (for example, the penetration width of the second welding spot 600 is set to 0.01mm, 0.05mm, 0.08mm, etc.), it will result in that the welding between the second current collector plate 400 and the second tab 220 is not firm, so that the second current collector plate 400 and the second tab 220 are prone to crack, and even the second current collector plate 400 is prone to fall off.

[0061] In some embodiments, referring to FIG. 1 to FIG. 3, the winding core 200 has a first central hole 230 pointing from the first tab 210 end to the second tab 220 end, the first current collector plate 300 has a second central hole 310, and the second current collector plate 400 has a third central hole 410. The second central hole 310 and the first central hole 230 are arranged in alignment, and the third central hole 410 and the first central hole 230 are arranged in alignment.

[0062] Specifically, in the present embodiment, the shell 100 of the cylindrical battery is provided with a liquid injection hole for injecting electrolyte into the shell 100, so that the winding core 200 is soaked in the electrolyte, and ions can migrate in the electrolyte, thereby realizing the charging and discharging of the cylindrical battery. In order to improve the effect of soaking electrolyte in the winding core 200, a hollow first central hole 230 is arranged inside the winding core 200. After the electrolyte is injected into the shell 100, the electrolyte will flow into the first central hole 230, and then the electrolyte will gradually spread from the first central hole 230 to both sides of the winding core 200, thereby ensuring that the electrolyte uniformly soaks the winding core 200, which is conducive to improving the effect of soaking electrolyte in the winding core 200 and improving the charging and discharging performance of the cylindrical battery.

[0063] Further, since the first current collector plate 300 is welded with the first tab 210, the first current collector plate 300 is in close contact with the first tab 210 end of the winding core 200, and since the second current collector plate 400 is welded with the second tab 220, the second current collector plate 400 is in close contact with the second tab 220 end of the winding core 200. The first current collector plate 300 and the second current collector plate 400 will block both ends of the first central hole 230, causing the electrolyte to be unable to flow into the first central hole 230, and thus the electrolyte cannot spread from the first central hole 230 to both sides of the winding core 200, which ultimately easily leads to poor effect of soaking electrolyte in the winding core 200, affecting the charging and discharging performance of the cylindrical battery. In the present embodiment, the first current collector plate 300 is provided with a second central hole 310 aligned with the first central hole 230, and the second current collector plate 400 is provided with a third central hole 410 aligned with the first central hole 230, which is conducive to the electrolyte flowing into the first central hole 230 through the second central hole 310 and the third central hole 410, and then the electrolyte stored in the first central hole 230 will gradually spread to both sides of the winding core 200, thereby improving the effect of soaking electrolyte in the winding core 200 and ensuring that the electrolyte can uniformly soak the winding core 200.

[0064] In some embodiments, referring to FIGS. 4-7, 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 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 tab 220, and the separator is arranged between the first current collector 240 and the second current collector 250. Wherein, the first current collector 240, the second current collector 250 and the separator are stacked and wound to form the winding core 200.

[0065] Specifically, in the present embodiment, the first current collector 240 can be a negative current collector, and the second current collector 250 can be a positive current collector. At this time, the first active material coating layer 241 is a negative active material coating layer, the first tab 210 is a negative tab, the second active material coating layer 251 is a positive active material coating layer, and the second tab 220 is a positive tab. Alternatively, the first current collector 240 can be a positive current collector, and the second current collector 250 can be a negative current collector. At this time, the first active material coating layer 241 is a positive active material coating layer, the first tab 210 is a positive tab, the second active material coating layer 251 is a negative active material coating layer, and the second tab 220 is a negative tab.

[0066] Further, the first active material coating layer 241 and the first current collector 240 are in electronic conduction, the second active material coating layer 251 and the second current collector 250 are in electronic conduction, and the first current collector 240 and the second current collector 250 are provided with a separator. The separator can prevent the first current collector 240 and the second current collector 250 from directly contacting each other, thereby avoiding short circuit in the cylindrical battery and ensuring the safety of the cylindrical battery. However, the separator can allow ions (for example, lithium ions) to migrate between the first current collector 240 and the second current collector 250, thereby realizing the charging and discharging of the cylindrical battery.

[0067] Further, when the first current collector 240, the second current collector 250, and the separator are laminated, the first empty foil area 242 and the second empty foil area 252 are respectively arranged opposite 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 roll core 200, as the first tab 210 and the second tab 220 of the cylindrical battery.

[0068] Further, in some embodiments, taking the cylindrical battery as an example of a lithium ion battery, the negative current collector can be a copper foil, the positive current collector can be an aluminum foil, the negative active material coating layer can be a graphite material, and the positive active material coating layer can be a lithium-rich compound material (for example, the positive active material coating layer can be LiFePO4, LiMn2O4, etc.).

[0069] In some embodiments, referring to FIGS. 4-7, along the thickness direction of the first current collector 240, the first current collector 240 has first active material coating layers 241 arranged opposite to each other on both sides. Along the thickness direction of the second current collector 250, the second current collector 250 has second active material coating layers 251 arranged opposite to each other on both sides.

[0070] Specifically, in the present embodiment, the first current collector 240 is double-sided coated with the first active material coating layer 241, and the second current collector 250 is double-sided coated with the second active material coating layer 251, so that the coating space of the first current collector 240 and the second current collector 250 can be effectively utilized, thereby facilitating the improvement of the energy density of the cylindrical battery.

[0071] In some embodiments, with reference to FIGS. 4-7, the width W3 of the first active material coating layer 241 and the width W4 of the second active material coating layer 251 satisfy: 2mm≤W3-W4≤5mm. Exemplarily, for example, the value of W3-W4 can be 2mm, 3mm, 4mm, 5mm, etc.

[0072] Specifically, in the present embodiment, the first active material coating layer 241 is a negative active material coating layer, and the second active material coating layer 251 is a positive active material coating layer. When coating the active material coating layer on the current collector, the width of the negative active material coating layer needs to be set slightly wider than that of the positive active material coating layer, so as to ensure that the ions deintercalated from the positive active material coating layer can be completely absorbed by the negative active material coating layer during charging of the cylindrical battery, thereby preventing the lithium dendrites from being precipitated from the negative active material coating layer due to the limited lithium intercalation capacity of the negative active material coating layer, so as to prevent the first current collector 240 and the second current collector 250 from being directly contacted due to the puncture of the separator, thereby causing internal short circuit of the cylindrical battery and affecting the safety of the cylindrical battery.

[0073] Further, the coating width difference 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, the coating width difference between the first active material coating layer 241 and the second active material coating layer 251 is prevented from being too small (exemplarily, for example, the value of W3-W4 is 0.5mm, 1mm, 1.5mm, etc.), so as to ensure that the deintercalated ions can be completely absorbed, thereby preventing the risk of the puncture of the separator. On the other hand, the coating width difference between the first active material coating layer 241 and the second active material coating layer 251 is prevented from being too large (exemplarily, for example, the value of W3-W4 is 5.5mm, 6mm, 7mm, etc.), so as to prevent the energy density of the cylindrical battery from being reduced, thereby preventing the cylindrical battery from having poor battery performance, slow charging speed, and low endurance.

[0074] In some embodiments, the first current collector 240 is a negative current collector, and correspondingly, the first active material coating layer 241 is a negative active material coating layer, and the first tab 210 is a negative tab. The second current collector 250 is a positive current collector, and correspondingly, the second active material coating layer 251 is a positive active material coating layer, and the second tab 220 is a positive tab.

[0075] Correspondingly, another embodiment of the present application further provides an electronic device comprising the cylindrical battery of any of the above embodiments. Illustratively, the electronic device can be an electric vehicle, a new energy vehicle, etc.

[0076] Specifically, in the present embodiment, the electronic device using the cylindrical battery can ensure safety during operation.

[0077] Thanks to the improvements of the cylindrical battery, the electronic device of the present embodiment has the same technical effects as the cylindrical battery, which will not be repeated here.

[0078] It should be noted that other contents of the cylindrical battery and the electronic device disclosed in the present application can be referred to the prior art, which will not be repeated here.

[0079] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields within the concept of the present application, and the contents of the present application specification and drawings are included in the patent protection scope of the present application.

Claims

1. A cylindrical battery, comprising: a housing; a jelly-roll disposed inside the housing, the jelly-roll having a first tab and a second tab disposed oppositely; a first current collector disposed at one end of the housing close to the first tab, a first welding spot being disposed between the first current collector and the first tab; a second current collector disposed at one end of the housing close to the second tab, a second welding spot being disposed between the second current collector and the second tab; wherein a first overlap region is between two adjacent first welding spots, and a second overlap region is between two adjacent second welding spots.

2. The cylindrical battery according to claim 1, wherein An area S1 of the first overlap region and an area S2 of the first welding spot satisfy: 20%≤S1 / S2≤80%; an area S3 of the second overlap region and an area S4 of the second welding spot satisfy: 20%≤S3 / S4≤80%.

3. The cylindrical battery according to claim 1, wherein, A total area S5 of the first welding spot and an area S6 of the first current collector satisfy: S5 / S6≥50%; a total area S7 of the second welding spot and an area S8 of the second current collector satisfy: S7 / S8≥50%.

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

5. The cylindrical battery according to claim 1, wherein, The jelly-roll has a first central hole pointing from the first tab end to the second tab end, the first current collector has a second central hole, and the second current collector has a third central hole; wherein the second central hole is aligned with the first central hole, and the third central hole is aligned with the first central hole.

6. The cylindrical battery according to claim 1, wherein, The jelly-roll comprises: a first current collector, along a width direction of the first current collector, the first current collector being provided with a first active material coating layer and a first empty foil region, the first empty foil region forming the first tab; a second current collector, along a width direction of the second current collector, the second current collector being provided with a second active material coating layer and a second empty foil region, the second empty foil region forming the second tab; a separator, the separator being disposed between the first current collector and the second current collector; wherein the first current collector, the second current collector, and the separator are stacked and wound to form the jelly-roll.

7. The cylindrical battery according to claim 6, wherein Along a thickness direction of the first current collector, two sides of the first current collector have the first active material coating layer disposed oppositely; Along a thickness direction of the second current collector, two sides of the second current collector have the second active material coating layer disposed oppositely.

8. The cylindrical battery according to claim 6, wherein, A width W3 of the first active material coating layer and a width W4 of the second active material coating layer satisfy: 2mm≤W3-W4≤5mm.

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

10. Electronic device comprising the cylindrical battery according to any one of claims 1 to 9.

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