Cylindrical battery, battery pack, and electronic device

Abstract

The utility model provides a kind of cylindrical battery, battery pack and electronic device, the cylindrical battery includes: shell assembly, shell assembly includes shell and cover plate, one end of shell is shell mouth, cover plate covers in shell mouth to define accommodating cavity, and cover plate is connected with shell by first solder mark;Electrode assembly is located in accommodating cavity;Protective layer is set to the circumferential surface of shell assembly;And coating, including the first coating of the outer surface of cover plate away from electrode assembly and the second coating of being set on circumferential surface, first coating and second coating are continuously arranged, coating covers first solder mark;Wherein, protective layer and second coating have gap in the axial direction of shell assembly, the thickness of protective layer is less than the thickness of second coating.The above technical solution can at least improve the insulation protection effect of cylindrical battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more specifically, to a cylindrical battery, a battery pack, and an electronic device. Background Technology

[0002] In the field of new energy batteries, the application of rechargeable batteries is becoming increasingly widespread. For example, rechargeable batteries (such as lithium-ion batteries) can be used in vehicles, energy storage, mobile phones, tablets, wearable devices, power banks, e-cigarettes, digital products, power tools, power units, and energy storage devices. One type of rechargeable battery is the cylindrical battery. A cylindrical battery generally includes a casing, a cover plate, and an electrode assembly. The electrode assembly includes a positive electrode, a separator, and a negative electrode, which are stacked sequentially to form a wound electrode assembly, then encapsulated in the casing, and finally sealed by the cover plate.

[0003] Typically, a protective layer is wrapped around the outer perimeter of a cylindrical battery casing to provide insulation. However, improvements are still needed in the protection of cylindrical batteries. Utility Model Content

[0004] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a cylindrical battery, battery pack and electronic device to at least improve the protection effect of cylindrical batteries.

[0005] To achieve the above objectives, an embodiment of the present invention provides a cylindrical battery, comprising: a housing assembly including a housing and a cover plate, one end of the housing being a housing opening, the cover plate being fitted onto the housing opening to define a receiving cavity, and the cover plate being connected to the housing via a first solder joint; an electrode assembly located in the receiving cavity; a protective layer covering the peripheral side surface of the housing assembly; and a coating comprising a first coating disposed on the outer surface of the cover plate facing away from the electrode assembly and a second coating disposed around the peripheral side surface, the first coating and the second coating being continuously disposed, and the coating covering the first solder joint; wherein the protective layer and the second coating have a gap in the axial direction of the housing assembly, and the thickness of the protective layer is less than the thickness of the second coating.

[0006] In some embodiments, the axial width of the gap is B mm, the axial height of the housing assembly is H mm, and 0.005 ≤ B / H ≤ 0.08.

[0007] In some embodiments, the first solder mark is located on the peripheral side, the second coating covers the first solder mark, the width of the second coating in the axial direction is W mm, 0.5≤W≤5, and / or, the thickness of the second coating is T μm, 50≤T≤200.

[0008] In some embodiments, at least one second solder mark is formed on the outer surface of the cover plate, and the cover plate is connected to the electrode assembly or the current collector through the second solder mark. The current collector is electrically connected to the electrode assembly, wherein: the first coating covers the second solder mark.

[0009] In some embodiments, the cover plate has a support portion protruding toward the electrode assembly, the support portion forming a groove on the outer surface of the cover plate, the second solder mark being located at the bottom of the groove, and the first coating and the second coating being integrally formed.

[0010] In some embodiments, the cover plate is provided with at least one groove, the at least one groove being configured to open along the groove to form a pressure relief area; the at least one groove is located on the inner surface of the cover plate facing the electrode assembly, and the first coating is located outside the pressure relief area.

[0011] In some embodiments, the cover plate includes a cover plate body, an anti-rust metal layer disposed on the inner surface and the outer surface of the cover plate body, the anti-rust metal layer being formed by a pre-plating nickel process, and the thickness of the anti-rust metal layer covering the surface of the groove being less than the thickness of the anti-rust metal layer on the surface of the cover plate body.

[0012] In some embodiments, the cover plate includes a cover plate body and a rust-proof metal layer disposed on the outer surface. After the cover plate is covered with the rust-proof metal layer, it is processed to form at least one groove, such that the thickness of the rust-proof metal layer covering the surface of the groove is less than the thickness of the rust-proof metal layer on the surface of the cover plate body. A first coating covers at least one groove. The at least one groove is configured to be able to open along the groove to form a pressure relief area. The first coating directly covers the groove, or, along the direction away from the cover plate body, the surface of the groove is sequentially provided with the rust-proof metal layer and the first coating.

[0013] In some embodiments, the protective layer is an adhesive tape, and the thickness of the protective layer ranges from 40 μm to 150 μm.

[0014] In some embodiments, the protective layer includes a layer of adhesive and a layer of substrate stacked together, and the thickness of the protective layer is less than or equal to 90 μm; or, the protective layer includes multiple layers of adhesive and multiple layers of substrate, wherein the adhesive and substrate are stacked alternately, and the thickness of the protective layer is greater than 90 μm.

[0015] In some embodiments, the first coating is annular and its outer periphery is connected to the second coating.

[0016] Embodiments of this application also provide a battery pack including any of the cylindrical batteries described above, the cylindrical batteries being placed in a recess in a bracket, wherein one edge of a protective layer is adjacent to a second coating layer, and at least one edge of the coating layer and the protective layer is located within the recess.

[0017] Embodiments of this application also provide an electronic device including any of the battery packs described above.

[0018] The beneficial technical effects of this utility model include:

[0019] By setting a protective layer and combining it with a coating that covers the cover plate and the first solder mark of the casing, the cylindrical battery and its first solder mark can be effectively protected. The process is simple, easy to operate, and has a high yield. By setting the thickness of the second coating on the peripheral side of the casing assembly to be thicker than the protective layer and leaving a gap between them, the protective layer can be prevented from covering the coating, and the protective layer can be provided with edge protection. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1A A schematic diagram of an electronic device, using a vehicle as an example, is shown.

[0022] Figure 1B This is a schematic diagram of a bracket according to an embodiment of this application.

[0023] Figure 1C This is a partially enlarged structural diagram of a cylindrical battery placed in a bracket.

[0024] Figure 2A A front view of a cylindrical battery according to this embodiment is shown.

[0025] Figure 2B It shows Figure 2A The diagram shows a cross-sectional view of the cylindrical battery.

[0026] Figure 2C It shows Figure 2A The diagram shows a top view of the cylindrical battery.

[0027] Figure 3A A front view of a cylindrical battery according to another embodiment is shown.

[0028] Figure 3B It shows Figure 3A The diagram shows a cross-sectional view of the cylindrical battery.

[0029] Figure 4A According to the embodiments of this application Figure 3A A schematic diagram of the cross-section of the cylindrical battery at section C1-C1.

[0030] Figure 4B yes Figure 4A A magnified view of a portion of region A1 in the diagram.

[0031] Figure 5A It shows Figure 3A A top view of the cover plate.

[0032] Figure 5B It shows Figure 3A Isometric view of the cover plate. Detailed Implementation

[0033] To better understand the spirit of the embodiments of this application, the following description, in conjunction with some preferred embodiments of this application, will provide further details. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other.

[0034] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0035] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0036] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0037] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0038] Typically, a protective layer (such as a protective adhesive layer) is wrapped around the outer perimeter of the cylindrical battery casing. However, this outer protective layer cannot cover the battery cover plate and cannot protect the solder marks at the cover plate. If a protective layer is applied to the outside of the casing and cover plate using a full spraying method, it will result in a lower yield rate and increased susceptibility to impacts and damage.

[0039] Furthermore, during battery transport or assembly, the battery may be placed into a tray with positioning grooves. The battery's cover side is placed in the corresponding groove to load the battery into the tray. During this process, the edge of the protective layer is placed into the groove, which makes the edge of the protective layer susceptible to damage from the sidewalls of the groove, causing the edge of the protective layer to locally lift up. Based on at least the above issues, improvements are still needed in the protection of cylindrical batteries.

[0040] Embodiments of this application provide a cylindrical battery, a battery pack, and an electronic device. The cylindrical battery can be used in electronic devices. See also Figure 1A This utility model provides an electronic device 1000. For ease of explanation, the following embodiments use a vehicle as an example to illustrate the electronic device 1000. See also... Figure 1A The vehicle has a battery pack 1002 installed inside. The battery pack 1002 may include multiple cylindrical batteries. The battery pack 1002 may be located at the bottom, front, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, the battery pack 1002 can serve as the vehicle's operating power source. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power.

[0041] As an example, electronic device 1000 is a vehicle, which can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power support for the vehicle's movement or the operation of electrical components within the vehicle. However, in some other embodiments, electronic device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0042] Battery pack 1002 may include multiple cylindrical batteries. During the transport or assembly of cylindrical batteries, the cylindrical batteries of battery pack 1002 can be placed in a bracket. Figure 1B This is a schematic diagram of a bracket according to an embodiment of this application. Figure 1C This is a partially enlarged structural diagram showing the cylindrical battery placed in the support bracket. See also... Figure 1B and Figure 1C As shown, the bracket 300 may be provided with a plurality of grooves 305 for positioning the cylindrical battery 100. Each groove 305 is used to place a single cylindrical battery 100. One end of the cylindrical battery 100 is provided with a terminal post 120, and the other end may be fitted with a cover plate and placed in the corresponding groove 305.

[0043] Figure 2A A front view of a cylindrical battery according to this embodiment is shown. Figure 2B It shows Figure 2A The diagram shows a cross-sectional view of the cylindrical battery. Figure 2C It shows Figure 2A The diagram shows a top view of a cylindrical battery. The cylindrical battery 100 may include a housing assembly, which includes a housing 110 and a cover plate 140. Specifically, the housing 110 may include an end wall 111 and a side wall 112 surrounding the end wall 111 and forming a receiving cavity. The electrode assembly 130 may be received in the receiving cavity. A protective layer 220 may be provided on the circumferential side surface of the side wall 112. The protective layer 220 may surround and cover at least one circumference of the side wall 112.

[0044] One end of the sidewall 112 is a shell opening 113. A cover plate 140 covers the shell opening 113. The cover plate 140 can be welded to the shell 110 to seal the connection between the cover plate 140 and the shell 110. The cover plate 140 and the shell 110 are welded together to form a first weld mark 290 at the transition between the cover plate 140 and the shell 110. The transition between the cover plate 140 and the shell 110 is the location where the cover plate 140 and the shell 110 are welded together. In some embodiments, the first weld mark 290 may be coplanar with the peripheral surface of the sidewall 112. In other embodiments, the first weld mark 290 may be coplanar with the outer surface of the cover plate 140 facing away from the electrode assembly 130. This application does not limit the position of the first weld mark 290 or the specific connection structure between the cover plate 140 and the shell 110.

[0045] In some embodiments, a coating 250 may be provided on the peripheral surfaces of the cover plate 140 and the sidewall 112. The coating 250 may be formed by a spraying process and is therefore referred to as a coating. The coating 250 may include a first coating 252 and a second coating 254. The first coating 252 is disposed on the outer surface of the cover plate 140 facing away from the electrode assembly 130, and the second coating 254 is disposed around the peripheral surface of the housing assembly. In some embodiments, the peripheral surface of the housing assembly may be the sidewall 112; in other embodiments, the peripheral surface of the housing assembly may be formed by the sidewall 112 and the outer surface of the cover plate 140. The first coating 252 and the second coating 254 are continuously disposed. The first coating 252 may be annular (e.g., ...). Figure 2C As shown in the diagram, the outer periphery 252e of the first coating 252 is connected to the second coating 254. The coating 250 can cover the first weld mark 290 at the transition between the cover plate 140 and the housing 110. The first weld mark 290 at the transition between the cover plate 140 and the housing 110 is the location that needs to be protected. If adhesive tape is used for protection, the adhesion between the tape and the first weld mark is weak and prone to failure due to the uneven surface of the first weld mark 290. In particular, when the first weld mark 290 is located on the outer surface of the cover plate 140 away from the electrode assembly 130, it needs to be applied from the outer surface of the cover plate 140 away from the electrode assembly 130 to the side wall 112 to form a complete coverage. However, applying adhesive tape on a flat surface is difficult in terms of operation. If overall spraying is used for protection, it will also increase the overall process difficulty. The technical solution of this application can effectively protect the weld mark by setting a protective layer 220 and combining it with the coating 250. The process is simple, easy to operate, and has a high yield.

[0046] In some embodiments, the coating 250 can be formed by spraying any suitable insulating material. In some embodiments, the coating 250 can be a material with high corrosion resistance, such as a polymer material selected from polyacrylate, polyurethane, or epoxy resin. In some embodiments, the material of the coating 250 can be formulated into a slurry and formed by spraying.

[0047] The second coating 254 and the protective layer 220 are separated by a gap Ga along the axial direction Z of the housing 110. That is, there is a gap Ga between the edges 251 of the second coating 254 and the edges 221 of the protective layer 220 that are adjacent to each other. Furthermore, the thickness of the protective layer 220 can be less than the thickness of the second coating 254. Here, the thickness of the protective layer 220 and the thickness of the second coating 254 can refer to their average thicknesses, respectively. If the thicknesses of the protective layer 220 and / or the second coating 254 are not uniform or have poor consistency, then the thickness can be the maximum thickness.

[0048] Combination Figure 1CAs shown, when the cylindrical battery 100 is placed into the groove 305 of the holder 300, one side of the cover plate 140 is positioned within the groove 305. The coating 250 may be located within the groove 305. The edge 221 of the protective layer 220 and a portion connected to the edge 221 may be located within the groove 305. If the thickness of the protective layer 220 is greater than the thickness of the second coating 254, the edge (e.g., edge 221) of the protective layer 220 may be damaged or partially lifted when the cylindrical battery 100 is placed into the groove 305 of the holder 300. By setting the thickness of the second coating 254 to be thicker than that of the protective layer 220 and maintaining a gap Ga between them, the protective layer 220 can be prevented from covering the coating 250, and the sidewalls of the groove 305 can be prevented from damaging the edge of the protective layer 220, thus providing edge protection for the protective layer 220.

[0049] Figure 3A A front view of a cylindrical battery according to another embodiment is shown. Figure 3B It shows Figure 3A The diagram shows a cross-sectional view of a cylindrical battery. In some embodiments, the cylindrical battery may be a 4680 cylindrical battery (outer diameter 46mm, height 80mm), a 4695 cylindrical battery (outer diameter 46mm, height 95mm), or a 46120 cylindrical battery (outer diameter 46mm, height 120mm).

[0050] Combination Figure 3A and Figure 3B As shown, the cylindrical battery 100 may include a housing 110 and a cover plate 140. Specifically, the housing 110 may include an end wall 111 and a side wall 112 surrounding the end wall 111 and forming a receiving cavity. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 111 and the side wall 112 can be achieved in various ways, such as integral stamping, integral casting, or separate welding. The side wall 112 may be cylindrical or follow any other closed-loop contour that can match the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 is cylindrical and surrounds the outer edge of the end wall 111. In some embodiments, the housing 110 may be made of various materials, such as copper, iron, aluminum, steel (e.g., SPCC), aluminum alloy, etc.

[0051] The electrode assembly 130 is housed within a cavity enclosed by the sidewall 112. The electrode assembly 130 is primarily formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material, the positive active material being coated on the surface of the positive current collector; the positive current collector includes a coated area with the active material and an uncoated area without the active material, the uncoated area of ​​the positive current collector forming the positive electrode tab of the electrode assembly 130. The negative electrode sheet includes a negative current collector and a negative active material, the negative active material being coated on the surface of the negative current collector; the negative current collector includes a coated area with the active material and an uncoated area without the active material, the uncoated area of ​​the negative current collector forming the negative electrode tab of the electrode assembly 130. Taking a lithium-ion secondary battery as an example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. The separator can be made of PP (polypropylene) or PE (polyethylene), etc. The electrode assembly 130 can have a central through hole 133, which can keep the space at both ends of the electrode assembly 130 more smoothly connected, and can be used as an exhaust path for the gas generated by the electrode assembly 130 during operation.

[0052] A housing opening 113 may be formed at one end of the sidewall 112 opposite to the end wall 111. A cover plate 140 covers the housing opening 113 and seals it. Opposite polarity tabs of the electrode assembly 130 extend from their axially opposite ends. In some embodiments, the negative tab may face the housing opening 113, and the positive tab may face the end wall 111. The electrode post 120 may pass through the end wall 111 and be insulated and fixedly connected to it. Electrical insulation between the electrode post 120 and the end wall 111 of the housing 110 can be achieved in various ways. For example, insulation can be achieved by placing an insulating washer between the electrode post 120 and the end wall 111. In some embodiments, the electrode post 120 may be riveted to the end wall 111. The electrode post 120 can be constructed in any suitable form that allows it to pass through the end wall 111 and be electrically connected to the positive tab of the electrode assembly 130. The electrode post 120 may be made of a conductive metallic material. For example, the material of pole 120 can be aluminum (Al), and it can be used as the positive pole.

[0053] The first current collector 162 and the second current collector 164 can be disposed at opposite ends of the electrode assembly 130 and physically connected to the electrode assembly 130 to achieve electrical connection. Specifically, the first current collector 162 can be welded to the first tab (e.g., the negative tab) of the electrode assembly 130 and welded to the cover plate 140 to electrically connect the first tab to the cover plate 140. The second current collector 164 can be welded to the second tab (e.g., the positive tab) of the electrode assembly 130 and welded to the electrode post 120 to electrically connect the second tab to the electrode post 120.

[0054] The materials of the first current collector 162 and the second current collector 164 can be selected according to the polarity of the tabs they are connected to. For example, if the first current collector 162 is connected to the negative tab, then the material of the first current collector 162 can be copper. If the second current collector 164 is connected to the positive tab, then the material of the second current collector 164 can be aluminum. The shape and structure of the second current collector 164 and the first current collector 162 are also not limited, as long as a stable and reliable electrical connection can be achieved. The housing 110, the cover plate 140, and the electrode assembly 130 can be arranged coaxially.

[0055] Figure 4A According to the embodiments of this application Figure 3A A schematic diagram of the cross-section of the cylindrical battery at section C1-C1. Figure 4B yes Figure 4A A magnified view of a portion of region A1 in the diagram. (Combined with...) Figures 3A to 4B As shown, a protective layer 220 is disposed on and covers the outer surface of the sidewall 112. In some embodiments, the protective layer 220 may be an insulating layer. In some embodiments, the protective layer 220 may be insulating tape. The protective layer 220 may cover the peripheral side surface of the sidewall 112. The protective layer 220 may surround the sidewall 112 at least once around its perimeter.

[0056] The coating 250 includes a first coating 252 and a second coating 254. The first coating 252 is disposed on the outer surface 140a of the cover plate 140 facing away from the electrode assembly 130. The second coating 254 is disposed on a portion of the peripheral side surface of the housing assembly and surrounds the sidewall 112 upwardly. The first coating 252 and the second coating 254 are continuously disposed and can be integrally formed by a single spraying. The second coating 254 is spaced apart from the protective layer 220 on the sidewall 112 by a gap Ga. The cover plate 140 and the sidewall 112 of the housing 110 are connected by a first solder joint 290. The first solder joint 290 may be located at the transition between the cover plate 140 and the sidewall 112 to seal the connection between the cover plate 140 and the housing 110. The first solder joint 290 may be formed by welding, and the coating 250 covers the first solder joint 290. The first weld mark 290 at the transition between the cover plate 140 and the housing 110 is a location that needs to be protected to prevent rusting. By setting a protective layer 220 and combining it with a coating 250, the weld mark can be effectively protected. The process is simple, easy to operate, and has a high yield.

[0057] In some embodiments, the thickness of the protective layer 220 is less than the thickness of the second coating 254. By setting the thickness of the second coating 254 on the peripheral side surface to be thicker than that of the protective layer 220, and maintaining a gap Ga between them, it is possible to prevent the protective layer 220 from covering the coating 250, thus preventing the battery from being placed into the recess 305 of the holder 300 (see...). Figure 1C When the groove sidewall is damaged, the edge of the protective layer 220 is damaged, thus providing edge protection for the protective layer 220.

[0058] In some embodiments, the protective layer 220 is an insulating tape, and the thickness of the protective layer 220 ranges from 40 μm to 150 μm. In some embodiments, the thickness of the protective layer 220 is less than or equal to 90 μm, in which case the protective layer 220 is considered thin, and can be composed of a layer of adhesive and a layer of substrate layer stacked on top of each other. In some embodiments, the thickness of the protective layer 220 is greater than 90 μm, in which case the protective layer 220 is considered thick, and the protective layer 220 may include multiple layers of adhesive and multiple layers of substrate, wherein the adhesive and substrate layers are stacked alternately. The protective layer 220 is adhered to the sidewall 112 by the adhesive layer connected to the sidewall 112. When the protective layer 220 has a relatively thick thickness, if the protective layer 220 is formed by a single layer of adhesive and a single layer of substrate, the thickness of the substrate layer will be too thick, and the adhesive layer is easily crushed and damaged during the bending process of the protective layer 220 while covering the sidewall 112. Therefore, when the thickness of the protective layer 220 is greater than 90 μm, the protective layer 220 is formed by multiple layers of adhesive and multiple layers of substrate, which can effectively prevent the adhesive layer from being crushed and damaged.

[0059] In some embodiments, the gap Ga between the protective layer 220 and the second coating 254 has a width of B mm in the axial Z direction, and the height of the cylindrical battery 100 is H mm. In some embodiments, 0.005 ≤ B / H ≤ 0.08. Here, the height H mm of the cylindrical battery 100 refers to the height of the cover plate 140 and the housing 110 in the axial Z direction, specifically, the maximum distance from the outer surface of the end wall 111 along the axial Z direction to the outer surface 140a of the cover plate 140. If B / H is less than 0.005, the width of the gap Ga will be too small, resulting in a narrow process window when the coating 250 and the protective layer 220 are set separately, making it difficult to control. Once the coating 250 overlaps with the protective layer 220, the outer contour size of the battery will be too large. If B / H is greater than 0.08, the width of the gap Ga will be too large, and the exposed area of ​​the side wall 112 will also be too large, leading to a reduction in the insulation protection effect of the side wall 112, for example, the exposed area may only be partially accommodated in the groove 305. By limiting the range of the ratio B / H between the width of the gap Ga and the height of the battery to 0.005≤B / H≤0.08, the width of the gap Ga can be avoided to be too large or too small, so as to balance the appropriate process window and the outer contour size of the battery, as well as the insulation protection effect on the sidewall 112.

[0060] In this embodiment, the edge of the cover plate 140 overlaps the end of the side wall 112. A first solder mark 290 is located at the connection between the end of the side wall 112 and the cover plate 140 to seal the connection between the cover plate 140 and the side wall 112. In this embodiment, the peripheral side of the housing assembly is formed by the outer side of the side wall 112 and the cover plate 140. The first solder mark 290 is located on the peripheral side of the housing assembly. The first solder mark 290 is covered by a second coating 254. The width of the second coating 254 in the axial direction Z is W mm, and in some embodiments, 0.5 ≤ W ≤ 5. If W is less than 0.5, the width of the second coating 254 will be too small, which may result in the second coating 254 not covering the first solder mark 290. If W is greater than 5, the width of the second coating 254 will be too large, and the area on the peripheral side where the second coating 254 is provided will be too large. Since the second coating 254 may be easily scratched and chipped, as many protective layers 220 as possible are used on the side wall 112 for protection. By configuring the width W mm of the second coating 254 to 0.5≤W≤5, it can be ensured that the second coating 254 can cover and protect the first solder mark 290, while the sidewall 112 can be protected by the largest possible area of ​​the protective layer 220, so as to ensure the reliability of the protective effect.

[0061] In some embodiments, the thickness of the second coating 254 is T μm, where 50 ≤ T ≤ 200. The housing 110 and the cover plate 140 are welded to form a first weld mark 290, and residual burrs may exist on the surface of the first weld mark 290. If the thickness of the second coating 254 is too small, burrs may puncture the second coating 254 during battery transport or assembly, leading to protection failure. If the thickness of the second coating 254 is too large, and the width W mm exceeds 5 mm, the second coating 254 may easily detach due to large stress changes during the drying process. Setting the thickness T μm of the second coating 254 to 50 ≤ T ≤ 200 can prevent the second coating 254 from being punctured by burrs and reduce the risk of the second coating 254 detaching.

[0062] Figure 5A It shows Figure 3A A top view of the cover plate 140. Figure 5B It shows Figure 3A Isometric view of cover plate 140. Further integration Figure 5A and Figure 5B As shown, the cover plate 140 is welded to the current collector via a second solder mark 195. At least one second solder mark 195 is formed on the outer surface 140a of the cover plate 140. In this embodiment, the cover plate 140 is connected to the first current collector 162 via the second solder mark 195, and the first current collector 162 is electrically connected to the electrode assembly 130. It should be understood that in other embodiments, the cover plate 140 may also be connected to other current collectors via the second solder mark 195 to electrically connect to the electrode assembly 130. Specifically, in this embodiment, the cover plate 140 is welded to the first current collector 162 via the second solder mark 195, and the first current collector 162 is further welded to the tabs of the electrode assembly 130 to electrically connect the cover plate 140 and the electrode assembly 130 via the first current collector 162. It should also be understood that in other embodiments, the cover plate 140 may be connected to the electrode assembly 130 via the second solder mark 195.

[0063] The first coating 252 can be applied according to the position of the second solder mark 195, so that the first coating 252 covers the second solder mark 195. In this embodiment, the second solder mark 195 can be located in the edge area of ​​the cover plate 140 near the side wall 112, and the first coating 252 can cover the second solder mark 195. The second solder mark 195 is also the location where the cylindrical battery needs to be protected. Covering the second solder mark 195 with the first coating 252 can effectively protect the second solder mark 195. In some embodiments, the first coating 252 can extend continuously in the edge area of ​​the cover plate 140, making the first coating 252 annular. Furthermore, the outer periphery of the first coating 252 can be connected to the second coating 254. The coating 250 formed by spraying can simultaneously cover the first solder mark 190 and the second solder mark 195 on the outer surface of the battery, which can effectively protect solder marks located on different surfaces, and has the advantages of simple process, easy operation, and high yield compared to the method of applying tape.

[0064] More specifically, the outer surface 140a of the cover plate 140 may be provided with at least one support portion 149 protruding toward the electrode assembly 130, and the support portion 149 forms a groove 146 on the outer surface 140a of the cover plate 140. Figures 5A to 5B Four support portions 149 and corresponding four grooves 146 are shown as an example. The plurality of grooves 146 may be arranged at equal intervals circumferentially on the cover plate 140. The support portions 149 may be welded to the first manifold 162 to form a second weld mark 195 located at the bottom of the groove 146. In this embodiment, the first coating 252 may extend to the bottom of the groove 146 to cover the second weld mark 195. In some embodiments, the coating 250 may at least cover the entire bottom of each groove 146 to cover the second weld mark 195. In some embodiments, the edge 250e of the coating 250 away from the sidewall 112 may be located within the groove 146, specifically, on the sidewall 112 of the groove 146 away from the housing 110. The first coating 252 and the second coating 254 may be integrally formed. Since the coating 250 is formed by spraying, a full spraying method is permitted to form a continuous, integral first coating 252 and second coating 254 on the sidewall 112 and the outer side of the cover plate 140.

[0065] The inner surface 140b of the cover plate 140 facing the electrode assembly 130 may have at least one groove 143. The groove 143 is located in a region of the cover plate 140 where the thickness and strength are relatively weak. The groove 143 is configured to open along the groove 143 to form a pressure relief area. For example, when the gas pressure inside the housing 110 exceeds a certain threshold, the weaker groove 143 will rupture and open, and the area surrounded by the groove 143 will form a pressure relief area. In this way, the groove 143 can be used as a battery explosion-proof valve structure to at least partially open the cover plate 140 when the gas pressure inside the housing 110 reaches a certain level, so as to release the pressure inside the housing 110 and thus prevent heat propagation. The groove 143 can be an annular structure around the center of the cover plate 140, for example, it can be circular or elliptical. In some embodiments, the groove 143 can be formed by stamping the cover plate 140.

[0066] In this embodiment, the first coating 252 on the outer surface 140a is located outside the pressure relief area defined by the groove 143. That is, the coating 250 covers the groove 143. This prevents the first coating 252 from affecting the opening of the groove 143 and the burst pressure during opening.

[0067] Furthermore, the cover plate 140 may also include a cover plate body, an anti-rust metal layer disposed on the inner surface of the cover plate body and the outer surface of the cover plate body, the anti-rust metal layer being formed by a pre-plating nickel process, and the processing method of the groove 143 causing the thickness of the anti-rust metal layer covering its surface to be less than the thickness of the anti-rust metal layer on the surface of the cover plate body, for example, the groove 143 may be formed by stamping, machining, laser processing and other methods.

[0068] In other embodiments, the cover plate 140 may include a cover plate body and a rust-resistant metal layer disposed on the outer surface 140a of the cover plate 140. This rust-resistant metal layer is disposed on the outer surface of the cover plate body and is used to prevent the cover plate 140 from rusting or corroding. In some embodiments, the rust-resistant metal layer on the outer surface 140a of the cover plate 140 may be a metal plating layer, such as a pre-plated nickel layer formed using a pre-plating nickel process. A rust-resistant metal layer is also disposed on the inner surface of the cover plate. In some embodiments, the material of the cover plate body may be, for example, copper, iron, aluminum, steel (e.g., SPCC), aluminum alloy, etc. After the cover plate 140 is covered with the rust-resistant metal layer, the cover plate 140 may be machined to form at least one groove 143, such that the thickness of the rust-resistant metal layer covering the surface of the groove 143 is less than the thickness of the rust-resistant metal layer on the surface of the cover plate body. That is, when machining the groove 143, part of the rust-resistant metal layer on the surface of the groove 143 may be removed, or all of the rust-resistant metal layer on the surface of the groove 143 may be removed. The groove 143 can be formed on the outer surface 140a of the cover plate 140. In an embodiment where the anti-rust metal layer on the surface of the groove 143 is completely removed, the first coating 252 can directly cover the groove 143. Alternatively, in an embodiment where the anti-rust metal layer on the surface of the groove 143 is partially removed, the surface of the groove 143 is sequentially provided with an anti-rust metal layer (i.e., the unremoved anti-rust metal layer) and the first coating 252 in a direction away from the cover plate body. Since the anti-rust metal layer on the surface of the cover plate 140 is damaged during the formation of the groove 143, resulting in thinning or complete removal of the anti-rust metal layer, the cover plate is prone to corrosion and rust at the groove 143. By covering the groove 143 with the first coating 252, the first coating 252 can cover the damaged area of ​​the anti-rust metal layer caused by the formation of the groove 143, thus protecting the damaged area and solving the problem of easy corrosion of the cover plate due to the formation of the groove 143.

[0069] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A cylindrical battery, characterized in that, include: A housing assembly includes a housing and a cover plate, one end of the housing being a housing opening, the cover plate being fitted onto the housing opening to define a receiving cavity, and the cover plate being connected to the housing by a first solder joint; The electrode assembly is located in the receiving cavity; A protective layer covers the peripheral surfaces of the housing assembly; as well as The coating includes a first coating disposed on the outer surface of the cover plate facing away from the electrode assembly and a second coating disposed around the peripheral side, wherein the first coating and the second coating are continuously disposed, and the coating covers the first solder mark; The protective layer and the second coating layer have a gap in the axial direction of the housing assembly, and the thickness of the protective layer is less than the thickness of the second coating layer.

2. The cylindrical battery according to claim 1, characterized in that, The width of the gap in the axial direction is B mm, and the height of the housing assembly in the axial direction is H mm. 0.005≤B / H≤0.

08.

3. The cylindrical battery according to claim 1, characterized in that, The first solder mark is located on the peripheral side surface, and the second coating covers the first solder mark. Wherein, the width of the second coating in the axial direction is W mm, 0.5≤W≤5, and / or, the thickness of the second coating is T μm, 50≤T≤200.

4. The cylindrical battery according to claim 1, characterized in that, At least one second solder mark is formed on the outer surface of the cover plate, and the cover plate is connected to the electrode assembly or current collector through the second solder mark. The current collector is electrically connected to the electrode assembly, wherein the first coating covers the second solder mark.

5. The cylindrical battery according to claim 4, characterized in that, The cover plate has a support portion that protrudes toward the electrode assembly. The support portion forms a groove on the outer surface of the cover plate. The second solder mark is located at the bottom of the groove. The first coating and the second coating are integrally formed.

6. The cylindrical battery according to claim 1, characterized in that, The cover plate is provided with at least one groove, which is configured to open along the groove to form a pressure relief area; The at least one groove is located on the inner surface of the cover plate facing the electrode assembly, and the first coating is located outside the pressure relief area.

7. The cylindrical battery according to claim 6, characterized in that, The cover plate includes a cover plate body, an anti-rust metal layer disposed on the inner surface and the outer surface of the cover plate body, the anti-rust metal layer being formed by a pre-plating nickel process, and the thickness of the anti-rust metal layer covering the surface of the groove being less than the thickness of the anti-rust metal layer on the surface of the cover plate body.

8. The cylindrical battery according to claim 1, characterized in that, The cover plate includes a cover plate body and a rust-proof metal layer disposed on the outer surface. After the cover plate covers the rust-proof metal layer, it is processed to form at least one groove, such that the thickness of the rust-proof metal layer covering the surface of the groove is less than the thickness of the rust-proof metal layer on the surface of the cover plate body. The first coating covers the at least one groove. The at least one groove is configured to open along the groove to form a pressure relief area; the first coating directly covers the groove, or, along the direction away from the cover plate body, the surface of the groove is sequentially provided with the anti-rust metal layer and the first coating.

9. The cylindrical battery according to claim 1, characterized in that, The protective layer is an adhesive tape, and the thickness of the protective layer ranges from 40 μm to 150 μm.

10. The cylindrical battery according to claim 9, characterized in that, The protective layer comprises a layer of adhesive and a layer of substrate stacked together, and the thickness of the protective layer is less than or equal to 90 μm; or, the protective layer comprises multiple layers of adhesive and multiple layers of substrate, wherein the adhesive and the substrate are stacked alternately, and the thickness of the protective layer is greater than 90 μm.

11. The cylindrical battery according to any one of claims 1 to 9, characterized in that, The first coating is annular and its outer periphery is connected to the second coating.

12. A battery pack, characterized in that, The cylindrical battery comprising any one of claims 1 to 11, wherein the cylindrical battery is placed within a groove in a bracket. Wherein, one edge of the protective layer is adjacent to the second coating, and at least the edge of the coating and the protective layer is located within the groove.

13. An electronic device, characterized in that, Includes the battery pack as described in claim 12.

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