Battery and electric device

Abstract

The utility model provides a battery and a power utilization device, and relates to the technical field of batteries, the battery comprises: a housing assembly, which comprises a housing and a cover plate, one end of the housing along the axial direction is provided with an opening, and the cover plate seals the opening; the electrode assembly is arranged in the inner cavity of the shell, and a tab is arranged at one end, facing the cover plate, of the electrode assembly; a first heat conduction structure and a second heat conduction structure are arranged between the tab and the cover plate, the first heat conduction structure and the second heat conduction structure are arranged at intervals in the radial direction of the cover plate, heat generated on the tab is transferred to the cover plate by the first heat conduction structure and the second heat conduction structure, and the first heat conduction structure and the second heat conduction structure are electrically connected with the tab and the cover plate respectively. According to the battery disclosed by the utility model, at least two heat conduction areas exist between the electrode assembly and the cover plate, so that a heat conduction path is increased, and the heat dissipation efficiency of the battery is favorably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery and an electrical device. Background Art

[0002] With the development of social economy, more and more electrical equipment uses batteries as energy storage and supply devices, such as new energy vehicles, communication base stations, energy storage containers, etc.

[0003] Current battery designs often pursue high energy density and high output power, generating a lot of heat when large current output is applied. Due to the small number of heat dissipation channels between the electrode assembly and the external cooling assembly, heat will be concentrated inside the battery, affecting the safety performance of the battery. Utility Model Content

[0004] In view of the above problems, the utility model provides a battery and an electrical device, wherein two heat conduction areas are provided between the current collecting plate and the cover plate, thereby improving the heat dissipation efficiency of the battery.

[0005] The utility model provides a battery, comprising: a shell assembly, comprising an outer shell and a cover plate, wherein one end of the outer shell along the axial direction is provided with an opening, and the cover plate seals the opening; an electrode assembly, arranged in the inner cavity of the outer shell, and one end of the electrode assembly facing the cover plate is provided with a pole ear; a first heat-conducting structure and a second heat-conducting structure are provided between the pole ear and the cover plate, the first heat-conducting structure and the second heat-conducting structure are arranged at intervals along the radial direction of the cover plate, the first heat-conducting structure and the second heat-conducting structure transfer the heat generated on the pole ear to the cover plate, and the first heat-conducting structure and the second heat-conducting structure are electrically connected to the pole ear and the cover plate respectively.

[0006] In some embodiments, the edge of the cover plate includes an annular boss protruding toward one side of the electrode assembly, the outer diameter of the annular boss is adapted to the inner diameter of the shell, and the annular boss is embedded in the opening.

[0007] In some embodiments, the battery further includes: a current collecting plate, the current collecting plate being disposed at one end of the electrode assembly, the current collecting plate being welded to the cover plate and the electrode tab respectively, and at least two welding points are formed between the current collecting plate and the cover plate, and the two welding points respectively constitute the first heat conducting structure and the second heat conducting structure.

[0008] In some embodiments, the first heat conductive structure is located in a middle region of the collecting plate.

[0009] In some embodiments, the second heat conducting structure is located in a region of the collecting plate corresponding to the annular boss.

[0010] In some embodiments, the collecting plate includes a plate body and a folded edge portion, the outer diameter of the plate body is adapted to the inner diameter of the outer shell, one end of the folded edge portion is connected to the edge of the plate body, at least part of the structure of the folded edge portion extends in a direction parallel to the plate body, and the folded edge portion is welded to the annular boss to form the second heat-conducting structure.

[0011] In some embodiments, the collecting plate includes a first thickened portion and a second thickened portion, the first thickened portion is welded to the cover plate to form the first heat-conducting structure, and the second thickened portion is welded to the cover plate to form the second heat-conducting structure.

[0012] In some embodiments, the material of the first thickened portion is the same as that of the cover plate; and / or the material of the second thickened portion is the same as that of the cover plate.

[0013] In some embodiments, the first heat-conducting structure is arranged in the middle area of ​​the collecting plate, and a portion of the adjacent edge of the collecting plate is bent to form a folded edge portion, and the folded edge portion extends along the axial direction of the cover plate and toward one side of the cover plate. The folded edge portion is embedded between the annular boss and the outer shell, and is welded to the annular boss to form the second heat-conducting structure.

[0014] In some embodiments, the cover plate and the tab are welded to form the first heat-conducting structure and the second heat-conducting structure.

[0015] In some embodiments, the battery is a cylindrical battery.

[0016] In some embodiments, the end of the shell opposite to the cover plate includes a top plate, the battery also includes a pole, the pole is passed through the top plate, the end of the electrode assembly facing the pole includes a positive pole ear, the pole is electrically connected to the positive pole ear, the pole ear at the end of the electrode assembly facing the cover plate is a negative pole ear, and the shell is electrically connected to the negative pole ear.

[0017] The second aspect of the utility model further provides an electrical device, comprising: the battery described in the first aspect of the utility model.

[0018] According to the battery of the utility model, a first heat-conducting structure and a second heat-conducting structure are arranged between the pole ear and the cover plate, so that there are two heat-conducting areas between the collecting plate and the cover plate, so that the heat generated by the electrode assembly can be transferred to the cover plate through the first heat-conducting structure, and can be transferred to the cover plate through the second heat-conducting structure, thereby increasing the heat conduction path and optimizing the temperature field distribution on the cover plate side, which helps to improve the heat dissipation efficiency of the battery and makes the battery heat dissipation method more suitable for system-level thermal management requirements, thereby expanding the application range of the battery, and at least one of the first heat-conducting structure and the second heat-conducting structure can also be used to achieve electrical connection between the pole ear and the cover plate, which is conducive to simplifying the overall structure, making the overall implementation method relatively simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the structure of batteries in some embodiments of the utility model;

[0021] Figure 2 For along Figure 1 The cross-sectional view of the AA section, Figure 2 The second heat-conducting structure is integrally formed on the collecting plate;

[0022] Figure 3 It is a schematic diagram of the structure of batteries in some embodiments of the utility model;

[0023] Figure 4 For along Figure 3 Sectional view of the CC section;

[0024] Figure 5 for Figure 4 The enlarged view of the area D is shown in the middle circle. Figure 5 The second heat conducting structure and the current collecting plate form a composite structure;

[0025] Figure 6 for Figure 3 A schematic diagram of the structure of the current collecting plate in FIG.

[0026] Figure 7 It is a schematic diagram of the structure of batteries in some embodiments of the utility model;

[0027] Figure 8 For along Figure 7 Sectional view of the EE section;

[0028] Fig. 9 for Figure 8 The middle circle shows an enlarged view of site F;

[0029] Fig.10 for Figure 8 A schematic diagram of the structure of the current collecting plate in FIG.

[0030] Fig.11 This is a schematic diagram of the structure of batteries in some embodiments of the utility model. Fig.11 The electrode lugs of the electrode assembly are welded to the cover plate to form a first heat-conducting structure.

[0031] Description of reference numerals:

[0032] 100-battery;

[0033] 1- Shell assembly;

[0034] 11-housing; 12-cover plate; 121-annular boss; 122-blocking cover; 123-first groove; 124-second groove;

[0035] 2-electrode assembly; 21-electrode ear;

[0036] 3-current collecting plate; 301-plate body; 302-folded edge; 303-avoidance gap;

[0037] 31-Current plate body;

[0038] 4-a first heat conducting structure;

[0039] 5- The second heat conducting structure. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0041] With the development of social economy, more and more electrical devices use batteries as energy storage and supply devices. Electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. The embodiments of the present application do not impose special restrictions on the above-mentioned electrical devices.

[0042] The electrical device may include: a device body and a battery. The device body may include a battery compartment, the battery is disposed in the battery compartment and is electrically connected to the device body, for example, a power supply interface may be provided in the battery compartment, and the battery may be connected to the power supply interface.

[0043] In the embodiments of the present application, the battery may be a secondary battery, which refers to a battery cell that can be used continuously by activating the active material by allowing electricity to flow after the battery is discharged. The battery may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application are not limited thereto.

[0044] At present, the collector plate of some battery models is only welded to the cover plate in a single local area (such as the middle area) to make the cover plate charged. This method results in only one heat dissipation path formed by the welding area between the collector plate and the cover plate. At the end of the electrode assembly, the heat can only be transferred to the cover plate through the welding area between the collector plate and the cover plate, and then dissipated to the outside to achieve heat dissipation. The heat dissipation path is long, the heat dissipation efficiency is low, and it is difficult to meet the needs of system-level thermal management.

[0045] In view of this, this embodiment provides a battery 100, referring to Figure 1-Figure 10 The battery 100 includes: a shell assembly 1 and an electrode assembly 2. The shell assembly 1 includes a shell 11 and a cover plate 12. The shell 11 may be cylindrical. An opening is provided at one end of the shell 11 in the axial direction. The cover plate 12 is sealed at the opening. The cover plate 12 may be a negative electrode cover plate 12.

[0046] The electrode assembly 2 may include a positive electrode sheet, a negative electrode sheet and a separator, which are stacked and wound in sequence to form the electrode assembly 2, that is, the electrode assembly 2 is a wound battery cell. The electrode assembly 2 is disposed in the inner cavity of the housing 11, and a pole ear 21 is disposed at one end of the electrode assembly 2.

[0047] The first heat-conducting structure 4 and the second heat-conducting structure 5 are provided between the pole lug 21 and the cover plate 12, and the first heat-conducting structure 4 and the second heat-conducting structure 5 are arranged at intervals along the radial direction of the cover plate 12, and the first heat-conducting structure 4 and the second heat-conducting structure 5 can transfer the heat generated on the pole lug 21 to the cover plate 12. In addition, the first heat-conducting structure 4 and the second heat-conducting structure 5 are electrically connected to the pole lug 21 and the cover plate 12, respectively. In other words, two current paths are formed between the pole lug 21 and the cover plate 12, namely the first heat-conducting structure 4 and the second heat-conducting structure 5. At this time, it is equivalent to that there are two parallel branches between the pole lug 21 and the cover plate 12. Since the parallel resistance is smaller than the series resistance, the total heat generation is reduced when the total current is the same, which can reduce the heat dissipation pressure of the battery 100.

[0048] The first heat-conducting structure 4 and the second heat-conducting structure 5 are structures for realizing electrical connection between the electrode tab 21 and the cover plate 12 , and can be formed by welding, or can also be formed by mechanical connection between metal parts.

[0049] According to the battery 100 of the embodiment of the utility model, a first heat-conducting structure 4 and a second heat-conducting structure 5 are arranged between the pole ear 21 and the cover plate 12, so that there are two heat-conducting areas between the collecting plate 3 and the cover plate 12, so that the heat generated by the electrode assembly 2 can be transferred to the cover plate 12 through the first heat-conducting structure 4, and can also be transferred to the cover plate 12 through the second heat-conducting structure 5, thereby increasing the heat conduction path, optimizing the temperature field distribution on the side of the cover plate 12, and helping to improve the heat dissipation efficiency of the battery 100, so that the heat dissipation method of the battery 100 is more suitable for system-level thermal management requirements, thereby expanding the application scope of the battery 100, and the first heat-conducting structure 4 and the second heat-conducting structure 5 as two current paths between the pole ear 21 and the cover plate 12 are conducive to reducing the total heat generation, thereby reducing the heat dissipation pressure of the battery 100, and the overall implementation method is relatively simple and easy to implement.

[0050] In some embodiments, reference Figure 2 , Figure 5 , Fig. 9, an annular boss 121 is provided at the edge of the cover plate 12 facing the electrode assembly 2, that is, the annular boss 121 protrudes from the inner surface of the cover plate 12, and the annular boss 121 extends along the circumference of the cover plate 12. The annular boss 121 is arranged adjacent to the edge of the cover plate 12. For example, the annular boss 121 can be formed by bending the inner surface and the outer surface of the cover plate 12 toward the inside of the battery 100. In this case, the portion of the outer surface of the cover plate 12 corresponding to the annular boss 121 is formed into a groove-like structure; or, the annular boss 121 can also be formed by only the inner surface of the cover plate 12 protruding toward the inside of the battery 100. In this case, the portion of the outer surface of the cover plate 12 corresponding to the annular boss 121 can be formed into a plane, or a concave-convex structure can be provided as required; the annular boss 121 can be formed into a complete circular ring, or it can include a plurality of boss segments spaced apart along the circumference. The outer diameter of the annular boss 121 is adapted to the inner diameter of the housing 11, and the annular boss 121 is embedded in the opening.

[0051] The cover plate 12 is fixed to the housing 11 by embedding the annular boss 121 into the opening. In some possible embodiments, the annular boss 121 and the housing 11 may be interference fit to improve the connection stability between the cover plate 12 and the housing 11; or, other structural parts may be embedded between the annular boss 121 and the housing 11 to achieve a tight connection between the annular boss 121 and the housing 11 and improve the sealing. Of course, in order to further improve the sealing at the opening and the stability of the connection between the cover plate 12 and the housing 11, the cover plate 12 and the housing 11 may also be welded, such as laser welding.

[0052] A rib is provided radially outwardly of the annular boss 121 , and the rib abuts against the end of the shell 11 to prevent the cover plate 12 from sinking entirely into the inner cavity of the shell 11 . In addition, when the cover plate 12 and the shell 11 are welded, the rib can also provide a welding position.

[0053] In some embodiments, reference Figure 2 , Figure 5 , Fig. 9 The battery 100 may further include a current collecting plate 3, which is disposed at one end of the electrode assembly 2, and is welded to the electrode tab 21 and the cover plate 12, respectively, wherein at least two welding points are formed between the current collecting plate 3 and the cover plate 12, and the two welding points respectively constitute a first heat conducting structure 4 and a second heat conducting structure 5, so that the electrode assembly 2 can conduct current to the cover plate 12 through the current collecting plate 3.

[0054] That is to say, the current collecting plate 3 is connected and conducted with the cover plate 12 through the first heat conducting structure 4 and the second heat conducting structure 5. In this way, the present embodiment utilizes the welding area formed between the current collecting plate 3 and the cover plate 12 for conducting as the heat conducting area, so as to realize multi-path heat dissipation between the current collecting plate 3 and the cover plate 12. The implementation method is relatively simple and easy to implement. Moreover, the first heat conducting structure 4 and the second heat conducting structure 5 help to optimize the temperature field distribution.

[0055] Since the positive electrode side of the electrode assembly 2 is usually connected to the positive electrode current collecting plate, the current collecting plate 3 connected to the cover plate 12 in this embodiment is the negative electrode current collecting plate 3 of the battery 100, and accordingly, the cover plate 12 is the negative electrode cover plate 12.

[0056] In some embodiments, reference Figure 2 , Figure 5 , Fig. 9 , the first heat-conducting structure 4 is located in the middle area of ​​the current collecting plate 3, where the middle area includes the center point of the current collecting plate 3 in the radial direction and the area at a certain distance from the center point in the radial direction, and the distance can be reasonably set according to actual needs. In this way, the middle area of ​​the current collecting plate 3 and the cover plate 12 are welded, so that one of the heat-conducting areas is in the middle area of ​​the current collecting plate 3, which is conducive to the heat around the heat-conducting area being evenly transferred to the heat-conducting area, and transferred to the cover plate 12 through the heat-conducting area, and the heat-conducting area can be prevented from interfering with the explosion-proof valve on the cover plate 12, for example, the explosion-proof valve is constructed so that its thickness is less than the thickness of other parts of the cover plate 12.

[0057] In some embodiments, reference Figure 5 , the second heat-conducting structure 5 is located in the area of ​​the current collecting disk 3 corresponding to the annular boss 121. Since the annular boss 121 itself has a certain thickness in the axial direction, it can fill a part of the gap between the cover plate 12 and the current collecting disk 3, thereby helping to reduce the thickness of the area of ​​the current collecting disk 3 corresponding to the annular boss 121, saving materials and reducing costs. In addition, the annular boss 121 can also be used to apply a certain pressure to the current collecting disk 3 and the electrode assembly 2, so that their position inside the battery 100 is more stable, thereby improving the overall reliability of the battery 100.

[0058] In some embodiments, at least part of the second heat-conducting structure 5 along the radial direction is stacked with the collecting disk 3. For example, the second heat-conducting structure 5 as a whole is located on the upper side of the collecting disk 3, that is, the projection of the second heat-conducting structure 5 in the reference plane is located within the projection of the collecting disk 3 in the reference plane, and the reference plane is perpendicular to the axis of the collecting disk 3; or, a part of the second heat-conducting structure 5 along the radial direction is overlapped on the edge of the collecting disk 3. At this time, the part of the second heat-conducting structure 5 close to the inner side along the radial direction can be recessed along the axial direction to form a sink, and the edge of the collecting disk 3 is in the sink. In this way, the space occupied in the height direction can be reduced. In addition, a part of the second heat-conducting structure 5 is against the edge of the electrode assembly 2, so that the electrode assembly 2 can directly transfer heat to the second heat-conducting structure 5 through the pole ear, further shortening the length of the heat transfer path and improving the heat dissipation efficiency.

[0059] In some embodiments, the current collecting disc 3 may include a disc body 301 and a folded edge portion 302. The outer diameter of the disc body 301 is adapted to the inner diameter of the housing 11. For example, the outer diameter of the disc body 301 may be equal to the inner diameter of the housing 11, or slightly smaller than the inner diameter of the housing 11, so as to facilitate the assembly of the current collecting disc 3. One end of the folded edge portion 302 is connected to the edge of the disc body 301. At least part of the structure of the folded edge portion 302 extends in a direction parallel to the disc body 301. The folded edge portion 302 is welded with the annular boss 121 to form the second heat conducting structure 5. In other words, the folded edge portion 302 may be formed by bending the edge of the current collecting disc 3. After bending, the thickness of the corresponding part of the current collecting disc 3 is increased, which is convenient for contact with the cover plate 12 for heat dissipation and welding. In addition, compared with the separate provision of heat conducting parts, the bending process is simpler and the current collecting disc 3 is easier to assemble.

[0060] For example, the folding portion 302 may include a first section and a second section, wherein the first section extends along the axial direction of the battery 100, or the first section may also extend at an angle, or the first section may be arc-shaped or any other shape, and the second section extends along the radial direction of the battery 100 to facilitate contact and welding with the cover plate 12, and the two ends of the first section are respectively connected to the edge of the disk body 301 and the second section. At this time, the folding portion 302 is roughly L-shaped. By setting the first section, the overall height of the folding portion 302 can be conveniently adjusted to facilitate contact with the cover plate 12. By adjusting the radial width of the second section, the contact area between the folding portion 302 and the cover plate 12 can be adjusted to maximize the heat conduction efficiency.

[0061] Considering that the current collecting disk 3 is a circular structure, wrinkles are easily generated when the portion adjacent to the edge is folded to form the folded edge portion 302, resulting in an uneven surface of the current collecting disk 3, affecting the welding effect with the pole ear 21 and the space occupied by it. In order to avoid wrinkles during the folding process, in this embodiment, a plurality of avoidance notches 303 can be set at the edge of the current collecting disk 3, and the plurality of avoidance notches 303 are arranged at intervals along the circumference of the current collecting disk 3. The avoidance notches 303 can be set at the edge of the current collecting disk 3, for example, by forming the avoidance notches 303 through a stamping process, and then performing a folding process to form the folded edge portion 302. By setting the avoidance notches 303, it is possible to avoid mutual extrusion between different parts of the edge, thereby preventing wrinkles and reducing the difficulty of the process.

[0062] In some embodiments, the side of the annular boss 121 facing away from the electrode assembly 2 includes a first groove 123, and the bottom wall of the first groove 123 is welded to the current collecting plate 3 to form a second heat-conducting structure 5. By setting the first groove 123, when laser penetration welding is adopted, the welding equipment can be extended into the first groove 123 to act on the bottom wall of the first groove 123, and the heat can be quickly transmitted through the bottom wall to the current collecting plate 3, so that the annular boss 121 is welded to the edge of the current collecting plate 3, and the bulge formed at the weld mark portion can be prevented from protruding from the upper surface of the cover plate 12, causing the surface of the cover plate 12 to be uneven, and affecting the contact between the cover plate 12 and the heat dissipation cold plate of the thermal management system.

[0063] In some embodiments, in combination Fig.10 The current collecting plate 3 includes a current collecting plate body 31 and a first thickened portion, and the first thickened portion is welded to the cover plate 12 to form a first heat conducting structure 4. That is to say, the thickness of the first thickened portion can be greater than the thickness of the remaining parts of the current collecting plate 3. By thickening the first thickened portion, when the current collecting plate 3 and the cover plate 12 are connected by laser penetration welding, the current collecting plate 3 can be prevented from being welded through, thereby preventing damage to the electrode assembly 2 and ensuring the welding quality.

[0064] It can be understood that when the collecting plate body 31 and the first thickened portion are made of the same material, the collecting plate body 31 and the first thickened portion can be an integrally formed structure; when the collecting plate body 31 and the second thickened portion are made of different materials, the collecting plate body 31 and the first thickened portion can be a composite integral structure.

[0065] In some embodiments, the material of the first thickened portion is the same as that of the cover plate 12. For example, the first thickened portion can be a generally used cold-rolled carbon steel sheet and strip (SPCC). In this way, the cover plate 12 and the first thickened portion have good conductivity and corrosion resistance. Of course, the utility model is not limited to this. The material of the first thickened portion and the cover plate 12 can also be other metal materials. By making the material of the first thickened portion the same as that of the cover plate 12, the two have the same melting point, and a relatively uniform weld mark can be formed during the cooling process of the molten pool after welding, thereby improving the welding quality. In addition, the requirements for the material of the main body of the collector plate 3 can be reduced, so that the main body of the collector plate 3 can be made of a different metal material from the cover plate 12 to fully improve its current capacity and reduce heat generation.

[0066] It can be understood that when the material of the collecting plate body 31 is different from that of the first thickened portion, for example, when the collecting plate body 31 is made of copper metal, since the first thickened portion is made of steel, the first thickened portion can be compounded to the collecting plate body 31 through a composite process to form a collecting plate 3 of a composite structure, that is, the collecting plate 3 is made of SPCC-Cu composite material, and the first thickened portion serves as one of the welding pads of the collecting plate 3 of the composite structure.

[0067] In some embodiments, the distance from the side surface of the first thickened portion facing the electrode assembly 2 to the outer surface of the cover plate 12 is the same as the distance from the side surface of the second heat-conducting structure 5 facing the electrode assembly 2 to the outer surface of the cover plate 12. In other words, the total thickness of the cover plate 12 and the current collecting plate 3 corresponding to the first thickened portion is the same as the total thickness of the corresponding portion of the second heat-conducting structure 5. In this way, the internal space of the battery 100 can be fully utilized to set the second heat-conducting structure 5, avoiding wasting the internal space of the battery 100 and improving space utilization.

[0068] In some embodiments, in combination Figure 5 , the current collecting plate 3 also includes a second thickened portion, and the second thickened portion is welded to the cover plate 12 to form a second heat-conducting structure 5. In other words, the thickness of the second heat-conducting structure 5 is greater than the thickness of the remaining parts of the current collecting plate 3 except the first heat-conducting structure 4 and the second heat-conducting structure 5. In this way, it is convenient to connect the second thickened portion and the cover plate 12 by laser penetration welding to prevent the current collecting plate 3 from being welded through, thereby avoiding damage to the electrode assembly 2 and improving the assembly yield. In addition, the first heat-conducting structure 4 and the second heat-conducting structure 5 are both connected to the cover plate 12 by welding, which is equivalent to the parallel connection of two branches. Since the total parallel resistance is less than the series resistance, under the condition of the same total current, the total heat generation of the two welding parts is reduced, which can alleviate the heat dissipation pressure.

[0069] It can be understood that when the collecting plate body 31 and the second thickened portion are made of the same material, the collecting plate body 31 and the second thickened portion can be an integrally formed structure; when the collecting plate body 31 and the second thickened portion are made of different materials, the collecting plate body 31 and the second thickened portion can be a composite integral structure.

[0070] In some embodiments, the material of the second thickened portion is the same as that of the cover plate 12. For example, the cover plate 12 and the second thickened portion can be generally used cold-rolled carbon steel sheets and steel strips (SPCC). In this way, the conductivity and corrosion resistance of the cover plate 12 and the second thickened portion are good. Of course, the utility model is not limited to this. The material of the second thickened portion and the cover plate 12 can also be other metal materials. By making the material of the second thickened portion the same as that of the cover plate 12, the melting points of the two are the same, and a relatively uniform weld mark can be formed during the cooling process of the molten pool after welding, thereby improving the welding quality. In addition, the requirements for the material of the main body of the collecting plate 3 can be reduced, so that the main body of the collecting plate 3 can be made of a different metal material from the cover plate 12 to fully improve its current flow capacity and reduce heat generation.

[0071] It can be understood that when the material of the collecting plate body 31 is different from that of the second thickened portion, for example, when the collecting plate body 31 is made of copper metal, since the second thickened portion is made of steel, the second thickened portion can be compounded to the collecting plate body 31 through a composite process to form a collecting plate 3 of a composite structure, that is, the collecting plate 3 is made of SPCC-Cu composite material, and the second thickened portion serves as one of the welding pads of the collecting plate 3 of the composite structure.

[0072] It can be understood that the SPCC layer is not provided in the area of ​​the current collecting plate 3 welded to the electrode tab 21 , so as to facilitate welding of the current collecting plate 3 and the copper electrode tab.

[0073] In some embodiments, when the first heat conducting structure 4 and the second heat conducting structure 5 are both welding areas of the collecting plate 3 and the cover plate 12 , the welding area S1 of the first heat conducting structure 4 and the welding area S2 of the second heat conducting structure 5 satisfy: S1 / S2≤1 / 8.8.

[0074] When the middle and edge of the current collecting disk 3 are welded to the cover plate 12, it is equivalent to that there are two electrical connection points between the electrode assembly 2 and the cover plate 12, wherein the current path one is: the pole ear 21-the middle of the current collecting disk 3-the middle of the cover plate 12-the edge of the cover plate 12; the current path two is the pole ear 21-the edge of the current collecting disk 3-the edge of the cover plate 12, and the two current paths are connected in parallel and finally converge at the edge of the cover plate 12.

[0075] For current path 1, its equivalent resistance is approximately equal to the resistance of the cover plate 12, and for current path 2, its equivalent resistance is approximately equal to the internal resistance of the collector plate 3;

[0076] Resistance of cover plate 12 / resistance of current collecting plate 3=ρcover*Tdisk / ρdisk*Tcover; ρcover and ρdisk are the resistivity of cover plate 12 and current collecting plate 3 respectively; Tdisk and Tcover are the thickness of current collecting plate 3 and cover plate 12 body respectively;

[0077] The main body of the cover plate 12 is steel, and the main body of the current collecting plate 3 is copper; by substituting their corresponding resistivity and thickness, we can get: ρcover*Tplate / ρplate*Tcover≈8.8;

[0078] Then the current ratio through the cover plate 12 and the current collecting plate 3 is: I1 / I2=Rplate / Rcover=1 / 8.8;

[0079] Assume that the welding area between the middle of the cover plate 12 and the current collecting plate 3 is S1, and the welding area between the edge of the cover plate 12 and the current collecting plate 3 is S2; if the current carrying capacity of the two welding points is to be the same, then I1 / S1=I2 / S2; then, S1 / S2=I1 / I2=1 / 8.8;

[0080] Considering the requirement of the battery 100 for heat dissipation efficiency, at the edge of the cover plate 12, due to the large current, the smaller S2 is, the faster the temperature rises; it is necessary to increase the area of ​​S2 to speed up heat dissipation; therefore, S2 should be increased, so under the premise of ensuring overcurrent, S1 / S2 can be less than 1 / 8.8,

[0081] When S1 / S2>1 / 8.8, the edge current capacity is weaker than the middle, and the heat dissipation capacity will also be insufficient.

[0082] In summary, when S1 / S2≤1 / 8.8, the heat dissipation capacity of the battery 100 can be fully guaranteed while ensuring the current-carrying capacity of the collecting plate 3 and the cover plate 12, thereby improving the performance of the battery 100.

[0083] refer to Figure 7-10 In addition to the solution of arranging the second heat-conducting structure 5 and the cover plate 12 in an axially stacked manner in the above-mentioned embodiment, the embodiment of the present application also provides another arrangement form of the second heat-conducting structure 5. Specifically, in the embodiment, the first heat-conducting structure 4 is arranged in the middle area of ​​the collecting plate 3, and the part adjacent to the edge of the collecting plate 3 is bent to form a folded edge portion 302, and the folded edge portion 302 extends along the axial direction of the cover plate 12 and toward one side of the cover plate 12. The folded edge portion 302 is embedded between the annular boss 121 and the outer shell 11, and the folded edge portion 302 is welded with the annular boss 121 to form the second heat-conducting structure 5. In this way, the annular boss 121 and the outer shell 11 can jointly clamp the folded edge portion 302, and heat can be transferred from the second heat-conducting structure 5 to the cover plate 12 and the outer shell 11 respectively, further increasing the heat dissipation path and improving the heat dissipation efficiency. In addition, there is no need to occupy additional height space, the assembly is simple, and the tightness of the fit between the annular boss 121 and the outer shell 11 can also be increased.

[0084] Optionally, the folded edge portion 302 of this embodiment extends along the axial direction of the battery 100, and the folded edge portion 302 can be flush with the end of the shell 11, or can be lower than the end of the shell 11. In this way, the processing method of the folded edge portion 302 is relatively simple, and it is easy to assemble, and the implementation cost is low.

[0085] In some embodiments, in order to facilitate the use of laser penetration welding for welding the cover plate 12 and the current collecting disk 3, a second groove 124 can be set at the position of the cover plate 12 opposite to the first heat-conducting structure 4 (for example, the middle area of ​​the cover plate 12). By setting the second groove 124, the thickness of the cover plate 12 at the welding position is reduced. During welding, the welding equipment can be extended into the second groove 124 and act on the bottom wall of the second groove 124, so that the welding heat can be quickly transferred from the second groove 124 side of the cover plate 12 to the current collecting disk 3, and then the heat reaches the current collecting disk 3, so as to smoothly complete the welding and ensure the welding quality. After the welding is completed, the flatness of the surface of the cover plate 12 is not guaranteed. The shell assembly 1 can also include a blocking cover 122. After the current collecting disk 3 and the cover plate 12 are welded, the blocking cover 122 can be sealed in the second groove 124, and the blocking cover 122 can be flush with the end face of the cover plate 12 or smoothly transition. So that the cover plate 12 is easy to connect with the external circuit, and at the same time, the appearance consistency of the battery 100 is also guaranteed. At this time, the heat transferred to the cover plate 12 through the first heat-conducting structure 4 can have three heat-conducting paths, namely, the sealing cover 122 as one of them, the part of the cover plate 12 adjacent to the first heat-conducting structure 4 as one, and the part of the cover plate 12 in contact with the second heat-conducting structure 5 as another. In this way, the heat dissipation path is further increased and the heat dissipation efficiency is improved.

[0086] refer to Fig.11 In addition to the above-mentioned solution of realizing electrical connection between the pole lug 21 and the cover plate 12 through the current collecting plate 3, the embodiment of the present application also provides another electrical connection method between the pole lug 21 and the cover plate 12. Specifically, in the present embodiment, the pole lug 21 and the cover plate 12 are electrically connected through the first heat conducting structure 4 and the second heat conducting structure 5. In other words, the current collecting plate is not provided in the present embodiment, and the first heat conducting structure 4 and the second heat conducting structure 5 both realize the electrical connection between the pole lug 21 and the cover plate 12 and realize the heat conduction between the pole lug 21 and the cover plate 12. In this way, compared with the solution of providing the current collecting plate 3, it is possible to reduce parts and reduce costs, while saving the internal space of the battery 100, which is conducive to improving the energy density of the battery 100, and can further shorten the heat transfer path, thereby improving the heat dissipation efficiency.

[0087] In some embodiments, reference Fig.11The cover plate 12 and the pole ear 21 are welded to form a first heat-conducting structure 4 and a second heat-conducting structure 5. In this way, the heat transfer path can be further shortened, thereby improving the heat dissipation efficiency, saving the internal space occupied by the collecting plate, and being beneficial to improving the energy density of the battery 100.

[0088] In a specific example, the battery 100 is a cylindrical battery, so the battery 100 has a relatively simple structure and is easy to manufacture.

[0089] Further, the end of the shell 11 opposite to the cover plate 12 may include a top plate, for example, the top wall of the shell 11 constitutes the top plate, and the battery 100 may also include a pole, the pole is penetrated through the top plate, and the end of the electrode assembly 2 facing the pole includes a positive pole ear 21, and the pole is electrically connected to the positive pole ear 21, for example, the positive pole ear 21 and the pole are electrically connected by welding the positive current collector. The pole ear 21 at the end of the electrode assembly 2 facing the cover plate 12 is a negative pole ear 21, and the shell 11 is electrically connected to the negative pole ear 21. In other words, the shell 11 in this embodiment can be negatively charged. In this way, the structure of the battery 100 is relatively simple and easy to manufacture.

[0090] It should also be noted that the electrical device provided in the embodiment of the present application, by setting the battery 100 in the above embodiment, has a high heat dissipation efficiency, which helps to alleviate the overall heat dissipation pressure of the electrical device and is more suitable for system-level thermal management requirements.

[0091] It should be noted that the embodiments represented by "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing specific features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments that are explicitly or not explicitly described.

[0092] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0093] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0094] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized in that: include: The housing assembly comprises a housing and a cover plate, wherein an opening is provided at one end of the housing along the axial direction, and the cover plate seals the opening; An electrode assembly is disposed in the inner cavity of the shell, and an electrode ear is disposed at one end of the electrode assembly facing the cover plate; A first heat-conducting structure and a second heat-conducting structure are provided between the electrode tab and the cover plate. The first heat-conducting structure and the second heat-conducting structure are arranged at intervals along the radial direction of the cover plate. The first heat-conducting structure and the second heat-conducting structure transfer the heat generated on the electrode tab to the cover plate. Furthermore, the first heat-conducting structure and the second heat-conducting structure are electrically connected to the electrode tab and the cover plate respectively.

2. The battery according to claim 1, characterized in that The edge of the cover plate comprises an annular boss protruding toward one side of the electrode assembly, the outer diameter of the annular boss is adapted to the inner diameter of the shell, and the annular boss is embedded in the opening.

3. The battery according to claim 2, characterized in that Also includes: A current collecting plate is arranged at one end of the electrode assembly, and the current collecting plate is welded to the cover plate and the electrode tab respectively, and at least two welding points are formed between the current collecting plate and the cover plate, and the two welding points respectively constitute the first heat-conducting structure and the second heat-conducting structure.

4. The battery according to claim 3, characterized in that The first heat-conducting structure is located in the middle area of ​​the collecting plate.

5. The battery according to claim 4, characterized in that The second heat-conducting structure is located in a region of the collecting plate corresponding to the annular boss.

6. The battery according to claim 3, characterized in that The collecting plate comprises a plate body and a folded edge portion, wherein the outer diameter of the plate body is adapted to the inner diameter of the shell, one end of the folded edge portion is connected to the edge of the plate body, and at least a part of the structure of the folded edge portion extends in a direction parallel to the plate body. The folded edge portion and the annular boss are welded to form the second heat conducting structure.

7. The battery according to any one of claims 3 to 6, characterized in that: The collecting plate includes a first thickened portion and a second thickened portion. The first thickened portion is welded to the cover plate to form the first heat-conducting structure, and the second thickened portion is welded to the cover plate to form the second heat-conducting structure.

8. The battery according to claim 7, characterized in that The material of the first thickened portion is the same as that of the cover plate; and / or the material of the second thickened portion is the same as that of the cover plate.

9. The battery according to claim 3, characterized in that The first heat-conducting structure is arranged in the middle area of ​​the collecting plate, and the part adjacent to the edge of the collecting plate is bent to form a folded edge portion, and the folded edge portion extends along the axial direction of the cover plate and toward one side of the cover plate. The folded edge portion is embedded between the annular boss and the outer shell, and is welded to the annular boss to form the second heat-conducting structure.

10. The battery according to claim 1, characterized in that The cover plate and the tab are welded to form the first heat-conducting structure and the second heat-conducting structure.

11. The battery according to claim 1, characterized in that The battery is a cylindrical battery.

12. The battery according to claim 11, characterized in that The end of the shell opposite to the cover plate includes a top plate, and the battery also includes a pole, which is passed through the top plate. The end of the electrode assembly facing the pole includes a positive pole ear, and the pole is electrically connected to the positive pole ear. The pole ear at the end of the electrode assembly facing the cover plate is a negative pole ear, and the shell is electrically connected to the negative pole ear.

13. An electrical device, characterized in that: include: The battery according to any one of claims 1 to 12.

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