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 shell and an electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly is of a winding structure formed by winding in the winding direction, the electrode assembly comprises a first pole piece, a second pole piece and a diaphragm arranged between the first pole piece and the second pole piece, the first pole piece and the second pole piece are opposite in polarity; wherein the first pole piece is led out from one end face of the electrode assembly to form a heat dissipation end portion, the heat dissipation end portion is in insulation contact with the shell, a first electric connection portion is arranged on the winding layer, located on the outermost layer, of the electrode assembly, and the first electric connection portion is electrically connected with the shell. According to the battery, the overcurrent function of the first pole piece at one end of the winding structure along the winding axis is cancelled, and the heat dissipation end part is in insulated contact with the shell, so that the heat dissipation end part of the first pole piece can be in contact with the shell for heat dissipation, heat generated by the inner layer, the middle layer and the outer layer of the pole piece can be timely discharged, and the heat transmission efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery and an electrical device. Background Technology

[0002] In related technologies, cylindrical battery cells are made by winding more than 70 layers of positive and negative electrode sheets and a separator, and then welding the cell, positive and negative current collectors, and the casing to form a current loop. However, during charging and discharging, a large amount of heat is generated between the electrodes due to the existence of contact resistance, ion diffusion resistance, and electron transport resistance. In related technologies, dense tab layers are formed at both ends of the cell and welded to the positive and negative current collectors. These tabs act as heat sources during charging and discharging, causing the temperature to be high. The heat between the middle and inner electrode layers is difficult to transfer to the casing along the foil-structure; it can only be conducted to the outer surface of the cell through interlayer heat conduction and then radiated to the casing, resulting in low heat transfer efficiency. Therefore, cylindrical batteries often have the risk of overheating during high-rate charging and discharging. How to solve the heat dissipation problem of cylindrical batteries is a technical problem that urgently needs to be solved in the battery industry. Utility Model Content

[0003] The purpose of this application is to provide a battery and an electrical device to solve the technical problem of poor heat dissipation performance of cylindrical batteries in the prior art.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, this application provides a battery, including: a casing and an electrode assembly, the electrode assembly being disposed within the casing, the electrode assembly being a wound structure wound along a winding direction, the electrode assembly including a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, the first electrode and the second electrode having opposite polarities; wherein, the first electrode extends from one end face of the electrode assembly to form a heat dissipation end, the heat dissipation end being in insulating contact with the casing, and a first electrical connection portion is provided on the outermost wound layer of the electrode assembly, the first electrical connection portion being electrically connected to the casing.

[0006] In one or more embodiments of this application, the first electrode includes a first current collector and an insulating and thermally conductive layer disposed on at least one side of the first current collector along the thickness direction, wherein the insulating and thermally conductive layer is disposed on the edge of the first current collector along the width direction, and the length of the insulating and thermally conductive layer is consistent with the length of the first current collector, and the side of the first electrode with the insulating and thermally conductive layer extends from one end face of the electrode assembly to form a heat dissipation end.

[0007] In one or more embodiments of this application, along the direction perpendicular to the winding axis of the winding structure, there is a gap between the insulating and heat-conducting layers of two adjacent first electrode sheets in the heat dissipation end.

[0008] In one or more embodiments of this application, the first electrode further includes a first active material layer disposed on at least one side of the first current collector along the thickness direction, the first active material layer and the insulating and thermally conductive layer being spaced apart along the width direction of the first current collector, wherein the sum of the thicknesses of the insulating and thermally conductive layer and the first current collector is less than the sum of the thicknesses of the first active material layer and the first current collector.

[0009] In one or more embodiments of this application, the length of the first active material layer is less than the length of the first current collector, so as to form an empty foil region on at least one side of the first current collector along the thickness direction. The empty foil region includes a first region and a second region. The second region is located between the insulating and thermally conductive layer and the first active material layer. The first region is located on one side of the length direction of the first active material layer. The thickness of the first current collector in the empty foil region is greater than the thickness of the first current collector in the first active material layer region. The thickness of the first current collector in the empty foil region is consistent with the thickness in the insulating and thermally conductive layer region.

[0010] In one or more embodiments of this application, a first electrical connection portion is disposed in a first region near the edge of the first electrode sheet along its length direction. The first electrical connection portion has a groove structure that protrudes in the direction of the outer shell, and the groove structure is welded to the outer shell.

[0011] In one or more embodiments of this application, the length of the first region is at least such that the first region forms the outermost winding layer of the winding structure.

[0012] In one or more embodiments of this application, after the electrode assembly is placed inside the housing, the gap between the winding structure and the housing is configured such that when the battery is fully charged, the outermost winding layer of the winding structure is in contact with the inner wall of the housing.

[0013] In one or more embodiments of this application, along the length direction of the insulating and thermally conductive layer, the first electrode sheet has at least one through hole in the region of the insulating and thermally conductive layer, the through hole penetrating both sides of the first electrode sheet in the thickness direction; and / or,

[0014] Along the length of the insulating and heat-conducting layer, the first electrode has at least one notch in the region of the insulating and heat-conducting layer.

[0015] Secondly, this application also provides an electrical device including the battery described in any of the first aspects.

[0016] Based on the above technical solution, the battery and power-consuming device provided in this application embodiment have at least the following beneficial effects:

[0017] The battery in this embodiment forms a heat dissipation end by extending the first electrode from one end face of the electrode assembly. Specifically, the first electrode forms a heat dissipation end along the winding direction at one end of the winding structure along the winding axis. This eliminates the current-carrying function of the first electrode at one end of the winding structure along the winding axis. The heat dissipation end is insulated from the outer casing, allowing for heat dissipation through contact between the heat dissipation end of the first electrode and the outer casing. Since the heat dissipation end is the end structure of the first electrode in the winding structure, it can conduct heat with all layers within the winding structure. This facilitates heat conduction from the inner, middle, and outer layers of the winding structure to the heat dissipation end, and then from the heat dissipation end to the outer casing. This effectively dissipates the heat generated in the inner, middle, and outer layers of the electrode, improving heat transfer efficiency and solving the technical problem of poor heat dissipation performance in cylindrical batteries. Simultaneously, the first electrical connection portion is located on the outermost winding layer of the winding structure, enabling electrical connection with the outer casing to achieve the current-carrying function. This eliminates the current collector connected to the first electrode in the prior art, reducing structural components and lowering manufacturing costs.

[0018] The electrical device provided in this application includes the battery described in any of the first aspects. This can improve the heat dissipation efficiency of the electrical device, thereby increasing its service life and safety. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the longitudinal cross-sectional structure of a battery provided in one or more embodiments of this application.

[0021] Figure 2 This is a schematic diagram of the longitudinal cross-sectional structure of the housing provided in one or more embodiments of this application.

[0022] Figure 3 This is a schematic diagram of the structure of the cover plate provided in one or more embodiments of this application.

[0023] Figure 4 This is a schematic diagram of the structure of the collector disk provided in one or more embodiments of this application.

[0024] Figure 5 This is a schematic diagram of the winding structure provided in one or more embodiments of this application.

[0025] Figure 6 This is a schematic diagram of the structure of the second electrical connection portion provided in one or more embodiments of this application.

[0026] Figure 7 This is a schematic diagram of the structure of the first electrode provided in one or more embodiments of this application.

[0027] Figure 8 This is a schematic diagram showing the state of contact between the heat dissipation end of the winding structure provided in one or more embodiments of this application and the cover plate.

[0028] Figure 9 This is a schematic diagram showing the state in which the heat dissipation end of the first electrode provided in one or more embodiments of this application is in contact with the cover plate.

[0029] Figure 10 This is a schematic diagram of the structure of the second electrode provided in one or more embodiments of this application.

[0030] In the picture:

[0031] 1-Second electrode; 2-First electrode; 3-Electrode assembly; 4-Cover plate; 5-Outer shell; 6-Current collector; 7-Insulating adhesive; 8-Diaphragm; 10-Second current collector; 11-Blank area; 12-Second active material layer; 20-First current collector; 21-Insulating and thermally conductive layer; 22-First active material layer; 23-First electrical connection; 24-Empty foil area; 31-Heat dissipation end; 32-Second electrical connection; 33-Finishing adhesive; 41-Cover plate body; 42-Injection hole; 50-Opening; 51-Outer shell body; 52-Electrode terminal; 53-Insulating sealing ring; 61-Terminal welding area; 62-Electrode tab welding area; 212-Through hole; 213-Notch; 241-First area; 242-Second area. Detailed Implementation

[0032] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0033] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0034] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0036] In related technologies, the cylindrical battery cell is formed by sequentially stacking and winding a separator, a negative electrode, another separator, and a positive electrode. Each electrode has a tab area at the edge of the active material region. By flattening or kneading this tab area, a dense tab layer is formed at both ends of the cell. The tab layer is then connected to the positive and negative current collectors and the outer casing through welding or other methods. To dissipate heat from the inside of the cylindrical battery in a timely manner, a heat pipe is built into the center hole of the cell. The pipe is made of thermally conductive materials such as copper or graphite. The heat pipe abuts against the cover plate of the outer casing, allowing heat from the center hole to be transferred to the cover plate along the heat pipe. Inside the cell, there is a certain gap between the cell's periphery and the outer casing. Heat exchange between the cell's periphery and the outer casing can only be achieved through thermal radiation, resulting in low heat transfer efficiency. In existing technologies, a thermally conductive ring is placed on the outer surface between the cell and the outer casing. This ring is composed of thermally conductive materials such as graphene and is sandwiched between the outer side of the cell and the outer casing to increase the heat dissipation efficiency of the cell's outer surface. However, the above-mentioned configuration can only dissipate heat from the central hole and the outer surface of the cell. The heat transfer efficiency of the internal electrodes is low, which may still lead to overheating risks during high-rate charging and discharging of cylindrical batteries. Furthermore, the above methods require additional structural components, increasing manufacturing costs. Moreover, the method of using a heat-conducting ring on the outside of the cell may further reduce the diameter of the cells that can be assembled, thus reducing battery capacity.

[0037] Based on the above considerations, in order to solve the technical problem of poor heat dissipation performance of cylindrical batteries in the prior art, this application provides a battery, including: a shell and an electrode assembly, the electrode assembly being disposed inside the shell, the electrode assembly being a wound structure wound along a winding direction, the electrode assembly including a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, the first electrode and the second electrode having opposite polarities; wherein, the first electrode is led out from one end face of the electrode assembly to form a heat dissipation end, the heat dissipation end being in insulating contact with the shell, and a first electrical connection portion is provided on the outermost wound layer of the electrode assembly, the first electrical connection portion being electrically connected to the shell.

[0038] In the technical solution of this application embodiment, by extending the first electrode of the electrode assembly from one end face of the electrode assembly to form a heat dissipation end, i.e., the first electrode forms a heat dissipation end at one end of the winding structure along the winding axis along the winding direction, the overcurrent function of the first electrode at one end of the winding structure along the winding axis is eliminated. The heat dissipation end is insulated from the outer shell, and thus the heat dissipation end of the first electrode can contact the outer shell for heat dissipation. Since the heat dissipation end is the end structure of the first electrode in the winding structure, it can conduct heat with all the winding layers inside the winding structure, which is beneficial to conduct heat from the inner, middle and outer layers of the winding structure to the heat dissipation end, and then conduct heat from the heat dissipation end to the outer shell, thereby timely dissipating the heat generated in the inner, middle and outer layers, improving the heat transfer efficiency, and thus solving the technical problem of poor heat dissipation performance of cylindrical batteries. At the same time, the first electrical connection part is set on the outermost winding layer of the winding structure, so that it is electrically connected to the outer shell to realize the overcurrent function, eliminating the current collector connected to the first electrode in the prior art, reducing structural components and reducing manufacturing costs.

[0039] The technical solutions of the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0040] Please refer to Figure 1 and Figure 5 This application provides a battery including: a housing 5 and an electrode assembly 3; the electrode assembly 3 is disposed inside the housing 5, and the electrode assembly 3 is a wound structure formed by stacking a separator 8, a first electrode 2, a separator 8 and a second electrode 1 and then winding them along the winding direction r, wherein the first electrode 2 and the second electrode 1 have opposite polarities, and the first electrode 2 extends from one end face of the electrode assembly 3 to form a heat dissipation end 31, that is, the first electrode 2 forms a heat dissipation end 31 at one end of the winding structure along the winding axis a along the winding direction r, and the heat dissipation end 31 is in insulating contact with the housing 5, and a first electrical connection part 23 is provided on the outermost winding layer of the winding structure, and the first electrical connection part 23 is electrically connected to the housing 5.

[0041] It should be noted that the outer casing 5 is a structural component used to house the electrode assembly 3. The outer casing 5 can be made of steel or aluminum. In some embodiments, the outer casing 5 can match the shape of the electrode assembly 3, for example, it can be a cylindrical structure. The electrode assembly 3 is disposed inside the outer casing 5. The electrode assembly 3 is a wound structure formed by stacking the diaphragm 8, the first electrode 2, the diaphragm 8, and the second electrode 1 and then winding them along the winding direction r. The electrode assembly 3 can be a cylindrical structure. The heat dissipation end 31 is insulated from the outer casing 5, meaning that no current flows between the heat dissipation end 31 and the outer casing 5, allowing for contact heat dissipation.

[0042] In some embodiments, the first electrode 2 may form the outermost winding layer of the winding structure.

[0043] In the technical solution of this application embodiment, by extending the first electrode 2 from one end face of the electrode assembly 3 to form a heat dissipation end 31, that is, by extending the first electrode 2 along the winding direction r to form a heat dissipation end 31 at one end of the winding structure along the winding axis a, the heat dissipation end 31 is insulated from the outer shell 5, thus eliminating the overcurrent function of the first electrode 2 at one end of the winding structure along the winding axis a. As a result, the heat dissipation end 31 of the first electrode 2 can contact the outer shell 5 for heat dissipation. Since the heat dissipation end 31 is the end structure of the first electrode 2 in the winding structure, it can conduct heat with all the winding layers inside the winding structure. This facilitates the heat conduction of the inner, middle and outer layers of the winding structure to the heat dissipation end, and then from the heat dissipation end to the outer shell. This allows the heat generated by the inner, middle and outer layers of the electrode to be discharged in a timely manner, improving the heat transfer efficiency and thus solving the technical problem of poor heat dissipation performance of cylindrical batteries. Meanwhile, the first electrical connection part 23 is disposed on the outermost winding layer of the winding structure, so that it is electrically connected to the outer casing 5 to realize the overcurrent function. This eliminates the current collector connected to the first electrode 2 in the prior art, reduces structural components, and lowers manufacturing costs. In addition, since the heat dissipation end 31 is disposed at one end of the winding structure along the winding axis a, the diameter of the winding structure is not compressed, and the battery capacity is not affected.

[0044] In some embodiments, please refer to Figure 2 and Figure 3The outer casing 5 includes a casing body 51 and a cover plate 4, with the cover plate 4 closing onto the opening of the casing body 51. In some embodiments, the casing body 51 has an opening 50 at one end along a first direction X and is closed at the other end along the first direction X. The casing body 51 has a receiving cavity for accommodating the electrode assembly 3. The cover plate 4 closes onto the opening 50 to isolate the electrode assembly 3 from the outside environment, and the heat dissipation end 31 is in insulating contact with the cover plate 4. Of course, in other embodiments, the heat dissipation end 31 may also be in insulating contact with the closed end. In other embodiments, the casing body 51 has openings 50 at both ends along the first direction X, and the cover plate 4 closes onto the openings 50 at both ends. The heat dissipation end 31 is in insulating contact with one of the cover plates 4 for heat dissipation. The first direction X may be the height direction of the casing 5.

[0045] In some embodiments, please refer to Figure 3 The cover plate 4 includes a cover plate body 41 and an injection hole 42 located on the cover plate body 41. The heat dissipation end 31 can contact the cover plate body 41, and the injection hole 42 is used to inject electrolyte into the housing 5. After the electrolyte injection is completed, it is sealed by a sealing pin.

[0046] In some embodiments, the first electrode 2 can be a negative electrode.

[0047] In some embodiments, please refer to Figure 7 and Figure 8 The first electrode 2 includes a first current collector 20 and an insulating and heat-conducting layer 21 disposed on at least one side of the first current collector 20 along the thickness direction. The insulating and heat-conducting layer 21 is disposed on the edge of the first current collector 20 along the width direction, and the length of the insulating and heat-conducting layer 21 is consistent with the length of the first current collector 20. The heat dissipation end 31 is configured to be wound from the side of the first electrode 2 where the insulating and heat-conducting layer 21 is disposed.

[0048] It should be noted that the first current collector 20 can be copper foil. The insulating and thermally conductive layer 21 is a structural component that can insulate the first current collector 20 from the outer casing 5 to prevent overcurrent and can conduct heat. The insulating and thermally conductive layer 21 can be coated on one side of the first current collector 20 along the thickness direction, or it can be coated on both sides of the first current collector 20 along the thickness direction. In some embodiments, the material of the insulating and thermally conductive layer 21 can be selected from alumina, silicon oxide, and boehmite. In some embodiments, the double-sided thickness of the insulating and thermally conductive layer 21 is 40-60 μm, for example, the double-sided thickness can be 40 μm, 50 μm, or 60 μm. In some embodiments, the width of the insulating and thermally conductive layer 21 is 1-3 mm, for example, the width can be 1 mm, 2 mm, or 3 mm. In other possible implementations, the insulating and thermally conductive layer 21 can also be attached to the first current collector 20 by means of adhesion, or the insulating and thermally conductive layer 21 can be provided on the outer casing 5 instead of the first current collector 20, which can also achieve the effect of insulating contact between the heat dissipation end 31 and the outer casing 5.

[0049] In the technical solution of this application embodiment, an insulating and heat-conducting layer 21 is provided on at least one side of the first current collector 20 of the first electrode 2 along the thickness direction, and then a heat dissipation end 31 is formed by winding the side of the first electrode 2 with the insulating and heat-conducting layer 21. The insulating and heat-conducting layer 21 can prevent overcurrent in the heat dissipation end 31, so that the first electrode 2 will not generate heat at the heat dissipation end 31. At the same time, the heat generated by the inner layer, middle layer and outer layer of the wound structure can be discharged in time by using the heat dissipation end 31 formed by the insulating and heat-conducting layer 21, thereby improving the heat transfer efficiency.

[0050] In some embodiments, please refer to Figure 8 or Figure 9 Along the direction perpendicular to the winding axis a of the winding structure, there is a gap between the insulating and heat-conducting layers 21 of two adjacent first electrode plates 2 in the heat dissipation end 31.

[0051] It should be noted that the gap between the insulating and heat-conducting layers 21 of two adjacent first electrode plates 2 in the heat dissipation end 31 can be understood as the heat dissipation end 31 and the outer shell 5 or the cover plate 4 of the outer shell 5 being not densely arranged, so that the gap between the adjacent insulating and heat-conducting layers 21 in the heat dissipation end 31 can serve as a heat dissipation channel, which is beneficial to dissipating the heat inside the electrode plate.

[0052] In some embodiments, please refer to Figure 7 The first electrode 2 further includes a first active material layer 22 disposed on at least one side of the first current collector 20 along the thickness direction. The first active material layer 22 and the insulating and thermally conductive layer 21 are spaced apart along the width direction of the first current collector 20. The sum of the thicknesses of the insulating and thermally conductive layer 21 and the first current collector 20 is less than the sum of the thicknesses of the first active material layer 22 and the first current collector 20.

[0053] It should be noted that, in some embodiments, the first active material layer 22 may be a negative electrode active material. The sum of the thicknesses of the first active material layer 22 and the first current collector 20 can be understood as the sum of the thicknesses of the first active material layer 22 and the first current collector 20 after roll forming. In some embodiments, the sum of the thicknesses of the insulating and thermally conductive layer 21 and the first current collector 20 is 5 to 10 μm smaller than the sum of the thicknesses of the first active material layer 22 and the first current collector 20 after roll forming, for example, it can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm smaller.

[0054] In the technical solution of this application embodiment, by making the sum of the thicknesses of the insulating heat-conducting layer 21 and the first current collector 20 less than the sum of the thicknesses of the first active material layer 22 and the first current collector 20, it is not easy for the insulating heat-conducting layer 21 to be stretched due to pressure when the first active material layer 22 is rolled during the manufacturing process. At the same time, it can further increase the gap between adjacent insulating heat-conducting layers 21 after winding, which is conducive to the timely discharge of heat inside the electrode.

[0055] In some embodiments, the length of the first active material layer 22 is less than the length of the first current collector 20, forming an empty foil region 24 on at least one side of the first current collector 20 along its thickness direction. The empty foil region 24 includes a first region 241 and a second region 242. The second region 242 is located between the insulating and thermally conductive layer 21 and the first active material layer 22, and the first region 241 is located on one side along the length direction of the first active material layer 22. The thickness of the first current collector 20 in the empty foil region 24 is greater than the thickness of the first current collector 20 in the first active material layer 22, and the thickness of the first current collector 20 in the empty foil region 24 is the same as the thickness in the region of the insulating and thermally conductive layer 21. In some embodiments, the width of the second region 242 and the width of the first current collector 20 in the insulating and thermally conductive layer 21 exceeds the width of the first active material layer 22 by 3 to 3.5 mm, for example, by 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, or 3.5 mm.

[0056] It should be noted that, in some embodiments, along the length direction of the first current collector 20, the first active material layer 22 extends from one side of the first current collector 20 to the other side, and the tail end of the first active material layer 22 is spaced apart from the tail end of the first current collector 20 by a certain distance. This forms a void foil region 24 at the tail end of the first active material layer 22 and in the gap region between the first active material layer 22 and the insulating and thermally conductive layer 21.

[0057] In the technical solution of this application embodiment, through the above-described configuration, the first region 241 of the empty foil region 24 can serve as the outermost layer of the winding structure, increasing the heat dissipation capacity of the outer layer of the winding structure without the need for additional structural components. The second region of the empty foil region 24 can isolate the first active material layer 22 and the insulating and thermally conductive layer 21, so that during charging and discharging, the active material in the first active material layer 22 can affect the insulating and thermally conductive layer 21, thus affecting its insulation and thermal conductivity. Furthermore, by making the thickness of the first current collector 20 in the empty foil region 24 greater than the thickness of the first current collector 20 in the first active material layer 22 region, and ensuring that the thickness of the first current collector 20 in the empty foil region 24 is consistent with the thickness in the insulating and thermally conductive layer 21 region, the contact area between the first current collector 20 and the outer casing 5 or the cover plate 4 of the outer casing 5 can be increased, thereby increasing heat dissipation and promptly dissipating the heat from the inner, middle, and outer layers of the electrode, thus improving the heat dissipation effect.

[0058] In some embodiments, please refer to Figure 7 The first electrical connection part 23 is located in the first region 241 near the edge of the first electrode 2 along its length. The first electrical connection part 23 has a groove structure that protrudes towards the outer shell 5, and the groove structure is welded to the outer shell 5.

[0059] It should be noted that the first electrical connection portion 23 can be the electrical lead-out terminal of the first electrode 2. In some embodiments, the depth of the protrusion groove of the first electrical connection portion 23 ensures that the first electrical connection portion 23 can contact the shell wall of the outer shell body 51 after the winding structure is inserted into the shell. In some embodiments, the first electrical connection portion 23 can be the negative terminal. In some embodiments, the width of the first electrical connection portion 23 of the protrusion structure can be 3 to 5 mm, for example, 3 mm, 4 mm or 5 mm. The groove depth of the first electrical connection portion 23 of the protrusion structure is 0.6 to 1.0 mm, for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm. The first electrical connection portion 23 can be formed by stamping a recess on the surface of the first region 241.

[0060] In the technical solution of this application embodiment, by setting the first electrical connection part 23 as a protruding groove structure facing the outer shell 5, after the winding structure is inserted into the shell, the protruding groove structure abuts against the inner side of the outer shell body 51, which facilitates subsequent welding with the shell wall. However, without the protruding groove, the outer ring of the winding structure cannot stably contact the shell wall due to the group margin design, and the high temperature of the penetration weld can easily burn through the outer diaphragm 8 during subsequent welding. With the first electrical connection part 23 of the groove structure in this application, an air wall can be provided in the recess facing away from the outer shell 5 to prevent heat conduction during welding. Therefore, the situation of the high temperature of the penetration weld burning through the outer diaphragm will not occur. In some embodiments, the inner side of the recess of the first electrical connection portion 23 facing away from the outer casing 5 may be filled with a heat insulation material. The thickness of the heat insulation material may be between 0.2 and 0.8 mm, for example, it may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm. The heat insulation material may be selected from polyurethane, asbestos and rock wool, thereby further reducing the impact of penetration welding on the outer membrane.

[0061] Unlike existing technologies that bond the copper foil (i.e., the negative electrode current collector) to the casing wall with conductive adhesive, this method has several drawbacks: First, conductive adhesive particles may migrate to the center of the electrode during electrolyte circulation, potentially causing tip discharge and rupture of the separator. Second, the current-carrying area is unstable, leading to differences in polarization within the same batch of cells. Third, the adhesive is prone to detachment under prolonged alkaline and high-temperature environments. In this embodiment, the first electrical connection portion 23 is welded to the casing 5, preventing separator rupture and ensuring a stable current-carrying area, thus improving battery lifespan.

[0062] In some embodiments, please refer to Figure 5 The length of the first region 241 is such that the first region 241 forms the outermost winding layer of the winding structure. In some embodiments, the tail end of the first region 241 is bonded with a finishing adhesive 33 to maintain the winding structure of the electrode assembly 3.

[0063] It should be noted that the outermost layer of the winding structure is entirely wrapped by the first region 241. This makes the outermost layer of the winding structure a heat dissipation structure, which facilitates the conduction of heat generated inside the electrode from the insulating heat-conducting layer 21 at the end to the outer shell 5 or the cover plate 4. At the same time, the heat generated outside the electrode can be directly radiated to the outer shell 5 through the foil of the first region 241, reducing the number of structural components and improving the heat transfer efficiency.

[0064] In some embodiments, please refer to Figure 1 After the electrode assembly 3 is placed inside the housing 5, the gap between the winding structure and the housing 5 is configured such that when the battery is fully charged, the outermost winding layer of the winding structure is in contact with the inner wall of the housing 5.

[0065] In the technical solution of this application embodiment, through the above settings, the outermost winding layer of the sleeve structure, namely the first region 241, can directly contact the inner wall of the outer casing 5 for heat dissipation when fully charged, thereby improving the heat dissipation efficiency during battery charging and discharging.

[0066] In some embodiments, please refer to Figure 1 and Figure 5 Along the length of the insulating and heat-conducting layer 21, the first electrode 2 has at least one through hole 212 in the region of the insulating and heat-conducting layer 21, and the through hole 212 extends through both sides of the first electrode 2 in the thickness direction. In some embodiments, the diameter of the through hole 212 can be 1 to 3 mm, for example, 1 mm, 2 mm or 3 mm.

[0067] In the technical solution of this application embodiment, by providing at least one through hole 212 in the region of the insulating and thermally conductive layer 21, with adjacent through holes 212 spaced apart, the through holes 212 allow the electrolyte to flow on both sides of the first electrode 2. The flow of the electrolyte can promote heat dissipation to a certain extent. In addition, during charging, the electrode expands and discharges the high-temperature electrolyte, while during discharging, the gaps between the insulating and thermally conductive layers 21 and the through holes 212 allow the low-temperature electrolyte to be drawn back for cooling. This further improves the heat dissipation effect.

[0068] In some embodiments, please refer to Figure 5 Along the length of the insulating and heat-conducting layer 21, the first electrode 2 has at least one notch 213 in the region of the insulating and heat-conducting layer 21.

[0069] It should be noted that in some embodiments, the interval between two adjacent notches 213 is set. The interval between two adjacent notches 213 is 3 to 10 mm, for example, the interval can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm. The height of the notch 213 can be 0.5 to 1 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm.

[0070] In the technical solution of this application embodiment, at least one notch 213 is provided in the region of the insulating and heat-conducting layer 21 of the first electrode 2 to facilitate the pre-forming of the heat dissipation end 31. This prevents the heat dissipation end 31 from forming a dense structure, increases the gap between the insulating and heat-conducting layers 21, increases the heat dissipation channels, and improves the heat dissipation effect.

[0071] In some embodiments, refer to Figure 8 or Figure 9The heat dissipation end 31 is bent and inclined towards the outside of the electrode assembly 3, and is in insulating contact with the outer shell 5. During assembly, the cover plate 4 or the outer shell 5 applies a certain downward pressure to the heat dissipation end 31, causing it to tilt towards the outside of the electrode assembly 3, so that the insulating thermally conductive layer 21 can abut against the cover plate 4 or the outer shell 5. However, it can be understood that the downward pressure applied to the heat dissipation end 31 by the cover plate 4 or the outer shell 5 does not cause the heat dissipation end 31 to form a dense structure; the gaps between the heat dissipation ends 31 serve as heat dissipation channels, which is beneficial for heat dissipation.

[0072] In some embodiments, please refer to Figure 2 and Figure 6 The housing 5 also includes an electrode terminal 52, which is located at the end of the housing body 51 away from the opening 50. The electrode terminal 52 is insulated from the housing body 51 by an insulating sealing ring 53.

[0073] In some embodiments, the second electrode 1 has a second electrical connection portion 32 at the other end of the winding structure along the winding axis a, and a current collector 6 is connected to the side of the second electrical connection portion 32 away from the heat dissipation end 31. The second electrical connection portion 32 is electrically connected to the electrode terminal 52 through the current collector 6.

[0074] In some embodiments, the second electrode 1 can be a positive electrode. The second electrical connection portion 32 can be the positive terminal. The electrode terminal 52 can be the positive terminal post. In some embodiments, please refer to... Figure 8 and Figure 10 The second electrode 1 includes a second current collector 10, a second active material layer 12 located on at least one side of the second current collector 10 along its thickness direction, and a blank area 11. The blank area 11 is disposed on one side of the second current collector 10 in its width direction and is adjacent to the second active material layer 12. The second current collector 10 may be an aluminum foil. In some embodiments, refer to... Figure 10 The blank area 11 is formed by laser die-cutting to create an angled tab. The second electrical connection portion 32 is formed by winding the blank area 11 along the winding axis a. The dense second electrical connection portion 32 is formed by pre-folding and flattening the wound blank area 11, as shown below. Figure 6 As shown.

[0075] In some embodiments, the height of the blank area 11 protruding from the second active material layer 12 can be X + 4 mm, where X is the height of the die-cut tab, preferably between 4 and 6 mm, for example, X = 4 mm, 5 mm, or 6 mm. 4 is the height of the separator 8 extending beyond the second active material layer 12.

[0076] In some embodiments, insulating adhesive 7 is wrapped around the outside of the second electrical connection portion 32 to prevent the second electrical connection portion 32 from contacting the housing 5, thereby insulating the second electrical connection portion 32 from the housing 5. In some embodiments, refer to... Figure 4 The collector plate 6 includes a terminal welding area 61 and an electrode welding area 62. The terminal welding area 61 is protruding to facilitate welding with the electrode terminal 52.

[0077] In some embodiments, please refer to Figure 8 In the battery electrode assembly 3 provided in this application embodiment, a second electrode 1, a first electrode 2, and two separators 8 are spaced apart. Along the winding axis a of the winding structure, the end of the first active material layer 22 of the first electrode 2 is higher than the end of the second active material layer 12 of the second electrode 1. In some embodiments, the end of the first active material layer 22 is 2 mm higher than the end of the second active material layer 12. That is, the width of the first active material layer 22 in the first electrode 2 is 4 mm wider than the width of the second active material layer 12 in the second electrode 1. In some embodiments, along the winding axis a of the winding structure, the end of the separator 8 is higher than the end of the first active material layer 22. In some embodiments, the end of the separator 8 is 2 mm higher than the end of the first active material layer 22. This ensures physical insulation between the first electrode 2 and the second electrode 1.

[0078] In some embodiments, please refer to Figure 9 In the battery of this application embodiment, the contact surface between the heat dissipation end 31 and the outer casing 5 or the cover plate 4 is 1 to 1.5 mm higher than the end of the separator 8.

[0079] In some embodiments, the assembly method may refer to the following:

[0080] During assembly, the second electrical connection portion 32 of the electrode assembly 3 is welded to the tab welding area 62, and the terminal welding area 61 is welded to the electrode terminal 52. The first electrical connection portion 23 protruding from the surface of the winding structure of the electrode assembly 3 directly contacts the inner wall of the outer casing 51, and the electrical connection is completed from the outside of the outer casing 5 through penetration welding. Then, the cover plate 4 is welded to the outer casing 5 to complete the sealing. The cover plate body 41 presses down on the heat dissipation end 31 by 0.2-0.5mm to ensure that the heat dissipation end 31 is in close contact with the cover plate body 41. Due to the slight pressure, a dense end face is not formed. Instead, the insulating and heat-conducting layer 21 of the heat dissipation end 31 bends slightly outward towards the winding structure. When heat is generated in the middle of the electrode, the heat is transferred to the cover plate 4 along the first current collector 20, which can improve the heat dissipation efficiency. Finally, liquid is injected through the injection hole 42, and the sealing nail is welded to complete the overall assembly of the battery.

[0081] On the other hand, this application also provides an electrical device, including the aforementioned battery. The electrical device can be a power source for the electrical device or an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0082] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery, characterized in that, include: Outer shell (5); An electrode assembly (3) is disposed inside the outer casing (5). The electrode assembly (3) is a wound structure wound along the winding direction (r). The electrode assembly (3) includes a first electrode (2), a second electrode (1), and a diaphragm (8) disposed between the first electrode (2) and the second electrode (1). The first electrode (2) and the second electrode (1) have opposite polarities. The first electrode (2) extends from one end face of the electrode assembly (3) to form a heat dissipation end (31). The heat dissipation end (31) is in insulating contact with the outer casing (5). A first electrical connection part (23) is provided on the outermost winding layer of the electrode assembly (3). The first electrical connection part (23) is electrically connected to the outer casing (5).

2. The battery according to claim 1, characterized in that, The first electrode (2) includes a first current collector (20) and an insulating and thermally conductive layer (21) disposed on at least one side of the first current collector (20) along the thickness direction. The insulating and thermally conductive layer (21) is disposed on the edge of the first current collector (20) along the width direction, and the length of the insulating and thermally conductive layer (21) is consistent with the length of the first current collector (20). The side of the first electrode (2) with the insulating and thermally conductive layer (21) extends from one end face of the electrode assembly (3) to form the heat dissipation end (31).

3. The battery according to claim 2, characterized in that, Along the direction perpendicular to the winding axis (a) of the winding structure, there is a gap between the insulating and heat-conducting layers (21) of two adjacent layers of the first electrode (2) in the heat dissipation end (31).

4. The battery according to claim 2 or 3, characterized in that, The first electrode (2) further includes a first active material layer (22) disposed on at least one side of the first current collector (20) along the thickness direction. The first active material layer (22) and the insulating and thermally conductive layer (21) are spaced apart along the width direction of the first current collector (20). The sum of the thicknesses of the insulating and thermally conductive layer (21) and the first current collector (20) is less than the sum of the thicknesses of the first active material layer (22) and the first current collector (20).

5. The battery according to claim 4, characterized in that, The length of the first active material layer (22) is less than the length of the first current collector (20) to form an empty foil region (24) on at least one side of the first current collector (20) along the thickness direction. The empty foil region (24) includes a first region (241) and a second region (242). The second region (242) is located between the insulating and thermally conductive layer (21) and the first active material layer (22). The first region (241) is located on one side of the length direction of the first active material layer (22). The thickness of the first current collector (20) in the empty foil region (24) is greater than the thickness of the first current collector (20) in the first active material layer (22). The thickness of the first current collector (20) in the empty foil region (24) is the same as the thickness in the region of the insulating and thermally conductive layer (21).

6. The battery according to claim 5, characterized in that, The first electrical connection part (23) is located in the first region (241) near the edge of the first electrode (2) along the length direction. The first electrical connection part (23) has a groove structure that protrudes in the direction of the outer shell (5), and the groove structure is welded to the outer shell (5).

7. The battery according to claim 6, characterized in that, The length of the first region (241) is at least such that the first region (241) forms the outermost winding layer of the winding structure.

8. The battery according to claim 7, characterized in that, After the electrode assembly (3) is placed inside the housing (5), the gap between the winding structure and the housing (5) is configured such that when the battery is fully charged, the outermost winding layer of the winding structure is in contact with the inner wall of the housing (5).

9. The battery according to claim 2, characterized in that, Along the length of the insulating and heat-conducting layer (21), the first electrode (2) has at least one through hole (212) in the region of the insulating and heat-conducting layer (21), the through hole (212) penetrating both sides of the first electrode (2) in the thickness direction; and / or, Along the length of the insulating and heat-conducting layer (21), the first electrode (2) has at least one notch (213) in the region of the insulating and heat-conducting layer (21).

10. An electrical appliance, characterized in that, Includes the battery as described in any one of claims 1 to 9.

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