Secondary battery and electronic device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-21
- Publication Date
- 2026-08-13
Smart Images
Figure CN2024083041_13082026_PF_FP_ABST
Abstract
Description
Secondary batteries and electronic devices Technical Field
[0001] This application relates to the field of energy storage technology, and more particularly to a secondary battery and an electronic device having the secondary battery. Background Technology
[0002] Secondary batteries (such as lithium-ion batteries) are widely used in electronic mobile devices, power tools, and electric vehicles. A secondary battery typically includes a casing, an electrode assembly housed within the casing, tabs connected to the electrode assembly, and an adapter connecting the tabs to the casing.
[0003] However, when a secondary battery is subjected to mechanical abuse (such as drops or impacts), the electrode assembly may wobble inside the casing, which may pull on the tabs. If the tabs detach from the adapter, it will reduce the reliability and lifespan of the secondary battery.
[0004] Summary of the Invention
[0005] In view of this, it is necessary to provide a secondary battery and an electronic device having the aforementioned secondary battery.
[0006] This application provides a secondary battery, including a housing, at least one electrode assembly disposed within the housing, and a plurality of first tabs. The electrode assembly includes a first electrode plate. The plurality of first tabs are respectively connected to the first electrode plates and extend out of the first electrode plates along a first direction. The secondary battery also includes a first adapter disposed within the housing. The first adapter includes a first connecting region, an adapter region, a bending region, and a second connecting region connected in sequence. The adapter region includes a first side and a second side disposed adjacent to each other. The first connecting region is connected to the first side and extends from the first side along a second direction perpendicular to the first direction. The bending region is connected to the second side and is bent relative to both the adapter region and the second connecting region. Viewed from the first direction, the adapter region and the second connecting region overlap. The first connecting region is connected to the first tab, and the second connecting region is connected to the housing.
[0007] In this application, the transition area and the second connection area together fill the gap between the housing and the electrode assembly, reducing the shaking of the electrode assembly within the housing when the secondary battery is subjected to mechanical abuse. Furthermore, even if the electrode assembly shakes within the housing and pulls on the first tab, the transition area connected to the bending area provides a large buffer space, reducing the possibility of the first tab detaching from the first transition piece, leading to a decrease in the secondary battery's output voltage or even its inability to continue charging and discharging. Therefore, this application can improve the reliability and lifespan of the secondary battery.
[0008] Based on the first aspect, in some possible implementations, the first tab includes a first segment connecting to the first electrode and a second segment connecting to the first segment, the second segment being bent relative to the first segment. Multiple second segments form a first connecting portion. A first connecting region is connected to the surface of the first connecting portion facing the electrode assembly. Therefore, it is advantageous to reduce the space occupied by the first tab on one side of the electrode assembly in the first direction, thereby increasing the energy density of the secondary battery.
[0009] Based on the first aspect, in some possible implementations, the multiple first tabs are divided into N tab groups, where N is a positive integer. Each tab group includes two tab bundles, in which the first segment extends in a direction away from each other, and the second segment bends and extends in a direction closer to each other. By bending each tab bundle independently, the length required for the second segments to overlap after bending the first tabs is smaller, thereby reducing the overall weight and production cost of the secondary battery.
[0010] Based on the first aspect, in some possible implementations, the number of electrode assemblies is one, and N tab groups are all connected to the first electrode plate of the electrode assembly.
[0011] Based on the first aspect, in some possible implementations, there are multiple electrode assemblies, with N tab groups respectively connected to the first electrode plates of multiple electrode assemblies. By dividing the first tabs of the multiple electrode assemblies into an even number of tab bundles and bending each tab bundle independently, the length required for the second segments to overlap after bending the first tabs is reduced, thereby reducing the overall weight and production cost of the secondary battery. Furthermore, when at least one electrode assembly has a quality problem, the problematic electrode assembly (and other electrode assemblies welded to it) can be removed separately, avoiding the risk of all electrode assemblies being scrapped simultaneously when the first tabs of all electrode assemblies are bent together.
[0012] Based on the first aspect, in some possible implementations, the first connection area includes N first partitions, each first partition being connected to the second segment of the first electrode in a electrode bundle. The N first partitions correspond one-to-one with the N electrode groups, thereby facilitating the connection of the first adapter to each electrode group.
[0013] Based on the first aspect, in some possible implementations, the first connection region further includes a second partition. The second partition connects to two adjacent first partitions and is connected to the first side. The arrangement of the second partition helps to reduce the resistance of the first partition, thereby reducing the internal resistance and improving the charging and discharging efficiency of the secondary battery.
[0014] Based on the first aspect, in some possible implementations, the second segments of the first electrode bundle are stacked and welded together to form a first welding area, thereby improving the connection strength between the second segments. The first connection area is welded to the second segment to form a second welding area, thereby improving the welding strength between the first connection area and the second segment. Viewed from the first direction, the first welding area and the second welding area are separated, thereby reducing the risk of over-welding at the first welding area.
[0015] Based on the first aspect, in some possible implementations, the secondary battery further includes a first adhesive element. The first adhesive element covers and bonds the first welding area and the second welding area. The first adhesive element also extends to the surface of the electrode assembly in a third direction, which is perpendicular to both the first and second directions. The first adhesive element can cover and bond the solder marks of the first and second welding areas, and connect the first tab to the electrode assembly integrally.
[0016] Based on the first aspect, in some possible implementations, there are two first adapters, which are arranged along a third direction that is perpendicular to both the first and second directions. The first partitions and N tab groups of the two first adapters correspond one-to-one, thereby facilitating the connection of the first adapters to each tab group.
[0017] Based on the first aspect, in some possible implementations, the transfer areas of the two first adapters are connected, which can further reduce the shaking of the first adapters within the housing during mechanical abuse.
[0018] Based on the first aspect, in some possible implementations, the second connection areas of the two first adapters are connected, which can further reduce the shaking of the first adapters within the housing during mechanical abuse.
[0019] Based on the first aspect, in some possible implementations, the secondary battery is a prismatic battery. The casing includes a first end wall and a second end wall disposed opposite each other in a first direction, a side wall connecting the first end wall and the second end wall, and a first electrode post disposed on the first end wall. The first electrode post is electrically isolated from the first end wall, and a second connection area is electrically connected to the first electrode post. Therefore, the first electrode post and the second electrode post can respectively exhibit the same polarity as the first electrode and the second electrode, and the first electrode post and the second electrode post can be used to connect external components.
[0020] Based on the first aspect, in some possible implementations, the first electrode post protrudes from the first end wall toward the electrode assembly. The second connection region includes a protruding section connected to the bending region and a straight section connected to the protruding section. The straight section is fixed to the first electrode post, and the protruding section is fixed to the first end wall. Therefore, by fixing the protruding section to the first end wall, the risk of the first adapter wobbling within the housing during mechanical abuse can be further reduced, and the connection reliability between the first electrode post and the straight section can also be improved.
[0021] Based on the first aspect, in some possible implementations, the protruding section is provided with an opening, and the first end wall is provided with a protrusion that passes through the opening. In this way, it is convenient for the first adapter to be fixed to the first end wall, and the protrusion can suppress the first adapter from swaying in the second or third direction within the housing.
[0022] Based on the first aspect, in some possible implementations, the secondary battery further includes a second adhesive element that adheres to the surface of the straight section facing the electrode assembly. The second adhesive element can cover the solder marks between the straight section and the first electrode post, as well as the cutting burrs on the straight section itself, reducing damage to the electrode assembly caused by such solder marks or burrs during mechanical abuse.
[0023] Based on the first aspect, in some possible implementations, the secondary battery further includes a third adhesive element, which adheres to the surface of the transition area facing the second connection area. The third adhesive element can further isolate the solder marks between the straight section and the first electrode post, as well as the cutting burrs of the straight section itself, reducing the damage to the electrode assembly caused by the aforementioned solder marks or burrs during mechanical abuse.
[0024] Based on the first aspect, in some possible implementations, along the second direction, the width of the bending area is W, the width of the transition area is W1, and the width of the second connection area is W2, where W is less than W1 and W2, thereby making the bending area easier to bend.
[0025] Based on the first aspect, in some possible implementations, the electrode assembly is a stacked structure and includes multiple first electrodes, which are stacked along a third direction, perpendicular to both the first and second directions. The stacked structure helps reduce the internal resistance of the secondary battery and improves its high-rate charge / discharge performance.
[0026] Based on the first aspect, in some possible implementations, the electrode assembly is a wound structure, with the central axis of the winding extending along a first direction. The wound structure is beneficial for improving the production efficiency of secondary batteries.
[0027] A second aspect of this application also provides an electronic device, including a battery compartment and a secondary battery as described above. The secondary battery is housed within the battery compartment. The electronic device is powered by the secondary battery, and the reliability and lifespan of the secondary battery are improved. Attached Figure Description
[0028] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0029] Figure 1 is a schematic diagram of the structure of a secondary battery provided in one embodiment of this application in some embodiments.
[0030] Figure 2 is a cross-sectional view of the secondary battery shown in Figure 1 along section line II-II in some embodiments.
[0031] Figure 3 is a cross-sectional view of the secondary battery shown in Figure 1 along section line III-III in some embodiments (separator membrane omitted).
[0032] Figure 4 is a cross-sectional view of the secondary battery shown in Figure 1 along section line IV-IV in some embodiments.
[0033] Figure 5 is a cross-sectional view of the secondary battery shown in Figure 1 along the cutting line VV in some embodiments.
[0034] Figure 6 is a cross-sectional view of the secondary battery shown in Figure 1 along section line II-II in some other embodiments.
[0035] Figure 7A is a schematic diagram of the structure of the second adapter and the second adapter in the deployed state of the secondary battery shown in Figure 3.
[0036] Figure 7B is a schematic diagram of the structure of the first adapter in the secondary battery shown in Figure 3 when viewed along the first direction.
[0037] Figure 7C is a schematic diagram of the structure of the first adapter shown in Figure 7A after it has been welded to the first electrode tab in some embodiments.
[0038] Figure 7D is a schematic diagram of the structure of the first adapter shown in Figure 7A after it has been welded to the first electrode tab in some other embodiments.
[0039] Figure 8 is a cross-sectional view along the cutting line VV of the secondary battery shown in Figure 1 in some other embodiments.
[0040] Figure 9 is a schematic diagram of the structure of the secondary battery shown in Figure 8 when the first adapter is in the unfolded state in some embodiments.
[0041] Figure 10 is a structural schematic diagram of the secondary battery shown in Figure 8 in some embodiments when the first adapter is in the unfolded state.
[0042] Figure 11 is a cross-sectional view of the secondary battery shown in Figure 1 along section line IV-IV in some other embodiments.
[0043] Figure 12 is a schematic diagram of the structure of the secondary battery shown in Figure 11 when the first adapter is in the unfolded state in some embodiments.
[0044] Figure 13 is a cross-sectional view of the secondary battery shown in Figure 1 along section line IV-IV in some other embodiments.
[0045] Figure 14 is a structural schematic diagram of the secondary battery shown in Figure 13 in some embodiments when the first adapter is in the unfolded state.
[0046] Figure 15 is a structural schematic diagram of the secondary battery shown in Figure 13 in some embodiments when the first adapter is in the unfolded state.
[0047] Figure 16 is a cross-sectional view of the secondary battery shown in Figure 1 along section line IV-IV in some embodiments.
[0048] Figure 17 is a cross-sectional view along the cutting line VV of the secondary battery shown in Figure 1 in some other embodiments.
[0049] Figure 18 is a schematic diagram of the structure of an electronic device provided in one embodiment of this application.
[0050] Key Component Symbols Explanation: Electronic Device 1; Housing 10; First End Wall 11; Second End Wall 12; Side Wall 13; First Terminal 14; Second Terminal 15; Electrode Assembly 20; First Electrode 21; Second Electrode 22; Separator 23; First Tab 30; Tab Assembly 30A; Tab Bundle 30B; First Segment 31; Second Segment 32; Second Tab 40; First Adapter 50; First Connection Area 51; Second Connection Area 52; Adapter Area 53; Bending Area 54; Second Adapter 60; First Adhesive 70; Second Adhesive 80; Third Adhesive 90; Secondary Battery 100; Battery Compartment 101; Protrusion 110; First Opening 111; Second Opening 112; First Current Collector 210; First Active Material Layer 211; Second Current Collector 220; Second Active Material Layer 221; First Connecting Part 320; First Section 511; Second Section 512; Protruding Section 521; Straight Section 522; First Side 531; Second Side 532; Opening 5210; First Direction X Second direction Y, Third direction Z, First side Z1, Second side Z2, Accommodation space S, First welding area S1, Second welding areaS2 widths W, W1, W2 winding center axis O
[0051] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation
[0052] The technical solutions in the embodiments of this application are described clearly and in detail below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.
[0053] The embodiments of this application will be described in detail below. However, this application may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to provide a thorough and detailed understanding of this application to those skilled in the art.
[0054] Additionally, for brevity and clarity, the dimensions or thicknesses of various components and layers may be enlarged in the accompanying drawings. Throughout the text, the same numerical values refer to the same elements. As used herein, the terms "and / or" and "and / or" include any and all combinations of one or more of the associated enumerated items. Furthermore, it should be understood that when element A is referred to as "connecting" element B, element A may be directly connected to element B, or there may be an intermediate element C and element A and element B may be indirectly connected to each other.
[0055] Furthermore, when describing the implementation of this application, the word "may" refers to "one or more implementations of this application".
[0056] The technical terms used herein are for the purpose of describing particular embodiments and are not intended to limit this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that the term "comprising," as used in this specification, means the presence of the described features, values, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof.
[0057] Spatial terms, such as "above," may be used herein for convenience in describing the relationship between one element or feature and another element (or feature) or feature (or feature) illustrated in the figures. It should be understood that, in addition to the directions depicted in the figures, spatial terms are intended to include different orientations of the device or apparatus during use or operation. For example, if the device in the figure is flipped, an element described as "above" or "on" other elements or features would be oriented "below" or "under" other elements or features. Therefore, the exemplary term "above" can include both above and below orientations. It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.
[0058] As used in this article, "parallel" and "perpendicular" are used to describe the ideal state between two components. In actual production or use, two components may exist in a state that is approximately parallel or perpendicular. For example, combined with numerical descriptions, parallel can refer to the angle between two straight lines within ±10°, parallel can also refer to the dihedral angle between two planes within ±10°, and parallel can also refer to the angle between a straight line and a plane within ±10°. Perpendicular can refer to the angle between two straight lines within 90±10°, perpendicular can also refer to the dihedral angle between two planes within 90±10°, and perpendicular can also refer to the angle between a straight line and a plane within 90±10°. The two components described as "parallel" or "perpendicular" do not have to be absolutely straight lines or planes; they can be approximately straight lines or planes. From a macroscopic perspective, if the overall direction of extension is a straight line or plane, the component can be considered a "straight line" or "plane".
[0059] In this application, the design relationships of greater than, less than, or not equal to parameter values need to exclude reasonable errors of the measuring equipment.
[0060] Please refer to Figures 1 to 5. One embodiment of this application provides a secondary battery 100, including a housing 10, at least one electrode assembly 20 disposed within the housing 10, an electrolyte (not shown), a plurality of first tabs 30, and a plurality of second tabs 40. Taking the number of electrode assemblies 20 as one, as shown in Figures 2 to 5, each electrode assembly 20 can be a stacked structure, including a plurality of first electrodes 21, a plurality of second electrodes 22, and a plurality of separators 23. In the stacked structure, the first electrodes 21 and second electrodes 22 are stacked alternately, with one second electrode 22 in every two adjacent first electrodes 21 and one first electrode 21 in every two adjacent second electrodes 22. The separators 23 are disposed between adjacent first electrodes 21 and second electrodes 22, and the separators 23 are used to prevent direct contact between the first electrodes 21 and second electrodes 22, thereby reducing the possibility of short circuits due to contact between the first electrodes 21 and second electrodes 22. The first tabs 30 are all electrically connected to the first electrode plate 21 and extend out of the first electrode plate 21 along the first direction X. The second tabs 40 are all electrically connected to the second electrode plate 22 and extend out of the second electrode plate 22 along the first direction X. Referring to Figure 6, in some embodiments, the electrode assembly 20 can also be a wound structure, in which case the winding center axis O of the electrode assembly 20 extends along the first direction X.
[0061] As shown in Figures 1 to 6, the housing 10 is made of metal. In some embodiments, the housing 10 includes a first end wall 11 and a second end wall 12 disposed opposite each other in a first direction X, a side wall 13 connecting the first end wall 11 and the second end wall 12, and a first electrode post 14 and a second electrode post 15 respectively disposed on the first end wall 11. The first electrode post 14 and the second electrode post 15 are electrically isolated from the first end wall 11. The first end wall 11 and the second end wall 12 may be arranged in parallel. The side wall 13 and the second end wall 12 enclose a receiving space S for accommodating the electrode assembly 20 and the electrolyte, and the first end wall 11 covers the receiving space S. In some embodiments, the secondary battery 100 is a prismatic battery. The side wall 13 and the second end wall 12 may be integrally formed, and the first end wall 11 and the side wall 13 may be welded or snap-fitted together. The housing 10 may be made entirely of steel. For example, the steel shell includes elements Fe and C, and may also include one or more of the elements Ni, Co, Al, Mn, Cr, Cu, Mg, Mo, S, Si, Ti, V, Pb, Sb, N, and P. For instance, the first end wall 11 is made of steel, as are the second end wall 12 and the side wall 13. As shown in Figure 3, the first end wall 11 has a first opening 111 and a second opening 112 spaced apart. The first pole post 14 and the second pole post 15 can be installed in the first opening 111 and the second opening 112 respectively by bonding or riveting.
[0062] A three-dimensional coordinate system is established based on three mutually perpendicular directions: a first direction X, a second direction Y, and a third direction Z. In the description of this embodiment, the first direction X is the direction in which the first electrode tab 30 extends from the first electrode piece 21, and also the direction from the second end wall 12 to the first end wall 11. The second direction Y is the direction from the first electrode post 14 to the second electrode post 15. The third direction Z is the stacking direction of the plurality of first electrode pieces 21. Although Figures 1 to 6 indicate that the third direction Z has a specific vector direction to illustrate the stacking direction of the plurality of first electrode pieces 21, it can be understood that the opposite direction can also be the stacking direction of the plurality of first electrode pieces 21. The third direction Z has a first side Z1 and a second side Z2 opposite to the first side Z1.
[0063] As shown in Figures 2 to 6, the first electrode 21 includes a first current collector 210 and a first active material layer 211 stacked in the third direction Z, with a first tab 30 connected to the first current collector 210. The first electrode 21 can be a positive electrode. Correspondingly, the first current collector 210 can be a positive current collector, and the first active material layer 211 can be a positive active material layer. The second electrode 22 includes a second current collector 220 and a second active material layer 221 stacked together, with a second tab 40 connected to the second current collector 220. The second electrode 22 can be a negative electrode. Correspondingly, the second current collector 220 can be a negative current collector, and the second active material layer 221 can be a negative active material layer.
[0064] The positive electrode current collector can be aluminum foil or nickel foil, and the negative electrode current collector can be at least one of copper foil, nickel foil, or carbon-based current collector. The positive electrode active material layer contains a positive electrode active material, which includes a compound that reversibly inserts and extracts lithium ions (lithiation intercalation compound). In some embodiments, the positive electrode active material may include a lithium transition metal composite oxide. This lithium transition metal composite oxide contains lithium and at least one element selected from cobalt, manganese, and nickel. In some embodiments, the positive electrode active material is selected from lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt ternary materials (NCM), lithium manganese oxide (LiMn2O4), and lithium nickel manganese oxide (LiNi). 0.5 Mn 1.5 At least one of lithium iron phosphate (LiFePO4) or lithium iron phosphate (LiFePO4).
[0065] The negative electrode active material layer comprises a negative electrode active material, which is a known negative electrode active material capable of reversible intercalation and deintercalation of active ions, and this application is not limited thereto. For example, it may be one or more combinations of graphite, soft carbon, hard carbon, carbon fiber, mesophase carbon microspheres, silicon-based materials, tin-based materials, lithium titanate, or other metals that can form alloys with lithium. Among them, graphite may be selected from one or more combinations of artificial graphite, natural graphite, and modified graphite; silicon-based materials may be selected from one or more combinations of elemental silicon, silicon oxide compounds, silicon-carbon composites, and silicon alloys; tin-based materials may be selected from one or more combinations of elemental tin, tin oxide compounds, and tin alloys.
[0066] The separator 23 comprises at least one of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polyimide, or aramid. For example, polyethylene includes at least one selected from high-density polyethylene, low-density polyethylene, or ultra-high molecular weight polyethylene. Polyethylene and polypropylene, in particular, have good effects on improving short-circuit performance.
[0067] As shown in Figures 3 to 5, the secondary battery 100 further includes a first adapter 50 and a second adapter 60 (the second adapter 60 is shown in Figure 3), both of which are disposed within the housing 10. In the first direction X, both the first adapter 50 and the second adapter 60 are located on the side of the electrode assembly 20 facing the first end wall 11. The first adapter 50 is connected to the first tab 30 and the housing 10, respectively, and the second adapter 60 is connected to the second tab 40 and the housing 10, respectively. In some embodiments, the first adapter 50 may be connected to the first terminal 14, and the second adapter 60 may be connected to the second terminal 15. Therefore, the first terminal 14 and the second terminal 15 may exhibit opposite polarities, allowing the secondary battery 100 to supply power to external components (not shown). For example, when the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode, the first terminal 14 is positive, and the second terminal 15 is negative. Furthermore, when the first adapter 50 connects the first tab 30 to the first pole post 14 and the second adapter 60 connects the second tab 40 to the second pole post 15, the first tab 30 and the second tab 40 are guided to the same end of the electrode assembly 20 through the two adapters.
[0068] Please refer to Figures 3, 4, 5, 7A, and 7B, where Figure 7A is a structural schematic diagram of the first adapter 50 in its unfolded state, and Figure 7B is a structural schematic diagram of the first adapter 50 after bending and viewed along the first direction X. The first adapter 50 includes a first connecting area 51, an adapter area 53, a bending area 54, and a second connecting area 52 connected in sequence. The adapter area 53 may be approximately square, including a first side 531 and a second side 532 arranged adjacently. The first connecting area 51 is connected to the first side 531. The connecting area 51 may extend from the first side 531 along the second direction Y. The bending area 54 is connected to the second side 532 and is bent relative to both the adapter area 53 and the second connecting area 52. As shown in Figure 7B, when viewed from the first direction X, the adapter area 53 and the second connecting area 52 overlap. Although Figure 7B shows a portion of the transition area 53 exposed within the second connection area 52, in other embodiments, the second connection area 52 may completely cover the transition area 53 when viewed from the first direction X. As shown in Figures 4 and 5, when viewed from the second direction Y, the first adapter 50 is approximately U-shaped. The first connection area 51 is connected to the first tab 30; for example, the first connection area 51 may be welded to the first tab 30 to improve connection strength and reliability. The second connection area 52 is connected to the housing 10; for example, the second connection area 52 may be welded to the first pole post 14 to improve connection strength and reliability. The material of the first adapter 50 may be aluminum, nickel, copper, steel, or nickel-plated copper. The material of the second adapter 60 may be aluminum, nickel, copper, steel, or nickel-plated copper. The first adapter 50 may be an integral structure, i.e., the first connection area 51, the transition area 53, the bending area 54, and the second connection area 52 are integrally connected. In other embodiments, the first connection area 51, the transition area 53, the bending area 54, and the second connection area 52 may also be connected as a whole by welding or other means.
[0069] As shown in Figures 7A and 7B, in some embodiments, the first adapter 50 may include at least two bends 54 spaced apart along the extension direction of the second side 532. Each bend 54 is connected to the second side 532 and bends relative to both the adapter 53 and the second connecting area 52. By providing at least two bends 54, the connection strength between the adapter 53 and the second connecting area 52 can be improved, while making the bends 54 themselves easier to bend. In some embodiments, along the arrangement direction of the adapter 53 and the first connecting area 51 (which can be understood as the second direction Y when the first adapter 50 is installed in the housing 10), the width of the bend 54 is W, the width of the adapter 53 is W1, and the width of the second connecting area 52 is W2. Wherein, W is less than W1 and W2, thereby making the bends 54 themselves easier to bend. Wherein, when the number of bending areas 54 is at least two, the width W of the bending area 54 refers to the sum of the widths of all bending areas 54 and the width of the gap between adjacent bending areas 54. The width W1 of the transition area 53 may be the same as or different from the width W2 of the second connecting area 52, and this application does not impose any restrictions.
[0070] Furthermore, as shown in Figures 3 and 7A, the second adapter 60 may be configured to have a structure similar to the first adapter 50, which will not be described in detail in this application.
[0071] When assembling the secondary battery 100, the electrode assembly 20 with the first tab 30 and the second tab 40 can be placed within the receiving space S formed by the second end wall 12 and the side wall 13. A first adapter 50 and a second adapter 60 (see FIG. 7A) are provided in an initially unfolded state. The first adapter 50 and the second adapter 60 are placed side-by-side on the side of the electrode assembly 20 with the first tab 30 and the second tab 40, and the first connection area 51 of the first adapter 50 and the first connection area (not shown in the figure) of the second adapter 60 are welded to the first tab 30 and the second tab 40, respectively. Then, the first end wall 11 with the first terminal post 14 and the second terminal post 15 is placed on the side of the first adapter 50 and the second adapter 60 facing the electrode assembly 20. The second connection area 52 of the first adapter 50 is welded to the first terminal post 14, and the second connection area (not shown in the figure) of the second adapter 60 is welded to the second terminal post 15. Then, the bending area 54 of the first adapter 50 and the bending area (not shown in the figure) of the second adapter 60 are simultaneously bent around the second direction Y, so that the first end wall 11 is flipped over the adapter area 53. At this time, viewed from the first direction X, the second connection area 52 connected to the first electrode post 14 and the adapter area 53 overlap. Then, the first end wall 11 is fixed to the side wall 13, completing the assembly of the secondary battery 100. Here, if the welding of the electrode tab to the adapter is called the first welding, and the welding of the electrode post to the adapter is called the second welding, by setting the second connection area 52 to be connected to the second side 532 of the adapter area 53 through the bending area 54, the first end wall 11 can be directly flipped over the adapter area 53 after the above two weldings, thus facilitating assembly. It is understood that the above assembly steps are only examples, and the assembly steps of this application are not limited to these.
[0072] In the secondary battery 100 of this application, the bending area 54 of the first adapter 50 is bent relative to both the adapter area 53 and the second connection area 52, so that when viewed from the first direction X, the adapter area 53 and the second connection area 52 overlap. The adapter area 53 and the second connection area 52 can jointly fill the gap between the first end wall 11 and the electrode assembly 20, reducing the shaking of the electrode assembly 20 within the housing 10 when the secondary battery 100 is subjected to mechanical abuse. Furthermore, even if the electrode assembly 20 shakes within the housing 10 and pulls the first tab 30, the adapter area 53 connected to the bending area 54 can provide a large buffer space, reducing the possibility that the first tab will detach from the first adapter 50, causing a decrease in the output voltage of the secondary battery 100 or even preventing it from continuing to charge and discharge. Therefore, this application can improve the reliability and service life of the secondary battery 100.
[0073] As shown in Figures 4 and 5, in some embodiments, the first tab 30 is bent. The first tab 30 includes a first segment 31 connecting the first electrode 21 and a second segment 32 connecting the first segment 31, the second segment 32 being bent relative to the first segment 31. By bending the first tab 30, it is beneficial to reduce the space occupied by the first tab 30 on one side of the electrode assembly 20 in the first direction X, thereby increasing the energy density of the secondary battery 100. Multiple second segments 32 together form a first connecting portion 320, and a first connecting region 51 is connected to the surface of the first connecting portion 320 facing the electrode assembly 20. Although Figure 4 shows a connection between the first connecting portion 320 and the transition region 53, it can be understood that since the first connecting region 51 in Figure 4 is actually located behind the transition region 53, the first connecting portion 320 is actually connected to the first connecting region 51 located behind the transition region 53.
[0074] In some embodiments, the plurality of first tabs 30 are divided into N tab groups 30A, where N is a positive integer. When the number of electrode components 20 in this embodiment is one, all N tab groups 30A are connected to the first electrode plate 21 of the electrode component 20. Each tab group 30A includes two tab bundles 30B, that is, the plurality of first tabs 30 are divided into a total of 2N, i.e., an even number of tab bundles 30B. For example, as shown in Figures 4 and 5, when N=1, the plurality of first tabs 30 are divided into two tab bundles 30B; as shown in Figure 8, when N=2, the plurality of first tabs 30 are divided into four tab bundles 30B. Each tab bundle 30B includes at least one first tab 30.
[0075] As shown in Figures 4, 5, and 8, in each tab bundle 30B of each tab group 30A, the first segment 31 extends in a direction away from each other, and the second segment 32 extends in a direction closer to each other, so that each tab bundle 30B can form a generally U-shaped structure. The second segments 32 of each tab bundle 30B are stacked on top of each other, thereby facilitating simultaneous electrical connection between the first connection region 51 and all the second segments 32 in each tab bundle 30B. In some embodiments, the first tabs 30 in the tab bundle 30B are bent to form a generally U-shaped structure. When the tab bundle 30B includes multiple first tabs 30, the tab bundle 30B has an innermost layer and an outermost layer. The innermost layer of the tab bundle 30B refers to the first tab 30 in the tab bundle 30B that is connected to the first connection region 51, while the outermost layer of the tab bundle 30B refers to the first tab 30 in the tab bundle 30B that is farthest from the first connection region 51 along the stacking direction. Compared to bending all the first tabs 30 together (e.g., all the first tabs 30 extend towards the first side Z1 and then towards the second side Z2), by dividing the multiple first tabs 30 into an even number of tab bundles 30B and bending each tab bundle 30B independently, the length required for the second segments 32 to overlap after bending the first tabs 30 is smaller. This is especially true when the electrode assembly 20 is thicker in the third direction Z (in which case the length required for the first tabs 30 is even greater when bending all the first tabs 30 together). This application can significantly reduce the length required for bending the first tabs 30, thereby reducing the overall weight and production cost of the secondary battery 100. To reduce the length required for bending the second tabs 40, the multiple second tabs 40 can also be divided into an even number of tab bundles. The bundling method of the multiple first tabs 30 can be the same as or different from the bundling method of the multiple second tabs 40. In some other embodiments, the multiple first tabs 30 may not be grouped. At this time, all the first tabs 30 are bent together (e.g., all the first tabs 30 extend towards the first side Z1 and then towards the second side Z2) and welded to the first connection area 51, thereby reducing the number of welding operations and simplifying the process.
[0076] As shown in Figures 5 to 7B, in some embodiments, the first connection region 51 includes N first partitions 511. The N first partitions 511 correspond one-to-one with the N tab groups 30A. For example, when multiple first tabs 30 are divided into one tab group 30A (i.e., N=1), the first connection region 51 includes only one first partition 511. As shown in Figures 8 and 9, when multiple first tabs 30 are divided into two tab groups 30A (i.e., N=2), the first connection region 51 includes two first partitions 511. Each first partition 511 is connected to the second segment 32 of the two tab bundles 30B of a tab group 30A. Both the first partitions 511 and the transition region 53 can be sheet-like structures. The plane containing the first partition 511 extends along the second direction Y and the third direction Z, and the plane containing the transition region 53 extends along the second direction Y and the third direction Z.
[0077] Referring to Figure 10, further, when the number of first partitions 511 is greater than one, the first connection area 51 may also include N second partitions 512, each second partition 512 being connected to the first side 531. Each second partition 512 is also connected to two adjacent first partitions 511. The arrangement of the second partitions 512 helps to reduce the resistance of the first partitions 511, thereby helping to reduce the internal resistance and improve the charging and discharging efficiency of the secondary battery 100.
[0078] As shown in Figures 11 and 12, in some embodiments, the number of first adapters 50 can also be two, and the two first adapters 50 are arranged along the third direction Z. The structures of the two first adapters 50 can be approximately the same. When the first connection area 51 of each first adapter 50 includes only one first partition 511, the two first adapters 50 have a total of two first partitions 511, which is similar to the structure in Figure 8. This can be applied to the case where multiple first tabs 30 are divided into two tab groups 30A (i.e., N=2), and each first partition 511 is connected to the second segment 32 of the two tab bundles 30B of a tab group 30A. The two first adapters 50 can respectively fill the gaps on both sides of the first pole post 14 in the third direction Z, reducing the impact of the first adapters 50 on the energy density of the secondary battery 100. It is understood that at least one first adapter 50's first connection area 51 may also include two first partitions 511. In this case, the two first adapters 50 may have more first partitions 511, making it applicable to situations where multiple first tabs 30 are divided into more tab groups 30A (e.g., N>2). The two first adapters 50 may be set apart in the third direction Z.
[0079] Alternatively, two first adapters 50 can be connected in the third direction Z. For example, as shown in Figures 13 and 14, the second connection areas 52 of the two first adapters 50 are connected. Or, as shown in Figure 15, the connection areas 53 of the two first adapters 50 can be connected. By connecting the two first adapters 50 in the third direction Z, the shaking of the first adapters 50 within the housing 10 during mechanical abuse can be further reduced.
[0080] Figures 7C and 7D show top views of the first tab 30 after it has been bent, with the second segment 32 welded and fixed to the first adapter 50. In some embodiments, the second segments 32 of the first tab 30 in each tab bundle 30B are stacked and welded together to form a first welding area S1, thereby improving the connection strength between the second segments 32. The first connection area 51 is welded to the second segment 32 to form a second welding area S2, thereby improving the welding strength between the first connection area 51 and the second segment 32. When manufacturing the secondary battery 100, each tab bundle 30B can be bent first using a welding head (not shown) to stack the second segments 32, and then the second segments 32 of each tab bundle 30B can be pre-welded and fixed to improve the connection strength between the second segments 32. Subsequently, the first adapter 50 is placed on the side of the second segment 32 facing the electrode assembly 20, and then the first connection area 51 of the first adapter 50 is welded and fixed to the second segment 32 using a welding head. The pre-welding and fixing of the second segment 32 facilitates the connection between the first connection area 51 and the second segment 32 of each first tab 30 of the tab bundle 30B.
[0081] In one embodiment, the number of first tabs 30 included in the two tab bundles 30B of a tab group 30A can be the same. This allows the same welding parameters (such as welding time and welding temperature) to be used to weld the second segment 32 of each tab bundle 30B, eliminating the need for frequent adjustments to welding parameters when welding different tab bundles 30B, simplifying the process, and improving the uniformity of welding quality. Furthermore, it also helps improve the flatness of the internal structure of the housing 10. In other embodiments, the number of first tabs 30 included in the two tab bundles 30B of a tab group 30A can also be different.
[0082] As shown in Figure 7C, in some embodiments, when viewed from the first direction X, the first welding area S1 and the second welding area S2 do not overlap, i.e., they are separated, thereby reducing the risk of over-welding at the first welding area S1. As shown in Figure 7D, in other embodiments, when viewed from the first direction X, the first welding area S1 and the second welding area S2 may also overlap, thereby improving the stability of the welding between the second segments 32 at the first welding area S1.
[0083] As shown in Figures 3 to 5, in some embodiments, the first electrode post 14 protrudes from the first end wall 11 toward the electrode assembly 20 to facilitate connection of the first electrode post 14 to the second connection area 52. The second connection area 52 includes a protruding section 521 connected to the bending area 54 and a straight section 522 connected to the protruding section 521. The protruding section 521 protrudes away from the electrode assembly 20 relative to the straight section 522. The straight section 522 is fixed to the portion of the first electrode post 14 protruding from the first end wall 11, for example, the straight section 522 can be welded to the portion of the first electrode post 14 protruding from the first end wall 11. The protruding section 521 is fixed to the first end wall 11. By fixing the protruding section 521 to the first end wall 11, the risk of the first adapter 50 shaking within the housing 10 during mechanical abuse can be further reduced, and the connection reliability between the first electrode post 14 and the straight section 522 can also be improved. Furthermore, the shape of the protruding section 521 also facilitates its fixation to the first end wall 11.
[0084] Furthermore, the protruding section 521 may be provided with an opening 5210. Correspondingly, the first end wall 11 is provided with a protrusion 110, which protrudes towards the electrode assembly 20. The protrusion 110 passes through the opening 5210, thereby facilitating the fixation of the first adapter 50 to the first end wall 11, and the protrusion 110 can suppress the first adapter 50 from wobbling in the second direction Y or the third direction Z within the housing 10. Furthermore, the protrusion 110 may also be fixed in the opening 5210 by means of interference fit, bonding, welding, etc., thereby making the second connection area 52 of the first adapter 50 more firmly fixed to the first end wall 11.
[0085] As shown in Figure 16, in some embodiments, the secondary battery 100 further includes a first adhesive member 70. At least a portion of the first adhesive member 70 is disposed on the side of the first connection portion 320 opposite to the electrode assembly 20 in the first direction X. This portion of the first adhesive member 70 can cover the weld marks of the first welding area S1 and the second welding area S2, as well as the cutting burrs of the first tab 30 itself, reducing damage to the housing 10 caused by the weld marks or burrs. The first adhesive member 70 can also extend to the two opposing surfaces of the electrode assembly 20 in the third direction Z, thereby connecting the first tab 30 to the electrode assembly 20 integrally. The first adhesive member 70 can be a single-sided adhesive containing an insulating material, which can be selected from at least one of polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polymethyl methacrylate, or polyethylene glycol. In other embodiments, the first adhesive member 70 can also be a ceramic coating.
[0086] The secondary battery 100 may further include a second adhesive member 80. In the first direction X, the second adhesive member 80 is disposed on the surface of the straight section 522 facing the electrode assembly 20. The second adhesive member 80 adheres to the surface of the straight section 522 facing the electrode assembly 20. The second adhesive member 80 can cover the solder joints between the straight section 522 and the first electrode post 14, as well as the cutting burrs of the straight section 522 itself, reducing damage to the electrode assembly 20 caused by such solder joints or burrs during mechanical abuse. The second adhesive member 80 may be a single-sided adhesive containing an insulating material, which may be selected from at least one of polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polymethyl methacrylate, or polyethylene glycol. In other embodiments, the second adhesive member 80 may also be a ceramic coating. This reduces the risk of solder joints piercing the first segment 31 of the first tab 30, thereby reducing the risk of the first tab 30 easily breaking during mechanical abuse.
[0087] The secondary battery 100 may further include a third adhesive member 90. In the first direction X, the third adhesive member 90 is disposed on the surface of the transition area 53 facing the second connection area 52. The third adhesive member 90 adheres to the surface of the transition area 53 facing the second connection area 52. The third adhesive member 90 can further isolate the solder joints between the straight section 522 and the first electrode post 14, as well as the cutting burrs of the straight section 522 itself, reducing damage to the electrode assembly 20 caused by the aforementioned solder joints or burrs during mechanical abuse. The third adhesive member 90 may be a single-sided adhesive containing an insulating material, which may be selected from at least one of polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polymethyl methacrylate, or polyethylene glycol. In other embodiments, the third adhesive member 90 may also be a ceramic coating.
[0088] Referring to Figure 17, in some embodiments, the number of electrode assemblies 20 is multiple. Multiple electrode assemblies 20 are connected in parallel or series to increase the supply voltage of the secondary battery 100. In this case, N tab groups 30A are respectively connected to the first electrode plates 21 of the multiple electrode assemblies 20, and each tab group 30A includes two tab bundles 30B. That is, in this embodiment, the first tabs 30 included in the multiple electrode assemblies 20 are divided into an even number of tab bundles 30B, and each tab bundle 30B is bent independently. Thus, after the first tabs 30 are bent, the length required for the second segments 32 to be stacked is smaller. Especially when the electrode assembly 20 is thick in the first direction X, this embodiment can significantly reduce the length required for bending the first tabs 30, thereby reducing the overall weight and production cost of the secondary battery 100. Furthermore, when at least one electrode assembly 20 has a quality problem, the problematic electrode assembly 20 (and other electrode assemblies 20 welded to it) can be removed individually, avoiding the risk of all electrode assemblies 20 being scrapped simultaneously when the first tabs 30 of all electrode assemblies 20 are bent together. Multiple electrode assemblies 20 can be stacked in the first direction X.
[0089] The secondary battery 100 of this application can be a lithium secondary battery, including lithium metal secondary batteries, lithium-ion secondary batteries, lithium polymer secondary batteries and lithium-ion polymer secondary batteries.
[0090] Referring to Figure 18, one embodiment of this application also provides an electronic device 1, including a battery compartment 101 and a secondary battery 100 housed within the battery compartment 101. The electronic device 1 is powered by the aforementioned secondary battery 100, and the reliability and lifespan of the secondary battery 100 are improved. In some embodiments, the electronic device 1 of this application may be, but is not limited to, a laptop computer, a pen input computer, a mobile computer, an e-book player, a portable telephone, a portable fax machine, a portable copier, a portable printer, a stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable CD player, a mini CD-ROM, a transceiver, an electronic notebook, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, a car, a motorcycle, an electric bicycle, a bicycle, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, household large-capacity batteries, and lithium-ion capacitors, etc.
[0091] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with this application are still within the scope of this application.
Claims
1. A secondary battery (100) comprising a housing (10), at least one electrode assembly (20) disposed within the housing (10), and a plurality of first tabs (30), wherein the electrode assembly (20) includes a first electrode plate (21), and the plurality of first tabs (30) are respectively connected to the first electrode plate (21) and extend out of the first electrode plate (21) along a first direction (X), wherein, The secondary battery (100) further includes a first adapter (50) disposed within the housing (10). The first adapter (50) includes a first connecting area (51), an adapter area (53), a bending area (54), and a second connecting area (52) connected in sequence. The adapter area (53) includes a first side (531) and a second side (532) disposed adjacent to each other. The first connecting area (51) is connected to the first side (531). The first connecting area (51) extends from the first side (531) along a second direction (Y). The second direction (Y) is perpendicular to the first direction (X). The bending area (54) is connected to the second side (532) and bends relative to both the adapter area (53) and the second connecting area (52). When viewed from the first direction (X), the adapter area (53) and the second connecting area (52) overlap. The first connection area (51) is connected to the first tab (30), and the second connection area (52) is connected to the housing (10).
2. The secondary battery (100) as described in claim 1, wherein, The first electrode tab (30) includes a first segment (31) connected to the first electrode plate (21) and a second segment (32) connected to the first segment (31). The second segment (32) is bent relative to the first segment (31). A plurality of the second segments (32) form a first connecting portion (320). The first connecting area (51) is connected to the surface of the first connecting portion (320) facing the electrode assembly (20).
3. The secondary battery (100) as described in claim 2, wherein, The plurality of first tabs (30) are divided into N tab groups (30A), where N is a positive integer. Each tab group (30A) includes two tab bundles (30B), in which the first segment (31) extends toward each other in a direction away from each other, and the second segment (32) extends toward each other in a direction close to each other.
4. The secondary battery (100) as described in claim 3, wherein, The number of electrode assemblies (20) is one, and the N tab groups (30A) are all connected to the first electrode plate (21) of the electrode assembly (20).
5. The secondary battery (100) as described in claim 3, wherein, The number of electrode assemblies (20) is multiple, and the N tab groups (30A) are respectively connected to the first electrode plate (21) of the multiple electrode assemblies (20).
6. The secondary battery (100) according to any one of claims 3 to 5, wherein, The first connection area (51) includes N first partitions (511), each of the first partitions (511) being connected to the second segment (32) of the first electrode (30) in a electrode bundle (30B).
7. The secondary battery (100) as described in claim 6, wherein, The first connection area (51) includes a second partition (512), which is connected to two adjacent first partitions (511) and is connected to the first edge (531).
8. The secondary battery (100) as described in claim 6 or 7, wherein, In the electrode bundle (30B), the second segment (32) of the first electrode (30) is stacked and welded to form a first welding area (S1), and the first connecting area (51) is welded to the second segment (32) to form a second welding area (S2). When viewed from the first direction (X), the first welding area (S1) and the second welding area (S2) are separated.
9. The secondary battery (100) as described in claim 8, wherein, The secondary battery (100) further includes a first adhesive (70) that covers and bonds the first welding area (S1) and the second welding area (S2), and the first adhesive (70) extends to the surface of the electrode assembly (20) in a third direction (Z), which is perpendicular to both the first direction (X) and the second direction (Y).
10. The secondary battery (100) according to any one of claims 1 to 9, wherein, There are two first adapters (50), and the two first adapters (50) are arranged along a third direction (Z), which is perpendicular to both the first direction (X) and the second direction (Y).
11. The secondary battery (100) as claimed in claim 10, wherein, The transition areas (53) of the two first adapters (50) are connected.
12. The secondary battery (100) as claimed in claim 10, wherein, The second connection areas (52) of the two first adapters (50) are connected.
13. The secondary battery (100) according to any one of claims 1 to 12, wherein, The secondary battery (100) is a prismatic battery. The housing (10) includes a first end wall (11) and a second end wall (12) disposed opposite each other in the first direction (X), a side wall (13) connected between the first end wall (11) and the second end wall (12), and a first electrode post (14) disposed on the first end wall (11). The first electrode post (14) is electrically isolated from the first end wall (11), and the second connection area (52) is electrically connected to the first electrode post (14).
14. The secondary battery (100) as claimed in claim 13, wherein, The first electrode post (14) protrudes from the first end wall (11) toward the electrode assembly (20). The second connection area (52) includes a protruding section (521) connected to the bending area (54) and a straight section (522) connected to the protruding section. The straight section (522) is fixed to the first electrode post (14), and the protruding section (521) is fixed to the first end wall (11).
15. The secondary battery (100) as claimed in claim 14, wherein, The protruding section (521) is provided with an opening (5210), and the first end wall (11) is provided with a protrusion (110) that passes through the opening (5210).
16. The secondary battery (100) as claimed in claim 14, wherein, The secondary battery (100) also includes a second adhesive (80) that adheres to the surface of the straight section (522) facing the electrode assembly (20).
17. The secondary battery (100) as claimed in claim 16, wherein, The secondary battery (100) also includes a third adhesive (90) which adheres to the surface of the transition area (53) facing the second connection area (52).
18. The secondary battery (100) according to any one of claims 1 to 17, wherein, Along the second direction (Y), the width of the bending area (54) is W, the width of the transition area (53) is W1, and the width of the second connection area (52) is W2, where W is less than W1 and W2.
19. The secondary battery (100) according to any one of claims 1 to 18, wherein, The electrode assembly (20) satisfies one of the following conditions: (1) The electrode assembly (20) is a stacked structure and includes a plurality of first electrode plates (21). The plurality of first electrode plates (21) are stacked along a third direction (Z). The third direction (Z) is perpendicular to both the first direction (X) and the second direction (Y). (2) The electrode assembly (20) is a wound structure, and the winding center axis (O) of the electrode assembly (20) extends along the first direction (X).
20. An electronic device (1) comprising a battery compartment (101), wherein, The electronic device (1) further includes a secondary battery (100) as claimed in any one of claims 1 to 19, the secondary battery (100) being housed in the battery compartment (101).