Battery device and electric appliance

Abstract

This application relates to the field of battery technology, and more particularly to a battery device and electrical equipment, including a battery and a conductive bus. The battery includes a casing, a cell, and terminals. The terminals are disposed on the casing. The cell includes a body and tabs connected to the body. The tabs and terminals are electrically connected via an adapter. The tabs are connected to the adapter via a first solder mark, and the terminals are connected to the adapter via a second solder mark. The conductive bus is connected to the terminals via a third solder mark. The projections of the first solder mark and the second solder mark at least partially overlap. The projections of the second solder mark and the third solder mark are at least partially offset. An insulating component is provided between the casing and the adapter. By offsetting the second and third solder marks, heat concentration during the welding process is reduced, ensuring the charging rate and insulation safety of the battery. By aligning the first and second solder marks, the transmission path of current from the tabs through the adapter to the terminals is shortened, effectively reducing internal resistance and improving the battery's charge / discharge rate and fast charging capability.

Description

Technical Field

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

[0002] With the rapid development of battery technology, people have put forward higher requirements for battery performance such as energy density, fast charging capability, and charge / discharge rate.

[0003] However, during high-rate charging and discharging of batteries, especially during fast charging, internal short circuits are prone to occur, which can lead to overall thermal runaway of the battery. Summary of the Invention

[0004] This application provides a battery device and electrical equipment that can improve battery rate performance while preventing internal short circuits, thereby enhancing battery safety.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] On the one hand, this application provides a battery device, including a battery and a conductive busbar for electrically connecting the battery;

[0007] The battery includes a casing, a cell, and terminals. The casing forms an accommodating space, the cell is disposed within the accommodating space, the terminals are disposed on the casing, and a conductive bus is electrically connected to the terminals. The cell includes a body and a tab connected to the body. The tab and the terminals are electrically connected via an adapter. The tab is connected to the adapter via a first solder mark, the terminals are connected to the adapter via a second solder mark, and the conductive bus is connected to the terminals via a third solder mark.

[0008] In the width or length direction of the shell, the projection of the first solder mark and the projection of the second solder mark at least partially overlap, and the maximum size of the overlapping area is bmm.

[0009] In the height direction of the shell, the projection of the second solder mark is at least partially offset from the projection of the third solder mark, and the maximum dimension between any point in the non-overlapping region of the projection of the third solder mark and the projection of the second solder mark is amm.

[0010] An insulating component is provided between the housing and the adapter, and the thermal weight loss rate of the insulating component is k%.

[0011] a, b, and k satisfy: 0.0036 ≤ a / (k×b) ≤ 109.6491.

[0012] On the other hand, this application provides an electrical device, including an electrical device and the aforementioned battery device, wherein the battery device is used to provide electrical energy to the electrical device.

[0013] The battery device and electrical equipment provided in this application effectively disperse the welding heat-affected zone by setting the third solder joint connecting the terminal post to the conductor busbar and the second solder joint connecting the adapter to the terminal post to be at least partially staggered in the height direction. This avoids excessive heat concentration in the corresponding area of ​​the insulating component, thereby preventing burn-through or damage to the insulating component. Simultaneously, by limiting the thermal weight loss rate of the insulating component and coordinating it with the overlap dimensions of the first and second solder joints and the staggered dimensions of the second and third solder joints, the structural integrity and insulation performance of the insulating component are ensured under welding thermal shock. This prevents the adapter from colliding with the casing due to insulation failure, which could lead to internal short circuits and thermal runaway, thus improving battery safety. Furthermore, by controlling the first solder joint connecting the tab to the adapter and the second solder joint connecting the terminal post to the adapter to be at least partially overlapped in the width or length direction of the casing, the current transmission path from the tab through the adapter to the terminal post is shortened. This ensures uniform current distribution even during ultra-high current charging and discharging, effectively reducing internal resistance and thus improving the battery's charge / discharge rate and fast charging capability. The staggered design of the third and second weld marks reduces weld fatigue and cracking caused by stress concentration, making the electrical connection between the poles, adapters and conductors more stable and reliable, improving the mechanical stability and electrical connection reliability of the battery device, thereby extending the battery's service life. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the battery device provided in the embodiments of this application;

[0016] Figure 2 for Figure 1 One of the exploded structural diagrams of the battery in the battery device shown;

[0017] Figure 3 for Figure 1 The second partially exploded structural diagram of the battery in the battery device shown;

[0018] Figure 4 for Figure 1 A cross-sectional view of the battery in the battery device shown;

[0019] Figure 5 for Figure 4 An enlarged structural diagram of part A of the battery shown;

[0020] Figure 6 for Figure 2 One of the structural schematic diagrams of the adapter and tabs of the battery shown;

[0021] Figure 7 for Figure 1 One of the schematic diagrams of a partial structure of the battery shown;

[0022] Figure 8 for Figure 1 The second schematic diagram of a partial structure of the battery shown;

[0023] Figure 9 for Figure 2 The second schematic diagram of the adapter and tabs of the battery shown;

[0024] Figure 10 for Figure 2 The third schematic diagram of the adapter and tab structure of the battery shown;

[0025] Figure 11 for Figure 1 The diagram shows the structural connection between the conductive busbar, terminals, and adapter of the battery device.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100-Battery; 10-Casing; 11-Accommodation space; 20-Cell; 21-Body; 22-Taper; 30-Terminal post; 31-Third solder mark; 40-Adapter; 41-First solder mark; 411-First sub-solder mark; 412-Second sub-solder mark; 42-Second solder mark; 43-Notch; 431-Sub-notch; 50-Insulator; 200-Battery assembly; 201-Conducting busbar. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] With the rapid development of battery technology, people have put forward higher requirements for battery performance such as energy density, fast charging capability, and charge / discharge rate.

[0030] However, during high-rate charging and discharging of batteries, especially during fast charging, internal short circuits are prone to occur, which can lead to overall thermal runaway of the battery.

[0031] To overcome the shortcomings of existing technologies, after repeated consideration and verification, the inventors discovered that the main cause of internal short circuits in batteries is the overlap between the tab solder marks and the terminal post solder marks. This leads to the melting of the lower plastic during the welding process. As the battery is used, the insulation of the lower plastic fails, causing overlap between the cover plate and the adapter plate, resulting in a short circuit. By staggering the solder marks between the conductor and the terminal post, and between the terminal post and the adapter plate, the heat concentration during the welding process can be reduced. Simultaneously, controlling the overlap between the tab and terminal post solder marks can improve the current transfer rate inside and outside the battery, while also controlling the temperature resistance of the insulation components, thereby ensuring the battery's charging rate and insulation safety.

[0032] In view of this, this application provides a battery device, including a battery and a conductive busbar for electrically connecting the battery;

[0033] The battery includes a casing, a cell, and terminals. The casing forms an accommodating space, the cell is disposed within the accommodating space, the terminals are disposed on the casing, and a conductive bus is electrically connected to the terminals. The cell includes a body and a tab connected to the body. The tab and the terminals are electrically connected via an adapter. The tab is connected to the adapter via a first solder mark, the terminals are connected to the adapter via a second solder mark, and the conductive bus is connected to the terminals via a third solder mark.

[0034] In the width or length direction of the shell, the projection of the first solder mark and the projection of the second solder mark at least partially overlap, and the maximum size of the overlapping area is bmm.

[0035] In the height direction of the shell, the projection of the second solder mark is at least partially offset from the projection of the third solder mark, and the maximum dimension between any point in the non-overlapping region of the projection of the third solder mark and the projection of the second solder mark is amm.

[0036] An insulating component is provided between the housing and the adapter, and the thermal weight loss rate of the insulating component is k%.

[0037] a, b, and k satisfy: 0.0036 ≤ a / (k×b) ≤ 109.6491.

[0038] By setting the third solder joint connecting the terminal block to the busbar and the second solder joint connecting the adapter to the terminal block to be at least partially staggered in the height direction, the heat-affected zone of welding is effectively dispersed, avoiding excessive heat concentration in the corresponding area of ​​the insulation component, thereby preventing burn-through or damage to the insulation component. Simultaneously, by limiting the thermal weight loss rate of the insulation component and coordinating it with the overlap dimensions of the first and second solder joints and the staggered dimensions of the second and third solder joints, the structural integrity and insulation performance of the insulation component are ensured to be maintained under welding thermal shock. This prevents the adapter from colliding with the casing due to insulation failure, which could lead to internal short circuits and thermal runaway, thus improving battery safety. Furthermore, by controlling the first solder joint connecting the tab to the adapter and the second solder joint connecting the terminal block to the adapter to be at least partially overlapped in the width or length direction of the casing, the current transmission path from the tab through the adapter to the terminal block is shortened, ensuring uniform current distribution even during ultra-high current charging and discharging, effectively reducing internal resistance, and thus improving the battery's charge / discharge rate and fast charging capability. The staggered design of the third and second weld marks reduces weld fatigue and cracking caused by stress concentration, making the electrical connection between the poles, adapters and conductors more stable and reliable, improving the mechanical stability and electrical connection reliability of the battery device, thereby extending the battery's service life.

[0039] The contents of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can have a clearer and more detailed understanding of the contents of this application.

[0040] The specific structure of the battery device and various possible implementation methods are described in detail below.

[0041] Figure 1 This is a schematic diagram of the structure of the battery device provided in the embodiments of this application. Figure 2 for Figure 1 One of the exploded structural diagrams of the battery in the battery device shown. Figure 3 for Figure 1 The second part of the exploded structure diagram of the battery in the battery device shown. Figure 4 for Figure 1 A cross-sectional view of the battery in the battery device shown. Figure 5 for Figure 4 An enlarged structural diagram of part A of the battery shown. Figure 6 for Figure 2 One of the schematic diagrams of the adapter and tabs of the battery shown. Figure 7 for Figure 1 One of the schematic diagrams of a partial structure of the battery shown. Figure 8 for Figure 1 The second schematic diagram shows a partial structure of the battery. Figure 9 for Figure 2 The second schematic diagram of the adapter and tabs of the battery shown. Figure 10 for Figure 2 The third schematic diagram of the battery adapter and tabs shown. Figure 11 for Figure 1 The diagram shows the structural connection between the conductive busbar, terminals, and adapter of the battery device.

[0042] like Figure 1 As shown in the embodiment of this application, the battery device 200 is used in electrical equipment.

[0043] The battery device 200 includes a battery 100 and a busbar 201. The busbar 201 is used to electrically connect two corresponding batteries 100 or to enable external output of the battery 100.

[0044] The battery 100 can store chemical energy and controllably convert chemical energy into electrical energy. In the recyclable battery 100, after discharge, the active materials in the battery 100 can be activated by charging so that it can continue to be used.

[0045] In one possible implementation, battery 100 is a prismatic battery 100.

[0046] The battery device 200 can serve as an operating power source or a driving power source for electrical devices, replacing or partially replacing fuel or natural gas to provide driving power for vehicles. Electrical devices include: energy storage devices, electric ships, aircraft, laptops, power tools, electric bicycles, electric motorcycles, electric cars, military equipment, aerospace, and many other technological fields.

[0047] The busbar 201 electrically connects the terminals 30 (battery current output terminals) of at least two batteries 100 to realize the series or parallel connection of multiple battery cells.

[0048] The busbar 201 is a conductive metal strip used to draw current from the battery 100 for use by electrical equipment; it is typically made of aluminum or copper. The busbar 201 is primarily used to draw current from the terminal 30.

[0049] The conductive busbar 201 is made of materials such as metals or alloys such as copper, aluminum, tungsten, and manganese, or copper-aluminum composite materials, which have good electrical conductivity.

[0050] The busbar 201 is usually welded to the pole post 30. Welding methods include resistance welding and laser welding.

[0051] like Figure 2 and Figure 3As shown, the battery 100 includes a casing 10, a battery cell 20, and terminals 30. The casing 10 forms a receiving space 11. The battery cell 20 is disposed within the receiving space 11. The terminals 30 are disposed on the casing 10. A conductive bus 201 is electrically connected to the terminals 30. The battery cell 20 includes a body 21 and tabs 22. The tabs 22 are connected to the body 21. The tabs 22 and terminals 30 are electrically connected via an adapter 40.

[0052] The housing 10 is a component used to provide a receiving space to house electrode assemblies and other components and isolate them from the outside environment; the housing 10 generally includes a body with an opening at at least one end and a receiving cavity, and the opening of the housing can be closed by a cover plate to seal and isolate the internal environment of the battery cell from the external environment.

[0053] The material of the housing 10 includes at least one of copper, iron, aluminum, stainless steel, and aluminum alloy.

[0054] In one possible implementation, the housing 10 includes a cover plate, and the pole post 30 is fixedly connected to the cover plate.

[0055] In one possible implementation, the cover plate serves only as the surface on the housing 10 of the battery 100 where the terminal post 30 is located. It can be the end face that blocks the opening of the housing 10, or any end face of the housing 10 that is not open.

[0056] The cover plate is a plate-shaped component used to install the pole post 30. Typically, the cover plate has through holes for installing the pole post 30. The cover plate can be a metal plate, such as steel, aluminum, or titanium, integrally formed with the metal housing 10 or welded together. The cover plate can also be a non-metallic plate, such as a plastic cover plate, connected to the housing 10 by injection molding, bonding, or other methods.

[0057] The cover plate can be the encapsulation side of the battery 100, that is, the end cap of the battery 100, which is combined with the housing 10 by laser welding or edge sealing, etc., to seal the opening end of the housing 10 and achieve the final sealing of the battery 100.

[0058] In other words, the cover is a component that closes the opening of the casing to isolate the internal environment of the battery cell from the external environment.

[0059] The cover plate is usually equipped with explosion-proof devices, such as explosion-proof valves. The cover plate may also have a liquid injection hole, which is sealed after liquid injection.

[0060] The cover can also be other end faces of the battery 100.

[0061] The terminal 30 is an external electrical connection terminal of the battery 100, used to lead the internal current of the battery 100 to an external circuit, and typically includes a positive terminal and a negative terminal. One terminal 30 is connected to the positive tab 22 of the cell 20 and is insulatedly fixed to the cover plate; this terminal 30 is usually the positive terminal. The other terminal 30 is connected to the negative tab 22 of the cell 20 and is insulatedly fixed to the cover plate; this terminal 30 is usually the negative terminal.

[0062] Terminals are used to electrically connect electrode assemblies located inside the housing to external devices (adjacent batteries or other electrical equipment) located outside the housing. The battery can discharge to external devices through the cell output terminals (tabs) and the external device output terminals (terminals), and an external power source can charge the battery through the terminals and tabs. Terminals can be directly electrically connected to the cell tabs, or they can be electrically connected to the tabs through metal adapters.

[0063] The electrode post includes at least one of the following metals: copper, aluminum, aluminum alloy, copper-aluminum alloy, etc.

[0064] In one possible implementation, a limiting flange can be provided on the cover plate to fix the pole post 30 to the limiting flange. Alternatively, a limiting ring can be provided on the cover plate to fix the top end of the pole post 30, and the limiting ring and the cover plate can be welded together. The cover plate can also be provided with a through hole, through which the pole post 30 may or may not pass through the through hole. The pole post 30 and the cover plate can be fixed by means of press riveting, flange riveting, spin riveting, etc., or connected by means of injection molding, bonding, etc.

[0065] The battery cell 20 is the core energy storage component of the battery 100, assembled from a positive electrode, a negative electrode, and a separator through winding or stacking. Active materials are coated on the positive and negative electrodes, undergoing electrochemical reactions during charging and discharging. The lithium-ion battery cell 20 primarily operates by the movement of lithium ions between the positive and negative electrodes. The battery cell 20 is immersed in an electrolyte and sealed within the casing 10.

[0066] A battery cell is the component in a battery where electrochemical reactions occur; it is the smallest unit in a battery capable of carrying out electrochemical reactions such as charging and discharging.

[0067] A battery cell is the basic unit in a battery, typically consisting of a positive electrode, a negative electrode, and a separator. Battery cells can be either wound or stacked. The main body of a battery cell includes the positive electrode, the negative electrode, and the separator located between the positive and negative electrodes.

[0068] A separator is placed between the positive and negative electrode plates to separate them and prevent short circuits caused by contact. The separator can be at least one of glass fiber, non-woven fabric, polyethylene (PE), polypropylene (PP), and polyvinylidene fluoride.

[0069] Lithium-ion cells primarily function by the insertion and extraction of lithium ions between the positive and negative electrode plates. In cylindrical cells, a three-layer thin-film structure is wound into a cylindrical electrode assembly, while in cuboid cells, the thin-film structure is wound or stacked into an electrode assembly with a roughly cuboid shape.

[0070] The positive electrode is one of the core components in a battery that carries the positive electrode active material. During charging, metal ions (e.g., lithium ions) are released from the positive electrode active material (oxidation reaction), migrate through the electrolyte, and intercalate into the negative electrode. During discharging, metal ions (e.g., lithium ions in a lithium battery) are released from the negative electrode and intercalated into the positive electrode active material (reduction reaction), thus realizing the storage and release of lithium ions.

[0071] A positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is coated on at least one surface of the positive current collector and includes: a positive active material, a conductive agent, and a binder. The positive active material includes, but is not limited to, at least one of the following: lithium phosphates, lithium transition metal oxides and their respective modified compounds, or other conventional materials that can be used as positive active materials for batteries. These positive active materials can be used alone or in combination. The lithium phosphates include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Lithium transition metal oxides include, but are not limited to, at least one of lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, and their modified compounds.

[0072] The positive electrode current collector includes a conductive metal foil, which can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium with a silver-plated surface. Composite current collectors can also be used, which may include a polymer base layer and a metal layer. Composite current collectors are formed by forming a metal material (aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer substrate (such as polyethylene terephthalate, polyethylene terephthalate, polyethylene, polyethylene, etc.).

[0073] The positive electrode conductive agent includes, but is not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, Super P, etc.), carbon nanotubes, graphene and carbon nanofibers.

[0074] The positive electrode binder includes, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0075] During battery charging, active ions (such as Li) from the positive electrode are embedded in the negative electrode, while electrons from the positive electrode are transferred to the negative electrode through the external circuit to maintain charge balance. During discharge, active ions (such as Li) previously embedded in the negative electrode can be released, while electrons from the negative electrode are transferred to the negative electrode through the external circuit to maintain charge balance, thus achieving energy storage and release.

[0076] The negative electrode sheet includes a negative current collector and a negative active layer disposed on at least one surface of the negative current collector. The negative current collector is a conductive metal foil, which can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium with a silver-plated surface. The negative current collector can also be a composite current collector, which may include a polymer base material and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base material (such as a base material of polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene, etc.). The negative active layer includes a negative active material, conductive components, and adhesives.

[0077] The negative electrode active material can be carbon-based materials such as graphite, porous carbon, hard carbon, soft carbon, and mesophase carbon microspheres, or silicon-based materials such as elemental silicon, silicon oxides, silicon-carbon composites, and silicon-ammonia composites. The conductive agent can be conductive carbon black, carbon nanotubes, etc., and the binder can be styrene-butadiene rubber, polyacrylic acid, etc.

[0078] The main body 21 is the part of the battery cell 20 used for energy storage. The tab 22 is the part used to conduct electrical energy from the main body 21. The tab 22 can be directly processed from the positive and negative electrode plates in the battery cell 20 by cutting or other processing. The tab 22 can also be a conductive component that is electrically connected to the positive and negative electrode plates by welding or other means.

[0079] The tab is located on one side of the positive / negative current collector cell and is separately or integrally formed with the current collector. It is electrically connected to the current collector to conduct the current on the corresponding current collector. When the tab and the current collector are separately set, the tab and the current collector can be connected by welding.

[0080] The tabs are made of a metal material with good electrical conductivity (such as copper, aluminum, copper or nickel); including at least one of copper, iron, aluminum, aluminum alloys, etc.

[0081] The adapter 40 is a conductive metal sheet located between the end face of the body 21 and the terminal 30, typically made of aluminum foil or nickel sheet. The main function of the adapter 40 is to collect the current from the positive and negative tabs 22 and conduct it evenly and with low resistance to the corresponding terminal 30. The adapter 40 is usually connected to the tabs 22 and the terminal 30 by soldering.

[0082] The adapter 40 is used to connect the battery output terminal (tab) and the battery output terminal (terminal assembly) to electrically connect the battery cell to the battery output terminal. The adapter is made of at least one of the following materials: copper, iron, aluminum, and aluminum alloy.

[0083] like Figure 6 As shown, the electrode tab 22 is connected to the adapter 40 via a first solder mark 41. The electrode post 30 is connected to the adapter 40 via a second solder mark 42.

[0084] like Figure 4 and Figure 5 As shown, the conductive bus 201 is connected to the pole post 30 through the third solder mark 31.

[0085] The first weld mark 41 refers to the weld mark formed by welding the adapter 40 to the electrode lug 22. The second weld mark 42 refers to the weld mark formed by welding the adapter 40 to the electrode post 30.

[0086] The welding methods for the first weld mark 41 and the second weld mark 42 can be ultrasonic, laser, resistance, or other methods that can weld the adapter 40 to the corresponding material. For example, the first weld mark 41 can be ultrasonically welded to the tab 22 and the adapter 40, in which case the first weld mark 41 is an ultrasonic weld mark. Alternatively, multiple tabs can be pre-welded by ultrasonic welding to form a tab 22, and then laser welding can be used to weld the tab 22 to the adapter 40 for fixation, in which case the first weld mark 41 is a laser weld mark.

[0087] In one possible implementation, the pole post 30 penetrates the housing 10, but this is not the only possible implementation. In other possible implementations, the pole post 30 is directly disposed on the housing 10 without penetrating the housing 10, and the overall structure is achieved by the adapter 40 penetrating the housing 10.

[0088] In one possible implementation, the positive electrode 22 and the negative electrode 22 are located on the same side of the body 21, but this is not a limitation. In other possible implementations, the positive electrode 22 and the negative electrode 22 may also be located on both sides of the body 21.

[0089] In the width or length direction of the housing 10, the projection of the first solder mark 41 and the projection of the second solder mark 42 at least partially overlap. The maximum size of the overlapping area is b mm.

[0090] Among them, such as Figure 1 As shown, the first direction X is the length direction of the housing 10. The second direction Y is the width direction of the housing 10. The third direction Z is the height direction of the housing 10. That is, the pole post 30 is disposed on one side of the housing 10 in the height direction. The extension direction of the longer side of the surface of the housing 10 on which the pole post 30 is located is the length direction of the housing 10, and the extension direction of the shorter side is the width direction of the housing 10.

[0091] The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0092] In one possible implementation, all projections in this application are orthographic projections.

[0093] In the width direction of the housing 10, the projection of the first solder mark 41 indicates that the projection line is parallel to the second direction Y, and the projection plane is perpendicular to the second direction Y, that is, the projection plane is parallel to the plane formed by the first direction X and the third direction Z, and the projection area of ​​the first solder mark 41 on the projection plane.

[0094] The projection of the first solder mark 41 along the length of the housing 10 indicates that the projection line is parallel to the first direction X and the projection surface is perpendicular to the first direction X, that is, the projection surface is parallel to the plane formed by the second direction Y and the third direction Z, and the projection area of ​​the first solder mark 41 on the projection surface.

[0095] The projection of the first solder mark 41 and the projection of the second solder mark 42 at least partially overlap, that is, on the projection plane formed by the first direction X and the third direction Z, or on the projection plane formed by the second direction Y and the third direction Z, there is an overlapping area between the orthographic projection of the first solder mark 41 and the orthographic projection of the second solder mark 42.

[0096] In one possible implementation, since both the first solder mark 41 and the second solder mark 42 are located on the adapter 40, the upper limit of the maximum size of the overlapping area of ​​the first solder mark 41 and the second solder mark 42 in the third direction Z is the thickness of the adapter 40. Because the adapter 40 is relatively thin, the size of the overlapping area in the third direction Z is smaller than the size of the overlapping areas in the other two directions. Therefore, in the width direction of the housing 10, the maximum size of the overlapping area of ​​the projections of the first solder mark 41 and the second solder mark 42 can be approximated as the maximum size of their overlap in the first direction X. And in the length direction of the housing 10, the maximum size of the overlapping area of ​​the projections of the first solder mark 41 and the second solder mark 42 can be approximated as the maximum size of their overlap in the second direction Y.

[0097] In one possible implementation, on the width direction of the side of the housing 10 where the pole post 30 is located, the projection of the first solder mark 41 and the projection of the second solder mark 42 partially overlap, and the maximum size of the overlapping area in the length direction of the housing 10 is b. However, this is not the only possible implementation. In other possible implementations, the projections of the first solder mark 41 and the second solder mark 42 partially overlap in the length direction of the housing 10, and the maximum size of the overlapping area in the width direction of the housing 10 is b.

[0098] Furthermore, by controlling the first solder mark 41 connecting the tab 22 to the adapter 40 and the second solder mark 42 connecting the terminal post 30 to the adapter 40 to at least partially overlap in the width or length direction of the housing 10, the transmission path of current from the tab 22 through the adapter 40 to the terminal post 30 is shortened, the transmission rate of current inside and outside the battery 100 is improved, and the current distribution is ensured to be uniform even during ultra-high current charging and discharging, effectively reducing internal resistance, thereby improving the charge and discharge rate and fast charging capability of the battery 100.

[0099] In one possible implementation, the second solder mark 42 is located in the middle of the adapter 40 along the width direction of the housing 10. Two first solder marks 41 are located outside the second solder mark 42.

[0100] In the height direction of the housing 10, the projection of the second solder mark 42 is at least partially offset from the projection of the third solder mark 31. In the projection direction, the maximum dimension between any point in the non-overlapping region of the projection of the third solder mark 31 and the projection of the second solder mark 42 and the projection of the second solder mark 42 is a mm.

[0101] In the height direction of the housing 10, the projection of the second solder mark 42 indicates that the projection line is parallel to the third direction Z, and the projection plane is perpendicular to the third direction Z, that is, the projection plane is parallel to the plane formed by the first direction X and the second direction Y, and the projection area of ​​the second solder mark 42 on the projection plane.

[0102] Dimension a is the maximum distance between the non-overlapping area and the projection of the second solder mark 42 in the plane formed by the first direction X and the second direction Y. That is, the direction of dimension a may be the first direction X, the second direction Y, or any direction formed by the combination of the first direction X and the second direction Y.

[0103] By setting the third weld 31 connecting the terminal post 30 to the busbar 201 and the second weld 42 connecting the adapter 40 to the terminal post 30 to be at least partially staggered in the height direction, the heat-affected zone of welding is effectively dispersed, avoiding excessive heat concentration in the corresponding area of ​​the insulating component 50 during welding, thereby preventing burn-through or damage to the insulating component 50. The staggered design of the third weld 31 and the second weld 42 also reduces weld fatigue and cracking caused by stress concentration, making the electrical connection between the terminal post 30, the adapter 40 and the busbar 201 more stable and reliable, improving the mechanical stability and electrical connection reliability of the battery device 200, thereby extending the service life of the battery 100.

[0104] An insulating element 50 is provided between the housing 10 and the adapter 40. The thermal weight loss rate of the insulating element 50 is k%.

[0105] The insulating component 50 is a non-conductive plate located between the adapter 40 and the housing 10, serving to insulate and isolate the adapter 40 and the housing 10. Through the reliable creepage distance and clearance provided by the insulating component 50, microscopic defects such as burrs, sharp corners, and weld spatters may exist on the adapter 40 and the housing 10. Air insulation alone could easily cause electric field concentration at these points. The insulating component 50 completely covers the side of the adapter 40 facing the housing 10, isolating it from the housing 10.

[0106] An insulating component is disposed between the terminal and the lower surface of the battery casing to insulate the terminal (electrode terminal) from the lower surface (or bottom surface) of the battery casing and to insulate the cell from the cover plate, thereby reducing the risk of short circuit.

[0107] The insulating component can be plastic, rubber, or other insulating materials. The plastic can include at least one of polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), and polyvinyl chloride (PVC). The rubber can include at least one of fluororubber, nitrile rubber, or isobutyl rubber.

[0108] The insulating component can be fixed to the cover plate by an adapter or by heat fusion.

[0109] In one possible implementation, the insulating element 50 is fixed to the cover plate.

[0110] Thermogravimetric loss is a key indicator for measuring the proportion of mass loss of a material during heating, and it directly reflects its decomposition temperature, volatile content, and thermal stability.

[0111] a, b, and k satisfy: 0.0036 ≤ a / (k×b) ≤ 109.6491.

[0112] Meanwhile, by limiting the thermal weight loss rate of the insulating component 50, the temperature resistance of the insulating component 50 is controlled, and it is coordinated with the overlapping dimensions of the first and second solder marks 42 and the staggered dimensions of the second and third solder marks 31. When the staggered distance between the second solder mark 42 and the third solder mark 31 increases, i.e., when 'a' increases, the size of the overlapping area of ​​the first solder mark 41 and the second solder mark 42 can be increased, i.e., 'b' can be increased. At the same time, the thermal stability of the insulating component 50 can be adjusted, i.e., the thermal weight loss rate 'k' can be adjusted so that 'a / (k×b)' meets a suitable range, so that the battery has a faster current transmission rate and better fast charging capability. At the same time, it avoids the problem that the heat generated during the welding process of the first solder mark 41, the second solder mark 42, and the third solder mark 31 could cause the insulating component 50 to melt, resulting in the adapter 40 overlapping with the shell 10 and causing a short circuit, thereby affecting the battery insulation performance and improving the safety of the battery 100.

[0113] The test method for the thermal weight loss rate k is as follows: the battery is discharged to the lower limit voltage at a rate of 0.33C, the battery is disassembled, the insulating parts are taken out, and the insulating parts are dried at 50℃ for 4 hours. 20mg of the dried insulating parts are placed in a NETZSCH thermogravimetric analyzer TG209F1. Under a nitrogen atmosphere, the initial temperature is 40℃, and the temperature is increased to 800℃ at a rate of 10℃ / min. After holding at the constant temperature for 10min, the temperature is lowered to room temperature, and the mass of the insulating parts is measured and recorded as m. The thermal weight loss rate k% is calculated according to the formula k% = ((20-m) / 20) × 100%.

[0114] The test methods for a and b are as follows: use vernier calipers to measure the value of b, which is the overlap of the first weld mark 41 and the second weld mark 42 in the width direction, and the value of a, which is the misalignment between the second weld mark 42 and the third weld mark 31.

[0115] In one possible implementation, a satisfies: 1mm≤a≤15mm.

[0116] Parameter 'a' directly quantifies the staggered spacing between the second weld mark 42 and the third weld mark 31. By setting the lower limit of 'a', a minimum safe distance must be maintained between the second weld mark 42 and the third weld mark 31 in vertical space during welding, avoiding direct superposition of welding heat sources. This effectively separates the heat-affected zones of the two weld points, reducing the risk of damage to the lower insulating component 50 due to heat accumulation. By setting the upper limit of 'a', the transmission path of current from the adapter 40 through the terminal post 30 to the busbar 201 is limited, ensuring that the current distance between the second weld mark 42 and the third weld mark 31 is within a certain range. This reduces internal resistance, improves the transmission rate of internal and external current in the battery 100, and thus improves the charge / discharge rate and fast charging capability of the battery 100.

[0117] like Figure 7As shown, in one possible implementation, along the length direction of the housing 10, the distance between the third solder mark 31 and the adjacent end of the housing 10 is less than the distance between the second solder mark 42 and the end of the housing 10. The ends of the housing 10 are the two side edges of the housing 10 in the first direction X.

[0118] By placing the third solder mark 31 on the outside of the housing 10, and since the second solder mark 42 is staggered from the third solder mark 31, the position of the second solder mark 42 in the length direction of the housing 10 is restricted, and the second solder mark 42 is confined to the middle region of the housing. Since the first solder mark 41 connecting the tab 22 and the adapter 40 is restricted by the lead-out position of the tab 22 in the middle region of the housing 10, the distance between the first solder mark 41 and the second solder mark 42 is reduced, thereby shortening the current transmission path, reducing the resistance of the conductive path, increasing the current transmission rate, reducing the internal ohmic loss and heat generation of the battery 100 during high-rate charging and discharging, and improving the current transmission efficiency and power performance of the battery 100.

[0119] The third weld mark 31, which generates a large amount of welding heat and serves as an external heat source interface, is arranged on the outer side of the end of the housing 10, with a large distance between it and the core area inside the battery 100. Some of the heat generated during welding and operation can be directly dissipated to the external space of the battery 100 or the module heat dissipation structure, reducing radial heat radiation and conduction to the area where the internal cell 20 and the insulating component 50 are located, which is beneficial to long-term reliability.

[0120] like Figure 11 As shown, in one possible implementation, the projection of the third solder mark 31 surrounds the projection of the second solder mark 42 in the height direction of the housing 10. That is, on the projection plane parallel to the first direction X and the second direction Y, the projection of the third solder mark 31 is annular, and the projection of the second solder mark 42 is located in the middle of the projection of the third solder mark 31.

[0121] In one possible implementation, the projection of the third solder mark 31 is a circular ring, a square ring, or other pattern with a blank center.

[0122] By surrounding the second solder mark 42 with the third solder mark 31, the contact area between the third solder mark 31 and the electrode post 30 and the conductive bus 201 is increased, thereby increasing the effective conductive cross-sectional area and welding area, reducing the internal resistance of the third solder mark 31. Current can flow from the conductive bus 201 into / out of the electrode post 30 evenly through the entire surrounding third solder mark 31, avoiding the current congestion effect. This allows the temperature of the third solder mark 31 to be reduced during charging and discharging, enabling it to safely and stably carry higher currents and meet the requirements of ultra-high rate charging and discharging.

[0123] The surrounding third weld 31 firmly connects the conductive bus 201 to the pole post 30, enhancing the mechanical integrity and vibration and impact resistance of the electrical connection node, thereby preventing connection failure caused by weld cracking.

[0124] In one possible implementation, when the third solder mark 31 is located on the outside of the housing 10, the size of the projection of the second solder mark 42 in the height direction of the housing 10 is M, where M satisfies: 2mm≤M≤8mm.

[0125] The size of the projection of the second solder mark 42 is within the plane formed by the first direction X and the second direction Y. The range of the projection size of the second solder mark 42 is that the direction of the size may be the first direction X, the second direction Y, or any direction formed by the combination of the first direction X and the second direction Y.

[0126] The projected size of the second weld mark 42 determines the effective conductive cross-sectional area of ​​the conductive interface. Setting a lower limit for the size ensures that the connection has sufficient minimum current carrying capacity, preventing excessively high local current density and increased resistance due to an excessively small welding area, which could lead to abnormal heating and performance bottlenecks, thus ensuring that the basic rate requirements of the battery 100 design are met. Setting an upper limit for the size avoids unnecessary excessive enlargement of the welding area. An excessively large second weld mark 42 requires a longer welding time and a higher total heat input, which would increase the heat-affected zone and exacerbate thermal deformation, causing a longer thermal load on the insulator 50, thereby affecting the insulation performance of the insulator 50.

[0127] In one possible implementation, when the third solder mark 31 is located on the outside of the housing 10, the size of the projection of the third solder mark 31 in the height direction of the housing 10 is N, where N satisfies: 2mm≤N≤4mm.

[0128] The size of the projection of the third solder mark 31 is within the plane formed by the first direction X and the second direction Y. The range of the projection size of the third solder mark 31 is that the direction of the size may be the first direction X, the second direction Y, or any direction formed by the combination of the first direction X and the second direction Y.

[0129] In one possible implementation, the third solder mark 31 is annular, and the size of the third solder mark 31 is its annular width.

[0130] The third solder mark 31 is the interface through which the battery 100 exchanges energy with the external circuit via the busbar 201. Its size directly determines the current-carrying capacity and mechanical connection strength. Setting a lower limit for the size ensures that the connection has the minimum safe current-carrying capacity to meet the maximum output / input current of the battery 100, preventing overheating under high current conditions due to increased contact resistance caused by an excessively small size, or even melting of the solder joint. Setting an upper limit for the size avoids unnecessary excessive enlargement of the welding area. An excessively large third solder mark 31 requires a longer welding time and a higher total heat input, which will increase the heat-affected zone and aggravate thermal deformation, causing a longer heat load on the underlying insulating component 50, thereby affecting the insulation performance of the insulating component 50.

[0131] When the third weld mark 31 is designed to surround the second weld mark 42 in the height direction, its size range ensures the shape of the surround weld, ensuring that each surround weld mark produced has uniform penetration, consistent width and closure, thereby reliably realizing the increased current carrying capacity and uniform stress brought about by the surround weld.

[0132] In one possible implementation, the projection of the second solder mark 42 surrounds the projection of the third solder mark 31 in the height direction of the housing 10. That is, on the projection plane parallel to the first direction X and the second direction Y, the projection of the second solder mark 42 is annular, and the projection of the third solder mark 31 is located in the middle of the projection of the second solder mark 42.

[0133] The annular second solder mark 42 can increase the size of the second solder mark 42 on the adapter 40, thereby shortening the distance between the second solder mark 42 and the first solder mark 41, reducing the current transmission path, thereby reducing resistance and improving overcurrent capacity.

[0134] like Figure 8 As shown, in one possible implementation, along the length direction of the housing 10, the distance between the third solder mark 31 and the adjacent end of the housing 10 is greater than the distance between the second solder mark 42 and the end of the housing 10. The ends of the housing 10 are the two side edges of the housing 10 in the first direction X.

[0135] By placing the welding position of the second solder mark 42 (connecting the adapter 40 and the terminal post 30) closer to the outer side of the end of the housing 10, the distance between it and the first solder mark 41 (connecting the terminal tab 22 and the adapter 40) is increased. This avoids the first solder mark 41 and the second solder mark 42 being too close, causing the heat generated during welding to overlap and melt or cause thermal damage. It also prevents the adapter 40 from colliding with the housing 10 due to insulation failure, which could lead to a short circuit inside the battery 100.

[0136] Furthermore, by placing the second solder mark 42 externally, the space in the middle area of ​​the battery 100 casing 10 is freed up, allowing the first solder mark 41, the adapter 40, and the connected tab 22 to have a more spacious and reasonable layout, reducing assembly stress and thermal expansion stress caused by the compact structure.

[0137] In one possible implementation, when the second solder mark 42 is located on the outside of the housing 10, the size of the projection of the second solder mark 42 in the height direction of the housing 10 ranges from 3mm to 10mm.

[0138] The size of the projection of the second solder mark 42 is within the plane formed by the first direction X and the second direction Y. The range of the projection size of the second solder mark 42 is that the direction of the size may be the first direction X, the second direction Y, or any direction formed by the combination of the first direction X and the second direction Y.

[0139] The projected size of the second weld mark 42 determines the effective conductive cross-sectional area of ​​the conductive interface. Setting a lower limit for the size ensures that the connection has sufficient minimum current carrying capacity, preventing excessively high local current density and increased resistance due to an excessively small welding area, which could lead to abnormal heating and performance bottlenecks, thus ensuring that the basic rate requirements of the battery 100 design are met. Setting an upper limit for the size avoids unnecessary excessive enlargement of the welding area. An excessively large second weld mark 42 requires a longer welding time and a higher total heat input, which would increase the heat-affected zone and exacerbate thermal deformation, causing a longer thermal load on the insulator 50, thereby affecting the insulation performance of the insulator 50.

[0140] In one possible implementation, when the second solder mark 42 is located on the outside of the housing 10, the projected size of the third solder mark 31 in the height direction of the housing 10 ranges from 3mm to 5mm.

[0141] The size of the projection of the third solder mark 31 is within the plane formed by the first direction X and the second direction Y. The range of the projection size of the third solder mark 31 is that the direction of the size may be the first direction X, the second direction Y, or any direction formed by the combination of the first direction X and the second direction Y.

[0142] The third solder mark 31 is the interface through which the battery 100 exchanges energy with the external circuit via the busbar 201. Its size directly determines the current-carrying capacity and mechanical connection strength. Setting a lower limit for the size ensures that the connection has the minimum safe current-carrying capacity to meet the maximum output / input current of the battery 100, preventing overheating under high current conditions due to increased contact resistance caused by an excessively small size, or even melting of the solder joint. Setting an upper limit for the size avoids unnecessary excessive enlargement of the welding area. An excessively large third solder mark 31 requires a longer welding time and a higher total heat input, which will increase the heat-affected zone and aggravate thermal deformation, causing a longer heat load on the underlying insulating component 50, thereby affecting the insulation performance of the insulating component 50.

[0143] In one possible implementation, the distance between the second solder mark 42 and the third solder mark 31 along the height direction of the housing 10 is y, where y satisfies: 3.5mm≤y≤15mm.

[0144] The parameter y directly controls the degree of thermal interference between the second weld mark 42 and the third weld mark 31 during welding. By setting a lower limit, the minimum safe spatial distance between the heat-affected zones of the two weld points during welding is ensured, thereby preventing the heat-affected zones from overlapping and merging due to the weld points being too close, and preventing the lower insulating component 50 from failing due to accumulated heat, thus affecting the insulation effect between the casing 10 and the adapter 40, the terminal post 30, or the cell 20. By setting an upper limit, excessive distance is avoided, which would cause the current path to become circuitous, increase impedance, and generate more heat during high-rate charging and discharging, thus affecting the high-rate charging and discharging performance of the battery.

[0145] In one possible implementation, the projection of the second solder mark 42 at least partially overlaps with the projection of the third solder mark 31 in the height direction of the housing 10.

[0146] By aligning the projection of the second solder mark 42 with the projection of the third solder mark 31, the current transmission path from the second solder mark 42 to the third solder mark 31 is vertical and the shortest, eliminating the current detour in the horizontal direction, reducing the contact resistance and transmission impedance at the connection, and improving the overall electrical efficiency.

[0147] In one possible implementation, the distance between the second solder mark 42 and the third solder mark 31 along the height direction of the housing 10 ranges from 3mm to 12mm.

[0148] Setting a lower limit ensures the minimum safe spatial distance between the heat-affected zones of the two solder joints during welding, thus preventing the heat-affected zones from overlapping and merging due to the solder joints being too close, and preventing the lower insulating component 50 from failing due to accumulated heat. Setting an upper limit avoids an excessively long current transmission path from the second solder mark 42 to the third solder mark 31, which could affect charging and discharging performance.

[0149] In one possible implementation, the second solder mark 42 and the third solder mark 31 are spaced apart along the length of the housing 10.

[0150] By setting the projection of the second weld mark 42 and the third weld mark 31 at intervals, the two main welding heat sources are separated, preventing the insulation component 50 from melting due to excessive local temperature caused by the heat superposition of the two weld points being close together. This reduces the safety problems of overlapping and internal short circuits of the adapter 40-shell 10 caused by thermal failure of the insulation component 50.

[0151] In one possible implementation, the projection of the first solder mark 41 and the projection of the second solder mark 42 at least partially overlap in the width direction of the housing 10.

[0152] That is, on the projection plane formed by the first direction X and the third direction Z, there is an overlapping area between the orthographic projection of the first solder mark 41 and the orthographic projection of the second solder mark 42.

[0153] By aligning the projections of the first solder mark 41 and the second solder mark 42 in the width direction of the housing 10, the transmission path of current from the tab 22 through the adapter 40 to the terminal post 30 is shortened, reducing internal resistance and decreasing energy loss and heat generation of the battery 100 during high-rate charging and discharging. This also improves the transmission rate of current inside and outside the battery 100, ensuring uniform current distribution even during ultra-high-current charging and discharging, effectively reducing internal resistance, and thus improving the charge / discharge rate and fast charging capability of the battery 100.

[0154] Meanwhile, the fact that the projection of the first solder mark 41 coincides with the projection of the second solder mark 42 aligns the two functional areas on the adapter 40 used to connect the tab 22 and the pole post 30, thereby simplifying the shape design of the adapter 40, making it easier to manufacture, and improving production yield and efficiency.

[0155] In one possible implementation, b satisfies: 1mm ≤ b ≤ 15mm.

[0156] Parameter b directly determines the width of the shortest effective conductive path for current to flow from the first solder mark 41 to the second solder mark 42. By setting a lower limit, sufficient overlap area is ensured between the first and second solder marks, providing a minimum and low-resistance effective conductive path for current within the adapter, guaranteeing efficient current transmission. By setting an upper limit, excessive overlap area is prevented. A larger overlap area in the welding region may lead to heat accumulation of the solder marks during welding, increasing thermal damage to the insulation component 50 and potentially causing an internal short circuit.

[0157] In one possible implementation, the projection of the first solder mark 41 and the projection of the second solder mark 42 at least partially coincide along the length of the housing 10. Along the width of the housing 10, the interval between the first solder mark 41 and the second solder mark 42 is x, where x satisfies: 1mm ≤ x ≤ 20mm.

[0158] Parameter x ensures a balance between thermal safety and electrical performance. By setting a lower limit, direct superposition of welding heat sources is prevented, effectively separating the heat-affected zones of the two weld points. This reduces the risk of damage to the insulation component 50 caused by heat accumulation, which could lead to an internal short circuit caused by the overlap between the adapter 40 and the housing 10.

[0159] By setting an upper limit, the transmission path of current from the tab 22 through the adapter 40 to the terminal 30 is limited, ensuring that the current distance between the first solder mark 41 and the second solder mark 42 is within a certain range, reducing the current path, thereby reducing the internal resistance, improving the transmission rate of the internal and external current of the battery 100, and thus improving the charge and discharge rate and fast charging capability of the battery 100.

[0160] In one possible implementation, the distance between the second weld mark 42 and the third weld mark 31 along the height direction of the housing 10 is y. x and y satisfy: 4mm ≤ x + y ≤ 32mm.

[0161] The sum of parameters x and y, x+y, ensures a balance between thermal safety and electrical performance, specifically through overall spatial control from the first internal solder mark 41 to the third external interface solder mark 31. By setting a lower limit, direct superposition of welding heat sources is prevented, effectively separating the heat-affected zones between the three solder points. This reduces the risk of damage to the underlying insulation component 50 due to heat accumulation, thus preventing internal short circuits caused by the overlap between the adapter 40 and the housing 10.

[0162] By setting an upper limit, the transmission path of current from the tab 22 through the adapter 40 to the terminal 30, and from the adapter 40 through the terminal 30 to the busbar 201 is limited. This ensures that the current distance between the first solder mark 41 and the second solder mark 42, and between the second solder mark 42 and the third solder mark 31, is within a certain range. This reduces the current path, thereby lowering the internal resistance and improving the transmission rate of the internal and external current of the battery 100. As a result, the charge / discharge rate and fast charging capability of the battery 100 are improved.

[0163] like Figure 9 As shown, in one possible implementation, the tab 22 is located between the adapter 40 and the insulator 50, that is, the tab 22 is placed on top.

[0164] In the top-mounted tab 22 layout, the tab 22 is located on the adapter 40, which makes the connection at the top of the battery device 200 more compact. This reduces the thickness of the tab 22 on the top of the cell 20, shortens the space occupied by the tab 22, saves space in the height direction, improves the space utilization rate inside the cell 20, and allows the cell 20 to be set larger, thereby increasing the energy density of the battery device 200.

[0165] Meanwhile, when the cell 20 expands during cycling, the resulting expansion force pushes the tab 22 upwards. The adapter 40 directly bears and transmits this expansion force, thereby reducing the structural deformation of the tab 22 and improving the mechanical integrity of the battery 100 under long-term cycling.

[0166] In one possible implementation, when the tab 22 is located between the adapter 40 and the insulator 50, a satisfies: 1.5mm ≤ a ≤ 15mm.

[0167] Parameter 'a' directly quantifies the staggered spacing between the second weld mark 42 and the third weld mark 31. By setting the lower limit of 'a', a minimum safe distance must be maintained between the second weld mark 42 and the third weld mark 31 in vertical space during welding, avoiding direct superposition of welding heat sources. This effectively separates the heat-affected zones of the two weld points, reducing the risk of damage to the lower insulating component 50 due to heat accumulation. By setting the upper limit of 'a', the transmission path of current from the adapter 40 through the terminal post 30 to the busbar 201 is limited, ensuring that the current distance between the second weld mark 42 and the third weld mark 31 is within a certain range. This reduces internal resistance, improves the transmission rate of internal and external current in the battery 100, and thus improves the charge / discharge rate and fast charging capability of the battery 100.

[0168] In one possible implementation, there are two tabs 22, which are respectively disposed on both sides of the adapter 40 along the width direction of the housing 10. The two tabs 22 are respectively connected to the adapter 40 via a first solder mark 41.

[0169] In one possible implementation, the first solder mark 41 includes a first sub-solder mark 411 and a second sub-solder mark 412. Along the width direction of the housing 10, the first sub-solder mark 411 and the second sub-solder mark 412 are located on both sides of the second solder mark 42.

[0170] Since the first solder mark 41 is used to weld the tab 22, dividing the first solder mark 41 into a first sub-solder mark 411 and a second sub-solder mark 412 allows the thicker tab 22 to be divided into two relatively thinner tabs 22 for separate welding. Welding the thicker tab 22 requires more heat. By dividing it into two sub-solder marks, the heat required for each sub-solder mark is reduced. Simultaneously, the welding heat is distributed across two spatially separated sub-solder marks. Compared to concentrating the heat in a single, high-heat first solder mark 41, this avoids excessively high peak temperatures and excessively large heat-affected zones in localized areas, reducing thermal damage to the insulation component 50. Furthermore, it avoids the problem of large layering along the tab 22 lead-out direction when the tab 22 is thick, which would reduce the welding area of ​​the first solder mark 41, increase its resistance, and affect battery overcurrent.

[0171] A single first solder mark 41 would cause the current flowing out of the tab 22 to concentrate and surge into the adapter 40 from one side, resulting in uneven current distribution on the adapter 40. By using two spatially separated sub-solder marks, the current is forced to flow out of the tab 22 and simultaneously injected into the adapter 40 through the two sub-solder marks, so that the current enters the adapter 40 from both sides in the width direction, making the current distribution more uniform. This reduces the lateral current density of the adapter 40 body 21 and effectively avoids local ohmic overheating caused by current congestion on one side of the path, thereby improving the overall current carrying capacity and the temperature rise uniformity during long-term operation.

[0172] At the same time, after welding is completed, the two sub-weld marks form a physical constraint on the tab 22 from both sides, limiting the minor displacement or swing that the tab 22 may undergo in subsequent use.

[0173] In one possible implementation, the adapter 40 is provided with a notch 43. Along the width direction of the housing 10, the notch 43 is located between the first sub-solder mark 411 and the second sub-solder mark 412.

[0174] The purpose of setting the notch 43 is to form overcurrent protection in the battery device 200, which melts the adapter 40 when the current is too large, preventing thermal runaway due to excessive current.

[0175] The size of the notch 43 must strike a balance between thermal safety and electrical performance. Its range directly limits the boundaries of the functional effectiveness and safety of the battery device 200. Setting an upper limit prevents the notch 43 from becoming excessively wide. An overly large notch 43 would affect current flow, forcing the current to detour, increasing path resistance, and impacting the charge / discharge rate and fast-charging capability of the battery 100. Simultaneously, an overly large notch 43 would weaken the overall rigidity and bending resistance of the adapter 40 in the width direction, making it more prone to deformation under stress and affecting the mechanical stability of the connection. Setting a lower limit ensures that the notch 43 is not too narrow. An overly narrow notch 43 would result in excessive overcurrent, failing to guarantee melting and thermal runaway protection in the event of excessive current.

[0176] In one possible implementation, the notch 43 may be provided on one side or both sides of the adapter 40 along the length of the housing 10.

[0177] like Figure 10 As shown, in one possible implementation, the adapter 40 is provided with at least two sub-notches 431. Along the width direction of the housing 10, the sub-notches 431 are located between the first sub-solder mark 411 and the second sub-solder mark 412. At least two sub-notches 431 are spaced apart in the width direction of the housing 10.

[0178] The design of multiple sub-notches 431 can achieve the purpose of setting notches 43, namely, to provide overcurrent protection and to improve the overall strength of the adapter 40 and prevent deformation of the adapter 40. Multiple sub-notches 431 can significantly improve the bending stiffness and overall stability of the adapter 40 in the width direction, and its effect is far superior to a single large notch 43 of the same total width.

[0179] In one possible implementation, the spacing between the sub-notches 431 along the width direction of the housing 10 ranges from 5 mm to 20 mm.

[0180] The spacing between the sub-notches 431 affects the strength of the adapter 40 and the distance between the first solder mark 41 and the second solder mark 42. By setting a lower limit, the adapter 40 is ensured to have sufficient mechanical strength. Too small a spacing means that the adapter 40 has lower strength and is prone to deformation. At the same time, it is prone to breakage under vibration or stress. Since the sub-notches 431 are all located between the first solder mark 41 and the second solder mark 42, by setting an upper limit, the distance between the first solder mark 41 and the second solder mark 42 is indirectly limited. This prevents the problem of increased resistance and increased heat generation caused by the increased current distance between the first solder mark 41 and the second solder mark 42. At the same time, by reducing the current path, the internal resistance is reduced, and the transmission rate of the internal and external current of the battery 100 is improved, thereby improving the charge and discharge rate and fast charging capability of the battery 100.

[0181] In one possible implementation, the size range of the sub-notch 431 in the width direction of the housing 10 is [value missing].

[0182] By setting an upper limit, the sub-notch 431 is prevented from becoming excessively wide. An excessively large sub-notch 431 would affect current overcurrent, forcing the current to detour, increasing path resistance, and impacting the charge / discharge rate and fast charging capability of the battery 100. Simultaneously, an excessively large sub-notch 431 would weaken the overall rigidity and bending resistance of the adapter 40 in the width direction, making it more prone to deformation under stress and affecting the mechanical stability of the connection. By setting a lower limit, the sub-notch 431 is ensured not to be too narrow. An excessively narrow sub-notch 431 would result in a large overcurrent, failing to guarantee fuse tripping under excessive current and thus failing to achieve thermal runaway protection.

[0183] In one possible implementation, in the width direction of the housing 10, the projection of the notch 43 at least partially coincides with the projection of the first solder mark 41, and there is a gap between the projection of the notch 43 and the projection of the second solder mark 42.

[0184] In the width direction of the housing 10, the projection of the notch 43 indicates that the projection line is parallel to the second direction Y, and the projection plane is perpendicular to the second direction Y, that is, the projection plane is parallel to the plane formed by the first direction X and the third direction Z, and the projection area of ​​the notch 43 on the projection plane.

[0185] The projection of the notch 43 and the projection of the first solder mark 41 at least partially overlap, that is, on the projection plane formed by the first direction X and the third direction Z, there is an overlapping area between the orthographic projection of the notch 43 and the orthographic projection of the first solder mark 41.

[0186] There is a gap between the projection of the notch 43 and the projection of the second solder mark 42, that is, on the projection plane formed by the first direction X and the third direction Z, the orthographic projection of the notch 43 and the orthographic projection of the second solder mark 42 do not coincide.

[0187] After heat is generated from the first solder mark 41, it is directly blocked by the gap 43 in the area overlapping with the first solder mark 41 when it is conducted to the sides and the middle area in the width direction. This achieves direct and effective isolation of the heat source and prevents the heat generated by the first solder mark 41 from spreading laterally to the second solder mark 42 and affecting the insulating component 50, causing the insulating component 50 to melt and causing the adapter 40 to overlap with the shell 10, resulting in an internal short circuit.

[0188] The projection of the notch 43 and the second solder mark 42 is spaced apart, so that the notch 43 is far away from the second solder mark 42. This ensures the integrity of the main current interface at the connection point from the adapter 40 to the terminal 30. The second solder mark 42 is a key interface for current to flow out to the external circuit. The notch 43 keeps a distance from it, ensuring that the current flow path in this area is the shortest. This avoids the increased internal resistance caused by the longer path of the current after bypassing the notch 43 and entering the second solder mark 42. This improves the transmission rate of the internal and external current of the battery 100, thereby improving the charge and discharge rate and fast charging capability of the battery 100.

[0189] In one possible implementation, the distance between the projection of the notch 43 and the projection of the second solder mark 42 along the length of the housing 10 ranges from 1 mm to 10 mm.

[0190] If the interval is too small, it means that the notch 43 and the second solder mark 42 are too close in space along the length direction, which weakens the heat insulation function of the notch 43. When heat is generated from the first solder mark 41 and conducted through the adapter 40, it can bypass the notch 43 and be conducted to the area of ​​the second solder mark 42, resulting in a reduction in the heat insulation effect, an increase in heat generation, and the melting of the insulating part 50, causing the adapter 40 to overlap with the shell 10 and causing an internal short circuit.

[0191] If the spacing is too large, although sufficient thermal isolation is ensured, the current flowing from the first solder mark 41 area to the second solder mark 42 must detour, lengthening the current transmission path between the first solder mark 41 and the second solder mark 42, resulting in increased resistance. This leads to severe overall heat generation during battery 100 operation, especially during high-current charging and discharging.

[0192] In one possible implementation, the tab 22 comprises at least two layers of tabs. The tabs extend along the length of the cell 20. Along the extension direction of the tab 22, the dimensions of the at least two layers of tabs are different.

[0193] Since the tab 22 is led out from the cell 20 through multiple layers of tabs, if all the tabs are of equal length and too large, due to the top position of the tab 22, after the tab 22 is bent out, some of the tabs will extend beyond the overall position of the tab 22, resulting in too much coverage of the adapter piece. This will cause the end or edge of the tab to enter or get very close to the welding area of ​​the second solder mark 42, thus interfering with the welding of the second solder mark 42.

[0194] In one possible implementation, the size of the tabs gradually increases along the stacking direction of at least two layers of tabs.

[0195] When the smaller tab is located on the inside of the stack and the larger tab is located on the outside, the tab 22 naturally forms a relatively flat cross-section in the bending area. This provides a flat welding base for the first weld mark 41 to be welded to the adapter 40, which is conducive to forming a weld point with sufficient area and strong bonding.

[0196] In one possible implementation, a, b, and k satisfy: 0.0067 ≤ a / (k×b) ≤ 20.5346.

[0197] By limiting the thermal weight loss rate of the insulating component 50, controlling its temperature resistance, and coordinating its overlap dimensions with the first and second solder marks 42 and the staggered dimensions with the second and third solder marks 31, the insulating component 50 maintains its structural integrity and insulation performance under welding thermal shock. This prevents the adapter 40 from colliding with the housing 10 due to insulation failure, which could lead to internal short circuits and thermal runaway in the battery 100, thus improving the safety of the battery 100.

[0198] In one possible implementation, b and k satisfy: 1mm ≤ b ≤ 15mm; and / or, 0.1% ≤ k ≤ 20%.

[0199] Parameter b directly determines the width of the shortest effective conductive path for current to flow from the first solder mark 41 to the second solder mark 42. By setting a lower limit, a minimum but effective conductive path is ensured, guaranteeing efficient current transmission. By setting an upper limit, excessively large overlapping areas are prevented. A larger overlapping area in the welding region could lead to heat accumulation of the solder marks during welding, increasing the risk of thermal damage to the insulation component 50 and potentially causing an internal short circuit.

[0200] The parameter k determines the thermal stability of the insulating component 50. By setting a lower limit, premature failure of the insulating component 50 is prevented, ensuring its stability at the battery 100's maximum operating temperature and during localized overheating. This prevents the adapter 40 from colliding with the casing 10, which could lead to internal short circuits and thermal runaway within the battery 100. By setting an upper limit, the material's performance is limited, thereby reducing material and processing costs.

[0201] In one possible implementation, the thickness of the insulating member 50 in the height direction of the housing 10 ranges from 1 mm to 5 mm.

[0202] The purpose of the insulating element 50 is to provide sufficient dielectric strength to prevent short circuits between high-voltage components (such as the adapter 40 and the tab 22) and the housing 10. The thickness range of this element directly defines the boundary between safety and compactness. Setting a lower limit ensures the electrical safety of the battery device 200, preventing insulation breakdown, while also providing sufficient mechanical strength. Setting an upper limit prevents excessive thickness from wasting space, reducing energy density, and increasing the cost of the battery device 200.

[0203] In one possible implementation, the thickness of the regions on both sides of the insulating member 50 is greater than the thickness of the middle region of the insulating member 50 in the width or length direction of the housing 10. b satisfies: 1mm ≤ b ≤ 14mm.

[0204] That is, the edge region of the insulating member 50 is thicker, which can be in the width direction of the housing 10, with the two sides of the insulating member 50 being thicker. Alternatively, it can be in the length direction of the housing 10, with the two sides of the insulating member 50 being thicker.

[0205] By making the thickness of the insulating component 50 greater on both sides and less in the middle, a synergistic effect of enhanced edge sealing and central heat dissipation is achieved. The thickened sides enhance the reliability of the edge seal, effectively preventing electrolyte leakage or the intrusion of external contaminants. The thinned middle area reduces thermal resistance, facilitating faster heat dissipation. Simultaneously, the thinned middle area also reduces weight and saves material, achieving lightweight design and lower costs.

[0206] In one possible implementation, the battery device 200 includes a plurality of batteries 100, and a conductive bus 201 electrically connects at least two adjacent batteries 100.

[0207] By welding the conductive busbar 201 to the battery 100 terminals 30 to form surface contact, the contact resistance and overall resistance are lower than those of point contact wires. This reduces ohmic losses during energy transfer between batteries 100, improving the overall charging and discharging efficiency of the battery 100 system. Simultaneously, the conductive busbar 201 can carry large currents, enabling it to safely and stably handle the high currents generated during charging and discharging of the battery 100, especially during high-power output, thus avoiding safety issues caused by wire overheating or melting.

[0208] The busbar 201 is not only an electrical pathway, but also provides a robust mechanical connection and structural integration. The busbar 201 locks multiple independent battery cells 100 together at the top, enhancing the overall mechanical integrity and vibration and shock resistance of the entire battery device 200.

[0209] In one possible implementation, the distance between the third solder mark 31 in two adjacent batteries 100 ranges from 12mm to 80mm.

[0210] The distance between the third solder marks 31 in two adjacent batteries 100 is the spacing between the projections of the two third solder marks 31 in the plane formed by the first direction X and the second direction Y. That is, the direction of the distance may be the first direction X, the second direction Y, or any direction formed by the combination of the first direction X and the second direction Y.

[0211] The third solder mark 31 is the fixing point of the conductive busbar 201, and the distance between the two determines the mechanical stress state of the conductive busbar 201. By setting a lower limit, sufficient spacing is ensured between the two third solder marks 31 to prevent excessive stress concentration. This prevents the expansion of the battery cell 20, vibration, or even small displacements caused by thermal expansion and contraction from causing extreme stress at the solder joint, leading to solder joint cracking or fatigue fracture of the conductive busbar 201. By setting an upper limit, excessive suspension span of the conductive busbar 201 is prevented from easily generating excessive deflection under stress, which could potentially cause interference or short circuits with other components.

[0212] In one possible implementation, this application provides a method for preparing a lithium-ion battery, the preparation process of which is as follows:

[0213] (1) Preparation of the positive electrode:

[0214] The prepared positive electrode active material, conductive agent (acetylene black), and binder (PVDF) are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the positive electrode sheet is obtained.

[0215] Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98): (4~1): (4~1).

[0216] (2) Preparation of negative electrode:

[0217] The negative electrode active material, conductive agent (acetylene black), thickener (carboxymethyl cellulose (CMC)), and binder (styrene-butadiene rubber (SBR)) are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained.

[0218] Specifically, the ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96): (4~2): (2~1): (4~1).

[0219] (3) Preparation of electrolyte:

[0220] Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0221] (4) Preparation of the diaphragm:

[0222] Polyethylene film is selected as the diaphragm.

[0223] (5) Preparation of lithium-ion batteries:

[0224] The aforementioned positive electrode, separator, and negative electrode are sequentially wound or stacked to form a bare cell with tabs. The bare cell is then electrically connected to a cover plate with terminals via an adapter. The adapter is welded to the terminals to form a second weld mark, and the adapter is welded to the tabs to form a first weld mark. Before welding the terminals to the adapter, an insulating component is placed between the adapter and the cover plate. After welding, the bare cell is placed in the battery casing, which is a square casing. The battery is then dried, injected with electrolyte, and then packaged, left to stand, formed, and calibrated to obtain a lithium-ion battery.

[0225] The positive electrode active material can be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0226] The negative electrode active material can be selected from one or more of the following negative electrode active main materials: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0227] Battery pack manufacturing method

[0228] Ten batteries are selected, and one end of the conductive busbar is welded to the battery terminal to form a third weld mark. The other end of the conductive busbar is then welded to the terminal of another battery, thereby connecting multiple batteries through the conductive busbar to form a battery pack.

[0229] The electrode temperature test is specifically conducted as follows: Following the above preparation method, five batteries were prepared for each embodiment and comparative example. The batteries of each embodiment and comparative example were connected to a temperature sensor at 25°C, and charged at a constant current rate of 4C until the battery voltage reached its upper limit. Then, constant voltage charging was switched until the battery current dropped to 0.05C. The temperature change of the electrode terminals was recorded throughout the charging process. The temperature of the five battery terminals in each embodiment and comparative example was measured, and the highest value was recorded. If the highest electrode temperature was less than or equal to 45°C, the test result was considered good; if the highest electrode temperature was greater than 45°C but less than 65°C, it was considered qualified; and if the highest electrode temperature was greater than or equal to 65°C, it was considered unqualified.

[0230] When the positive electrode active material of the battery is a nickel-cobalt-manganese ternary cathode, the upper limit voltage is 4.25V and the lower limit voltage is 2.5V. When the positive electrode active material of the battery is lithium iron phosphate, the upper limit voltage is 3.6V and the lower limit voltage is 2.5V.

[0231] In this test, the active material for the positive electrode of the battery was selected from LiNi. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, all other positive electrode materials meet the above test requirements, and the mass ratio of positive electrode active material: conductive agent: binder meets 96:2:2; the negative electrode active material is selected from artificial graphite, and the ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2; the bare cell is selected as a wound cell, and other cell forms meet the above test requirements.

[0232] The insulation component thickness reduction rate test is specifically as follows: Following the above preparation method, five batteries were prepared for each embodiment and comparative example to form one battery pack. The minimum thickness of the insulation component corresponding to the area enclosed by the first and second solder marks was recorded as h1. The batteries of each embodiment and comparative example were charged at a constant current rate of 1C3C at 25°C until the battery voltage reached the upper limit voltage. Then, constant voltage charging was switched until the battery current dropped to 0.05C. After standing for 5 minutes, the batteries were discharged at a 1C3C rate until the lower limit voltage was reached. After standing for 5 minutes, this cycle was repeated 500 times. The batteries were then disassembled, and the minimum thickness of the insulation component corresponding to the area enclosed by the first and second solder marks was measured as h2. According to the formula: thinning rate = ((h1-h2) / h1)×100%, if the thinning rate ≤2%, it is considered good; if the thinning rate is greater than 2% and ≤10%, it is considered qualified; and if it is greater than 10%, it is considered unqualified.

[0233] When the positive electrode active material of the battery is a nickel-cobalt-manganese ternary cathode, the upper limit voltage is 4.25V and the lower limit voltage is 2.5V. When the positive electrode active material of the battery is lithium iron phosphate, the upper limit voltage is 3.6V and the lower limit voltage is 2.5V.

[0234] The positive electrode active material used in this test was selected from LiNi. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, other positive electrode materials all meet the above test requirements. The mass ratio of positive electrode active material: conductive agent: binder meets 96:2:2. The negative electrode active material is selected from artificial graphite. The ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2. The bare cell is selected as a wound cell. Other cell forms all meet the above test requirements.

[0235] It should be noted that the following table compares multiple sets of embodiments and comparative data.

[0236] Table 1 presents the data from pole temperature testing and insulation thickness reduction rate testing for multiple sets of embodiments and comparative examples.

[0237]

[0238] The battery device 200 provided in this application embodiment includes a battery 100 and a conductive bus 201 for electrically connecting the battery 100. The battery 100 includes a housing 10, a battery cell 20, and terminals 30. The housing 10 forms a receiving space 11. The battery cell 20 is disposed within the receiving space 11. The terminals 30 are disposed on the housing 10. The conductive bus 201 is electrically connected to the terminals 30. The battery cell 20 includes a body 21 and a tab 22 connected to the body 21. The tab 22 is electrically connected to the terminals 30 via an adapter 40. The tab 22 is connected to the adapter 40 via a first solder mark 41. The terminals 30 are connected to the adapter 40 via a second solder mark 42. The conductive bus 201 is connected to the terminals 30 via a third solder mark 31. In the width or length direction of the housing 10, the projection of the first solder mark 41 and the projection of the second solder mark 42 at least partially overlap, and the maximum size of the overlapping area is b. In the height direction of the housing 10, the projection of the second solder mark 42 is at least partially offset from the projection of the third solder mark 31, and the maximum dimension between any point in the non-overlapping area of ​​the third solder mark 31 and the second solder mark 42 and the second solder mark 42 is a. An insulating member 50 is provided between the housing 10 and the adapter 40. The thermal weight loss rate of the insulating member 50 is k. a, b, and k satisfy: ≤ a / (k×b) ≤.

[0239] By setting the third solder mark 31 connecting the terminal post 30 to the conductive bus 201 and the second solder mark 42 connecting the adapter 40 to the terminal post 30 to be at least partially staggered in the height direction, the welding heat-affected zone is effectively dispersed, avoiding excessive heat concentration in the corresponding area of ​​the insulating component 50, thereby preventing burn-through or damage to the insulating component 50. At the same time, by limiting the thermal weight loss rate of the insulating component 50 and coordinating it with the overlapping dimensions of the first and second solder marks 42 and the staggered dimensions of the second and third solder marks 31, it is ensured that the insulating component 50 can maintain its structural integrity and insulation performance under welding thermal shock, thereby preventing the adapter 40 from colliding with the casing 10 due to insulation failure, which could lead to internal short circuits and thermal runaway in the battery 100, thus improving the safety of the battery 100. Furthermore, by controlling the first weld 41 connecting the tab 22 to the adapter 40 and the second weld 42 connecting the terminal 30 to the adapter 40 to at least partially overlap in the width or length direction of the casing 10, the transmission path of current from the tab 22 through the adapter 40 to the terminal 30 is shortened. This ensures uniform current distribution even during ultra-high current charging and discharging, effectively reducing internal resistance and thus improving the charge / discharge rate and fast charging capability of the battery 100. The staggered design of the third weld 31 and the second weld 42 also reduces weld fatigue and cracking caused by stress concentration, making the electrical connection between the terminal 30, the adapter 40, and the busbar 201 more stable and reliable. This improves the mechanical stability and electrical connection reliability of the battery device 200, thereby extending the service life of the battery 100.

[0240] This application also provides an electrical device, including an electrical appliance and a battery device 200 as described in any of the above embodiments. The battery device 200 is used to provide electrical energy to the electrical appliance.

[0241] Since the electrical device in this embodiment includes the battery device 200 described in any of the above embodiments, the structure and beneficial effects of the electrical device including the battery device 200 will not be described in detail here.

[0242] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0243] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0244] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0245] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90° or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0246] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery device, characterized by, Includes a battery and a conductive busbar for electrically connecting the battery; The battery includes a casing, a cell, and terminals. The casing forms an accommodating space, the cell is disposed within the accommodating space, the terminals are disposed on the casing, and a conductive bus is electrically connected to the terminals. The cell includes a body and tabs connected to the body. The tabs are electrically connected to the terminals via an adapter. The tabs are connected to the adapter via a first solder mark, the terminals are connected to the adapter via a second solder mark, and the conductive bus is connected to the terminals via a third solder mark. In the width or length direction of the housing, the projection of the first solder mark and the projection of the second solder mark at least partially overlap, and the maximum size of the overlapping area is bmm. In the height direction of the housing, the projection of the second solder mark is at least partially offset from the projection of the third solder mark, and the maximum dimension between any point in the non-overlapping region of the projection of the third solder mark and the projection of the second solder mark and the projection of the second solder mark is amm. An insulating component is provided between the housing and the adapter, and the thermal weight loss rate of the insulating component is k%. a, b, and k satisfy: 0.0036 ≤ a / (k×b) ≤ 109.6491.

2. The battery device according to claim 1, characterized in that, a satisfies: 1mm≤a≤15mm.

3. The battery device according to claim 1, characterized in that, Along the length of the housing, the distance between the third solder mark and the adjacent end of the housing is less than the distance between the second solder mark and the end of the housing.

4. The battery device according to claim 3, characterized in that, In the height direction of the housing, the projection of the third solder mark surrounds the projection of the second solder mark.

5. The battery device according to claim 4, characterized in that, In the height direction of the housing, the projected dimension of the second solder mark is M, where M satisfies: 2mm ≤ M ≤ 8mm; and / or, The projected size of the third solder mark is N, where N satisfies: 2mm≤N≤4mm.

6. The battery device according to claim 1, characterized in that, Along the length of the housing, the distance between the third solder mark and the adjacent end of the housing is greater than the distance between the second solder mark and the end of the housing.

7. The battery device according to claim 6, characterized in that, In the height direction of the housing, the projected size of the second solder mark ranges from 3mm to 10mm; and / or, The projected size of the third solder mark is in the range of 3mm-5mm.

8. The battery device according to claim 1, characterized in that, Along the height direction of the housing, the distance between the second solder mark and the third solder mark is y, where y satisfies: 3.5mm≤y≤15mm.

9. The battery device according to claim 1, characterized in that, In the height direction of the housing, the distance between the second solder mark and the third solder mark ranges from 3mm to 12mm.

10. The battery device according to claim 1, characterized in that, Along the length of the housing, the second solder mark and the third solder mark are spaced apart.

11. The battery device according to claim 1, characterized in that, In the width direction of the housing, the projection of the first solder mark and the projection of the second solder mark at least partially overlap.

12. The battery device according to claim 1, characterized in that, b satisfies: 1mm≤b≤15mm.

13. The battery device according to claim 1, characterized in that, Along the width direction of the housing, the interval between the first solder mark and the second solder mark is x, where x satisfies: 1mm≤x≤20mm.

14. The battery device according to claim 13, characterized in that, Along the height direction of the shell, the distance between the second solder mark and the third solder mark is y, where x and y satisfy: 4mm≤x+y≤32mm.

15. The battery device according to any one of claims 1-14, characterized in that, The electrode tab is located between the adapter and the insulating component.

16. The battery device according to claim 15, characterized in that, a satisfies: 1.5mm≤a≤15mm.

17. The battery device according to any one of claims 1-14, characterized in that, The electrode includes two tabs, and along the width direction of the housing, the two tabs are respectively disposed on both sides of the adapter. The first solder mark includes a first sub-solder mark and a second sub-solder mark, and along the width direction of the housing, the first sub-solder mark and the second sub-solder mark are respectively located on both sides of the second solder mark.

18. The battery device according to claim 17, characterized in that, The adapter has a notch located between the first sub-weld mark and the second sub-weld mark along the width direction of the housing.

19. The battery device according to claim 17, characterized in that, The adapter is provided with at least two sub-notches. Along the width direction of the housing, the sub-notches are located between the first sub-weld and the second sub-weld. In the width direction of the housing, at least two sub-notches are spaced apart.

20. The battery device according to claim 19, characterized in that, Along the width direction of the housing, the spacing between the sub-notches ranges from 5mm to 20mm.

21. The battery device according to claim 18, characterized in that, In the width direction of the housing, the projection of the notch at least partially coincides with the projection of the first solder mark, and there is a gap between the projection of the notch and the projection of the second solder mark.

22. The battery device according to any one of claims 1-14, characterized in that, The tab includes at least two layers of tab plates, which are led out along the length of the battery cell. Along the lead-out direction of the tab, the dimensions of the at least two layers of tab plates are different.

23. The battery device according to any one of claims 1-14, characterized in that, a, b, and k satisfy: 0.0067 ≤ a / (k×b) ≤ 20.5346.

24. The battery device according to any one of claims 1-14, characterized in that, b and k satisfy: 1mm≤b≤15mm; and / or, 0.1%≤k≤20%.

25. The battery device according to any one of claims 1-14, characterized in that, In the height direction of the housing, the thickness of the insulating element ranges from 1mm to 5mm.

26. The battery device according to any one of claims 1-14, characterized in that, In the width or length direction of the housing, the thickness of the two side regions of the insulating member is greater than the thickness of the middle region of the insulating member, and b satisfies: 1mm≤b≤14mm.

27. The battery device according to any one of claims 1-14, characterized in that, The battery device includes a plurality of said batteries, and the conductive bus is electrically connected to at least two adjacent said batteries.

28. The battery device according to claim 27, characterized in that, The distance between the third solder marks in two adjacent batteries ranges from 12mm to 80mm.

29. An electrical appliance, comprising an electrical device and a battery device as described in any one of claims 1-28, the battery device being used to provide electrical energy to the electrical device.

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