Battery cell, battery, electrical apparatus, and energy storage apparatus

Abstract

A battery cell (1), a battery (100), an electrical apparatus, and an energy storage apparatus. The battery cell (1) comprises: a casing (10), having an accommodating space (A); electrode terminals (22) disposed in the casing (10); and at least one electrode assembly (30) disposed in the accommodating space (A), the electrode assembly (30) comprising a main body portion (31) and tabs (32) disposed on the main body portion (31), each tab (32) comprising multiple tab pieces (32a), and each tab (32) being directly connected to an electrode terminal (22). The described structure can improve the reliability and decrease the weight of a battery cell, and even a battery.

Description

Battery cell, battery, electric device and energy storage device

[0001] Cross-reference to related applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202421483290.5, filed on June 26, 2024, entitled “Battery cell, battery, electric device and energy storage device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of batteries, and in particular to a battery cell, a battery, an electric device and an energy storage device. BACKGROUND

[0004] New energy batteries are increasingly widely used in life and industry. For example, new energy vehicles equipped with batteries have been widely used, and batteries are also increasingly used in the energy storage field and the like.

[0005] In new energy vehicles equipped with batteries, the batteries can be used to provide power in whole or in part. In the energy storage field, the batteries can be installed in an energy storage box or directly installed at a user side. With the continuous expansion of the application field of power batteries, not only higher requirements are put forward for the performance of the batteries, but also higher requirements are put forward for the reliability and lightweight of the batteries.

[0006] SUMMARY

[0007] To solve the above technical problems, the present disclosure provides a battery cell, a battery, an electric device and an energy storage device with high reliability and lightweight.

[0008] The present disclosure is implemented by the following technical solutions.

[0009] A first aspect of the present disclosure provides a battery cell, comprising: a shell having an accommodation space; an electrode terminal arranged in the shell; at least one electrode assembly arranged in the accommodation space, the electrode assembly comprising a main body part and a tab arranged on the main body part, the tab comprising a plurality of tab pieces, and the tab being directly connected to the electrode terminal.

[0010] The tab comprises a plurality of tab pieces, and the tab is directly connected to the electrode terminal, which can improve the overcurrent capacity to adapt to the high-rate charging and discharging demand, shorten the overcurrent path, reduce the impedance in the charging and discharging process of the battery cell, and thus reduce the temperature rise, so that even in the use scenario of high-rate charging and discharging of the battery cell, the adverse effects of high temperature on the performance of the battery can be alleviated, and the risk of thermal runaway of the battery cell can be reduced, thereby improving the reliability of the battery cell. In addition, the adapter piece is omitted, so that the battery cell and even the battery are more lightweight.

[0011] In some embodiments, the tab has a connecting portion and a gathered portion, the connecting portion is connected between the main body portion and the gathered portion, the gathered portion is formed by a plurality of tab pieces being connected together in layers, and the gathered portion is directly connected with the electrode terminal.

[0012] The gathered portion is formed by a plurality of tab pieces being connected together in layers, so that when the gathered portion is directly connected with the electrode terminal, the same connection effect as that of the adapter piece and the electrode terminal can be achieved, that is, without reducing the connection effect of the tab and the electrode terminal, the impedance caused by the use of the adapter piece in the past is reduced.

[0013] In some embodiments, a first welding connection portion is formed in the gathered portion, the plurality of tab pieces are connected together by the first welding connection portion, the gathered portion and the electrode terminal are connected with each other by a second welding connection portion, and in the same projection plane perpendicular to the thickness direction of the gathered portion, the projection of the second welding connection portion and the projection of the first welding connection portion have an overlapping portion.

[0014] The plurality of tab pieces are connected together by the first welding connection portion, so that the connection between the plurality of tab pieces in the gathered portion is more compact, and the projection of the second welding connection portion and the projection of the first welding connection portion have an overlapping portion, so that the gathered portion and the electrode terminal connected by the second welding connection portion are more reliable in connection, the risk of false welding is reduced, thereby improving the overcurrent capacity during high-rate charging and discharging, and the temperature rise is also reduced.

[0015] In some embodiments, in the same projection plane perpendicular to the thickness direction of the gathered portion, the projection of the second welding connection portion does not exceed the projection of the first welding connection portion.

[0016] Therefore, all the second welding connection portions are located within the area of the first welding connection portion, further improving the connection reliability between the gathered portion and the electrode terminal.

[0017] In some embodiments, the area of the projection of the second welding connection portion accounts for 30% to 100% of the area of the projection of the first welding connection portion.

[0018] The appropriate welding area between the gathered portion and the electrode terminal can not only meet the overcurrent requirement, but also play a role in overcurrent protection.

[0019] In some embodiments, the gathered portion is configured in a plate structure.

[0020] The internal structure of the gathered portion in the plate structure is more compact, so that when the gathered portion is directly connected with the electrode terminal, it can be closer to the connection effect of the adapter piece and the electrode terminal in the past, thereby further improving the overcurrent performance and the connection reliability.

[0021] In some embodiments, the gathered portion is formed by ultrasonic welding of a plurality of tab pieces.

[0022] The plurality of tab pieces are tightly adhered and pressed together by high-frequency vibration of the ultrasonic welding head, so that the gathered portion is in a compact structure like a plate. Thus, reliable connection can be achieved even if the gathered portion is laser-welded to the electrode terminal.

[0023] In some embodiments, the gathered portion is laser-welded to the electrode terminal.

[0024] Since the gathered portion is connected together in a compact structure by the plurality of tab pieces, reliable connection can be achieved by laser welding as in the past by the adapter piece, the risk of false welding is reduced, the connection reliability is improved, and the processing efficiency can also be improved.

[0025] In some embodiments, the end of the connection portion connected to the gathered portion is located at the center of the thickness direction of the main body portion.

[0026] Thus, the tab-in-center structure makes the overcurrent paths of each tab piece substantially the same, the overcurrent is more uniform, the temperature rise of the battery monomer under high-rate charging and discharging can be reduced, and thus the cycle life of the battery monomer can be significantly improved. In addition, the tab-in-center structure facilitates welding to the electrode terminal.

[0027] In some embodiments, the electrode terminal includes a positive electrode terminal and a negative electrode terminal; the tab includes a positive tab and a negative tab, the positive tab and the negative tab are arranged at the same end of the main body portion, the positive tab is directly connected to the positive electrode terminal, and the negative tab is directly connected to the negative electrode terminal.

[0028] The positive tab and the negative tab are directly connected to the positive electrode terminal and the negative electrode terminal, respectively, which can reduce the internal impedance of the battery, reduce the temperature rise of the battery during charging and discharging, and improve the reliability of the battery.

[0029] In some embodiments, two electrode assemblies are provided, the tabs of the same polarity of the two electrode assemblies are connected, and the tabs of each electrode assembly are directly connected to the electrode terminal through the gathered portion thereof.

[0030] The two electrode assemblies are directly connected to the electrode terminal through the gathered portion thereof, respectively, which can reduce the internal impedance of the battery, reduce the temperature rise of the battery during charging and discharging, and improve the reliability of the battery while improving the capacity of the battery.

[0031] In some embodiments, the two electrode assemblies are arranged opposite to each other along the thickness direction of the main body portion.

[0032] The two electrode assemblies arranged opposite to each other reduce the space occupation of the shell, which is conducive to improving the volume energy density of the battery.

[0033] A second aspect of the present disclosure provides a battery, comprising: a box body; at least one battery monomer provided by the first aspect, the battery monomer being arranged in the box body.

[0034] The third aspect of the present disclosure provides a power consuming device, which comprises the battery cell provided in the first aspect or the battery provided in the second aspect, and the battery is capable of providing electric energy for the power consuming device.

[0035] The fourth aspect of the present disclosure provides an energy storage device, which comprises the battery cell provided in the first aspect or the battery provided in the second aspect, and the battery is capable of storing electric energy and providing electric energy.

[0036] Inventive effects:

[0037] According to the embodiments of the present disclosure, the reliability and light weight of the battery cell and even the battery can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are intended to depict only preferred embodiments of the disclosure and therefore should not be considered to narrow its scope. The drawings are not necessarily to scale, and certain features can be exaggerated to better illustrate and explain the present disclosure. Throughout the drawings, like reference numerals will be used to refer to like components.

[0039] FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present disclosure;

[0040] FIG. 2 is a perspective exploded schematic diagram of a battery according to some embodiments of the present disclosure;

[0041] FIG. 3 is a perspective exploded schematic diagram of a battery cell according to some embodiments of the present disclosure;

[0042] FIG. 4 is a structural schematic diagram of an electrode assembly and an end cover connected together according to some embodiments of the present disclosure;

[0043] FIG. 5 is an exploded schematic diagram of an electrode assembly and an end cover according to some embodiments of the present disclosure;

[0044] FIG. 6 is an enlarged schematic diagram of a partial structure of the electrode assembly in FIG. 5;

[0045] FIG. 7 is an enlarged schematic diagram of a partial structure of an electrode assembly according to some other embodiments of the present disclosure;

[0046] FIG. 8 is a structural schematic diagram of an end cover according to some embodiments of the present disclosure;

[0047] FIG. 9 is a top view of an end cover according to some embodiments of the present disclosure;

[0048] FIG. 10 is an enlarged schematic diagram of a partial cross-sectional structure of an end cover according to some embodiments of the present disclosure;

[0049] FIG. 11 is a cross-sectional schematic diagram of a pressing member pressing a tab onto an electrode terminal according to some embodiments of the present disclosure.

[0050] Reference Signs List:

[0051] 1000 - vehicle

[0052] 100 - battery; 200 - controller; 300 - motor

[0053] 1 - battery

[0054] 2 - case; 3 - lower case; 4 - upper case

[0055] 10 - outer case; 11 - housing; 12 - first outer case wall

[0056] 22 - electrode terminal; 22a - positive electrode terminal; 22b - negative electrode terminal; 221 - first connecting portion; 221a - connecting surface; 222 - second connecting portion; 231 - positioning portion; 231a - first surface; 231b - second surface; 2211 - terminal disc; 2221 - terminal plate; 23 - insulating member; 233 - protruding portion; 234 - explosion-proof valve avoiding hole; 235 - liquid injection avoiding hole

[0057] 30 - electrode assembly; 31 - main body portion; 32 - tab; 32a - tab piece; 32c - positive electrode tab; 32d - negative electrode tab; 321 - connecting portion; 322 - gathering portion; 322b - second welding connecting portion; 322c - first welding connecting portion

[0058] O - center; X - layer thickness direction; Y - thickness direction; Z - length direction; S - pressing member DETAILED DESCRIPTION

[0059] The embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present disclosure, and therefore only serve as examples, and cannot be used to limit the protection scope of the present disclosure.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure; the terms "include" and "have" and any variations thereof used herein are intended to cover a non-exclusive inclusion.

[0061] In the description of the embodiments of the present disclosure, the technical terms "first", "second", "third" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0062] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the disclosure. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment.

[0063] In the description of the embodiments of the disclosure, the term“and / or” is merely an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character“ / ” herein generally represents an“or” relationship between the front and rear associated objects.

[0064] In the description of the embodiments of the disclosure, the technical terms“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“circumferential” and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, be operated or used, and therefore cannot be understood as a limitation on the embodiments of the disclosure.

[0065] In the description of the embodiments of the disclosure, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connection”,“connection”,“fixing” and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the disclosure can be understood according to the specific circumstances.

[0066] In the description of the embodiments of the disclosure, unless otherwise explicitly specified and limited, the technical term“contact” should be understood in a broad sense, which can be direct contact or contact through an intermediate medium layer, which can be contact between two objects in contact without interaction force, or contact between two objects in contact with interaction force.

[0067] In the embodiments of the disclosure, the battery cell can be a secondary battery, which refers to a battery that can be activated by charging after the battery cell is discharged.

[0068] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, or the like, and the embodiments of the present disclosure are not limited thereto.

[0069] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During charging and discharging of the battery, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can function to prevent short circuiting of the positive and negative electrodes while allowing the active ions to pass through.

[0070] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0071] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0072] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0073] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present disclosure is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or two or more thereof can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0074] In some embodiments, the positive electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When the foamed metal is used as the positive electrode, the surface of the foamed metal can be free of positive electrode active material, or can be provided with positive electrode active material. As an example, the foamed metal can be filled or / and deposited with lithium source material, potassium metal or sodium metal. The lithium source material can be lithium metal and / or lithium-rich material.

[0075] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0076] As an example, the negative electrode current collector can employ a metal foil, foamed metal or composite current collector. For example, as the metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0077] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0078] In some embodiments, the separator is a separator film. The present disclosure does not have a specific limitation on the type of separator film, and any known porous structure separator film with good chemical stability and mechanical stability can be selected.

[0079] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0080] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions as ion transmission and separation of the positive and negative electrodes.

[0081] In some embodiments, the battery cell further includes an electrolyte, which functions as ion conduction between the positive and negative electrodes. The present disclosure does not have a specific limitation on the type of electrolyte, which can be selected as needed. The electrolyte can be in a liquid state, a gel state or a solid state.

[0082] In some embodiments, the electrode assembly is in a wound structure. The positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0083] In some embodiments, the electrode assembly is a laminated structure.

[0084] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets are alternately stacked.

[0085] As an example, a plurality of positive electrode sheets are provided, and the negative electrode sheet is folded to form a plurality of folded segments which are stacked.

[0086] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded segments which are stacked.

[0087] As an example, a plurality of separators are provided, and each of the separators is provided between any adjacent positive electrode sheet or negative electrode sheet.

[0088] As an example, the separators are continuously provided, and each of the separators is provided between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0089] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0090] In some embodiments, the electrode assembly is provided with a tab, and the tab can guide current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0091] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate the electrode assembly and other components such as electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0092] As an example, the battery cell can be a cylindrical battery, a prismatic battery, a pouch battery, or other shapes of batteries, and the prismatic battery includes a square battery, a blade battery, a polygonal battery, such as a hexagonal battery, etc., without specific limitation in the present disclosure.

[0093] In some embodiments, the housing includes an end cap and a shell, and the shell is provided with an opening, and the end cap closes the opening to form a sealed space for accommodating the electrode assembly and electrolyte and other substances. The shell can be provided with one or more openings. The end cap can also be provided with one or more openings.

[0094] In some embodiments, the housing is provided with a pressure relief mechanism. The pressure relief mechanism is used to release the internal pressure of the battery.

[0095] In some embodiments, the battery mentioned in the present disclosure can be a battery module, and the battery module includes one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in a mixed manner by a busbar. The multiple battery cells are arranged and fixed to form a battery module.

[0096] In some embodiments, the battery mentioned in the present disclosure can also be a battery pack, which includes a box body and at least one battery monomer or battery module, and the battery monomer or battery module is accommodated in the box body.

[0097] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0098] In the following, the present disclosure will be described in detail.

[0099] At present, new energy batteries are more and more widely used in life and industry. New energy batteries are not only applied to energy storage power supply systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, not only higher requirements are put forward for the performance of the battery, but also higher requirements are put forward for the reliability and lightweight of the battery.

[0100] The battery monomer will heat up during the charging and discharging process, and the greater the internal impedance of the battery monomer, the more obvious the heating. Usually, the tab and the electrode terminal of the battery monomer are connected through a transition piece, and the transition piece will generate a large impedance during the charging and discharging process of the battery monomer, resulting in serious heating of the battery monomer. In addition, for battery monomers with high-rate charging and discharging performance, the current flowing through the transition piece is larger, so the heating is more obvious, which will adversely affect the cycle life of the battery monomer, and even the risk of thermal runaway may occur, resulting in poor reliability of the battery monomer and even the battery.

[0101] In view of this, the present disclosure provides a battery, comprising: a shell having an accommodation space; an electrode terminal arranged in the shell; at least one electrode assembly arranged in the accommodation space, the electrode assembly comprising a main body part and a tab arranged on the main body part, the tab comprising a plurality of tab pieces, and the tab being directly connected to the electrode terminal.

[0102] By including a plurality of tab pieces in the tab and directly connecting the tab to the electrode terminal, the overcurrent capacity can be improved to adapt to the high-rate charging and discharging demand, while the overcurrent path can be shortened and the impedance during the charging and discharging process of the battery monomer can be reduced, thereby reducing the temperature rise. Therefore, even in the use scenario of high-rate charging and discharging of the battery monomer, the adverse effects of high temperature on the performance of the battery monomer can be alleviated, and the risk of thermal runaway of the battery monomer can be reduced, thereby improving the reliability of the battery monomer and even the battery. In addition, since the transition piece is omitted, the battery monomer and even the battery are more lightweight.

[0103] The battery provided by the embodiments of the present disclosure can be a battery pack. The battery pack can also be used in, but is not limited to, an electric device such as an energy storage power system, a vehicle, a ship, or an aircraft.

[0104] The battery provided by the embodiments of the present disclosure can be a battery pack. The battery pack can also be used in, but is not limited to, an electric device such as an energy storage power system, a vehicle, a ship, or an aircraft. Using the battery pack can provide higher total energy.

[0105] The embodiments of the present disclosure provide an electric device including the above-mentioned battery cell or battery for providing electric energy. The electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric aircraft toy, and the like. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0106] In the following embodiments, for the convenience of description, the electric device of an embodiment of the present disclosure is taken as a vehicle 1000 for example. The following is described in conjunction with the accompanying drawings.

[0107] FIG. 1 is a structural schematic diagram of a vehicle 1000 provided by some embodiments of the present disclosure. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, and the like. As shown in FIG. 1, the vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the working power demand of the vehicle 1000 during starting, navigation, and driving.

[0108] In some embodiments of the present disclosure, the battery 100 can not only be used as an operating power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0109] FIG. 2 is a perspective exploded schematic diagram of a battery provided by some embodiments of the present disclosure. As shown in FIG. 2, the battery 100 includes a box body 2, and the box body 2 includes a lower box body 3 and an upper box body 4. The lower box body 3 and the upper box body 4 are covered together to form a containing space for containing the battery cell 1.

[0110] In the battery 100, the battery cells 1 can be multiple, and the multiple battery cells 1 can be connected in series, in parallel, or in a mixed connection, where the mixed connection means that the multiple battery cells 1 are connected in series and in parallel. The multiple battery cells 1 can be directly connected in series, in parallel, or in a mixed connection, and the whole of the multiple battery cells 1 is placed in the accommodating space formed by the lower box body 3 and the upper box body 4. Of course, the battery 100 can also be in the form that the multiple battery cells 1 are first connected in series, in parallel, or in a mixed connection to form a battery module, and the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are accommodated in the accommodating space formed by the lower box body 3 and the upper box body 4. The battery 100 can also include other structures, for example, the battery 100 can also include a current combing component for realizing the electrical connection between the multiple battery cells 1.

[0111] In the following, some embodiments of the present disclosure will be described in detail with reference to FIGS. 3 to 11.

[0112] FIG. 3 is a perspective exploded schematic view of a battery cell according to some embodiments of the present disclosure; FIG. 4 is a schematic view of the structure of an electrode assembly and an end cover connected together according to some embodiments of the present disclosure; FIG. 5 is a schematic view of the structure of an electrode assembly and an end cover exploded according to some embodiments of the present disclosure; wherein the positional relationship between the electrode assembly 30 and the end cover shown in FIG. 4 can be regarded as a perspective view of the electrode assembly 30 in FIG. 3 flattened in an end-to-end state along a direction away from each other, at this time, the tab of the electrode assembly 30 is flattened from the bent shape in FIG. 3 to a flat shape; or it can also be regarded as a perspective view presented in the process of connecting the tab 32 and the electrode terminal 22 in the battery manufacturing process.

[0113] FIG. 6 is a schematic view of the partial structure of the electrode assembly in FIG. 5 enlarged; FIG. 7 is a schematic view of the partial structure of the electrode assembly according to another embodiment of the present disclosure enlarged; wherein the tab 32 of the electrode assembly 30 in FIGS. 6 and 7 are both in the perspective view of the tab 32 in the unbent state, and the perspective view of the tab 32 in the bent state can be seen with reference to the electrode assembly 30 shown in FIG. 3.

[0114] FIG. 8 is a schematic view of the structure of an end cover according to some embodiments of the present disclosure, wherein the end cover is shown with a pressing piece S placed on each of the two electrode terminals 22; FIG. 9 is a top view of an end cover according to some embodiments of the present disclosure, wherein one of the two electrode terminals 22 is placed with a pressing piece S, and the other one is not placed with a pressing piece; FIG. 10 is a schematic view of the partial section of an end cover according to some embodiments of the present disclosure enlarged, wherein the electrode terminal 22 is not placed with a pressing piece S; and FIG. 11 is a schematic view of the section of the pressing piece pressing the tab to the electrode terminal according to some embodiments of the present disclosure.

[0115] In the embodiments of the present disclosure, the direction of the arrow Z in the diagram is defined as a first direction Z, the direction of the arrow Y is defined as a second direction Y, and the direction of the arrow X is defined as a third direction X. The first direction Z, the second direction Y, and the third direction X are perpendicular to each other.

[0116] In some embodiments, the direction of the arrow X can also represent the stacking direction X of the plurality of tab pieces 32a, and the thickness direction X of the end cover. The direction of the arrow Y can also represent the width direction Y of the end cover. The direction of the arrow Z can also represent the length direction Z of the main body part 31 and the length direction Z of the end cover. In addition, those skilled in the art can understand that the main body part 31 in FIGS. 4-7 is a flattened perspective view of the main body part 31 in FIG. 3. Therefore, the thickness direction of the main body part 31 in FIGS. 4-7 is the same as the thickness direction of the folding part 322, and the thickness direction of the main body part 31 in FIG. 3 is perpendicular to the thickness direction of the folding part 322.

[0117] The embodiments of the present disclosure provide a battery monomer 1. Referring to FIGS. 3-7, the battery monomer 1 includes a shell 10, an electrode terminal 22, and at least one electrode assembly 30. The shell 10 has a containing space A. The electrode terminal 22 is arranged on the shell 10. The at least one electrode assembly 30 is arranged in the containing space A. The electrode assembly 30 includes a main body part 31 and a tab 32 arranged on the main body part 31. The tab 32 includes a plurality of tab pieces 32a. The tab 32 is directly connected to the electrode terminal 22.

[0118] The shell 10 has a containing space A for containing the electrode assembly 30. In addition, the containing space A can also contain electrolyte and other components.

[0119] For example, referring to FIG. 3, the shell 10 has a plurality of shell walls surrounding the containing space A. The plurality of shell walls include a first shell wall 12. The first shell wall 12 can be an end cover of the battery monomer 1. The remaining shell walls of the plurality of shell walls surround a shell 11 having an opening. The electrode assembly 30 is received in the containing space A through the opening. The opening is closed by the first shell wall 12 to form the containing space A for containing the electrode assembly 30. The electrode terminal 22 can be arranged on the first shell wall 12.

[0120] The shape of the first shell wall 12 can be adapted to the shape of the opening of the shell 11. The material of the first shell wall 12 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The embodiments of the present disclosure do not make special limitations on this. For example, the first shell wall 12 can be made of a material with certain hardness and strength, such as aluminum alloy. In this way, the first shell wall 12 is not easy to deform when subjected to extrusion and collision, so that the battery monomer 1 can have higher structural strength.

[0121] In some embodiments, an insulating member can also be arranged between the first shell wall 12 and the opening of the shell 11 to reduce the risk of short circuit and to seal. In some embodiments, the first shell wall 12 can also include a pressure relief mechanism for relieving the internal pressure of the battery monomer 1 when the internal pressure reaches a threshold value.

[0122] The shell 10 can have various shapes, such as a cuboid, a cylinder, a hexagonal prism, etc., and a suitable shell 10 can be determined according to the specific shape of the electrode assembly 30. The material of the shell 10 can be metal or non-metal, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, aluminum plastic, etc., and the present disclosure does not make special limitations on this.

[0123] The electrode terminal 22 is electrically connected to the electrode assembly 30 for outputting or inputting electric energy. When there are multiple battery monomers 1, the electrode terminals 22 of the battery monomers 1 can also be connected through a busbar component, so that the multiple battery monomers are connected in series and / or in parallel.

[0124] The number of electrode assemblies 30 can be one, two or more. Each electrode assembly 30 includes a main body part 31 and a tab 32 arranged on the main body part 31. For example, the main body part 31 includes a positive electrode sheet, a negative electrode sheet, and a separator interposed between the positive electrode sheet and the negative electrode sheet. In one example, the positive electrode sheet, the separator, and the negative electrode sheet can be wound at least two turns to form a wound structure; in another example, the positive electrode sheet, the separator, and the negative electrode sheet can also be stacked to form a laminated structure.

[0125] The tab 32 includes a plurality of tab pieces 32a (shown in FIGS. 6 and 7), each of which is connected to the main body part 31, and each of which can be integrated with the main body part 31.

[0126] The tab 32 can conduct current from the main body part 31. The plurality of tab pieces 32a can improve the current-carrying capacity and better adapt to high-rate charging and discharging requirements.

[0127] The tab 32 includes a plurality of tab pieces 32a, and the tab 32 is directly connected to the electrode terminal 22, which can improve the current-carrying capacity to adapt to high-rate charging and discharging requirements, shorten the current-carrying path, reduce the impedance during charging and discharging of the battery monomer 1, and thus reduce the temperature rise. Therefore, even in the use scenario of high-rate charging and discharging of the battery monomer 1, the adverse effects of high temperature on the performance of the battery monomer 1 can be alleviated, and the risk of thermal runaway of the battery monomer 1 can be reduced, thereby improving the reliability of the battery monomer 1 and even the battery 100; in addition, the omission of the adapter piece makes the battery monomer 1 and even the battery 100 more lightweight.

[0128] In some embodiments, the tab 32 has a connecting portion 321 connected between the main body portion 31 and a gathered portion 322 formed by a plurality of tab pieces 32a connected together in layers, and the gathered portion 322 is directly connected to the electrode terminal 22.

[0129] The plurality of tab pieces 32a connected together in layers in the gathered portion 322 means that the plurality of tab pieces 32a are connected together in layers in the thickness direction of the tab pieces 32a and are gathered together by being brought close to each other, so that the gathered portion 322 is formed as a compact integrated structure.

[0130] After the electrode assembly 30 is wound to form a wound structure, the plurality of tab pieces 32a can be loose, and the gap between the tab pieces 32a in the layering direction (third direction X in FIG. 6) is large. The connection of the loose tab pieces 32a to the electrode terminal 22 can be unstable, for example, there is a risk of a virtual weld during welding, resulting in poor overcurrent capacity and failing to meet the high-rate charge and discharge requirements.

[0131] To this end, the plurality of loose tab pieces 32a are gathered together and connected in layers to form a compact gathered portion 322, and the compact gathered portion 322 is directly connected (e.g., laser welding) to the electrode terminal 22, which can achieve reliable connection. As an example, the compact gathered portion 322 can have a plate-like structure similar to the conventional adapter piece, so that when the compact gathered portion 322 is directly connected (e.g., laser welding) to the electrode terminal 22, the same connection effect as the adapter piece and the electrode terminal 22 can be substantially achieved.

[0132] The plurality of tab pieces 32a connected together in layers in the gathered portion 322 form a compact integrated structure, so that the gathered portion 322 is more reliably directly connected to the electrode terminal 22, reducing the risk of virtual connection, thereby improving the overcurrent capacity of the tab 32. That is, even if the conventional adapter piece is omitted, the overcurrent capacity of the tab 32 can be improved to meet the high-rate charge and discharge requirements without reducing the connection effect of the tab 32 and the electrode terminal 22, and the impedance during charging and discharging of the battery cell 1 can be reduced, thereby reducing the temperature rise, alleviating the adverse effects of high temperature of the battery cell 1 on performance and cycle life, and reducing the risk of thermal runaway of the battery cell 1, thereby improving the reliability of the battery cell 1 and even the battery 100.

[0133] In some embodiments, the gathered portion 322 is formed with a first welding connection portion 322c, the plurality of tab pieces 32a are connected together by the first welding connection portion 322c, and the gathered portion 322 and the electrode terminal 22 are connected to each other by a second welding connection portion 322b. In the same projection plane perpendicular to the thickness direction X of the gathered portion 322, the projection of the second welding connection portion 322b and the first welding connection portion 322c have an overlapping portion.

[0134] In the same projection plane perpendicular to the thickness direction X of the gathered portion 322, the projection of the second welded connection portion 322b and the first welded connection portion 322c has an overlapping portion, which can be understood as that in the gathered portion 322, the plurality of tab pieces 32a are connected together by welding to form the first welded connection portion 322c having a certain area, and the gathered portion 322 and the electrode terminal 22 are connected together by welding within the area of the first welded connection portion 322c to form the second welded connection portion 322b.

[0135] For example, first, the plurality of tab pieces 32a located in the gathered portion 322 can be ultrasonic pre-welded to form the first welded connection portion 322c (ultrasonic welding mark) in the gathered portion 322, which tightly connects the plurality of tab pieces 32a located in the gathered portion 322 together to form an integrated structure, and then the gathered portion 322 and the electrode terminal 22 are connected by laser welding within the area of the first welded connection portion 322c to form the second welded connection portion 322b (laser welding mark) between the gathered portion 322 and the electrode terminal 22, so that the second welded connection portion 322b at least partially overlaps with the first welded connection portion 322c.

[0136] Therefore, the plurality of tab pieces 32a are connected together by the first welded connection portion 322c to make the connection between the plurality of tab pieces 32a located in the gathered portion more compact, and the projection of the second welded connection portion 322b and the first welded connection portion 322c has an overlapping portion, so that the connection between the gathered portion 322 and the electrode terminal 22 connected by the second welded connection portion 322b is more reliable, reducing the risk of false welding, thereby improving the overcurrent capacity during high-rate charging and discharging, and also reducing the temperature rise.

[0137] In some embodiments, in the same projection plane perpendicular to the thickness direction X of the gathered portion 322, the projection of the second welded connection portion 322b does not exceed the projection of the first welded connection portion 322c.

[0138] Therefore, all the second welded connection portions 322b are located within the area of the first welded connection portion 322c, further improving the connection reliability between the gathered portion 322 and the electrode terminal 22.

[0139] In some embodiments, the area of the projection of the second welded connection portion 322b accounts for 30% to 100% of the area of the projection of the first welded connection portion 322c. For example, the area of the projection of the second welded connection portion 322b accounts for 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, 100% of the area of the projection of the first welded connection portion 322c.

[0140] The welding area between the retractable part 322 and the electrode terminal 22 is within a suitable range, which can meet the overcurrent requirements and play the role of overcurrent protection.

[0141] In some embodiments, the retractable portion 322 is configured as a plate-like structure.

[0142] Plate-like structures can be rectangular, square, oval, or other shapes.

[0143] The internal structure of the plate-shaped retractable part 322 is more compact, so that when the retractable part 322 is directly connected to the electrode terminal 22, it can more closely resemble the effect of the previous adapter plate and electrode terminal 22 connection, thereby further improving the current carrying capacity and connection reliability.

[0144] In some embodiments, along the thickness direction X of the gathering portion 322, the gathering portion 322 has an overlapping portion with the electrode terminal 22.

[0145] The gathering portion 322 and the electrode terminal 22 are stacked on each other along the thickness direction X of the gathering portion 322. The gathering portion 322 may completely overlap with the electrode terminal 22 or partially overlap with the electrode terminal 22.

[0146] This allows for a further shortening of the current path of tab 32, reducing impedance, further lowering battery temperature, and improving battery performance and reliability.

[0147] In some embodiments, the end of the connecting portion 321 that is connected to the retracting portion 322 is located on one side of the thickness direction center O of the main body portion 31 (as shown in FIG7) or at the thickness direction center O of the main body portion 31 (as shown in FIG6).

[0148] Referring to Figure 7, multiple tabs 32a are all clustered together toward one side of the center O in the thickness direction of the main body 31, thus deviating from the convergence portion 322 of the center O.

[0149] Multiple tabs 32a form a centrally located convergence portion 322, which helps to reduce the internal resistance of the battery cell 1, reduce the temperature rise of the battery cell 1 during high-rate discharge, and improve battery performance and reliability.

[0150] Referring to Figure 6, the end of the connecting part 321 that connects to the gathering part 322 is generally located at the center O in the thickness direction of the main body part 31.

[0151] Multiple tabs 32a converge toward the center O in the thickness direction of the main body 31 (X direction in Figure 6, Y direction in Figure 3) to form a centrally located gathering portion 322. The end of the connecting portion 321 that connects to the gathering portion 322 is generally located at the center O in the thickness direction of the main body 31. This can be broadly understood as being within the allowable manufacturing or measurement error range.

[0152] Thus, the tabs 32 are centrally located in the collection portion 322 so that the flow paths of the respective tab pieces 32a are substantially the same, the flow is more uniform, and the temperature rise of the battery monomer 1 under high-rate charging and discharging can be reduced, thus the cycle life of the battery monomer 1 can be significantly improved. In addition, the centrally located structure of the tab 32 facilitates welding with the electrode terminal 22.

[0153] In some embodiments, referring to FIGS. 4 and 5, the electrode terminal 22 includes a positive electrode terminal 22a and a negative electrode terminal 22b; the tab 32 includes a positive electrode tab 32c and a negative electrode tab 32d, the positive electrode tab 32c and the negative electrode tab 32d are respectively arranged at the same end of the main body portion 31, the positive electrode tab 32c is directly connected with the positive electrode terminal 22a, and the negative electrode tab 32d is directly connected with the negative electrode terminal 22b.

[0154] The positive electrode terminal 22a and the negative electrode terminal 22b are arranged at intervals along the length direction Z of the end cover. The positive electrode tab 32c and the negative electrode tab 32d are respectively led out from the same end of the main body portion 31 and arranged at intervals along the length direction Z of the electrode assembly 30. The positive electrode tab 32c includes a plurality of positive electrode tab pieces, the plurality of positive electrode tab pieces are connected together in layers to form a positive electrode collection portion, and the positive electrode collection portion is directly connected with the positive electrode terminal 22a. The negative electrode tab 32d includes a plurality of negative electrode tab pieces, the plurality of negative electrode tab pieces are connected together in layers to form a negative electrode collection portion, and the negative electrode collection portion is directly connected with the negative electrode terminal 22b.

[0155] The positive electrode tab 32c and the negative electrode tab 32d are respectively directly connected with the positive electrode terminal 22a and the negative electrode terminal 22b, which can reduce the internal impedance of the battery, reduce the temperature rise of the battery during charging and discharging, and improve the reliability of the battery. In addition, the positive electrode tab 32c and the negative electrode tab 32d are arranged at the same end of the main body portion 31, which helps to improve the space utilization of the housing, thereby improving the volume energy density of the battery monomer 1.

[0156] In some embodiments, the electrode assembly 30 is provided with at least two, the tabs of the at least two electrode assemblies 30 are connected with the same polarity, and the tabs 32 of each electrode assembly 30 are directly connected with the electrode terminal 22 through the respective collection portion 322.

[0157] The at least two electrode assemblies 30 are respectively directly connected with the electrode terminal 22 through the respective collection portion 322, which can reduce the internal impedance of the battery monomer 1, reduce the temperature rise of the battery during charging and discharging, improve the reliability of the battery, and also improve the capacity of the battery, and can better meet the demand for high-rate discharging.

[0158] In some embodiments, referring to FIGS. 8-11, the electrode terminal 22 penetrates the first housing wall 12 and has a first connecting portion 221 located in the accommodation space A (shown in FIG. 3), the first connecting portion 221 has a connecting surface 221a close to the electrode assembly 30 along the first housing wall thickness direction X (the third direction X in FIG. 8), and the connecting surface 221a is connected with the tab 32; the insulating member 23 includes a positioning portion 231, the positioning portion 231 is arranged around the outer periphery of the first connecting portion 221, and the positioning portion 231 has a first surface 231a close to the electrode assembly 30 along the first housing wall thickness direction X, and the first surface 231a is flush with at least a portion of the connecting surface 221a close to the positioning portion 231.

[0159] The electrode terminal 22 is arranged on the first housing wall 12 and is used to be connected with the tab 32 to output and input electric energy. When there are multiple battery monomers 1, the electrode terminals 22 of the battery monomers 1 can also be connected through a busbar to make the multiple battery monomers 1 in series and / or in parallel. The material of the electrode terminal 22 can be various conductive metals, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. For example, the electrode terminal 22 sometimes exists in the form of a pole.

[0160] The electrode terminal 22 penetrates the first housing wall 12 and has a first connecting portion 221 located in the accommodation space A, which can be that the electrode terminal 22 has a first connecting portion 221 at least partially protruding from the side along the first housing wall thickness direction X (the third direction X), i.e., along the first housing wall thickness direction X, the first connecting portion 221 has a height H1 exceeding the first housing wall 12. Referring to FIG. 11, the height H1 is the distance between the surface (the connecting surface 221a) of the first connecting portion 221 away from the side of the first housing wall 12 along the first housing wall thickness direction X and the surface of the first housing wall 12 away from the electrode assembly 30. For example, referring to FIGS. 3 and 11, along the first housing wall thickness direction X, a portion of the first connecting portion 221 protrudes from the first housing wall 12 and is located in the accommodation space A, and another portion extends to the outside of the housing 10 through the first housing wall 12 and is connected with a second connecting portion 222, which can be used to connect an external busbar.

[0161] The first connecting portion 221 has a connecting surface 221a close to the electrode assembly 30 along the first housing wall thickness direction X, and the first connecting portion 221 is connected with the tab 32 through the connecting surface 221a. The connecting surface 221a can be directly connected with the tab 32. The connection mode can be welding, bonding, etc. The shape of the connecting surface 221a can be square, circular, oval, or other shapes.

[0162] The insulating member 23 is used to isolate the electrode terminal 22 and the first housing wall 12 to reduce the risk of short circuit. The material of the insulating member 23 can be plastic, rubber, etc. with insulation properties.

[0163] The insulating member 23 includes a positioning portion 231 which is arranged around the outer periphery of the first connecting portion 221, and can be protruded from the first housing wall 12 on the same side as the first connecting portion 221 along the first housing wall thickness direction X. The positioning portion 231 can surround the first connecting portion 221 entirely or partially, and can play a role of positioning and insulation for the first connecting portion 221. For example, the positioning portion 231 is in the form of a closed ring which surrounds the outer periphery of the first connecting portion 221.

[0164] The positioning portion 231 has a first surface 231a which is located on the side close to the electrode assembly 30 along the first housing wall thickness direction X, and the first surface 231a is flush with at least the portion of the connecting surface 221a close to the positioning portion 231. The first surface 231a being flush with at least the portion of the connecting surface 221a close to the positioning portion 231 can be understood as that the first surface 231a is slightly lower than, slightly higher than, or flush with the connecting surface 221a along the first housing wall thickness direction X, and the height difference between the first surface 231a and the connecting surface 221a can be within the range allowed by the machining error. The first surface 231a can be flush with the portion of the connecting surface 221a close to the positioning portion 231, or the first surface 231a can be flush with the entire connecting surface 221a. For example, the entire connecting surface 221a can be a flat surface, and the first surface 231a is flush with the flat surface.

[0165] The first surface 231a can be understood as having a specified extension along the first direction Z (the first housing wall length direction) and / or the second direction Y (the first housing wall width direction), so that the first surface 231a can provide sufficient support space for the pressing member S to support the pressing member S when the pressing member S presses the tab 32 against the electrode terminal 22. The range of the extension can be determined based on the size of the pressing member, so that the support space formed by the first surface 231a can reach the extent of supporting the pressing member S. The first surface 231a supporting the pressing member S can be understood as that the entire pressing member S can be supported by the first surface 231a, i.e., the entire pressing member S is located on the first surface 231a, when the pressing member S presses the tab 32; or a part of the pressing member S is supported by the first surface 231a, i.e., a part of the pressing member S is located on the first surface 231a, for example, referring to FIG. 11, a part of the pressing member S is supported by the first surface 231a, and the other part is supported by the connecting surface 221a of the first connecting portion 221, i.e., the first surface 231a of the positioning portion 231 and the connecting surface 221a of the first connecting portion 221 jointly support the pressing member S. Of course, the entire pressing member S can also be supported by the first surface 231a.

[0166] As an example, with reference to FIGS. 9, 10 and 11, in the process of directly welding the tab 32 to the electrode terminal 22, the pressing member S first presses the tab 32 against the connecting surface 221a, so that the tab 32 is located between the connecting surface 221a and the pressing member S, and the pressing member S is wrapped around the welding area of the tab 32 and the connecting surface 221a, for example, the center of the pressing member S can be substantially coincided with the center of the first connecting portion 221, the pressing member S is supported by the first surface 231a of the positioning portion 231 and the connecting surface 221a of the first connecting portion 221, thereby more closely pressing the tab 32 against the connecting surface 221a, then the welding head is inserted into the annular space of the pressing member S to perform welding operation on the tab 32 and the connecting surface 221a, so that the connecting surface 221a and the tab 32 are firmly welded together. The pressing member S can also reduce the splashing of particles during welding and reduce the risk of short circuit of the battery monomer 1.

[0167] By providing the positioning portion with the first surface 231a and the first surface 231a being flush with the connecting surface 221a of the first connecting portion 221, in the process of connecting the tab 32 to the electrode terminal 22, the first surface 231a can provide a support space for the pressing member S, thereby reducing the gap between the tab 32 and the electrode terminal 22, and further making the connection of the tab and the electrode terminal more reliable, improving the connection reliability, while not only not increasing the weight of the battery monomer 1 too much, but also not increasing the cost too much, thereby facilitating the lightweight and cost control of the battery. If the support space for the pressing member is provided by increasing the volume of the electrode terminal 22, the weight of the battery monomer 1 will be greatly increased, which is not conducive to the lightweight of the battery monomer 1, and the cost is high.

[0168] In some embodiments, with reference to FIGS. 9, 10 and 11, the pressing member S has a pressing surface S1 for pressing the tab 32 against the connecting surface 221a, the connecting surface 221a has a size D1 along the first shell wall length direction Z, the first surface 231a has a size D2 along the first shell wall length direction Z, the pressing surface S1 has a size D3 along the first shell wall length direction Z, the connecting surface 221a has a size W1 along the first shell wall width direction Y, the first surface 231a has a size W2 along the first shell wall width direction Y, and the pressing surface S1 has a size W3 along the first shell wall width direction Y, wherein D1 + 2D2 ≥ D3 and W1 + 2W2 ≥ W3.

[0169] D3 can be the distance between the two opposite outer edges of the pressing member S along the first shell wall length direction Z, and W3 can be the distance between the two opposite outer edges of the pressing member S along the first shell wall width direction Y. The size D2 of the positioning portion 231 along the first shell wall length direction Z and the size W2 along the first shell wall width direction Y can be adjusted according to the size of the pressing member S.

[0170] In the tab 32 and electrode terminal 22 connecting process, the tab 32 is pressed on the connecting surface 221a of the first connecting part 221 by the pressing piece S, and since D1+2D2≥D3, W1+2W2≥W3, at least part of the pressing piece S is supported by the first surface 231a of the positioning part 231, so that the tab 32 is more closely pressed on the connecting surface 221a of the first connecting part 221, improving the connection reliability.

[0171] In some embodiments, the absolute value of the height difference between the first surface 231a and the connecting surface 221a along the thickness direction X of the first shell wall is within the range of 0mm to 0.3mm.

[0172] The first surface 231a can be slightly lower or slightly higher or flush with the connecting surface 221a, and the height difference between the two can be within the error range allowed by processing.

[0173] Controlling the height difference between the first surface 231a and the connecting surface 221a within a suitable error range allows the pressing piece S to more smoothly fit the tab 32 to the connecting surface 221a, improving the connection reliability.

[0174] In some embodiments, the thickness of the first surface 231a along the length direction Z of the first shell wall and / or the width direction Y of the first shell wall is greater than or equal to 1mm and less than or equal to 3mm.

[0175] In the prior art, the thickness of the positioning part 231 is generally less than 1mm, and only serves the purpose of positioning the first connecting part 221. The positioning part 231 of the present disclosure not only serves the purpose of positioning the first connecting part 221, but also has the function of supporting the pressing piece S, so that the pressing piece S can more closely press the tab 32 on the first connecting part 221, facilitating subsequent welding, reducing the risk of false welding, and improving the connection reliability.

[0176] In some embodiments, the electrode terminal 22 further comprises a second connecting part 222 located outside the shell 10 along the thickness direction X of the first shell wall, and the second connecting part 222 is connected with the first connecting part 221. The second connecting part 222 can be riveted with the first connecting part 221 or the two can be formed as an integral structure.

[0177] The second connecting part 222 can be used to connect external bus components, and through the bus components, multiple battery monomers 1 can be connected together to form a battery module, improving the capacity of the battery and meeting the demand for high-power electricity consumption.

[0178] In some embodiments, the electrode terminal 22 comprises a terminal plate 2221 and a terminal disc 2211 connected to each other, the first connecting part 221 comprises the terminal disc 2211, and the terminal disc 2211 comprises a connecting surface 221a. The terminal plate 2221 and the terminal disc 2211 can be riveted or integrated.

[0179] The terminal disc 2211 is in a disc shape, such as a circular disc or an elliptical disc, and can be made of copper, iron, aluminum, stainless steel, aluminum alloy or other conductive metal.

[0180] The terminal disc 2211 comprises the connecting surface 221a, which is generally flat, so that the connecting surface 221a is more closely attached to the tab 32, facilitating subsequent connection and improving connection reliability.

[0181] In some embodiments, the second connecting part 222 comprises the terminal plate 2221.

[0182] The terminal plate 2221 is in a plate shape and has a flat surface for connection with the busbar component. The terminal plate 2221 can be circular, square or other shapes. The material of the terminal plate 2221 can be the same as or different from that of the terminal disc 2211.

[0183] The second connecting part 222 comprises the terminal plate 2221, so that the connecting surface 221a is more closely attached to the busbar component, facilitating subsequent connection and improving connection reliability.

[0184] In some embodiments, the positioning part 231 has a second surface 231b that is arranged around the outer periphery of the first connecting part 221 and in contact with the outer surface of the first connecting part 221.

[0185] The shape of the positioning part 231 can be adapted to the shape of the first connecting part 221. Since the positioning part 231 is flush with the first connecting part 221 along the thickness direction of the first housing wall 12, the positioning part 231 more stably surrounds the first connecting part 221, improving positioning stability and reducing the risk of movement of the tab 32 during connection (such as welding) with the first connecting part 221, which is conducive to connection reliability.

[0186] In some embodiments, the insulating part 23 further comprises a portion 232 (shown in FIG. 10) between the first connecting part 221 and the first housing wall 12 along the thickness direction X of the first housing wall.

[0187] The portion 232 between the first connecting part 221 and the first housing wall 12 is used to isolate the first connecting part 221 from the first housing wall 12, reducing the risk of short circuit. It can be understood that the portion 232 between the first connecting part 221 and the first housing wall 12 has a through hole for the first connecting part 221 to pass through.

[0188] In some embodiments, the insulating member 23 further comprises a protruding portion 233 protruding toward the side of the electrode assembly 30 along the thickness direction X of the first shell wall.

[0189] The protruding portion 233 can be used to abut against the main body portion 31 of the electrode assembly 30, reducing the risk of the electrode assembly 30 shaking.

[0190] For example, the first shell wall 12 (e.g., an end cap) is further provided with an explosion-proof valve and a liquid injection hole, and the insulating member 23 comprises an insulating body, which is provided with an explosion-proof valve avoiding hole 234 corresponding to the explosion-proof valve and a liquid injection avoiding hole 235 corresponding to the liquid injection hole.

[0191] In the following, specific examples of embodiments of the present disclosure will be described with reference to FIGS. 3-11.

[0192] The battery cell 1 of the embodiments of the present disclosure comprises a shell 10, an electrode terminal 22, and an electrode assembly 30.

[0193] The shell 10 comprises a plurality of shell walls, including a first shell wall 12, and the remaining shell walls surround a shell body 11 having an opening. The first shell wall 12 can be an end cap of the battery cell 1, and the first shell wall 12 closes the opening to form an accommodating space A for accommodating the electrode assembly 30 with the shell body 11.

[0194] Referring to FIGS. 8-11, the electrode terminal 22 is provided on the first shell wall 12, and the insulating member 23 is provided between the first shell wall 12 and the shell body 11. The electrode terminal 22 comprises a first connecting portion 221 penetrating through the first shell wall 12 and protruding from the first shell wall 12 along the thickness direction X thereof toward the side of the electrode assembly 30 (shown in FIG. 3), and a second connecting portion 222 protruding from the first shell wall 12 along the thickness direction X thereof away from the electrode assembly 30, and the second connecting portion 222 is riveted to the first connecting portion 221.

[0195] The insulating member 23 includes a positioning portion 231 protruding from the first housing wall 12 along the thickness direction X toward the side of the electrode assembly 30 (shown in FIG. 1) and surrounding the outer periphery of the first connecting portion 221, and the positioning portion 231 functions to position the first connecting portion 221. The positioning portion 231 has a first surface 231a facing the electrode assembly 30 along the thickness direction X of the first housing wall, and the first connecting portion 221 has a connecting surface 221a facing the electrode assembly 30 along the thickness direction X of the first housing wall, and the first surface 231a is flush with the connecting surface 221a. Specifically, the height of the first connecting portion 221 protruding from the first housing wall 12 is H1, the height of the positioning portion 231 protruding from the first housing wall 12 is H2, and the difference between H1 and H2 is within the range of 0 mm to 0.3 mm. The first connecting portion 221 is directly welded to the tab 32 of the electrode assembly 30 through the connecting surface 221a, and the first surface 231a is used to support the pressing member S during the process of connecting the tab 32 to the first connecting portion 221, so that the pressing member S presses the tab 32 against the connecting surface 221a of the first connecting portion 221.

[0196] Referring to FIGS. 3 to 5, each electrode assembly 30 includes a main body portion 31 and two tabs 32 provided on the main body portion 31 and respectively extending from the same end of the main body portion 31, each tab 32 includes a plurality of tab pieces 32a, the tab 32 has a connecting portion 321 connected between the main body portion 31 and a gathered portion 322, the gathered portion 322 is connected together via ultrasonic welding of the plurality of tab pieces 32a to form a compact and integral plate-like structure, and an ultrasonic welding mark is formed on the gathered portion 322, the gathered portion 322 has an overlapping portion with the electrode terminal 22 along the thickness direction X of the gathered portion 322, the connecting surface 221a of the electrode terminal 22 is directly connected to the gathered portion 322 by laser welding, and a laser welding mark (second welding connecting portion 322b shown in FIG. 4) is formed on the gathered portion 322, wherein the laser welding mark coincides with the ultrasonic welding mark, the gathered portion 322 is bent relative to the connecting portion 321, and the main body portions 31 of the two electrode assemblies 30 are arranged face to face along the thickness direction Y (shown in FIG. 3).

[0197] First, the plurality of tab pieces 32a of each electrode assembly 30 are brought together toward the same position and stacked together by an ultrasonic welding device to form a tab 32 having a gathered portion 322 and a connecting portion 321, such that the gathered portion 322 is configured as a compact unitary plate structure, and an ultrasonic weld is formed on the gathered portion 322; then, the compact gathered portion 322 of the electrode assembly 30 is stacked on the connecting surface 221a of the first connecting portion 221 of each electrode terminal 22 along the layer thickness direction X; next, the gathered portion 322 is pressed against the connecting surface 221a by a ring-shaped pressing member S, which is supported by the connecting surface 221a and the first surface 231a together, so that the gathered portion 322 is attached to the connecting surface 221a; after that, a welding head is inserted into the interior of the pressing member S to perform laser welding at the position of the ultrasonic weld of the gathered portion 322 to weld the gathered portion 322 and the connecting surface 221a together, thereby completing the welding operation of the tab 32 of the electrode assembly 30 and the electrode terminal 22. After that, the pressing member S is removed, and the two main body portions 31 are each rotated 90 degrees toward each other, so that they are arranged face to face along the thickness direction (shown in FIG. 3), so that the gathered portion 322 is bent relative to the connecting portion 321, and then the two electrode assemblies 30 are placed into the housing 10 with the first housing wall 12 closing the opening of the housing 10.

[0198] The present disclosure also provides a battery 100, which includes the case 2 and at least one battery cell 1 mentioned above.

[0199] Referring to FIG. 2, the case 2 includes a lower case 3 and an upper case 4, which are overlapped with each other to form a space for accommodating the battery cell 1.

[0200] The present disclosure also provides an electric device, which includes the battery cell 1 or the battery 100 mentioned above for providing electric energy.

[0201] The present disclosure also provides an energy storage device, which includes the battery cell 1 or the battery 100 mentioned above for providing electric energy, and the battery cell 1 is capable of storing and providing electric energy.

[0202] The energy storage device can be an energy storage case or an energy storage cabinet. The energy storage cabinet includes a plurality of battery compartments for accommodating the battery cell 1. In addition, the energy storage cabinet can also include a thermal management assembly, a power control assembly, and the like.

[0203] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure is described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present disclosure, and they should be covered in the scope of the present disclosure. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the present disclosure.

Claims

1. A battery cell comprising: a case having an accommodation space; an electrode terminal provided to the case; at least one electrode assembly provided in the accommodation space, the electrode assembly including a main body portion and a tab provided to the main body portion, the tab including a plurality of tab pieces, the tab being directly connected to the electrode terminal.

2. The battery cell according to claim 1, wherein the tab has a connecting portion and a gathered portion, the connecting portion being connected between the main body portion and the gathered portion, the gathered portion being formed by the plurality of tab pieces being connected together in layers, the gathered portion being directly connected to the electrode terminal.

3. The battery cell according to claim 2, wherein a first welded connecting portion is formed in the gathered portion, the plurality of tab pieces being connected as one body by the first welded connecting portion, the gathered portion and the electrode terminal are connected to each other by a second welded connecting portion, a projection of the second welded connecting portion and a projection of the first welded connecting portion having an overlapping portion in a same projection plane perpendicular to a thickness direction of the gathered portion.

4. The battery cell according to claim 3, wherein the projection of the second welded connecting portion does not exceed the projection of the first welded connecting portion in the same projection plane perpendicular to the thickness direction of the gathered portion.

5. The battery cell according to claim 3 or 4, wherein an area of the projection of the second welded connecting portion accounts for 30% to 100% of an area of the projection of the first welded connecting portion.

6. The battery cell according to any one of claims 1 to 5, wherein the gathered portion is configured in a plate-like structure.

7. The battery cell according to any one of claims 1 to 6, wherein an end of the connecting portion connected to the gathered portion is located at a center of the thickness direction of the main body portion.

8. The battery cell according to any one of claims 1 to 7, wherein the electrode terminal includes a positive electrode terminal and a negative electrode terminal; the tab includes a positive tab and a negative tab, the positive tab and the negative tab being provided to a same end of the main body portion, the positive tab being directly connected to the positive electrode terminal, the negative tab being directly connected to the negative electrode terminal.

9. The battery cell according to any one of claims 1 to 8, wherein two of the electrode assemblies are provided, the tabs of the same polarity of the two electrode assemblies being electrically connected, the tabs of each of the electrode assemblies being directly connected to a same one of the electrode terminals via the gathered portion of each of the electrode assemblies, respectively.

10. The battery cell according to any one of claims 1 to 9, wherein the two electrode assemblies are provided opposite to each other along the thickness direction of the main body portion.

11. A battery comprising: a case; at least one battery cell according to any one of claims 1 to 10, the battery cell being provided in the case.

12. An electrical device including the battery cell according to any one of claims 1 to 10 or the battery according to claim 11, the battery being capable of providing electric power to the electrical device.

13. An energy storage device comprising the battery cell of any one of claims 1 to 10 or the battery of claim 11, the battery capable of storing electrical energy and capable of providing electrical energy.

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