Battery monomer, battery device, power utilization device and energy storage device

Abstract

A battery cell (100), a battery device (400), a power device and an energy storage device. A battery cell (100) comprises a housing (1), at least one electrode assembly (2), an electrode terminal (3) and an electrical connector (4). A containing cavity (1a) is formed in the shell (1), the shell (1) comprises a first wall (11), and a mounting hole is formed in the first wall (11). The at least one electrode assembly (2) is located in the accommodating cavity (1a), and the electrode assembly (2) comprises an electrode main body (21) and a tab (22) connected with the electrode main body (21). And the electrode terminal (3) is arranged in the mounting hole in a penetrating manner. The electrical connector (4) connects the electrode terminal (3) and the tab (22). Wherein each tab (22) comprises a welding part (21), under the condition that the number of the tabs (22) with the same polarity is multiple, the welding parts (21) of the tabs (22) with the same polarity are at least partially overlapped to form an overlapping part (2211), and the overlapping part (2211) is welded with the electric connecting piece (4) to form a welding mark (5).

Description

Battery cell, battery device, power utilization device and energy storage device TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of batteries, in particular to a battery cell, a battery device, a power utilization device and an energy storage device. BACKGROUND

[0002] New energy batteries are increasingly widely used in life and industry. For example, new energy vehicles equipped with battery devices have been widely used. In addition, battery devices are also increasingly used in the field of energy storage and the like.

[0003] With the continuous development of battery technology, how to reduce the size of the battery cell and improve the production efficiency of the battery cell is one of the research topics in the industry.

[0004] SUMMARY

[0005] To solve the above technical problems, the present disclosure provides a battery cell, a battery device, a power utilization device and an energy storage device with smaller size, lower production cost and higher production efficiency.

[0006] The present disclosure is implemented by the following technical solutions.

[0007] The first aspect of the present disclosure provides a battery cell, comprising: a shell, an accommodation cavity is formed inside the shell, the shell comprises a first wall, the first wall is formed with a mounting hole; at least one electrode assembly located in the accommodation cavity, the electrode assembly comprises an electrode body and a tab connected with the electrode body; an electrode terminal penetrating the mounting hole; and an electrical connector connecting the electrode terminal and the tab; wherein the tab comprises a welding portion, in the case that the number of tabs with the same polarity is multiple, the welding portions of each tab with the same polarity at least partially overlap to form an overlapping portion, and the overlapping portion is welded with the electrical connector to form a welding mark.

[0008] The tabs with the same polarity of the battery cell of the present disclosure at least partially overlap to form an overlapping portion, and are welded with the electrical connector at the overlapping portion. Therefore, only one welding is needed to realize the connection between the tab and the electrical connector, which can reduce the number of weldings, thereby facilitating the improvement of production efficiency and the reduction of production cost.

[0009] In addition, since the multiple tabs with the same polarity are welded with the electrical connector to form only one welding mark, compared with the case that multiple tabs are respectively welded to form multiple welding marks, the space occupied by multiple welding marks can be saved, thereby the size of the electrical connector can be reduced, and the size of the battery cell can be effectively reduced, so that the battery cell can be better applied to the installation environment with limited space, and the energy density of the battery cell will not be affected.

[0010] In some embodiments, the thickness direction of the electrode body is the first direction; along the first direction, the width of the overlapping portion is greater than the width of the welding mark.

[0011] In this way, the welding mark can be completely located in the overlapping area of the tab, so as to improve the connection area between the tabs, and further improve the welding reliability, reduce the possibility of poor welding or welding failure between the tabs, and improve the welding quality.

[0012] In some embodiments, the welding mark is located in the central region of the overlapping portion.

[0013] In this way, the welding reliability between the tabs with the same polarity can be further improved, so that the multiple tabs that overlap each other at the overlapping portion can be fully welded. In addition, the welding mark is located in the central region of the overlapping portion, so that the extension lengths of the tabs on the opposite sides along the first direction are the same, the possibility of overstretching of one side tab is reduced, and the reliability of the battery cell is improved.

[0014] In some embodiments, the electrical connector includes a tab connecting portion, an electrode terminal connecting portion, and an intermediate connecting portion, the tab connecting portion connects the tab, the electrode terminal connecting portion connects the electrode terminal, and the intermediate connecting portion connects the tab connecting portion and the electrode terminal connecting portion; the electrode terminal connecting portion and the tab connecting portion extend along a second direction, the intermediate connecting portion extends along a third direction, and the tab connecting portion is closer to the first wall than the electrode terminal connecting portion in the third direction; the welding portion of the tab is welded to the side of the tab connecting portion away from the first wall; the first direction, the second direction, and the third direction are perpendicular to each other.

[0015] In this way, the tab connecting portion and the electrode terminal connecting portion have a certain height difference along the third direction, so that the overlapping portion of the tab can be located in the space generated by the height difference between the tab connecting portion and the electrode terminal connecting portion, so that the overlapping portion does not occupy too much space in the accommodation cavity of the shell, and the tab can be overlapped and welded with the electrical connector without affecting the energy density of the battery cell.

[0016] In some embodiments, the battery cell further includes an insulating member located on the side of the first wall facing the electrode assembly; each of the tabs further includes a bending portion connected to the welding portion, the bending portion protrudes toward the side of the first wall relative to the welding portion in the third direction; along the first direction, the width of the tab connecting portion is less than the first size; wherein the first size is the width of the insulating member along the first direction minus the width of the bending portion of each tab connected to the tab connecting portion along the first direction.

[0017] Since the tab needs to be bent when connecting with the tab connecting part, when the size of the tab connecting part is less than the first size, enough space is provided in the shell to accommodate the bent part of the tab, thereby meeting the process requirement of tab bending and improving the connection reliability between the tab and the electrical connecting piece.

[0018] In some embodiments, the first size is the width of the insulating piece in the first direction minus 6 millimeters.

[0019] In this way, most of the tab folding process requirements can be met, and enough distance can be provided between the insulating piece and the tab connecting part to accommodate the bent part of most of the tabs.

[0020] In some embodiments, in the first direction, the width of the tab connecting part is greater than the width of the welding mark.

[0021] In this way, the tab connecting part can have enough space for the overlapping part of the tab to be welded, thereby improving the welding reliability of the tab and the electrical connecting piece.

[0022] In some embodiments, in the third direction, the height of the intermediate connecting part is the distance between the bottom end surface of the electrode terminal and the insulating piece minus the distance between the tab connecting part and the insulating piece.

[0023] In this way, while ensuring the installation accuracy of the electrical connecting piece, a height difference in the third direction can be formed between the tab connecting part and the electrode terminal connecting part of the electrical connecting piece, so that the overlapping part of the tab can be located in the space formed by the height difference, so that the overlapping part does not occupy too much space in the shell, and the tab can be welded to the electrical connecting piece by one welding mark, thereby reducing the thickness of the battery monomer without affecting the energy density of the battery monomer, reducing the number of welds, and reducing production costs.

[0024] In some embodiments, the tab connecting part has an accommodation space on at least one side in the first direction, and the bent part is accommodated in the accommodation space.

[0025] In this way, the accommodation space on the side of the electrical connecting piece in the first direction can be fully utilized, the space occupied by the tab in the height direction (third direction) is reduced, and the tab is not located entirely below the electrical connecting piece, thereby facilitating the improvement of the space utilization rate in the shell of the battery monomer, reserving more space for the electrode body, and thereby increasing the volume of the electrode body without changing the size of the shell of the battery monomer, thereby improving the energy density of the battery monomer.

[0026] In some embodiments, in the first direction, the width of the bent part is less than the distance between the insulating piece and the tab connecting part.

[0027] Therefore, the bending part of the tab can be accommodated in the accommodation space while ensuring good tab appearance, thereby saving space occupied by the tab in the accommodation cavity along the third direction.

[0028] In some embodiments, the tab connecting part is flat; and / or the electrode terminal connecting part is flat.

[0029] Therefore, it is more conducive to connect the electrode terminal and the electrode terminal connecting part and the tab and the tab connecting part, respectively, to improve the connection reliability and make the stability of the electrical connector better.

[0030] In some embodiments, the electrode terminal includes a positive electrode terminal and a negative electrode terminal; the electrical connector includes a first electrical connector and a second electrical connector; the tab includes a plurality of positive electrode tabs and a plurality of negative electrode tabs, each of the positive electrode tabs is located on the same side as the positive electrode terminal, and / or each of the negative electrode tabs is located on the same side as the negative electrode terminal, each of the positive electrode tabs is connected to the positive electrode terminal through the first electrical connector, and each of the negative electrode tabs is connected to the negative electrode terminal through the second electrical connector.

[0031] Therefore, the positive electrode tabs at least partially overlap to form an overlapping part, and the overlapping part is welded to the first electrical connector, and the negative electrode tabs at least partially overlap to form an overlapping part, and the overlapping part is welded to the second electrical connector, so that the positive electrode tabs and the negative electrode tabs only need to be welded once to achieve connection with the first electrical connector and the second electrical connector, reducing the number of welds and improving production efficiency and reducing production costs. Moreover, since the positive electrode tabs and the negative electrode tabs are welded to the first electrical connector and the second electrical connector, respectively, each only forms one weld, which is conducive to reducing the thickness of the battery monomer and allowing the battery monomer to be better applied to the installation environment with limited space.

[0032] In addition, since the positive electrode tabs are located on the same side as the positive electrode terminal, and / or the negative electrode tabs are located on the same side as the negative electrode terminal, the connection of the tabs and the electrode terminals is more convenient, and the space in the shell of the battery monomer can be saved, which is conducive to improving the energy density of the battery monomer.

[0033] In some embodiments, the electrode terminal includes a positive electrode terminal and a negative electrode terminal; the electrical connector includes a first electrical connector and a second electrical connector; the tab includes a plurality of positive electrode tabs and a plurality of negative electrode tabs, each of the positive electrode tabs is located on a different side from the positive electrode terminal, and / or each of the negative electrode tabs is located on a different side from the negative electrode terminal, each of the positive electrode tabs is connected to the positive electrode terminal through the first electrical connector, and each of the negative electrode tabs is connected to the negative electrode terminal through the second electrical connector.

[0034] Thus, the positive tab at least partially overlaps to form an overlapping portion, and the overlapping portion is welded with the first electrical connector, and the negative tab at least partially overlaps to form an overlapping portion, and the overlapping portion is welded with the second electrical connector, so that the positive tab and the negative tab only need to be welded once to realize the connection with the first electrical connector and the second electrical connector, thereby reducing the number of welding, which is beneficial to improve the production efficiency and reduce the production cost. Moreover, since the positive tab and the negative tab are welded with the first electrical connector and the second electrical connector, each of them only forms one welding mark, so as to facilitate reducing the thickness size of the battery monomer, so that the battery monomer can be better applied to the installation environment with limited space.

[0035] In addition, since the positive tab and the positive terminal are located on different sides, and / or the negative tab and the negative terminal are located on different sides, thereby facilitating the flexibility of the connection between the tab and the electrode terminal, and facilitating the flexibility of the connection between the battery monomers when a plurality of battery monomers are grouped.

[0036] In some embodiments, the number of the electrode assemblies is multiple, and the multiple electrode assemblies are arranged side by side along a first direction, and the welding portions of the tabs with the same polarity of each electrode assembly are connected by the same electrical connector.

[0037] Thus, the number of assembly steps can be reduced, the assembly difficulty can be reduced, and the production cost can be reduced.

[0038] The second aspect of the present disclosure provides a battery device, comprising: a box body; and at least one battery monomer of the first aspect of the present disclosure, which is accommodated in the box body.

[0039] The battery device provided by the present disclosure can effectively reduce the size of the battery device due to the thin battery monomer provided by the first aspect, so that the battery device can be installed in an installation environment with limited size, and the production cost is low and the production efficiency is high. In addition, in the case that the size of the box body of the battery device does not change, more battery monomers can be accommodated in the box body, which is beneficial to improve the energy density of the battery device.

[0040] The third aspect of the present disclosure provides a power utilization device, comprising the battery monomer of the first aspect of the present disclosure or the battery device of the second aspect of the present disclosure for providing electric energy.

[0041] The power consuming device provided by the embodiments of the present disclosure can arrange more battery monomers or battery devices due to the smaller size of the battery monomers or battery devices provided by the first aspect or the second aspect, which is conducive to prolonging the power supply time of the battery monomers or battery devices to the power consuming device, and the power consuming device can also be well powered in the case of limited space.

[0042] The fourth aspect of the present disclosure provides a power storage device, which comprises the battery monomer of the first aspect or the battery device of the second aspect.

[0043] The power storage device provided by the embodiments of the present disclosure can arrange more battery monomers or battery devices due to the smaller size of the battery monomers or battery devices provided by the first aspect or the second aspect, which is conducive to prolonging the power supply time of the battery monomers or battery devices to the power storage device, and the power storage device can also be well powered in the case of limited space.

[0044] The embodiments of the present disclosure have the following beneficial effects:

[0045] According to the present disclosure, the size of the battery monomer in the thickness direction can be reduced, the number of welding times can be reduced, the production cost can be reduced, and the production efficiency can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0046] 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 included to provide a description of preferred embodiments and are not meant to limit the present disclosure. Moreover, the same reference numbers in all the drawings refer to the same or similar components. In the drawings:

[0047] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present disclosure;

[0048] FIG. 2 is a perspective exploded schematic diagram of a battery device provided by some embodiments of the present disclosure;

[0049] FIG. 3 is a perspective exploded schematic diagram of a battery monomer provided by some embodiments of the present disclosure;

[0050] FIG. 4 is a partial planar structural schematic diagram of a positive electrode sheet, a negative electrode sheet, and a separator of an electrode body provided by some embodiments of the present disclosure;

[0051] FIG. 5 is a planar structural schematic diagram of a battery monomer provided by some embodiments of the present disclosure;

[0052] FIG. 6 is an enlarged view of the circled A part in FIG. 5;

[0053] FIG. 7 is a perspective structural schematic view of an electrical connector according to some embodiments of the present disclosure;

[0054] FIG. 8 is a schematic cross-sectional view of a battery cell according to some embodiments of the present disclosure;

[0055] FIG. 9 is an enlarged view of the circled B portion in FIG. 8;

[0056] FIG. 10 is a partial schematic view of a tab connected to an electrical connector according to some embodiments of the present disclosure, in which one electrode body is shown;

[0057] FIG. 11 is a partial schematic view of a tab connected to an electrical connector according to some embodiments of the present disclosure, in which two electrode bodies are shown;

[0058] FIG. 12 is a partial schematic view of a tab connected to an electrical connector according to some embodiments of the present disclosure, in which four electrode bodies are shown;

[0059] FIG. 13 is a partial schematic cross-sectional view of a battery cell according to some embodiments of the present disclosure, from another perspective.

[0060] BRIEF DESCRIPTION OF THE DRAWINGS 1 - housing; 1a - accommodation cavity; 11 - first wall; 12 - sealing pocket; 2 - electrode assembly; 21 - electrode body; 211 - positive electrode tab; 212 - negative electrode tab; 213 - separator; 22 - tab; 221 - welding portion; 2211 - overlapping portion; 222 - bent portion; 223 - positive electrode tab; 224 - negative electrode tab; 3 - electrode terminal; 31 - positive electrode terminal; 32 - negative electrode terminal; 4 - electrical connector; 41 - tab connecting portion; 42 - electrode terminal connecting portion; 43 - intermediate connecting portion; 44 - first electrical connector; 45 - second electrical connector; 5 - solder mark; 6 - insulating member; 10 - accommodation space; 100 - battery cell; 200 - controller; 300 - motor; 400 - battery device; 401 - box body; 401a - cover body; 401b - bottom plate; 1000 - vehicle. DETAILED DESCRIPTION

[0061] Embodiments of the technical solutions of the present disclosure will be described in detail below with reference to the accompanying 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 limit the protection scope of the present disclosure.

[0062] 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 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 "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion.

[0063] In the description of the embodiments of the 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 indicated technical features. In the description of the embodiments of the disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0064] Reference herein to "an embodiment" 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 phrase appears at various locations in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0065] In the description of the embodiments of the disclosure, the term "and / or" is only a description of the 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 associated objects before and after it.

[0066] 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 based on 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 indicated device or element 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.

[0067] 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.

[0068] In the description of the embodiments of the present disclosure, unless explicitly defined and limited otherwise, the technical term "contact" should be interpreted broadly, which can be direct contact or contact through an intermediate medium layer, and can be contact between two objects in contact with each other without interaction force or contact between two objects in contact with each other with interaction force.

[0069] Hereinafter, the present disclosure will be described in detail.

[0070] At present, new energy batteries are increasingly 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, and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also increasing.

[0071] In the production and manufacturing process of the battery monomer, the electrode assembly in the battery monomer needs to be electrically connected to the electrode terminal arranged in the shell through the electrical connector (for example, the adapter plate), so that the current can be exported from the electrode assembly or imported into the electrode assembly.

[0072] In the related art, when the number of tabs with the same polarity in the battery monomer is multiple, each tab will be individually welded with the electrical connector, thereby forming multiple welding marks on the electrical connector. The size of the electrical connector will be limited by the size and number of the welding marks, that is, in order to meet the process requirements of welding, the width (size along the first direction) of the electrical connector may be large, thereby the thickness (size along the first direction) of the battery monomer may be large.

[0073] With the progress of science and technology, devices are gradually integrated and miniaturized, therefore, the application scenarios of the battery monomer with smaller thickness gradually increase, for example, in some cases where the installation space is very limited, the battery monomer with larger thickness obviously cannot be installed. In order to reduce the size of the battery monomer, the number of electrode assemblies inside the battery monomer or the size of the electrode body may be reduced, which will inevitably affect the energy density of the battery monomer.

[0074] The battery monomer provided by the embodiment of the present disclosure can be used in, but is not limited to, an energy storage power supply system, an electric device such as a vehicle, a ship or an aircraft, and an energy storage device such as an energy storage container or an energy storage cabinet.

[0075] Since the plurality of tab terminals with the same polarity are welded with the electric connecting piece to form only one welding mark, compared with the case that a plurality of welding marks are formed by welding a plurality of tab terminals respectively, the space occupied by the plurality of welding marks can be saved, so that the size of the electric connecting piece can be reduced, and the size of the battery monomer can be effectively reduced, so that the battery monomer can be better applied to an installation environment with limited space, and the energy density of the battery monomer will not be affected.

[0076] In addition, the tab terminals with the same polarity of the battery monomer of the present disclosure at least partially overlap to form an overlapping part, and are welded with the electric connecting piece at the overlapping part, so that the connection between the tab terminal and the electric connecting piece can be realized by welding only once, the number of welding times can be reduced, and the production efficiency can be improved and the production cost can be reduced.

[0077] The battery monomer provided by the embodiment of the present disclosure can be used in, but is not limited to, an energy storage power supply system, an electric device such as a vehicle, a ship or an aircraft, and an energy storage device such as an energy storage container or an energy storage cabinet.

[0078] The embodiment of the present disclosure provides an electric device including the above-mentioned battery monomer for providing electric energy, and the electric device includes, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, etc. 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, etc. The spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft, etc.

[0079] 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.

[0080] FIG. 1 is a structural schematic diagram of a vehicle 1000 according to 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 vehicle, a hybrid electric vehicle, or a range extended electric vehicle, etc. As shown in FIG. 1, the vehicle 1000 is internally provided with a battery monomer 100, which can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery monomer 100 can be used for power supply of the vehicle 1000, for example, the battery monomer 100 can be used as an operating power source 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 monomer 100 to supply power to the motor 300, for example, to meet the power demand of the vehicle 1000 during starting, navigation, and driving.

[0081] In some embodiments of the present disclosure, the battery monomer 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0082] FIG. 2 is a perspective exploded schematic diagram of a battery device 400 according to an embodiment of the present disclosure. As shown in FIG. 2, the battery device 400 includes a box body 401 and at least one battery monomer 100, and the box body 401 includes a cover body 401a and a bottom plate 401b. The cover body 401a is arranged above the bottom plate 401b, so as to form a containing area of the battery monomer 100 between the bottom plate 401b and the cover body 401a.

[0083] In the battery device 400, the battery monomer 100 can be multiple, and the multiple battery monomers 100 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that the multiple battery monomers 100 are connected in series and in parallel. The multiple battery monomers 100 can be directly connected in series, in parallel, or in a mixed connection, and then the whole of the multiple battery monomers 100 is placed in the containing space formed by the bottom plate 401b and the cover body 401a. Of course, the battery monomer 100 can also be that the multiple battery monomers 100 are first connected in series, in parallel, or in a mixed connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are contained in the containing space formed by the bottom plate 401b and the cover body 401a. The battery device 400 can further include other structures, for example, the battery device 400 can further include a current combing component for realizing electrical connection between the multiple battery monomers 100.

[0084] In the following, some embodiments of the present disclosure will be described in detail with reference to FIGS. 3 to 13.

[0085] FIG. 3 is a perspective exploded view of a battery cell according to some embodiments of the present disclosure. FIG. 4 is a partial plan view of a positive electrode tab, a negative electrode tab, and a separator of an electrode body according to some embodiments of the present disclosure. FIG. 5 is a plan view of a battery cell according to some embodiments of the present disclosure. FIG. 6 is an enlarged view of the portion A circled in FIG. 5. FIG. 7 is a perspective view of an electrical connector according to some embodiments of the present disclosure. FIG. 8 is a schematic cross-sectional view of a battery cell according to some embodiments of the present disclosure. FIG. 9 is an enlarged view of the portion B circled in FIG. 8. FIG. 10 is a partial schematic view of a connection between a tab and an electrical connector, in which one electrode body is shown, according to some embodiments of the present disclosure. FIG. 11 is a partial schematic view of a connection between a tab and an electrical connector, in which two electrode bodies are shown, according to some embodiments of the present disclosure. FIG. 12 is a partial schematic view of a connection between a tab and an electrical connector, in which four electrode bodies are shown, according to some embodiments of the present disclosure. FIG. 13 is a partial schematic cross-sectional view of a battery cell from another perspective according to some embodiments of the present disclosure.

[0086] In some embodiments of the present disclosure, a first direction, a second direction, and a third direction are set for ease of explanation, and the first direction, the second direction, and the third direction are perpendicular to each other, but those skilled in the art should understand that embodiments of the present disclosure are not limited to the case where the three directions are perpendicular to each other. For ease of explanation, as shown by arrows in FIGS. 3 to 11, the direction in which the arrow X is located is the first direction, the direction in which the arrow Y is located is the second direction, and the direction in which the arrow Z is located is the third direction. Sometimes, the direction in which the arrow Z points along the third direction is also referred to as “upward”, and the opposite direction is referred to as “downward”.

[0087] A first aspect of the present disclosure provides a battery cell 100, which includes a housing 1, at least one electrode assembly 2, an electrode terminal 3, and an electrical connector 4. The housing 1 has a receiving cavity 1a formed inside, and includes a first wall 11 having a mounting hole formed therein. The at least one electrode assembly 2 is located in the receiving cavity 1a, and includes an electrode body 21 and a tab 22 connected to the electrode body 21. The electrode terminal 3 is disposed in the mounting hole. The electrical connector 4 connects the electrode terminal 3 and the tab 22. The tab 22 includes a welding portion 221, and in the case where the number of tabs 22 of the same polarity is plural, the welding portions 221 of the tabs 22 of the same polarity at least partially overlap to form an overlapping portion 2211, and the overlapping portion 2211 is welded to the electrical connector 4 to form a welding mark 5.

[0088] The battery cell 100 refers to a basic unit capable of converting chemical energy and electrical energy to each other, and can be used to manufacture a battery device 400, thereby being used to supply power to an electric device or an energy storage device.

[0089] In the embodiments of the present disclosure, the battery cell 100 is a secondary battery cell, which refers to a battery cell that can be activated by charging after discharging to continue use.

[0090] The battery cell 100 can be a lithium ion battery cell, a sodium ion battery cell, a sodium lithium ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium sulfur battery cell, a magnesium ion battery cell, a nickel hydrogen battery cell, a nickel cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present disclosure are not limited thereto.

[0091] In the embodiments of the present disclosure, the battery cell 100 is a square cell. In some other embodiments, the battery cell 100 can also be a battery cell of other shapes, and the present disclosure does not have a particular limitation.

[0092] As shown in FIG. 3, the battery cell 100 includes a shell 1, which is an external protective shell of the battery cell 100, and an accommodation cavity la is formed inside the shell 1 for accommodating the electrode assembly 2, electrolyte, etc. The shell 1 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.

[0093] In some embodiments, the shell 1 can be a sealed structure or a non-sealed structure. As an example, when the shell 1 is a sealed structure, the shell 1 plays a role in protecting the electrode assembly 2 accommodated therein. The shell 1 and the electrode assembly 2 can further include a sealing bag 12 for packaging the electrode assembly 2 and the electrolyte. Specifically, the sealing bag 12 can be a bag-shaped insulating member or an aluminum-plastic film.

[0094] The electrode assembly 2 is a component where electrochemical reactions occur in the battery cell 100, and the electrode assembly 2 includes an electrode body 21. As shown in FIG. 4, the electrode body 21 includes a positive electrode sheet 211, a negative electrode sheet 212, and a separator 213, which are usually arranged in a stacked manner along the thickness direction (first direction) of the battery cell. During charging and discharging of the battery cell 100, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode sheet 211 and the negative electrode sheet 212. The separator 213 is disposed between the positive electrode sheet 211 and the negative electrode sheet 212, and can play a role in preventing short circuiting of the positive and negative electrode sheets while allowing the active ions to pass through.

[0095] In some embodiments, the positive electrode sheet 211 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.

[0096] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the opposite surfaces of the positive electrode current collector.

[0097] As an example, the positive current collector can employ a metal foil or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, nickel, or titanium, or the like can be employed. 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).

[0098] As an example, the positive 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 disclosure is not limited to these materials, and other conventional materials that can be used as a battery positive active material can also be used. These positive active materials can be used only one kind alone, or two or more kinds 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 simply 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.

[0099] In some embodiments, the positive sheet 211 can employ a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, or a foam alloy, or the like. When the foam metal is used as a positive electrode, the foam metal surface can not be provided with a positive active material, or of course can be provided with a positive active material. As an example, the foam metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0100] In some embodiments, the negative sheet 212 can include a negative current collector.

[0101] As an example, the negative current collector can employ a metal foil, a foam metal, or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, nickel, carbon, or titanium, or the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The foam metal can be a foam nickel, a foam copper, a foam aluminum, or a foam alloy, or the like. 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, 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). In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0102] In some embodiments, the separator 213 is a separator film. The present disclosure does not have a particular limitation on the type of separator film, and any publicly known porous structure separator film having good chemical stability and mechanical stability can be used.

[0103] 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.

[0104] In some embodiments, the separator 213 is a solid electrolyte.

[0105] In some embodiments, the electrode body 21 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0106] In some embodiments, the electrode body 21 is a stacked structure.

[0107] As an example, a plurality of positive electrode sheets 211 and a plurality of negative electrode sheets 212 can be provided, and the plurality of positive electrode sheets 211 and the plurality of negative electrode sheets 212 can be alternately stacked.

[0108] As an example, a plurality of positive electrode sheets 211 can be provided, and the negative electrode sheet 212 can be folded to form a plurality of folded sections that are stacked. One positive electrode sheet 211 can be interposed between adjacent folded sections.

[0109] As an example, both the positive electrode sheet 211 and the negative electrode sheet 212 can be folded to form a plurality of folded sections that are stacked.

[0110] As an example, a plurality of separators 213 can be provided, and each of the plurality of separators 213 can be interposed between any adjacent positive electrode sheet 211 or negative electrode sheet 212.

[0111] As an example, the separator 213 can be continuously provided, and the separator 213 can be interposed between any adjacent positive electrode sheet 211 or negative electrode sheet 212 by being folded or wound.

[0112] In some embodiments, the battery cell 100 further includes an electrolyte. The electrolyte functions to conduct ions between the positive electrode and the negative electrode. The present disclosure does not have a particular limitation on the type of electrolyte, and the electrolyte can be selected as needed. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0113] In some embodiments, the electrode assembly 2 includes a tab 22. The tab 22 can conduct electric current from the electrode body 21 or can conduct electric current to the electrode body 21. The tab 22 includes a positive electrode tab 223 and a negative electrode tab 224.

[0114] The electrode terminal 3 is arranged in a mounting hole of the first wall 11 of the shell 1 and partially located in the accommodation cavity 1a of the shell 1. The electrode terminal 3 is used to directly or indirectly electrically connect with the tab 22 of the electrode assembly 2 to output or input the electric energy of the electrode body 21 of the electrode assembly 2.

[0115] The first wall 11 is a wall surface of the shell 1 for mounting the electrode terminal 3. The first wall 11 cooperates with other wall surfaces of the shell 1 to form the accommodation cavity 1a for accommodating the electrode assembly 2. In the embodiment of the present disclosure, the electrode terminal 3 is mounted on the end cover, that is, the end cover constitutes the first wall 11 of the shell 1. In some other embodiments, if the electrode terminal 3 is mounted on other wall surfaces of the shell 1, the wall surface on which the electrode terminal 3 is mounted constitutes the first wall 11.

[0116] Exemplarily, the number of the electrode terminal 3 can be only one, the electrode terminal 3 is connected with one of the positive tab 223 or the negative tab 224, and the other tab of the positive tab 223 or the negative tab 224 is connected with the shell 1. The number of the electrode terminal 3 can also be two, and the two electrode terminals 3 are respectively connected with the positive tab 223 and the negative tab 224.

[0117] In the embodiment of the present disclosure, the electrode terminal 3 includes a positive terminal 31 and a negative terminal 32, the positive terminal 31 is connected with the positive tab 223, and the negative terminal 32 is connected with the negative tab 224. Therefore, the shell 1 is correspondingly formed with two mounting holes for mounting the positive terminal 31 and the negative terminal 32, respectively. It should be understood by those skilled in the art that in some other embodiments, the number of the electrode terminal 3 can also be more (more than two). When the number of the electrode terminal 3 is multiple, the multiple electrode terminals 3 can be mounted on the same wall surface of the shell 1 or on different wall surfaces of the shell 1. When the multiple electrode terminals 3 are respectively mounted on different wall surfaces of the shell 1, each wall surface on which the electrode terminal 3 is mounted can constitute the first wall 11.

[0118] Exemplarily, the electrode terminal 3 can be a pole, for example, and the electrode terminal 3 can be made of a conductive material to realize the conductive function of the electrode terminal 3.

[0119] In the embodiment of the present disclosure, the electrode terminal 3 is electrically connected with the tab 22 of the electrode assembly 2 through the electrical connector 4. The electrical connector 4 can also be referred to as a adapter.

[0120] In the related art, when the tabs are connected with the electrical connector, each tab with the same polarity is separately welded with different positions of the electrical connector, thereby forming multiple welding marks on the electrical connector. In order to ensure the stability and reliability of welding, a certain process space is also required between the welding area (welding mark) and the edge of the electrical connector and between different welding areas. Therefore, the electrical connector needs to have sufficient width (dimension along the first direction), which makes the width of the electrical connector larger, and further makes the thickness (dimension along the first direction) of the battery monomer larger.

[0121] With the progress of science and technology, devices are gradually integrated and miniaturized. Therefore, the application scenarios of battery monomers with smaller thickness gradually increase. For example, in some cases where the installation space is very limited, battery monomers with larger thickness cannot be installed. In order to reduce the size of the battery monomer, the number of electrode assemblies inside the battery monomer or the size of the electrode body can be reduced, which will inevitably affect the energy density of the battery monomer.

[0122] In the embodiments of the present disclosure, as shown in FIGS. 3, 5, 6 and 11, the number of electrode assemblies 2 is two, and each electrode assembly 2 has an electrode body 21 that leads out one positive tab 223 and one negative tab 224, that is, the number of tabs 22 with the same polarity is two, the two tabs 22 with the same polarity are arranged at intervals along the first direction, and the welding portions 221 of the tabs 22 with the same polarity at least partially overlap to form an overlapping portion 2211. Overlapping refers to the position where the projections of the welding portions 221 of the tabs 22 coincide with each other in the projection plane perpendicular to the third direction.

[0123] The welding portion 221 refers to the part of the tab 22 used for welding. The welding portion 221 is generally flat, which is beneficial to improve the stability of welding. However, those skilled in the art should understand that the welding portion 221 is not necessarily all areas welded with the electrical connector 4, but at least part of the welding portion 221 is welded with the electrical connector 4.

[0124] Since the tabs 22 are welded with the electrical connector 4 at the overlapping portion 2211, only one welding can simultaneously connect the two tabs 22 with the same polarity with the electrical connector 4, and only one welding mark 5 is formed after welding. In this way, the number of welding marks 5 after the tabs 22 are welded with the electrical connector 4 can be reduced, thereby saving the space occupied by the welding marks 5 themselves on the electrical connector 4, and the process space required when the welding marks 5 are welded on the electrical connector 4 can be saved, thereby the size of the electrical connector 4 can be appropriately reduced, and further the size of the battery monomer 100 can be reduced, so that the battery monomer 100 can be better applied to the installation environment with limited space, and the energy density of the battery monomer 100 will not be affected.

[0125] In addition, since the connection between the tab 22 and the electrical connecting member 4 can be achieved by only one welding, the number of welding can be reduced during the manufacturing process of the battery monomer 100, thereby improving the production efficiency, production rhythm and reducing the production cost.

[0126] As shown in FIG. 10, the number of the electrode assembly 2 in the shell 1 can be only one, and one electrode assembly 2 leads out two tabs with the same polarity. As shown in FIG. 12, the number of the electrode assembly 2 in the shell 1 can be four, each electrode assembly 2 leads out one tab 22, and each adjacent two electrode assemblies 2 overlap each other to form an integrated tab, and at least part of the two integrated tabs overlap to form an overlapping part 2211, and the overlapping part 2211 is welded with the electrical connecting member 4.

[0127] The number of the electrode assembly 2 in the battery monomer 100 is not specifically limited in the embodiments of the present disclosure, and the number of the electrode assembly 2 can be one, two or more (more than two). The number of the tab 22 led out by each electrode assembly 2 and the arrangement of the tab 22 are not specifically limited in the embodiments of the present disclosure, as long as the welding of the tabs 22 with the same polarity and the electrical connecting member 4 only forms one welding mark 5, that is, the welding of each tab 22 with the same polarity and the electrical connecting member 4 can be connected by only one welding.

[0128] In the embodiments of the present disclosure, the overlapping part 2211 of the tab 22 can be welded with the electrical connecting member 4 by ultrasonic welding. Ultrasonic welding is to transmit high-frequency vibration waves to the surface of the object to be welded, and under pressure, the surface of the object is rubbed to form a fusion between the molecular layers. Ultrasonic welding is a fast, clean and effective assembly process.

[0129] Of course, those skilled in the art should understand that in some other embodiments, the overlapping part of the tab 22 can also be welded with the electrical connecting member 4 by any other welding method.

[0130] In some embodiments of the present disclosure, the thickness direction of the electrode body 21 is the first direction. Along the first direction, the width of the overlapping part 2211 is greater than the width of the welding mark 5.

[0131] In some embodiments, the thickness direction of the battery cell 100 can also be referred to as the first direction, the opposite direction of the large face (the wall face with the largest area) of the shell 1 can also be referred to as the first direction, and the width direction of the electrical connection piece 4 can also be referred to as the first direction. The first direction can also be the direction in which the positive tab 211, the negative tab 212, and the separator 213 of the electrode body 21 are stacked. Those skilled in the art should understand that when the electrode body 21 is in a jelly-roll structure, the electrode body 21 includes a curved section and a flat section. In this case, the stacking direction of the positive tab, the negative tab, and the separator of the flat section is the first direction. In the specific examples shown in FIGS. 4 to 6, the up-down direction in FIGS. 4 to 5 is the first direction of the embodiments of the present disclosure.

[0132] Since the width of the overlapping portion 2211 is greater than the width of the welding mark 5 along the first direction, the welding mark 5 can be completely located in the overlapping area of the tabs 22 with the same polarity, thereby increasing the connection area between the tabs 22 with the same polarity at the overlapping portion 2211, so that the tabs 22 with the same polarity can be well welded to each other, the welding reliability is higher, and the possibility of occurrence of welding failure or false welding and other adverse conditions is reduced, and the welding quality is improved.

[0133] In some embodiments of the present disclosure, as shown in FIG. 6, the welding mark 5 is located in the central region of the overlapping portion 2211.

[0134] The central region refers to that the interval distance of the welding mark 5 along the first direction from the opposite sides of the overlapping portion 2211 along the first direction is substantially the same, and the interval distance of the welding mark 5 along the second direction from the opposite sides of the overlapping portion 2211 along the second direction is substantially the same, i.e., the welding mark 5 is generally symmetrically arranged along the central axis of the overlapping portion 2211.

[0135] Therefore, the welding reliability between the tabs 22 with the same polarity can be further improved, and the tabs 22 at the overlapping portion 2211 can be sufficiently welded.

[0136] In addition, the welding mark 5 is located in the central region of the overlapping portion 2211, which can make the extension lengths of the tabs 22 on the opposite sides along the first direction the same, reduce the possibility of overstretching of the tabs 22 on one side, and be beneficial to improving the reliability of the battery cell 100.

[0137] In some embodiments of the present disclosure, the electrical connector 4 includes a tab connecting portion 41, an electrode terminal connecting portion 42, and an intermediate connecting portion 43. The tab connecting portion 41 is connected to the tab 22, the electrode terminal connecting portion 42 is connected to the electrode terminal 3, and the intermediate connecting portion 43 connects the tab connecting portion 41 and the electrode terminal connecting portion 42. The electrode terminal connecting portion 42 and the tab connecting portion 41 extend in a second direction, the intermediate connecting portion 43 extends in a third direction, and the tab connecting portion 41 is closer to the first wall 11 than the electrode terminal connecting portion 42 in the third direction. The welding portion 221 of the tab 22 is welded to a side of the tab connecting portion 41 that faces away from the first wall 11. The first direction, the second direction, and the third direction are perpendicular to each other.

[0138] The extending direction of the tab connecting portion 41 and the electrode terminal connecting portion 42 is the second direction, which can also be referred to as the length direction of the electrical connector 4. The extending direction of the intermediate connecting portion 43 is the third direction, which can also be referred to as the height direction. In the specific examples shown in FIGS. 8 and 9, the left-right direction in FIGS. 8 and 9 is the second direction of the present disclosure, and the up-down direction is the third direction of the present disclosure.

[0139] As shown in FIGS. 7 and 9, the electrical connector 4 includes a tab connecting portion 41, an electrode terminal connecting portion 42, and an intermediate connecting portion 43. The tab connecting portion 41 is a structure in the electrical connector 4 for connecting to the tab 22, and the electrode terminal connecting portion 42 is a structure in the electrical connector 4 for connecting to the electrode terminal 3.

[0140] Exemplarily, the electrode terminal 3 can be welded to the electrode terminal connecting portion 42 by laser welding.

[0141] The intermediate connecting portion 43 is a component in the electrical connector 4 that connects the tab connecting portion 41 and the electrode terminal connecting portion 42, and the tab connecting portion 41 and the electrode terminal connecting portion 42 are respectively located on opposite sides of the intermediate connecting portion 43 in the second direction.

[0142] In some embodiments, the intermediate connecting portion 43 can be configured as a fuse portion, i.e., the intermediate connecting portion 43 includes a thinning region and / or a fuse hole, etc., so that when the current exceeds the rated value, i.e., when the current is too large, the intermediate connecting portion 43 can be fused, thereby disconnecting the connection between the tab connecting portion 41 and the electrode terminal connecting portion 42, thereby cutting off the electrical connection between the tab 22 and the electrode terminal 3, reducing the possibility of short circuit of the battery monomer 100, and making the battery monomer 100 more reliable.

[0143] Exemplarily, the electrical connector 4 can be formed in a one-piece structure, for example, a plate-shaped piece can be prepared by stamping, bending, cutting, etc. to form a one-piece electrical connector 4.

[0144] Exemplarily, the tab connecting portion 41, the electrode terminal connecting portion 42 and the intermediate connecting portion 43 of the electrical connector 4 can be in a split structure and then assembled together.

[0145] After the plurality of tabs 22 with the same polarity are at least partially overlapped to form the overlapping portion 2211, the size of the overlapping portion 2211 in the third direction is relatively large, and thus, the overlapping portion 2211 can occupy part of the space in the accommodating cavity 1a. In the embodiments of the present disclosure, since the intermediate connecting portion 43 extends in the third direction, the tab connecting portion 41 and the electrode terminal connecting portion 42 have a certain height difference in the third direction, so that the overlapping portion 2211 of the tab 22 can be located in the space generated by the height difference between the tab connecting portion 41 and the electrode terminal connecting portion 42, so that the overlapping portion 2211 does not excessively occupy the space in the accommodating cavity 1a of the shell 1, and thus, the tabs 22 can be overlapped and welded with the electrical connector 4 without affecting the energy density of the battery monomer 100.

[0146] In some embodiments of the present disclosure, the battery monomer 100 further comprises an insulating member 6 located on the side of the first wall 11 facing the electrode assembly 2. Each tab 22 further comprises a bending portion 222 connected with the welding portion 221, and the bending portion 222 protrudes towards the side where the first wall 11 is located in the third direction relative to the welding portion 221. In the first direction, the width of the tab connecting portion 41 is smaller than the first size. The first size is the width of the insulating member 6 in the first direction minus the width of the bending portion 222 of each tab 22 connected with the tab connecting portion 41 in the first direction.

[0147] The insulating member 6 is made of an insulating material and located between the first wall 11 and the electrode assembly 2. The insulating member 6 can be integrally preformed by plastic or assembled by plastic components. When the shell 1 is made of metal material, the insulating member 6 can electrically insulate the electrode assembly 2 from the first wall 11, and reduce the possibility of short circuit caused by the contact between the tab 22 and the first wall 11 made of metal material. In addition, the insulating member 6 can also support the electrode assembly 2 to some extent, and reduce the possibility of movement of the electrode assembly 2 inside the accommodating cavity 1a.

[0148] Exemplarily, the insulating member 6 can be a plastic frame.

[0149] The tab 22 needs to be bent when connected with the tab connecting portion 41. One end of the bending portion 222 is connected with the welding portion 221, and the other end is connected with the electrode main body 21. The embodiments of the present disclosure do not specifically limit the bending shape of the bending portion 222, and the tab 22 can be bent according to actual conditions.

[0150] Exemplarily, as shown in FIG. 11 and FIG. 13, the bending part 222 of the tab 22 protrudes towards the side where the first wall 11 is located along the third direction relative to the welding part 221, and the cross section of the bending part 222 of the embodiment of the present disclosure is generally inverted U-shaped when viewed along the second direction, and one side wall of the bending part 222 is generally inclined, so that the inclined side wall is less likely to interfere with the insulating member 6 (lower plastic) in the shell 1, and the space between the tab connecting part 41 and the inner wall of the shell 1 can be more fully utilized to accommodate the bending part 222 of the tab 22.

[0151] In addition, compared with the way of bending the tab 22 by 90° as shown in FIG. 12, the structure of the tab 22 shown in FIG. 11 and FIG. 13 is more compact, and the overall size along the third direction is smaller, so that the tab 22 occupies less space, saves the space in the accommodating cavity 1a of the shell 1, and further increases the space in the accommodating cavity 1a for accommodating the electrode body 21, which is beneficial to improve the energy density of the battery monomer 100.

[0152] Exemplarily, as shown in FIG. 12, when viewed along the second direction, the bending part 222 can be generally inverted L-shaped.

[0153] In the embodiment of the present disclosure, when the width of the tab connecting part 41 is less than the first size, enough space can be provided in the shell 1 to accommodate the bending part 222 of the tab 22, so as to meet the process requirements of the bending of the tab 22 and improve the connection reliability between the tab 22 and the electrical connecting member 4.

[0154] Generally, the process size required when a single tab 22 is bent is 3 mm, so that in the case where the tab 22 protrudes on both sides along the first direction, the process size required for the bending of the tab 22 is 6 mm, that is, at least 3 mm of space is reserved between one side of the insulating member 6 and the edge of the tab connecting part 41 to accommodate the bending part 222 of the tab 22, and then in the case where the tab 22 is on both sides, at least 6 mm of space needs to be reserved in total.

[0155] In some embodiments of the present disclosure, the first size is the width of the insulating member 6 along the first direction minus 6 millimeters.

[0156] As shown in FIG. 6, the size of the insulating member 6 along the first direction is V, and the size of the tab connecting part along the first direction is W, then W < V-6, in millimeters (mm). Of course, those skilled in the art should understand that when the electrode assembly 2 only has a tab 22 on one side along the first direction, W can be less than V-3.

[0157] Therefore, the process requirements of most tab 22 folding can be met, and enough distance size can be provided between the insulating member 6 and the tab connecting part 41 to accommodate the bending part 222 of most tabs 22.

[0158] In some embodiments of the present disclosure, along the first direction, the width of the tab connecting portion 41 is greater than the width of the welding mark 5.

[0159] In this way, the tab connecting portion 41 can have sufficient space for the overlapping portion 2211 of the tab to be welded, so that the welding reliability of the tab 22 and the electrical connecting piece 4 is higher.

[0160] Specifically, the tab 22 also needs to reserve a certain process gap when welding with the electrical connecting piece 4 to improve welding reliability, or reduce the possibility of welding failure and other adverse conditions due to errors. Generally, the welding mark 5 needs to meet a process gap of 1.5 mm on one side, and a process gap of 3 mm on both sides.

[0161] As shown in FIG. 6, the width of the welding mark 5 along the first direction is Z, then W>Z, and specifically, W>Z+3, in units of millimeters (mm).

[0162] In this way, the process requirements when the tab 22 is welded with the tab connecting portion 41 can be met, so that the tab connecting portion 41 has sufficient space for the overlapping portion 2211 of the tab 22 to be welded with the tab connecting portion 41, and the welding reliability when the tab 22 is welded with the electrical connecting piece 4 is improved.

[0163] In some embodiments of the present disclosure, along the third direction, the height of the intermediate connecting portion 43 is the distance dimension between the bottom end surface of the electrode terminal 3 and the insulating piece 6 minus the distance dimension between the tab connecting portion 41 and the insulating piece 6.

[0164] The bottom end surface of the electrode terminal 3 refers to the end surface of the electrode terminal 3 on the side facing the electrode assembly 2 along the third direction.

[0165] As shown in FIG. 9, along the third direction, the distance dimension between the bottom end surface of the electrode terminal 3 and the insulating piece 6 is N, and the distance dimension between the tab connecting portion 41 and the insulating piece 6 is M, then the dimension of the intermediate connecting portion 43 along the third direction is N-M.

[0166] A certain gap is reserved between the tab connecting portion 41 and the insulating piece 6, so that a certain error space can be reserved, which is more conducive to the installation of the electrical connecting piece 4.

[0167] Generally, along the third direction, the distance dimension M between the tab connecting portion 41 and the insulating piece 6 is within the range of 0.1 mm to 0.3 mm. Exemplarily, M can be 0.1 mm, 0.2 mm, or 0.3 mm, etc.

[0168] Thus, the height difference between the tab connecting portion 41 and the electrode terminal connecting portion 42 of the electrical connecting piece 4 along the third direction can be formed while ensuring the installation accuracy of the electrical connecting piece 4, so that the overlapping portion 2211 of the tab 22 can be located in the space formed by the height difference, so that the overlapping portion 2211 does not occupy too much space in the shell 1, and so that the tab 22 can be welded to the electrical connecting piece 4 by one welding mark 5, which reduces the thickness of the battery monomer 100 without affecting the energy density of the battery monomer 100, and reduces the welding times and production cost.

[0169] In some embodiments of the present disclosure, the tab connecting portion 41 has a receiving space 10 on at least one side along the first direction, and the bent portion 222 is accommodated in the receiving space 10.

[0170] Thus, the receiving space 10 on the side of the electrical connecting piece 4 along the first direction can be fully utilized, and the space occupied by the tab 22 in the height direction (third direction) is reduced, so that the tab 22 is not located below the electrical connecting piece 4 as a whole, thereby facilitating the improvement of the space utilization rate in the shell 1 of the battery monomer 100, reserving more space for the electrode body 21, and further increasing the volume of the electrode body 21 without changing the size of the shell 1 of the battery monomer 100, thereby improving the energy density of the battery monomer 100.

[0171] Along the third direction, the space region between the inner wall surface of the first wall 11 on the side facing the receiving cavity 1a and the surface of the tab connecting portion 41 on the side away from the first wall 11, and along the first direction, the space region between the tab connecting portion 41 and the inner wall surface of the shell 1, together define the receiving space 10 for accommodating the bent portion 222.

[0172] For example, at least part of the tab connecting portion 41 can be recessed to form a groove portion along the first direction, and the groove portion defines at least part of the receiving space 10.

[0173] For another example, along the first direction, sufficient space can be reserved between the electrical connecting piece 4 and the inner wall of the shell 1 to form the receiving space 10 for accommodating the bent portion 222 of the tab 22.

[0174] The embodiments of the present disclosure do not specifically limit the forming manner of the receiving space 10, as long as there is sufficient space to accommodate the tab 22.

[0175] In the third direction, the top surface of the bending portion 222 is substantially flush with the surface of the tab connecting portion 41 facing the first wall 11, or can be slightly higher than the surface of the tab connecting portion 41 facing the first wall 11, so that the area of the accommodation space 10 in the height direction can be fully utilized to accommodate more tabs 22, thereby providing more space for the electrode body 21 and increasing the energy density of the battery monomer 100.

[0176] The top surface of the bending portion 222 refers to the surface of the bending portion 222 closest to the first wall 11 in the first direction. Flush means that the top surface of the bending portion 222 is substantially in the same horizontal plane as the surface of the tab connecting portion 41 facing the first wall 11.

[0177] Of course, those skilled in the art should understand that in some other embodiments, for example, when the length of the tab 22 is short, the top surface of the bending portion 222 can also be lower than the surface of the tab connecting portion 41 facing the first wall 11, and the user can set it according to the actual situation.

[0178] In some embodiments of the present disclosure, in the first direction, the width of the bending portion 222 is smaller than the distance between the insulating member 6 and the tab connecting portion 41.

[0179] Therefore, while ensuring that the tab 22 has a good appearance, the bending portion 222 of the tab 22 can be accommodated in the accommodation space 10, thereby saving the space occupied by the tab 22 in the third direction in the accommodation cavity 1a, which is conducive to improving the energy density of the battery monomer 100. Moreover, the tab 22 is less likely to come into contact with the shell 1, reducing the possibility of short circuit of the battery monomer 100.

[0180] In some embodiments of the present disclosure, the tab connecting portion 41 is flat and / or the electrode terminal connecting portion 42 is flat.

[0181] Therefore, it is more conducive to connecting the electrode terminal 3 and the tab 22 to the electrode terminal connecting portion 42 and the tab connecting portion 41, respectively, to improve the connection reliability and make the stability of the electrical connection 4 better.

[0182] Of course, those skilled in the art should understand that in some other embodiments, the tab connecting portion 41 and the electrode terminal connecting portion 42 can also have any other suitable shape.

[0183] In some embodiments of the present disclosure, the electrode terminal 3 includes a positive electrode terminal 31 and a negative electrode terminal 32. The electrical connection 4 includes a first electrical connection 44 and a second electrical connection 45. The tab 22 includes a plurality of positive electrode tabs 223 and negative electrode tabs 224, each positive electrode tab 223 is located on the same side as the positive electrode terminal 31, and / or each negative electrode tab 224 is located on the same side as the negative electrode terminal 32, each positive electrode tab 223 is connected to the positive electrode terminal 31 through the first electrical connection 44, and each negative electrode tab 224 is connected to the negative electrode terminal 32 through the second electrical connection 45.

[0184] Thus, the positive electrode tabs 223 at least partially overlap to form an overlapping portion 2211, and the overlapping portion 2211 is welded to the first electrical connection 44, and the negative electrode tabs 224 at least partially overlap to form an overlapping portion 2211, and the overlapping portion 2211 is welded to the second electrical connection 45, so that the positive electrode tabs 223 and the negative electrode tabs 224 each only need to be welded once to achieve connection with the first electrical connection 44 and the second electrical connection 45, reducing the number of welds, which is beneficial to improve production efficiency and reduce production cost. Moreover, since the positive electrode tabs 223 and the negative electrode tabs 224 are welded to the first electrical connection 44 and the second electrical connection 45, respectively, each only forms one welding mark 5, which is beneficial to reduce the thickness of the battery monomer 100, so that the battery monomer 100 can be better applied to the installation environment with limited space.

[0185] In addition, since the positive electrode tabs 223 are located on the same side as the positive electrode terminal 31, and / or the negative electrode tabs 224 are located on the same side as the negative electrode terminal 32, the connection of the tab 22 and the electrode terminal 3 is more convenient, and the space in the shell of the battery monomer can be saved, which is beneficial to improve the energy density of the battery monomer.

[0186] For example, the positive electrode tabs 223 are located on the same side as the positive electrode terminal 31, and the negative electrode tabs 224 are located on the same side as the negative electrode terminal 32.

[0187] For another example, the positive electrode tabs 223 are located on the same side as the positive electrode terminal 31, and the negative electrode tabs 224 are located on different sides from the negative electrode terminal 32.

[0188] For another example, the positive electrode tabs 223 are located on the same side as the positive electrode terminal 31, and the negative electrode tabs 224 are located on different sides from the negative electrode terminal 32.

[0189] Those skilled in the art should understand that when the tab 22 and the electrode terminal 3 are located on the same side, the tab connecting portion 41 of the electrical connection 4 is generally in the form of a flat plate extending in one direction, and the positive electrode tabs 223 and the negative electrode tabs 224 can be located on the same side of the electrode body 21, or can be located on different sides of the electrode body 21, respectively.

[0190] Exemplarily, the positive electrode tabs 223 and the negative electrode tabs 224 are located on the same side of the electrode body 21, and the positive electrode terminal 31 and the negative electrode terminal 32 are located on the same side as the side on which the positive electrode tabs 223 and the negative electrode tabs 224 are located.

[0191] Exemplarily, the positive electrode tabs 223 and the negative electrode tabs 224 are located on different sides of the electrode body 21, the positive electrode terminal 31 is located on the same side as the side on which the positive electrode tabs 223 are located, and the negative electrode terminal 32 is located on the same side as the side on which the negative electrode tabs 224 are located.

[0192] In some embodiments of the present disclosure, the electrode terminal 3 includes a positive electrode terminal 31 and a negative electrode terminal 32. The electrical connection 4 includes a first electrical connection 44 and a second electrical connection 45. The tab 22 includes a plurality of positive electrode tabs 223 and a plurality of negative electrode tabs 224, each positive electrode tab 223 is located on a different side from the positive electrode terminal 31, and / or each negative electrode tab 224 is located on a different side from the negative electrode terminal 32, the positive electrode tabs 223 are connected to the positive electrode terminal 31 through the first electrical connection 44, and the negative electrode tabs 224 are connected to the negative electrode terminal 32 through the second electrical connection 45.

[0193] Thus, the positive electrode tabs 223 at least partially overlap to form an overlapping portion 2211, and the overlapping portion 2211 is welded to the first electrical connection 44, and the negative electrode tabs 224 at least partially overlap to form an overlapping portion 2211, and the overlapping portion 2211 is welded to the second electrical connection 45, so that the positive electrode tabs 223 and the negative electrode tabs 224 each only need to be welded once to achieve connection with the first electrical connection 44 and the second electrical connection 45, reducing the number of welds, which is beneficial to improve production efficiency and reduce production costs. Moreover, since the positive electrode tabs 223 and the negative electrode tabs 224 are welded to the first electrical connection 44 and the second electrical connection 45, respectively, each only forms one weld 5, so as to facilitate reducing the thickness dimension of the battery monomer 100, so that the battery monomer 100 can be better applied to the installation environment with limited space.

[0194] In addition, since the positive electrode tabs 223 are located on different sides from the positive electrode terminal 31, and / or the negative electrode tabs 224 are located on different sides from the negative electrode terminal 32, it is beneficial to improve the flexibility of the connection between the tab 22 and the electrode terminal 3, and when a plurality of battery monomers 100 are grouped, it is beneficial to improve the flexibility of the connection between the battery monomers 100.

[0195] Exemplarily, the positive electrode tabs 223 are located on different sides from the positive electrode terminal 31, and the negative electrode tabs 224 are located on different sides from the negative electrode terminal 32.

[0196] Exemplarily, the positive electrode tabs 223 are located on the same side as the positive electrode terminal 31, and the negative electrode tabs 224 are located on different sides from the negative electrode terminal 32.

[0197] Further exemplarily, the positive tab 223 and the positive terminal 31 are located at different sides, and the negative tab 224 and the negative terminal 32 are located at the same side.

[0198] Those skilled in the art should understand that, when the tab 22 and the electrode terminal 3 are located at different sides, the tab connecting portion 41 of the electrical connecting piece 4 is generally in the shape of "L" or inverted "L", that is, the tab connecting portion 41 includes two portions extending in different directions, one of which is in the same direction as the electrode terminal connecting portion 42, and the other of which is perpendicular to the extension direction of the electrode terminal connecting portion 42, thereby connecting the electrode terminal 3 and the tab 22 located at different sides.

[0199] In addition, when the tab 22 and the electrode terminal 3 are located at different sides, the positive tab 223 and the negative tab 224 can also be located at the same side of the electrode body 21, or can be located at different sides of the electrode body 21, respectively.

[0200] Exemplarily, the positive tab 223 and the negative tab 224 are located at the same side of the electrode body 21, and the positive terminal 31 and the negative terminal 32 are located at the side different from the side where the positive tab 223 and the negative tab 224 are located, at this time, the positive terminal 31 and the negative terminal 32 can be located at the same side, or can be located at different sides.

[0201] Further exemplarily, the positive tab 223 and the negative tab 224 are located at different sides of the electrode body 21, and the positive terminal 31 and the negative terminal 32 are located at the side different from the side where the positive tab 223 and the negative tab 224 are located, respectively.

[0202] Further exemplarily, the positive tab 223, the negative tab 224, the positive terminal 31 and the negative terminal 32 can be located at four different sides, respectively.

[0203] In some embodiments of the present disclosure, the number of the electrode assemblies 2 is multiple, and the multiple electrode assemblies 2 are arranged side by side along the first direction, and the welding portions 221 of the tabs 22 with the same polarity of each electrode assembly 2 are connected by the same electrical connecting piece 4.

[0204] The multiple electrode assemblies 2 can increase the energy density of the battery monomer 100. And the tabs 22 with the same polarity of the multiple electrode assemblies 2 connected by the same electrical connecting piece 4 can reduce the assembly steps of the battery monomer 100, reduce the assembly difficulty, and be conducive to reducing the production cost.

[0205] The second aspect of the present disclosure provides a battery device 400, which includes a box 401 and at least one battery monomer 100 of the first aspect of the present disclosure, and the battery monomer 100 is contained in the box 401.

[0206] The battery device 400 provided by the present disclosure can effectively reduce the size of the battery device 400 due to the inclusion of the battery cell 100 provided by the first aspect, so that the battery device 400 can be installed in an installation environment with limited size, and the production cost is low and the production efficiency is high.

[0207] In addition, in the case where the size of the box 401 of the battery device 400 does not change, more battery cells 100 can be accommodated in the box 401, which is beneficial to improve the energy density of the battery device 400.

[0208] The third aspect of the present disclosure provides a power utilization device, which comprises the battery cell 100 provided by the first aspect of the present disclosure or the battery device 400 provided by the second aspect of the present disclosure.

[0209] The power utilization device of the embodiment of the present disclosure can accommodate more battery cells 100 or battery devices 400 due to the inclusion of the battery cell 100 provided by the first aspect or the battery device 400 provided by the second aspect, so that the power utilization device can be powered by the battery cell 100 or the battery device 400 for a longer time, and the power utilization device can also be well powered in the case where the space of the power utilization device is limited.

[0210] The fourth aspect of the present disclosure provides an energy storage device, which comprises the battery cell 100 provided by the first aspect of the present disclosure or the battery device 400 provided by the second aspect of the present disclosure.

[0211] The energy storage device of the embodiment of the present disclosure can accommodate more battery cells 100 or battery devices 400 due to the inclusion of the battery cell 100 provided by the first aspect or the battery device 400 provided by the second aspect, so that the energy storage device can be powered by the battery cell 100 or the battery device 400 for a longer time, and the energy storage device can also be well powered in the case where the space of the energy storage device is limited.

[0212] Hereinafter, specific examples of some embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0213] As a specific example, the battery cell (battery cell 100) comprises a transition sheet (electrical connector 4), a bare battery cell (electrode body 21), and a tab 22 connected to the bare battery cell. The tabs with the same polarity are overlapped and welded to the transition sheet by a welding mark 5.

[0214] The adapter piece is arranged in a Z-shaped structure, including a first part (electrode terminal connecting part 42), a second part (tab connecting part 41), and a connecting part (intermediate connecting part 43). The first part and the second part are arranged at intervals in the Z direction (third direction), and the connecting part connects the first part and the second part. The first part is welded with the pole (electrode terminal 3), and the second part is welded with the tab. The second part is closer to the lower plastic (insulating part 6) than the first part.

[0215] The overlapping area (overlapping part 2211) of the tab completely covers the welding mark, and the welding mark is symmetrical with the center line at the overlapping part.

[0216] The size W of the adapter piece in the thickness direction of the battery cell (first direction) satisfies: V-6mm>W>Z+3mm; wherein the width of the lower plastic of the battery cell (size in the first direction) is V, and the width of the welding mark (size in the first direction) is Z.

[0217] The above embodiments are only used to illustrate the technical solutions of the present disclosure, but not to limit it. Although the present disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for part or all of the technical features. 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. Industrial applicability

[0218] Through the present disclosure, a battery monomer, a battery device, an electric device, and an energy storage device with small size, low production cost, and high production efficiency are provided.

Claims

1. A battery cell, wherein, The battery cell includes: a housing having an accommodation cavity formed therein, the housing including a first wall having a mounting hole formed therein; at least one electrode assembly located in the accommodation cavity, the electrode assembly including an electrode body and a tab connected to the electrode body; an electrode terminal passing through the mounting hole; and an electrical connector connecting the electrode terminal and the tab; wherein the tab includes a welding portion, and in a case where the number of tabs having the same polarity is plural, the welding portions of the tabs having the same polarity at least partially overlap to form an overlapping portion, and the overlapping portion is welded to the electrical connector to form a welding mark. 2.The battery cell according to claim 1, wherein a thickness direction of the electrode body is a first direction; in the first direction, a width of the overlapping portion is greater than a width of the welding mark. 3.The battery cell according to claim 1 or 2, wherein the welding mark is located in a central region of the overlapping portion. 4.The battery cell according to any one of claims 1 to 3, wherein the electrical connector includes a tab connecting portion connecting the tab, an electrode terminal connecting portion connecting the electrode terminal, and an intermediate connecting portion connecting the tab connecting portion and the electrode terminal connecting portion; the electrode terminal connecting portion and the tab connecting portion extend in a second direction, the intermediate connecting portion extends in a third direction, and the tab connecting portion is closer to the first wall than the electrode terminal connecting portion in the third direction; the welding portion of the tab is welded to a side of the tab connecting portion facing away from the first wall; the first direction, the second direction, and the third direction are perpendicular to each other. 5.The battery cell according to claim 4, wherein the battery cell further includes an insulating member located on a side of the first wall facing the electrode assembly; each of the tabs further includes a bent portion connected to the welding portion, the bent portion protrudes toward a side of the first wall in the third direction with respect to the welding portion; in the first direction, a width of the tab connecting portion is less than a first dimension; wherein the first dimension is a width of the insulating member in the first direction minus a width of the bent portion of each of the tabs connected to the tab connecting portion in the first direction. 6.The battery cell according to claim 5, wherein the first dimension is the width of the insulating member in the first direction minus 6 millimeters. 7.The battery cell according to claim 5 or 6, wherein in the first direction, the width of the tab connecting portion is greater than the width of the welding mark. 8.The battery cell according to any one of claims 5 to 7, wherein in the third direction, a height of the intermediate connecting portion is a distance dimension between a bottom end surface of the electrode terminal and the insulating member minus a distance dimension between the tab connecting portion and the insulating member. 9.The battery cell according to any one of claims 5 to 8, wherein the tab connecting portion has an accommodation space on at least one side in the first direction The bent portion is accommodated in the accommodation space.

10. The battery cell according to claim 9, wherein, In the first direction, a width of the bent portion is smaller than a distance dimension between the insulating member and the tab connecting portion.

11. The battery cell according to any one of claims 1 to 10, wherein, The tab connecting portion is flat; and / or The electrode terminal connecting portion is flat.

12. The battery cell according to any one of claims 1 to 11, wherein, The electrode terminal includes a positive electrode terminal and a negative electrode terminal; The electrical connecting member includes a first electrical connecting member and a second electrical connecting member; The tab includes a plurality of positive electrode tabs and a plurality of negative electrode tabs, each of the positive electrode tabs is located at the same side as the positive electrode terminal, and / or each of the negative electrode tabs is located at the same side as the negative electrode terminal, each of the positive electrode tabs is connected to the positive electrode terminal through the first electrical connecting member, and each of the negative electrode tabs is connected to the negative electrode terminal through the second electrical connecting member.

13. The battery cell according to any one of claims 1 to 11, wherein, The electrode terminal includes a positive electrode terminal and a negative electrode terminal; The electrical connecting member includes a first electrical connecting member and a second electrical connecting member; The tab includes a plurality of positive electrode tabs and a plurality of negative electrode tabs, each of the positive electrode tabs is located at a different side from the positive electrode terminal, and / or each of the negative electrode tabs is located at a different side from the negative electrode terminal, each of the positive electrode tabs is connected to the positive electrode terminal through the first electrical connecting member, and each of the negative electrode tabs is connected to the negative electrode terminal through the second electrical connecting member.

14. The battery cell according to any one of claims 1 to 13, wherein, The number of the electrode assemblies is a plurality, the plurality of the electrode assemblies are arranged side by side in a first direction, and the welding portions of the tabs with the same polarity of each of the electrode assemblies are connected through the same electrical connecting member.

15. A battery device, wherein, The battery device includes: a box; and at least one battery cell according to any one of claims 1 to 14, which is accommodated in the box.

16. An electrical device, comprising: The power consuming device includes the battery cell according to any one of claims 1 to 14 or the battery device according to claim 15 for providing electric energy.

17. An energy storage device, wherein, The energy storage device includes the battery cell according to any one of claims 1 to 14 or the battery device according to claim 15 for providing electric energy.

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