High-capacity battery

Abstract

High-capacity battery cell, comprising: a unit assembly in which a plurality of unit electrode assemblies are stacked, wherein a plurality of individual tab portions of the plurality of unit electrode assemblies are integrally connected to one another and connected to an integrated tab portion at one or each of the opposite ends of the unit assembly.

Description

CROSS REFERENCE TO RELATED APPLICATIONThis application claims priority to and the entire contents of Korean Patent Application No. 10-2024-0022010 filed on Feb. 15, 2024, the entire contents of which are incorporated herein for all purposes by this reference.BACKGROUND OF THE INVENTIONField of the InventionThe present disclosure relates to a high capacity battery cell.Description of the Prior ArtRecently, secondary batteries have attracted attention as promising energy sources because they are widely used in various fields such as IT products, automobiles and energy storage. Secondary batteries for IT products are required to have a long operation time, a small size and a light weight, while secondary batteries for automobiles are required to have high performance, durability and safety in order to avoid the risk of explosion. In the field of energy storage, secondary batteries are used to store surplus power generated by wind power or solar energy, and do not necessarily have sophisticated characteristics.In secondary batteries, the demand for high-capacity batteries having high energy density increases from day to day. To achieve this, attempts have been made to improve the wetting properties of an electrolyte. However, since these high capacity batteries are much larger and thicker than conventional batteries, various limitations are imposed on the structure of conventional secondary batteries and various problems in their provision.The above is merely intended to facilitate understanding of the background of the present disclosure, and does not mean that the present disclosure falls within the scope of the related art already known to those skilled in the art.Prior Art Documents(Patent Document 1) Korean Patent Application Publication No. 10-2016-0015098SUMMARY OF THE INVENTIONAccordingly, the present disclosure has been made in consideration of the above problems occurring in the related art, and an object of the present disclosure is to provide a high-capacity battery cell having various specifications by stacking and using a plurality of unit electrode assemblies.Another object of the present disclosure is to provide a high-power battery cell, wherein a tab integrated portion of a high-power battery cell can be effectively connected by a plurality of unit electrode assemblies.In order to achieve the above objects, according to an aspect of the present disclosure, there is provided a high capacity battery cell including: a unit assembly in which a plurality of unit electrode assemblies are stacked. A plurality of individual tab portions of the plurality of unit electrode assemblies may be integrally connected together and connected to an integrated tab portion at one or each of the opposite ends of the unit assembly.Here, the high-capacity battery cell may further include a single welding portion in which the plurality of single tab portions of the plurality of unit electrode assemblies are welded and joined to each other in a region other than a first region in which a bundle of a plurality of sheets of each of the unit electrode assemblies is integrally welded together, and an integrated welding portion in which the single welding portion is welded and joined to an integrated tab portion. The single welding portion and the integrated welding portion may be formed in pattern shapes that do not overlap in a second region that is a welding region.Moreover, the high-capacity battery cell may further include: a single welding portion in which the plurality of single tab portions of the plurality of unit electrode assemblies are welded and connected to each other; and an integrated welding portion in which the individual welding portion is welded and connected to an integrated tab portion. The single welding portion and the integrated welding portion may form welding areas of patterns that do not overlap in the second area.Moreover, the single welding portion may be formed along each of the opposite ends of the second region and may be formed such that concave and convex portions are alternately disposed inward to form an internal space, and the integrated welding portion may be formed in a complementary shape that does not overlap with the single welding portion in the internal space of the second region.Moreover, the single welding portion may be formed along the circumference of the second region, and the integrated welding portion may be formed in a shape that does not overlap with the single welding portion in the inner space of the circumference of the second region.The features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.All terms or words used in the specification and claims have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concepts belong. It will also be understood that terms, as defined in commonly used dictionaries, should be construed as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.According to the present disclosure, by providing a high-capacity battery cell by stacking and connecting a plurality of unit electrode assemblies, it is possible to realize a high-capacity battery cell having different specifications, thereby effectively expanding the degree of freedom in designing the thickness of a pouch type battery cell.By preventing welding for connecting an integrated tab portion from being performed overlapping in the same region when stacking and connecting a plurality of electrode units, electrical reliability and operation performance in connecting the integrated tab portion can be effectively secured.By complementing the structure of an electrode assembly to ensure the strength and stability of the connection between the individual electrode assemblies when they are stacked and bonded, the structural stability of the high-performance battery cell can be ensured.BRIEF DESCRIPTION OF THE DRAWINGSThe above and other objects, features and other advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is a perspective view showing a high capacity battery cell according to an embodiment of the present disclosure; FIGS. 2A and 2B are schematic partial plan and side views showing a step of welding a sheet bundle of a unit electrode assembly for a high-capacity battery cell according to an embodiment of the present disclosure; FIGS. 3A and 3B are schematic partial plan and side views showing a step of welding individual tab portions of a plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure; FIGS. 4A and 4B are schematic partial plan and side views showing a step of partially cutting the individual tab portions of the plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure; FIG. 5 is a plan view showing the individual tab portions of the plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure; and FIGS. 6A and 6B are schematic partial plan and side views showing a step of welding the individual tab portions and integrated tab portions of the plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure.DETAILED DESCRIPTION OF THE INVENTIONAs regards the reference numerals for the elements in the drawings, the same reference numerals are used in the different drawings to designate the same or similar elements.The terminology used herein is for the purpose of describing particular embodiments only and is not to be taken as limiting. The singular forms used herein also include the plural forms unless the context clearly indicates otherwise.The drawings may be shown schematically or exaggerated to illustrate embodiments. In this document, the terms "comprise," "may comprise," "include / comprise," or "may include / comprise" indicate the presence of certain features (e.g., a numerical value, function, operation, or element such as a part), but do not preclude the presence of other features.Terms such as "a", "another", "another", "first", "second", etc. are used only to distinguish one element from another element; these elements should not be limited by these terms.Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.FIG. 1 is a perspective view showing a high capacity battery cell according to an embodiment of the present disclosure.The high-capacity battery cell according to the embodiment of the present disclosure includes a unit array 10 in which a plurality of unit electrode arrays 11 are stacked. A plurality of individual tab portions 11a, 11b of the plurality of unit electrode assemblies 11 are integrally connected together and connected to an integrated tab portion 12, 13 at one or each of the opposite ends of the unit assembly 10.In the embodiment of the present disclosure, a unit electrode assembly 11 may refer to an electrode assembly in which a positive electrode plate, a negative electrode plate, and a separator provided for insulation between the positive electrode plate and the negative electrode plate are manufactured in a jelly roll shape. However, the shape of the electrode assembly is not limited to the jelly roll shape, but may be formed by various stacking methods.As illustrated in FIG. 1, the high-capacity battery cell according to the present embodiment may be formed by stacking a plurality of electrode units 11. Each of the plurality of electrode units 11 may be configured such that a plurality of foils are welded to form a positive electrode tab for positive pole electrical connection or a negative electrode tab for negative pole electrical connection. Therefore, a single tab portion 11 a, 11 bof the unit electrode assembly 11 can be formed as a negative electrode tab or a positive electrode tab by welding and joining the plurality of sheets together.That is, a bundle of a plurality of sheets may be integrally welded and joined in a first region 11 cto form the single tab portion 11 a, 11 bof the electrode unit 11. A single welding portion 21 for integrally welding and connecting the plurality of single tab portions 11 a, 11 bof the plurality of stacked unit electrode assemblies 11 may be formed in a second region 20 that is a different non-overlapping region than the first region 11 c. That is, the bundle of the plurality of sheets of the unit electrode assembly 11 may be welded in the first region 11 cto form the single tab portion 11 a, 11 b, and the plurality of single tab portions 11 a, 11 bmay be welded and joined together by the single weld portion 21 in the second region 20 other than the first region 11 c.As illustrated in FIG. 1, the integrated tab portions 12 and 13 including positive and negative electrodes may be re-welded and connected respectively in the second region 20 where the plurality of individual tab portions 11 a, 11 bof the plurality of unit electrode assemblies 11 are welded and connected to each other, thereby forming the high-capacity battery cell composed of the unit assembly 10.The second region 20 may include the single welding portion 21 in which the plurality of single tab portions 11 a, 11 bof the plurality of single electrode assemblies 11 are welded, and an integrated welding portion 22 in which the welded single tab portions 11 a, 11 bare welded again to form an integrated tab portion 12, 13. However, in the second region 20, the single welding portion 21 and the integrated welding portion 22 may be formed so as to take a space without overlapping each other. That is, it is possible to avoid overlapping welding operations in the same area.As illustrated in the partially enlarged view of FIG. 1, the single welding portion 21 of the high-capacity battery cell according to the embodiment of the present disclosure may be formed longitudinally along each of the opposite ends of the second region 20 and may be formed in a pattern in which concave and convex portions are formed alternately inward. Then, when welding and connecting the welded single tab portions 11 a, 11 bto the one integrated tab portion 12, 13, the welded single tab portions 11 a, 11 band the one integrated tab portion 12, 13 can be welded and connected to each other using the remaining region in which the single welded portion 21 of the second region 20 is not formed.That is, when the individual tab portions 11 a, 11 bof the plurality of electrode units 11 are welded and joined to each other and then the one integrated tab portion 12, 13 is welded and joined again thereto, it is possible to overcome spatial limitations for joining and to effectively secure the reliability of welding.The pattern shape of the second region 20 illustrated in FIG. 1 is only an example. The single welding portion 21 in which the plurality of single tab portions 11 a, 11 bof the plurality of single electrode assemblies 11 are welded and joined and the single welding portion 22 in which the welded single tab portions 11 a, 11 band the single tab portion 12, 13 are welded and joined can be formed in an appropriate ratio by considering the joining force or the area required for joining in each region.FIGS. 2A and 2B are schematic partial plan and side views illustrating a step of welding a foil bundle of a unit electrode assembly of a high capacity battery cell according to an embodiment of the present disclosure. FIGS. 3A and 3B are schematic partial plan and side views illustrating a step of welding individual tab portions of a plurality of unit electrode assemblies of the high-capacity battery cell according to an embodiment of the present disclosure. FIGS. 4A and 4B are schematic partial plan and side views showing a step of partially cutting the individual tab portions of the plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure. FIG. 5 is a plan view showing the individual tab portions of the plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure. FIGS. 6A and 6B are schematic partial plan and side views showing a step of welding the individual tab portions and integrated tab portions of the plurality of unit electrode assemblies of the high-capacity battery cell according to the embodiment of the present disclosure.The provision of the high-capacity battery cell according to the embodiment of the present disclosure includes: forming a single tab portion 11 a, 11 bby welding a first region 11 cof an end of a bundle of a plurality of sheets of a unit electrode assembly 11; stacking a plurality of unit electrode assemblies 11 and welding a plurality of single tab portions 11 a, 11 bto a single welding portion 21 of a second region 20; cutting the first region 11 cwith the exception of the second region 20; and welding the plurality of single tab portions 11 a, 11 band an integrated tab portion 12, 13 to an integrated welding portion 22 with the exception of the single welding portion 21 of the second region 20.First, the single tab portion 11 a, 11 bis formed by welding the first region 11 cof the one end of the bundle of the plurality of sheets of the unit electrode assembly 11. Here, the bundle of the plurality of sheets of the unit electrode assembly 11 is not illustrated, but this is a step of welding the bundle of the plurality of sheets (metal) to form positive and negative electrode plates of the unit electrode assembly 11 into electrode tabs.As illustrated in FIGS. 2A and 2B, the single tab portion 11 a, 11 bis formed by welding the first region 11 cof the bundle of the plurality of sheets of the unit electrode assembly 11. As described above, in the embodiment of the high-capacity battery cell according to the present disclosure, the unit electrode assembly 11 is exemplified in the form of a jelly roll in which a positive electrode plate, a negative electrode plate, and a separator formed between the positive and negative electrode plates are provided. However, it should be understood that the present disclosure includes various types of electrode assemblies depending on the stack shape.The bundle of the plurality of films on a side on which a positive or negative electrode tab of the electrode unit 11 is to be formed is welded in the first region 11 c. The first region 11 cmay be formed at an end of the single tab portion 11 a, 11 bof the electrode unit 11. Thereby, the second region 20 for welding the plurality of individual tab portions 11 a, 11 band for welding the plurality of individual tab portions 11 a, 11 band an integrated tab portion 12, 13 after stacking the plurality of individual electrode assemblies 11 is secured.The position of the first region 11 cis not particularly limited to the one end, but may be appropriately selected for the region for welding the plurality of individual tab portions 11 a, 11 bwelded to the integrated tab portion 12, 13 of the high-power battery cell, which will be described later.As shown in FIG. 2B, the bundle of the plurality of sheets of the unit electrode assembly 11 is welded in the first region 11 cto an appropriate width A to form the single tab portion 11 a, 11 b.Next, the plurality of electrode units 11 are stacked, and the plurality of individual tab portions 11 a, 11 bof the plurality of stacked electrode units 11 are welded to each other. After forming a unit assembly 10 by stacking the plurality of unit electrode assemblies 11, the plurality of individual tab portions 11 a, 11 bof the plurality of unit electrode assemblies 11 may be joined by welding to be joined to the one integrated tab portion 12, 13.In the case of stacking a plurality of electrode units 11, the present disclosure may also provide that the outside of each electrode unit 11 is covered with a predetermined film during the provision, which is then cured and fixed to maintain the stacking orientation or strength between the plurality of electrode units 11.Moreover, the plurality of electrode units 11 may be stacked by bonding to increase the stability or the fastening force of the connection between the plurality of electrode units 11.As illustrated in FIGS. 3A and 3B, the plurality of individual tab portions 11 a, 11 bmay be welded and joined together by the individual welding portion 21 having a predetermined width B in the second region 20 except for the first region 11 cof the individual tab portions 11 a, 11 b. Here, a welding method is used as an example, but various kinds of known joining methods for joining the plurality of individual tab portions 11 a, 11 bmay be used.The welding of the plurality of individual tab portions 11 a, 11 bmay be performed in a partial region of the second region 20. When simultaneously welding and connecting the plurality of individual tab portions 11 a, 11 band the one integrated tab portion 12, 13, it may be difficult to ensure reliability of the connecting force depending on the number of the plurality of unit electrode assemblies 11. For this reason, the plurality of individual tab portions 11 a, 11 bmay be primarily welded and joined to each other.In this case, the plurality of individual tab portions 11 a, 11 bmay be welded to the individual welding portion 21 leaving a predetermined region for welding the integrated tab portion 12, 13 in the second region 20. In this case, in view of the reliability of connection of the plurality of individual tab portions 11 a, 11 b, it is appropriate to form the individual welded portion 21 in a continuous shape in the width direction of the individual tab portions 11 a, 11 b.Moreover, concave and convex portions may be alternately formed inward while forming a predetermined inner space of the second region 20 to improve the joining force between the plurality of individual tab portions 11 a, 11 b.Subsequently, the first region 11 cin which the bundle of the plurality of sheets of the electrode unit 11 is welded is cut off at the individual tab portions 11 a, 11 b. In this case, the first region 11 cmay be cut without overlapping with the second region 20, so that the integrated tab portion 12, 13 may subsequently be welded in the second region 20.The first region 11 cfunctions to fix the plurality of individual tab portions 11 a, 11 bto be welded, thereby enhancing the reliability of alignment, etc., in the subsequent welding of the plurality of individual tab portions 11 a, 11 b. By cutting the first region 11 c, restrictions on the connection length of the tab integrated portion 12, 13 in the high-capacity battery cell or the space required for installing the high-capacity battery cell can be eliminated, thereby significantly improving the degree of freedom in design in installing the high-capacity battery cell.As illustrated in FIGS. 4A and 4B, the first region 11 cmay be cut and removed with respect to a side boundary of the second region 20 in which the plurality of individual tab portions 11 a, 11 bare welded. This can reduce an unnecessary welding area generated when the one integrated tab portion 12, 13 is joined. In addition, by connecting the integrated tab portion 12, 13 in a predetermined space in the second region 20, the entire protruding length of the integrated tab portion 12, 13 can be effectively controlled.As illustrated in FIG. 5, the integrated tab portion 12, 13 may be subsequently welded and joined in the integrated welding region 22, the remaining space of the second region 20 in which the plurality of individual tab portions 11 a, 11 bare welded.The single weld portion 21 and the integrated weld portion 22 of the second region 20 may have a complementary pattern and may be welded and joined in a shape that completely fills the second region 20. The shape of the pattern occupied by the single welding portion 21 and the integrated welding portion 22 of the second region 20 may be appropriately modified and changed to secure the minimum welding area required depending on the thickness or material of the plurality of the single tab portions 11 a, 11 b.Alternatively, although not illustrated, each of the single welding portion 21 and the integrated welding portion 22 may be formed on a first surface of the plurality of single tab portions 11 a, 11 bto correspond to the pattern of the single welding portion 21 and the integrated welding portion 22 of the second region 20, or the single welding portion 21 may be formed on the first surface of the plurality of single tab portions 11 a, 11 band the integrated welding portion 22 may be formed on a second surface of the plurality of single tab portions 11 a, 11 bsuch that welding is performed by the single welding portion 21 and the integrated welding portion 22.As illustrated in FIGS. 6A and 6B, the plurality of individual tab portions 11 a, 11 bmay be welded and joined together by the individual welding portion 21 of the second region 20, and the plurality of individual tab portions 11 a, 11 band the one integrated tab portion 12, 13 may be re-welded and joined together by the integrated welding portion 22 not overlapping with the individual welding portion 21 of the second region 20.That is, the single welding portion 21 may be formed to extend longitudinally at each of the opposite ends of the second region 20, and the integrated welding portion 22 may be formed in the remaining inner space between the respective single welding portions 21 of the second region 20 such that the plurality of the single tab portions 11 a, 11 band the integrated tab portion 12, 13 are welded and joined by the integrated welding portion 22.As described above, by primarily welding and joining the plurality of individual tab portions 11 a, 11 bto the individual welding portion 21 of the second region 20 and secondary welding and joining the integrated tab portion 12, 13 to the integrated welding portion 22 that does not overlap with the region for primary welding, it is possible to simultaneously ensure the tension and safety of the integrated tab portion 12, 13 joined to the plurality of individual tab portions 11 a, 11 b.The present disclosure has been described in detail by specific embodiments. The embodiments serve to specifically describe the present disclosure, but the present disclosure is not limited to them. It will be apparent to those skilled in the art that the present disclosure can be modified or changed in various forms without departing from the technical spirit of the present disclosure.Simple modifications or alterations of the present disclosure are within the scope of the present disclosure, and the detailed scope of the present disclosure will be better understood by the appended claims.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedKR 10-2024-0022010

[0001] KR 10-2016-0015098

[0006]

Claims

A high capacity battery cell comprising: a unit array in which a plurality of unit electrode arrays are stacked, wherein a plurality of individual tab portions of the plurality of unit electrode arrays are integrally connected to each other and connected to an integrated tab portion at one or each of the opposite ends of the unit array.The high-capacity battery cell according to claim 1, further comprising: a single welding portion in which the plurality of single tab portions of the plurality of unit electrode assemblies are welded and joined to each other in a region other than a first region in which a bundle of a plurality of sheets of each of the unit electrode assemblies is integrally welded together; and an integrated welding portion in which the single welding portion is welded and joined to an integrated tab portion, wherein the single welding portion and the integrated welding portion are formed in pattern shapes that do not overlap in a second region that is a welding region.The high-capacity battery cell according to claim 1, further comprising: a single welding portion in which the plurality of single tab portions of the plurality of unit electrode assemblies are welded and connected to each other; and an integrated welding portion in which the single welding portion is welded and connected to an integrated tab portion, wherein the single welding portion and the integrated welding portion form welding areas of patterns that do not overlap in the second area.The high capacity battery cell according to claim 3, wherein the single welding portion is formed along each of the opposite ends of the second region and is formed such that concave and convex portions are alternately disposed inward to form an internal space, and the integrated welding portion is formed in a complementary shape that does not overlap with the single welding portion in the internal space of the second region.The high capacity battery cell according to claim 3, wherein the single welding portion is formed along the circumference of the second region, and the integrated welding portion is formed so as not to overlap with the single welding portion in the inner space of the circumference of the second region.The high capacity battery cell according to claim 2, wherein the single welding portion is formed along each of the opposite ends of the second region and is formed such that concave and convex portions are alternately disposed inward to form an internal space, and the integrated welding portion is formed in a complementary shape that does not overlap with the single welding portion in the internal space of the second region.The high capacity battery cell according to claim 2, wherein the single welding portion is formed along the circumference of the second region, and the integrated welding portion is formed so as not to overlap with the single welding portion in the inner space of the circumference of the second region.

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