Battery cell and cell assembly comprising same

Abstract

The present invention relates to a battery cell. A battery cell according to one aspect of the present invention comprises: a cell body that accommodates an electrode laminate; and an electrode lead electrically connected to the electrode laminate, wherein the electrode lead may include: a lead body portion provided on one side of the cell body; and a recessed portion that is recessed inwardly from an edge of the lead body portion but is open in a thickness direction of the lead body portion.

Description

Battery cells and cell assemblies containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2024-0009658, dated January 22, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a battery cell and a cell assembly including the same, and more particularly, to a battery cell made of a secondary battery and a cell assembly including the same.

[0005] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These batteries are used not only in small products such as digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in larger products requiring high output, such as electric and hybrid vehicles, as well as in power storage devices that store surplus power or renewable energy, and as backup power storage devices.

[0006] Secondary batteries can be provided in the form of battery cells. Battery cells are classified into cylindrical, square, or pouch types depending on the shape of the housing material they accommodate, and depending on the shape of the electrode assembly, they are roughly classified into a jelly roll type in which a separator is interposed between long sheets of positive and negative electrodes coated with active materials, and wound; a stack type in which a plurality of positive and negative electrodes of a predetermined size are sequentially stacked while interposed between separators; and a stack / folding type in which stacked unit cells are wound with a long separator film.

[0007] Meanwhile, multiple battery cells may be joined together to form a cell assembly. This may be to increase the electrical capacity or voltage that can be charged and discharged. To this end, the electrode leads of the battery cells may be joined together. An electrode lead is a conductive member that protrudes or extends outside of a battery cell and is configured to connect the electrode assembly provided inside the battery cell to an external power source, load, or component. These electrode leads are typically provided in the form of films, sheets, wires, bus bars, or metal pieces.

[0008] However, a welding process was previously required to connect the electrode leads of a battery cell. The electrode leads of the battery cells were electrically connected by being welded directly to each other or by being welded together to a single bus bar, which served as an intermediate medium.

[0009] This conventional method of joining batteries required bending of the electrode leads to modularize the stacking of battery cells. Furthermore, it required additional components, such as busbars, to perform the welding process. Furthermore, after multiple battery cells were welded together, it was difficult to select and separate specific cells.

[0010] Accordingly, there has been a demand for the development of battery cells and cell assemblies including the same that can be joined to adjacent battery cells without using a welding process.

[0011] The present invention has been devised to solve the above problems, and the object of the present invention is to provide a battery cell that can be joined to another adjacent battery cell without a welding process, and a cell assembly including the same.

[0012] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0013] According to one aspect of the present invention, a battery cell is provided, comprising: a cell body accommodating an electrode laminate; and an electrode lead electrically connected to the electrode laminate, wherein the electrode lead comprises: a lead body portion provided on one side of the cell body; and a recessed portion recessed inwardly from an edge of the lead body portion but open in the thickness direction of the lead body portion.

[0014] At this time, the recessed portion may be provided so that the electrode leads of neighboring battery cells can be combined in a shape-fitting manner.

[0015] At this time, the recessed portion can be formed to penetrate in the thickness direction of the lead body portion.

[0016] At this time, the electrode lead may further include an inner connecting portion that is convexly protruded or concavely sunken into the inner wall of the recessed portion.

[0017] At this time, the inner joint portion may be provided in multiple numbers.

[0018] At this time, the inner wall of the recessed portion may include a first surface formed in the thickness direction of the lead body portion; and a second surface facing the first surface, and the inner connecting portion may include a first inner connecting portion formed on the first surface; and a second inner connecting portion formed on the second surface.

[0019] At this time, the lead body portion may extend in one direction along the edge of the cell body, and the first side and the second side may be arranged to face each other in the one direction.

[0020] At this time, the electrode lead may further include an outer connecting portion that is convexly protruded or concavely sunken on the outer surface of the lead body.

[0021] At this time, the outer joint can be spaced apart from the recessed portion in the direction in which the recessed portion is recessed.

[0022] At this time, the outer connecting portion may be provided in multiple numbers.

[0023] At this time, the outer coupling portion may include a first outer coupling portion formed on one surface of the lead body portion; and a second outer coupling portion formed on the other surface of the lead body portion so as to face the first outer coupling portion.

[0024] At this time, the electrode lead further includes an inner coupling portion that is convexly protruded or concavely recessed on the inner wall of the recessed portion; and an outer coupling portion that is convexly protruded or concavely recessed on the outer surface of the lead body portion, and one of the inner coupling portion and the outer coupling portion may be convexly protruded and the other may be concavely recessed.

[0025] At this time, the above-mentioned recessed portions may be provided in multiple numbers and spaced apart along the edge of the lead body portion.

[0026] At this time, the electrode leads may be provided in pairs.

[0027] At this time, the pair of electrode leads may be arranged oppositely with the cell body as the center.

[0028] At this time, the lead body part may have a plate shape.

[0029] According to another aspect of the present invention, a cell assembly is provided, comprising: a cell body accommodating an electrode stack; and a plurality of battery cells each including an electrode lead electrically connected to the electrode stack, the electrode lead comprising a plate-shaped lead body portion provided on one side of the cell body and a recessed portion that is concavely recessed inwardly from an edge of the lead body portion and is open in a thickness direction of the lead body portion, wherein electrode leads of adjacent battery cells among the plurality of battery cells are coupled to each other in a shape-fitting manner.

[0030] At this time, the plurality of battery cells include first and second battery cells, and the lead body portion of the first battery cell and the lead body portion of the second battery cell are arranged to be perpendicular to each other, and the recessed portion of the first battery cell and the recessed portion of the second battery cell can be coupled to each other.

[0031] At this time, the plurality of battery cells include first and second battery cells, and the electrode lead of the first battery cell further includes an inner joining portion that is convexly protruded or concavely sunken into the inner wall of the recessed portion, and the electrode lead of the second battery cell further includes an outer joining portion that is convexly protruded or concavely sunken into the outer surface of the lead body portion, and one of the inner joining portion and the outer joining portion is convexly protruded and the other is concavely sunken, and the inner joining portion of the first battery cell and the outer joining portion of the second battery cell can be coupled to each other in a shape-fitting manner.

[0032] At this time, the recessed portions are provided in n numbers (n is a natural number greater than or equal to 2) and are spaced apart along the edge of the lead body portion, and the plurality of battery cells include n battery cells stacked in a first direction; and n battery cells stacked in a second direction orthogonal to the first direction, and the n battery cells stacked in the second direction can be respectively combined in a shape-fitting manner to the n recessed portions of the battery cells stacked in the first direction.

[0033] According to one aspect of the present invention, an electrode lead of a battery cell is provided with a recessed portion that is concavely recessed inward from a rim but open in the thickness direction, so that an electrode lead of a battery cell adjacent to the recessed portion can be coupled in a shape-fitting manner.

[0034] Accordingly, a battery cell and a cell assembly including the same according to one aspect of the present invention can be electrically connected to another neighboring battery cell without using a welding process.

[0035] According to one aspect of the present invention, the electrode lead is provided with an outer coupling portion and / or an inner coupling portion so that it can be coupled with an electrode lead of another battery cell that is shaped and coupled to the recessed portion, so that the battery cells can be more strongly coupled and connected.

[0036] According to one aspect of the present invention, since the electrode lead has a plurality of recessed portions and is spaced apart along the edge, it can be combined and connected in a shape-fit manner with a plurality of other battery cells.

[0037] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0038] FIG. 1 is a perspective view of a battery cell according to a first embodiment of the present invention.

[0039] Figure 2 is an enlarged view of part A of Figure 1.

[0040] Figure 3 is a perspective view of part A of Figure 1 viewed from a different angle.

[0041] Figure 4 is a perspective view of part A of Figure 1 viewed from another angle.

[0042] Figure 5 is a perspective view of a cell assembly according to a first embodiment of the present invention.

[0043] Fig. 6 is a vertical cross-sectional view showing the electrode leads of the cell assembly illustrated in Fig. 5 connected to each other.

[0044] Fig. 7 is a horizontal cross-sectional view showing the electrode leads of the cell assembly illustrated in Fig. 5 connected to each other.

[0045] Figure 8 is a perspective view of a battery cell according to a second embodiment of the present invention.

[0046] Figure 9 is a perspective view of a cell assembly according to a second embodiment of the present invention.

[0047] Fig. 10 is a perspective view of a cell assembly according to a third embodiment of the present invention.

[0048] Preferred embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0049] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0050] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0051] Fig. 1 is a perspective view of a battery cell according to a first embodiment of the present invention. Fig. 2 is an enlarged view of portion A of Fig. 1. Fig. 3 is a perspective view of portion A of Fig. 1 viewed from a different angle. Fig. 4 is a perspective view of portion A of Fig. 1 viewed from still another angle. Fig. 5 is a perspective view of a cell assembly according to the first embodiment of the present invention. Fig. 6 is a vertical cross-sectional view showing a state in which electrode leads of the cell assembly illustrated in Fig. 5 are coupled to each other. Fig. 7 is a horizontal cross-sectional view showing a state in which electrode leads of the cell assembly illustrated in Fig. 5 are coupled to each other.

[0052] FIG. 5 discloses a cell assembly (1) according to a first embodiment of the present invention. Referring to FIG. 5, the cell assembly (1) according to the first embodiment of the present invention may be an assembly in which a plurality of battery cells (10a, 10b) are electrically connected to each other by being coupled together. Accordingly, the electric capacity and voltage charged and discharged in the cell assembly (1) may be increased.

[0053] At this time, in the cell assembly (1) according to the present embodiment, a plurality of battery cells (10a, 10b) are electrically connected by being combined in a shape-fitting manner. That is, in the present embodiment, the battery cells (10a, 10b) can be combined without using a welding process.

[0054] Through this, the cell assembly (1) according to the present embodiment can improve the problems of the joining method by welding process.

[0055] For example, according to the present embodiment, additional components such as bus bars for the welding process may not be required. As another example, according to the present embodiment, the electrode leads (30a, 30b) of the battery cells (10a, 10b) do not need to be bent for welding. As another example, according to the present embodiment, among multiple battery cells (10a, 10b) coupled to each other, only a specific battery cell (10a, 10b) can be separated, thereby reducing the maintenance cost of the cell assembly (1) and increasing the recycling rate.

[0056] Hereinafter, the configuration of the battery cells (10a, 10b) constituting the cell assembly (1) according to the first embodiment of the present invention will be described in detail. The battery cells (10a, 10b) may be battery cells according to the first embodiment of the present invention.

[0057] Referring to FIG. 1, a battery cell (10) according to a first embodiment of the present invention may include a cell body (20). The cell body (20) may be composed of an electrode assembly responsible for the charging and discharging function of the battery cell (10) and a case that accommodates the electrode assembly.

[0058] In this embodiment, the electrode assembly may be comprised of a cathode, an anode, and a separator interposed therebetween. The electrode assembly may be provided in a stacked, stack-folded, or jellyroll form, but its type or structure is not particularly limited. In this embodiment, the case may be provided in a pouch, square, or cylindrical form, but its type or structure is not particularly limited.

[0059] In this embodiment, it is explained on the premise that the cell body (20) is formed as a block-shaped body extending in the left-right direction (Y-axis direction) as shown.

[0060] Referring to FIGS. 1 to 4, a battery cell (10) according to the first embodiment of the present invention may include an electrode lead (30). The electrode lead (30) is a configuration for electrically connecting an electrode assembly provided in a cell body (20) to an external load, power source, or another neighboring battery cell.

[0061] In this embodiment, the electrode lead (30) may include a lead body portion (40) made of a conductive material. The lead body portion (40) may be provided on one side of the cell body (20).

[0062] At this time, in this embodiment, since the lead body part (40) is configured to be combined with a neighboring battery cell in a shape-fitting manner, it is desirable to have a certain rigidity so that the combination is stably maintained.

[0063] To this end, the lead body portion (40) may be provided as a block-shaped member or plate having a predetermined thickness in the vertical direction (Z-axis direction). In addition, at least a portion of the lead body portion (40) may be positioned inside the cell body (20) and may be directly or indirectly connected to the electrode assembly.

[0064] Meanwhile, in the present embodiment, the lead body portion (40) may extend along the edge of the cell body (20). As illustrated, the lead body portion (40) may extend along the edge provided in the front-back direction (X-axis direction) on the right side (positive direction of the Y-axis) of the cell body (20).

[0065] Of course, the lead body (40) may be formed to be curved at least in part as needed, taking into consideration the shape of the cell body (20), the bonding structure with other battery cells, etc.

[0066] Meanwhile, referring again to FIGS. 2 to 4, the electrode lead (30) of the battery cell according to the first embodiment of the present invention may include a recessed portion (50). The recessed portion (50) is a portion where another neighboring battery cell is connected to the electrode lead (30) in a shape-fit manner.

[0067] In this embodiment, the recessed portion (50) may be formed on the edge of the lead body portion (40). As an example, the edge of the lead body portion (40) may be an edge extending in the front-back direction (X-axis direction) on the right side (positive direction of the Y-axis) of the lead body portion (40) as illustrated in FIG. 2.

[0068] And, the recessed portion (50) can be positioned approximately at the center of the above-mentioned edge of the lead body portion (40). Of course, the position of the recessed portion (50) can be appropriately adjusted depending on the bonding structure with the neighboring battery cell.

[0069] In this embodiment, the recessed portion (50) may be formed by recessing to the left (negative direction of the Y-axis) toward the inside of the lead body portion (40) from the edge of the lead body portion (40). In addition, the recessed portion (50) may be open in the thickness direction of the lead body portion (40).

[0070] More specifically, as illustrated in FIGS. 1 and 2, the recessed portion (50) may be formed by penetrating in the vertical direction (Z-axis direction) in the thickness direction of the lead body portion (40). In other words, the upper portion of the recessed portion (50) may be opened through the upper surface (42) of the lead body portion (40), and the lower portion may be opened through the lower surface (44) of the lead body portion (40).

[0071] This configuration may be such that the electrode leads of neighboring battery cells are inserted into the recessed portion (50) of the battery cell (10) in the thickness direction (i.e., in the vertical direction) of the lead body portion (40). As a result, the battery cells can be coupled to each other in a shape-fitting manner.

[0072] Meanwhile, referring to FIGS. 2 to 4, in the present embodiment, the recessed portion (50) may include first to third surfaces (52 to 56). The first to third surfaces (52 to 56) may be surfaces forming the inner wall of the recessed portion (50).

[0073] In this embodiment, the first surface (52) may be a surface formed in the up-down direction (Z-axis direction) that is the thickness direction of the lead body part (40). The edge provided on the upper part of the first surface (52) may be connected to the upper surface (42) of the lead body part (40), and the edge provided on the lower part of the first surface (52) may be connected to the lower surface (44) of the lead body part (40).

[0074] In this embodiment, the second surface (54) may be a surface facing the first surface (52) but spaced apart in a predetermined direction. At this time, the direction in which the first surface (52) and the second surface (54) are spaced apart may be the forward-backward direction (X-axis direction) which is the extension direction of the lead body (40).

[0075] Accordingly, an electrode lead of another battery cell may be interposed between the first side (52) and the second side (54). At this time, the distance between the first side (52) and the second side (54) (hereinafter referred to as the width of the recessed portion (50)) may be equal to or slightly larger than the thickness of the electrode lead of the other battery cell.

[0076] Here, the difference between the width of the recess (50) and the thickness of the electrode leads of other battery cells can be determined by taking into account the tolerance for fitting. As a result, the electrode leads of other battery cells can be fitted between the first surface (52) and the second surface (54), thereby further increasing the bonding strength between the battery cells.

[0077] Meanwhile, in the present embodiment, the second surface (54) may extend in the thickness direction (i.e., up-down direction) of the lead body portion (40) so as to be parallel (or, parallel) to the first surface (52). The edge provided on the upper portion of the second surface (54) may be connected to the upper surface (42) of the lead body portion (40), and the edge provided on the lower portion of the second surface (54) may be connected to the lower surface (44) of the lead body portion (40).

[0078] However, the first side (52) and the second side (54) may be inclined at a predetermined angle with respect to each other as needed, or the first side (52) and the second side (54) may include a curved surface.

[0079] In this embodiment, a third surface (56) may be provided between the first surface (52) and the second surface (54). The third surface (56) may not be parallel to the first and second surfaces (52, 54). As illustrated, the third surface (56) may be perpendicular to the first and second surfaces (52, 54).

[0080] Accordingly, the first side (52) and the second side (54) can be connected by the third side (56). More specifically, the front side portion of the third side (56) can be connected to one side provided on the left side (negative direction of the Y-axis) of the first side (52), and the rear side portion can be connected to one side provided on the left side (negative direction of the Y-axis) of the second side (54) by the third side (56).

[0081] And, in this embodiment, the third surface (56) can extend in the thickness direction (i.e., the up-down direction) of the lead body part (40). The side provided on the upper side of the third surface (56) can be connected to the upper surface (42) of the lead body part (40), and the side provided on the lower side can be connected to the lower surface (44) of the lead body part (40).

[0082] This third surface (56) can perform the function of limiting the depth to which the electrode lead is inserted into the recessed portion (50) during the process of connecting the electrode lead of another battery cell to the recessed portion (50).

[0083] Referring again to FIGS. 2 to 5, the electrode lead (30) of the battery cell according to the first embodiment of the present invention may include an inner coupling portion (60). The inner coupling portion (60) is configured to increase the coupling force between the battery cell and another battery cell.

[0084] In this embodiment, the inner coupling portion (60) may be formed on the inner wall of the recessed portion (50). As illustrated, the inner coupling portion (60) may protrude from the inner wall of the recessed portion (50). Through this, the electrode lead of another battery cell inserted into the recessed portion (50) may be caught on the inner coupling portion (64). This may increase the bonding force between the battery cells.

[0085] As an example, the inner joint (60) may have a convex hemispherical or semi-elliptical shape, but is not limited thereto. As another example, the inner joint (60) may be provided in the shape of a polygonal pyramid or polygonal column, or may be provided in the shape of a curved hook.

[0086] At this time, in the present embodiment, the inner coupling portion (60) may be provided in multiple numbers. As illustrated, the inner coupling portion (60) may include a first inner coupling portion (62) formed on the first surface (52) and a second inner coupling portion (64) formed on the second surface (54).

[0087] Due to this, the electrode leads of the other battery cell inserted into the recessed portion (50) can be more strongly fixed to the inside of the recessed portion (50) by having both sides caught by the first and second inner connecting portions (62, 64), respectively.

[0088] Referring again to FIGS. 1 to 4, the electrode lead (30) of the battery cell according to the first embodiment of the present invention may include an outer coupling portion (70). The outer coupling portion (70) is configured to increase the coupling force between the battery cell and another battery cell.

[0089] In this embodiment, the outer coupling portion (70) may be formed on the outer surface of the lead body portion (40). As illustrated, the outer coupling portion (70) may be formed to be concavely recessed into the outer surface of the lead body portion (40).

[0090] As an example, the outer joint (70) may have a concave groove shape in the shape of a hemisphere or a semi-ellipse. As another example, the outer joint (70) may be provided in the shape of a ring that can be hooked, or may be provided in the shape of a groove in which the internal space is a polyhedron or a polygonal column.

[0091] This configuration may be to increase the bonding force between battery cells by having a protruding portion (e.g., an inner bonding portion) provided on an electrode lead of another battery cell hook onto an outer bonding portion (70) provided on an electrode lead (30) of the present battery cell.

[0092] At this time, in the present embodiment, the outer coupling portion (70) may be configured in multiple numbers. The multiple outer coupling portions (70) may include a first outer coupling portion (72) formed on the upper surface (42) of the lead body portion (40) as illustrated in FIG. 3. In addition, the multiple outer coupling portions (70) may include a second outer coupling portion (74) formed on the lower surface (44) of the lead body portion (40) as illustrated in FIG. 5.

[0093] At this time, in the present embodiment, the first outer coupling portion (72) and the second outer coupling portion (74) may be arranged to face each other in the thickness direction (i.e., the up-down direction) of the lead body portion (40). As a result, a more compact coupling structure between battery cells can be provided.

[0094] Meanwhile, in the present embodiment, the outer joint (70) may be positioned so as to be spaced apart from the recessed portion (50) in the direction in which it is recessed. With reference to Fig. 1, the outer joint (70) is positioned so as to be spaced apart from the recessed portion (50) to the left (negative direction of the Y-axis).

[0095] As shown in FIGS. 3 and 4, the first outer coupling portion (72) can be positioned between the recessed portion (50) and the cell body (20) and spaced to the left from the recessed portion (50). As shown in FIG. 5, the second outer coupling portion (74) can be positioned between the recessed portion (50) and the cell body (20) and spaced to the left from the recessed portion (50).

[0096] This may be a configuration that takes into account the method of joining battery cells. Specifically, the electrode leads of other battery cells are joined by moving along the direction in which the recessed portion (50) is sunk. That is, the electrode leads of other battery cells are moved along the path formed in the sunk direction. Accordingly, as one portion of the electrode lead is inserted into the recessed portion (50), the other portion faces the outer joining portion (70) and can be joined in a shape-fitting manner.

[0097] Meanwhile, in the present embodiment, the inner joint part (60) is configured to protrude convexly and the outer joint part (70) is recessed concavely. However, if necessary, the inner joint part (60) may be configured to recessed concavely and the outer joint part (70) may be configured to protrude convexly.

[0098] Referring back to FIG. 1, in this embodiment, the electrode leads (30) may be configured as a pair. At this time, one of the pair of electrode leads (30) may be a positive lead connected to the positive electrode of the electrode assembly, and the other may be a negative lead connected to the negative electrode of the electrode assembly.

[0099] At this time, in the present embodiment, a pair of electrode leads (30) may be arranged opposite each other with the cell body (20) as the center. Of course, the relative positions of the electrode leads (30) on one side may be appropriately changed as needed.

[0100] Meanwhile, in the present embodiment, a pair of electrode leads (30) are illustrated as having the same shape. However, a pair of electrode leads (30) may be configured to have different shapes or structures as needed.

[0101] Hereinafter, a cell assembly according to a first embodiment of the present invention will be described with different drawings.

[0102] Referring to FIG. 5, a cell assembly (1) according to a first embodiment of the present invention may include a plurality of battery cells (10a, 10b). At this time, the plurality of battery cells (10a, 10b) may include a first battery cell (10a) and a second battery cell (10b) that are adjacent to each other and are coupled in a shape-fitting manner. At this time, in the present embodiment, the first and second battery cells (10a, 10b) may be the battery cells (10) illustrated in FIGS. 1 to 4.

[0103] Referring again to FIG. 5, in this embodiment, the lead body part (40a) of the first battery cell (10a) and the lead body part (40b) of the second battery cell (10b) can be arranged to be perpendicular to each other.

[0104] In other words, the lead body part (40a) of the first battery cell (10a) may be arranged in the thickness direction of the lead body part (40b) of the second battery cell (10b), and the lead body part (40b) of the second battery cell (10b) may be arranged in the thickness direction of the lead body part (40a) of the first battery cell (10a). Here, the thickness direction of the lead body part (40b) of the second battery cell (10b) may be the front-back direction (X-axis direction) in the drawing, and the thickness direction of the lead body part (40a) of the first battery cell (10a) may be the up-down direction (Z-axis direction) in the drawing.

[0105] This arrangement may be for the purpose of allowing the recessed portion (50a) of the first battery cell (10a) and the recessed portion (50b) of the second battery cell (10b) to be coupled and fit together in a shape-fitting manner. This is because the recessed portions (50a, 50b) are open in the thickness direction of the lead body portion (40a, 40b) in which they are formed.

[0106] Below, the structure in which the recessed portion (50a) of the first battery cell (10a) and the recessed portion (50b) of the second battery cell (10b) are connected to each other is specifically described.

[0107] Referring to FIGS. 5 and 6, as the recessed portion (50a) of the first battery cell (10a) and the recessed portion (50b) of the second battery cell (10b) are engaged, the side portion of the lead body portion (40a) of the first battery cell (10a) can be fitted into the recessed portion (50b) of the second battery cell (10b). That is, the lead body portion (40a) of the first battery cell (10a) can be inserted between the first surface (52b) and the second surface (54b) of the second battery cell (10b).

[0108] Accordingly, the upper surface (42a) and the lower surface (44a) of the lead body (40a) of the first battery cell (10a) can be arranged adjacent to and facing each other, respectively, the first surface (52b) and the second surface (54b) of the recessed portion (50b) of the second battery cell (10b). In addition, the third surface (56a) of the recessed portion (50a) of the first battery cell (10a) and the third surface (56b) of the recessed portion (50b) of the second battery cell (10b) can be arranged adjacent to and facing each other.

[0109] Here, two sides being adjacent may mean that the two sides either touch each other, or, if not touching each other, are separated by a very small distance compared to their width or length.

[0110] At this time, the first and second inner coupling portions (62b, 64b) of the second battery cell (10b) can be fitted into the first and second outer coupling portions (72a, 74a) of the first battery cell (10a) in a shape-fitting manner, respectively. As a result, the inner coupling portions (62b, 64b) are caught on the outer coupling portions (72a, 74a), so that the lead body portion (40a) of the first battery cell (10a) may not fall out from the recessed portion (50b) of the second battery cell (10b).

[0111] Likewise, referring to FIGS. 5 and 7, as the recessed portion (50a) of the first battery cell (10a) and the recessed portion (50b) of the second battery cell (10b) are engaged, the side of the lead body portion (40b) of the second battery cell (10b) can be fitted into the recessed portion (50a) of the first battery cell (10a). That is, the lead body portion (40b) of the second battery cell (10b) can be inserted between the first surface (52a) and the second surface (54a) of the first battery cell (10a).

[0112] Accordingly, the upper surface (42b) and the lower surface (44b) of the lead body (40b) of the second battery cell (10b) can be arranged adjacent to and facing each other, respectively, the first surface (52a) and the second surface (54a) of the recessed portion (50a) of the first battery cell (10a). In addition, the third surface (56b) of the recessed portion (50b) of the second battery cell (10b) and the third surface (56a) of the recessed portion (50a) of the first battery cell (10a) can be arranged adjacent to and facing each other.

[0113] At this time, the first and second inner coupling portions (62a, 64a) of the first battery cell (10a) can be fitted into the first and second outer coupling portions (72b, 74b) of the second battery cell (10b) in a shape-fitting manner, respectively. As a result, the inner coupling portions (62a, 64a) are caught on the outer coupling portions (72b, 74b), so that the lead body portion (40b) of the second battery cell (10b) may not fall out from the recessed portion (50a) of the first battery cell (10a).

[0114] As described above, in the cell assembly (1) according to the first embodiment of the present invention, the electrode lead (30) of a battery cell (10) is connected to the electrode lead (30) of another adjacent battery cell (10) by shape fitting without using a welding process. Accordingly, in the cell assembly (1) according to the present embodiment, problems caused by the welding process can be improved.

[0115] Hereinafter, battery cells and cell assemblies including the same according to other embodiments of the present invention will be described with different drawings.

[0116] Fig. 8 is a perspective view of a battery cell according to a second embodiment of the present invention. Fig. 9 is a perspective view of a cell assembly according to a second embodiment of the present invention. Fig. 10 is a perspective view of a cell assembly according to a third embodiment of the present invention. In this case, the same reference numerals as in the previously illustrated drawings indicate the same components that perform the same functions.

[0117] FIG. 8 discloses a battery cell (110) according to a second embodiment of the present invention.

[0118] Referring to FIG. 8, a battery cell (110) according to a second embodiment of the present invention may include a cell body (20) and an electrode lead (130), and the electrode lead (130) may include a lead body portion (40), a recessed portion (50), an inner coupling portion (60), and an outer coupling portion (70).

[0119] At this time, in the battery cell (110) according to the second embodiment of the present invention, the number of recessed portions (50) of the electrode lead (130) may be n. As an example, as illustrated, the number of recessed portions (50) may be two. In addition, the n number of recessed portions (50) may be spaced apart and arranged along the edge of the lead body (40).

[0120] In this embodiment, each recessed portion (50) may be configured to allow electrode leads of different battery cells to be connected in a shape-fit manner. Accordingly, up to n different battery cells may be connected and electrically connected to a single battery cell (110).

[0121] Meanwhile, in the present embodiment, the number of inner coupling portions (60) and outer coupling portions (70) may be n, corresponding to the number of recessed portions (50). In addition, the n inner coupling portions (60) and outer coupling portions (70) may be positioned to correspond to the n recessed portions (50), respectively. Through this configuration, the bonding strength of the battery cells bonded to the battery cell (110) may be further increased.

[0122] FIG. 9 discloses a cell assembly (101) according to a second embodiment of the present invention.

[0123] Referring to Fig. 9, a cell assembly (101) according to a second embodiment of the present invention may be formed by combining a plurality of battery cells (110) with each other. In this case, the battery cells (110) may be battery cells (110) according to the second embodiment of the present invention. More specifically, the electrode leads (130) of the battery cells (110) may each include n number of recessed portions (50).

[0124] Meanwhile, the cell assembly (101) according to the second embodiment of the present invention may include n battery cells (110) stacked in the vertical direction (Z-axis direction). As an example, n may be 2, as illustrated in FIG. 9. In addition, the n battery cells (110) may be arranged such that the lead body portion (40) faces the front-back direction (X-axis direction).

[0125] In this embodiment, the cell assembly (101) may include n battery cells (110) stacked in a front-back direction (X-axis direction) perpendicular to the vertical direction (Z-axis direction). As an example, n may be 2 as illustrated. In addition, the n battery cells (110) may be arranged such that the lead body portion (40) faces the vertical direction (Z-axis direction).

[0126] In this embodiment, n recessed portions (50) of battery cells (110) stacked in the vertical direction (Z-axis direction) can be combined with n recessed portions (50) of battery cells (110) stacked in the front-back direction (X-axis direction) in a shape-fit manner.

[0127] In other words, n recessed portions (50) of battery cells (110) stacked in the front-back direction (X-axis direction) can be combined with n recessed portions (50) of battery cells (110) stacked in the up-down direction (Z-axis direction) in a shape-fit manner.

[0128] Meanwhile, the cell assembly (101) according to the second embodiment of the present invention may further include n battery cells (110) stacked in the front-back direction (X-axis direction) and / or n battery cells (110) stacked in the vertical direction (Z-axis direction). In addition, these battery cells (110) may be arranged in a row alternately along the left-right direction (Y-axis direction) and may be combined with each other in a shape-fitting manner. Through this, the cell assembly (101) may have a greater electric capacity and / or voltage.

[0129] FIG. 10 discloses a cell assembly (201) according to a third embodiment of the present invention. Referring to FIG. 10, the cell assembly (201) according to the third embodiment of the present invention may be composed of a plurality of unit cell assemblies (201). In this case, the unit cell assemblies (201) may be the cell assemblies (101) according to the second embodiment of the present invention described together with FIG. 9.

[0130] As illustrated, a plurality of unit cell assemblies (101) can extend parallel to each other along the left-right direction (Y-axis direction). In addition, a plurality of unit cell assemblies (101) can be arranged in a grid shape along the up-down direction (Z-axis direction) and the front-back direction (X-axis direction). Through this, a greater number of battery cells (110) can be electrically connected within a limited space without using a welding process.

[0131] Meanwhile, in the present embodiment, the manner in which the plurality of unit cell assemblies (101) are arranged is not particularly limited. As an example, the plurality of unit cell assemblies (101) may be stacked only in the vertical direction (Z-axis direction), or may be stacked only in the front-back direction (X-axis direction).

[0132] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0133] [Explanation of symbols]

[0134] 1, 101, 201: Cell assembly

[0135] 10, 110: Battery cells

[0136] 20: Cell body

[0137] 30, 130: Electrode leads

[0138] 40: Lead body

[0139] 50: Depression

[0140] 60: Inner joint

[0141] 70: Outer joint

Claims

1. A cell body accommodating an electrode stack; and comprising an electrode lead electrically connected to the electrode laminate; The above electrode leads are, A lead body portion provided on one side of the cell body; and A battery cell comprising a recessed portion that is recessed inwardly from the edge of the lead body portion but is open in the thickness direction of the lead body portion.

2. In paragraph 1, A battery cell in which the above-mentioned recessed portion is provided so that the electrode leads of adjacent battery cells can be connected in a shape-fitting manner.

3. In paragraph 1, The above-mentioned recessed portion is formed penetratingly in the thickness direction of the lead body portion, a battery cell.

4. In paragraph 1, The above electrode leads are, A battery cell further comprising an inner joining portion that is convexly protruded or concavely sunken into the inner wall of the above-mentioned recessed portion.

5. In paragraph 4, The above inner joint is provided in multiple numbers, battery cells.

6. In paragraph 5, The inner wall of the above-mentioned depression is, A first surface formed in the thickness direction of the lead body portion; and Including a second side facing the first side, The above inner joint is, a first inner joint formed on the first surface; and A battery cell comprising a second inner bonding portion formed on the second surface.

7. In paragraph 6, The above lead body portion extends in one direction along the edge of the cell body, A battery cell wherein the first side and the second side are arranged to face each other in the one direction.

8. In paragraph 1, The above electrode leads are, A battery cell further comprising an outer joining portion convexly protruding or concavely recessed on the outer surface of the lead body portion.

9. In paragraph 8, A battery cell, wherein the outer joint is spaced apart from the recessed portion in the direction in which the recessed portion is recessed.

10. In paragraph 8, The above outer joint is provided in multiple numbers, battery cells.

11. In paragraph 10, The above outer joint is, A first outer joint formed on one surface of the lead body; and A battery cell comprising a second outer coupling portion formed on the other surface of the lead body portion so as to face the first outer coupling portion.

12. In paragraph 1, The above electrode leads are, An inner joint portion convexly protruding or concavely sunken into the inner wall of the above-mentioned recess; and Further comprising an outer joint portion convexly protruding or concavely recessed on the outer surface of the lead body portion, A battery cell, wherein one of the inner joint portion and the outer joint portion is convexly protruded and the other is concavely sunken.

13. In paragraph 1, A battery cell having a plurality of recessed portions spaced apart from each other along the edge of the lead body.

14. In paragraph 1, The above electrode leads are provided in pairs, battery cells.

15. In paragraph 14, A battery cell wherein the above pair of electrode leads are arranged oppositely with the cell body as the center.

16. In paragraph 1, The above lead body portion is a battery cell having a plate shape.

17. A cell body accommodating an electrode stack; and A plurality of battery cells each including an electrode lead electrically connected to the electrode stack, the electrode lead including a plate-shaped lead body provided on one side of the cell body, and a recessed portion that is concavely recessed inwardly from the edge of the lead body but is open in the thickness direction of the lead body, A cell assembly in which electrode leads of neighboring battery cells among the plurality of battery cells are connected to each other in a shape-fitting manner.

18. In paragraph 17, The plurality of battery cells include first and second battery cells, The lead body of the first battery cell and the lead body of the second battery cell are arranged to be perpendicular to each other, A cell assembly in which the recessed portion of the first battery cell and the recessed portion of the second battery cell are joined to each other.

19. In paragraph 17, The plurality of battery cells include first and second battery cells, The electrode lead of the first battery cell is, Further comprising an inner joint portion convexly protruding or concavely sunken on the inner wall of the above-mentioned recessed portion, The electrode lead of the second battery cell is, Further comprising an outer joint portion convexly protruding or concavely recessed on the outer surface of the lead body portion, One of the inner joint portion and the outer joint portion is convexly protruded, and the other is concavely sunken, A cell assembly in which the inner joint of the first battery cell and the outer joint of the second battery cell are connected to each other in a shape-fitting manner.

20. In paragraph 17, The above-mentioned recessed portions are provided in n numbers (n is a natural number greater than or equal to 2) and are spaced apart along the edge of the lead body. The above plurality of battery cells, n battery cells stacked in the first direction; and It comprises n battery cells stacked in a second direction orthogonal to the first direction, A cell assembly in which n battery cells stacked in the first direction are each formed into a shape-fitting portion in the n recessed portions of the battery cells stacked in the second direction.

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