Battery cell, and battery pack and vehicle comprising same

Abstract

The present invention provides a battery cell and a battery pack and a vehicle that comprise the battery cell. The battery cell is characterized by comprising: a battery can which is composed of a bottom member and a sidewall member connected to the bottom member and extending in an axial direction, and has an opening part that is open at one end; an electrode assembly accommodated inside the battery can through the opening part of the battery can; and a current collecting plate having a plurality of tabs and connected to one end of the electrode assembly, wherein the plurality of tabs include a first tab and a second tab shorter than the first tab in an extension direction.

Description

Battery cells, battery packs including the same, and automobiles

[0001] The present invention relates to a battery cell, a battery pack including the same, and an automobile, and more specifically, to a battery cell for improving heat generation performance, a battery pack including the same, and an automobile.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2024-0189598 filed on December 18, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, not only for the primary advantage of drastically reducing the use of fossil fuels but also because they generate no by-products from energy use.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Consequently, the number of battery cells included in a battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, the current collector, a component of the battery cell, plays the role of efficiently collecting and discharging current, and has a significant impact on the performance and stability of the battery cell.

[0006] In conventional technology, current collector plates are primarily configured with a single-tap structure and designed to be electrically connected to the battery can. However, while the single-tap structure offers advantages in design simplicity and ease of manufacturing, it has limitations, such as the inability to handle sufficient discharge current or a high likelihood of performance degradation due to excessive heat generation.

[0007] Therefore, it is necessary to devise new structures and shapes that can lower the electrical resistance of the current collector and improve heat generation characteristics. Through this, there is a need for a current collector design that operates stably and enables efficient thermal management.

[0008] Accordingly, the technical problem to be solved by the present invention is to provide a battery cell, a battery pack including the same, and an automobile for improving the heat generation performance of a battery cell.

[0009] In addition, the invention provides a battery cell capable of reducing the resistance of the battery cell, a battery pack including the same, and a vehicle.

[0010] In addition, the invention provides a battery cell capable of improving the current flow of the battery cell, a battery pack including the same, and a vehicle.

[0011] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below.

[0012] To solve the above objective, the present invention provides a battery cell comprising: a battery can having an opening with one end open, the battery can being composed of a bottom member and a side wall member connected to the bottom member and extending axially; an electrode assembly accommodated inside the battery can through the opening of the battery can; and a current collector plate having a plurality of tabs and connected to one end of the electrode assembly, wherein the plurality of tabs includes a first tab and a second tab formed to have a shorter length in the extensional direction than the first tab.

[0013] For example, the first tab and the second tab may be positioned opposite each other with respect to the center of the current collector plate.

[0014] For example, at least one of the first tab and the second tab may have at least a portion of the area formed along an incision portion cut inwardly from the edge of the current collector plate for a predetermined length.

[0015] For example, at least one of the first tab and the second tab may be formed extending from the edge of the current collector plate.

[0016] For example, the first tab may have at least a portion formed along an incision cut inwardly for a predetermined length from the edge of the current collector plate, and the second tab may be formed extending from the edge of the current collector plate.

[0017] For example, the second tab may be formed with a length equal to the length of the first tab, excluding the length of the incision, in the extension direction.

[0018] For example, the first tab and the second tab may each be configured to protrude axially at a predetermined distance, either the same or different, from the center of the current collector plate.

[0019] For example, the first tab and the second tab may each have a folding portion configured to be folded axially from the main body portion of the current collector plate and a joining portion configured such that one end portion of each extension direction contacts each other.

[0020] For example, each of the above joints may be arranged facing each other so as to be in contact face-to-face.

[0021] For example, the first tab may comprise: a first bend portion configured to extend axially from the folding portion and be bent at a certain angle toward the second tab; an extension portion connected to the first bend portion and extending toward the second tab; and a second bend portion connected to the extension portion and bent at a certain angle toward the axial portion to be connected to the joint portion.

[0022] For example, the second tab may comprise: a first bending portion configured to extend axially from the folding portion and be bent at a certain angle toward the first tab; an extension portion connected to the first bending portion and extending toward the first tab; and a second bending portion connected to the extension portion and bent at a certain angle toward the axial portion to be connected to the joint portion.

[0023] For example, the first tab and the second tab may each be formed with a thickness equal to the thickness of the current collector plate.

[0024] For example, the first tab and the second tab may be formed with different lengths in the width direction.

[0025] For example, the first tab may be formed with a shorter length than the second tab in the width direction.

[0026] For example, the battery cell further includes a cap covering the opening of the battery can, and the current collector plate may be interposed between the electrode assembly and the cap and electrically connected.

[0027] For example, the second tab can be welded interposed between the cap and the first tab.

[0028] For example, the first tab and the second tab may be provided with a protrusion having a plurality of protrusions formed thereon.

[0029] For example, the first tab and the second tab may be welded together in an area including the protrusion.

[0030] For example, the current collector plate may be interposed between the electrode assembly and the bottom member and electrically connected.

[0031] In addition, the present invention provides a battery pack comprising at least one of the battery cells described above.

[0032] In addition, the present invention provides an automobile comprising at least one of the above-described battery packs.

[0033] A battery cell according to various embodiments of the present invention, a battery pack including the same, and a vehicle have the effect of improving the performance of the battery cell.

[0034] In addition, the battery cell according to various embodiments, the battery pack including the same, and the automobile have the effect of improving the resistance and current flow of the battery cell.

[0035] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0036] FIG. 1 is a schematic diagram showing a battery cell according to one embodiment of the present invention.

[0037] Figure 2 is a schematic diagram showing the electrode assembly of a battery cell according to Figure 1.

[0038] Figure 3 is a drawing for explaining each configuration of the electrode assembly according to Figure 2.

[0039] Figure 4 is a diagram illustrating the process of combining the electrode assembly and the current collector plate of a battery cell according to Figure 1.

[0040] FIG. 5 is a schematic diagram showing the state before the multiple tabs of the current collector plate of the battery cell according to FIG. 1 are folded.

[0041] Figure 6 is a drawing for explaining the collector plate according to Figure 5.

[0042] Figure 7 is an enlarged view of area Q of Figure 6.

[0043] FIGS. 8 and 9 are schematic drawings illustrating other embodiments of the current collector plate according to FIG. 5.

[0044] FIG. 10 is a drawing for explaining the state in which a plurality of taps of a current collector plate according to FIG. 5 come into contact with each other.

[0045] FIG. 11 is a drawing for explaining the state in which a plurality of taps of a current collector plate according to FIG. 8 come into contact with each other.

[0046] FIG. 12 is a drawing for explaining the state in which a plurality of taps of a current collector plate according to FIG. 9 come into contact with each other.

[0047] FIG. 13 is a drawing for explaining the different width-direction lengths of a plurality of tabs of a current collector plate of a battery cell according to FIG. 1.

[0048] FIG. 14 is a schematic diagram showing the protrusions of a plurality of tabs of a current collector plate of a battery cell according to FIG. 1.

[0049] FIG. 15 is a drawing for explaining how a plurality of tabs of a current collector plate of a battery cell according to FIG. 1 are combined with a cap.

[0050] FIG. 16 is a schematic cross-sectional view of a battery cell according to FIG. 1.

[0051] FIG. 17 is a schematic diagram showing a battery pack including a battery cell according to one embodiment of the present invention.

[0052] FIG. 18 is a schematic diagram showing a car including the battery pack of FIG. 16.

[0053] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0054] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0055] In addition, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar configurations are omitted, and the focus is on the differences.

[0056] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0057] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0058] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0059] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0060] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0061] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0062] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back may be used in this specification, these terms are used merely for convenience of explanation and may vary depending on the position or arrangement, rotation, or position of the observer, as is obvious to those skilled in the art of this invention.

[0063] The present invention may be implemented in the following embodiments, each independently. Furthermore, the present invention may be implemented in combination of two or more of the following embodiments. Each of the following embodiments may not only be implemented independently but may also be freely combined with one another.

[0064] For convenience of explanation, in this specification, the direction following the length direction of the winding axis of the electrode assembly wound in a jelly roll shape is referred to as the winding axis direction (Z). The direction in which the electrode assembly is wound along the winding axis is referred to as the winding direction (X). Furthermore, the direction moving away from or closer to the winding axis of the electrode assembly is referred to as the radial direction.

[0065]

[0066] FIG. 1 is a schematic diagram showing a battery cell (1) according to one embodiment of the present invention, FIG. 2 is a schematic diagram showing an electrode assembly (20) of the battery cell (1) according to FIG. 1, and FIG. 3 is a diagram for explaining each configuration of the electrode assembly (20) according to FIG. 2.

[0067] First, a schematic structure of a battery cell (1) according to one embodiment of the present invention will be described.

[0068] The battery cell (1) may be a cylindrical battery cell. For example, the battery cell (1) may be a cylindrical battery cell in which the ratio of the form factor (defined as the ratio of the diameter of the cylindrical battery cell to the height, i.e., the ratio of the diameter to the height) is greater than approximately 0.4.

[0069] Here, the form factor may refer to a value representing the diameter and height of a cylindrical battery cell. The cylindrical battery cell may be a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell by applying the numerical value representing the form factor. Here, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0070] Additionally, the battery cell (1) may be a cylindrical battery cell, for example, having a form factor ratio (ratio of diameter along the radial direction to height along the core axis direction) greater than approximately 0.4. For example, the diameter of the battery cell (1) may be 40 mm to 50 mm, and the height may be 60 mm to 130 mm. The form factor of the battery cell (1) may be, for example, 46110, 4875, 48110, 4880, or 4680.

[0071] However, the shape of the battery cell (1) according to the present invention is not limited by the above and can be applied to batteries of other shapes. For example, it can be applied to prismatic batteries.

[0072] Referring to FIGS. 1 to 3, the battery cell (1) according to the present embodiment mainly comprises a battery can (10) and an electrode assembly (20).

[0073] The battery can (10) may be a cylindrical structure for a cylindrical battery cell. In this case, a side wall member (11) may form the side of the cylinder of the battery can (10), and a bottom member (12) may be connected to the side wall member (11) to form one end of the cylinder. That is, the bottom member (12) may be a closed part of the battery can (10), and the other end of the battery can (10) facing the bottom member (12) may be open to form an opening.

[0074] The bottom member (12) may be in the shape of a disc with a through hole formed in the center, and the side wall member (11) may be in the shape of a cylinder surrounding the bottom member (12) and having a constant radius along the circumferential direction. The battery can (10) including the bottom member (12) and the side wall member (11) may be a member formed by a deep drawing process of a metal sheet having nickel plated on the surface of steel. Of course, the materials of the bottom member (12) and the side wall member (11) are not limited to this.

[0075] The battery cell (1) can accommodate an electrode assembly (20) inside the battery can (10) through an opening of the battery can (10).

[0076] The electrode assembly (20) may be configured such that the first electrode (21) and the second electrode (22) and the separator (28) interposed between them are wound around a winding axis.

[0077] The electrode assembly (20) after winding is completed may be in the form of a jelly-roll. When viewed from the top or bottom of the electrode assembly (20) in the XY plane, the outer shape of the electrode assembly (20) along the circumferential direction may be circular. However, the structure of the electrode assembly (20) is not limited by the embodiment and may have a winding structure well known in the art.

[0078] The first electrode (21), the second electrode (22), and the separator (28) can each be formed to have a predetermined width along the winding axis direction (Z) and to extend a predetermined length along the winding direction (X). The first electrode (21) may be an anode plate, and the second electrode (22) may be a cathode plate. Of course, the opposite may also be true.

[0079] The first electrode (21) and the second electrode (22) may be manufactured in the form of a sheet. The first electrode (21) and the second electrode (22) may be configured such that an active material layer (25) is applied to at least a portion of the surface of the metal foil (23). The first electrode (21) and the second electrode (22) may have a retaining portion (24) region where the active material layer (25) is applied and a non-retaining portion (26) region where the active material layer (25) is not applied.

[0080] The uncoated portion (26) can be exposed to the outside of the separator (28) while forming a plurality of winding turns based on the winding axis of the electrode assembly (20), and can be used as an electrode tab itself. That is, the positive plate and the negative plate may each include an uncoated portion (26) in which no active material is coated at the long side end in the winding axis direction (Z). In addition, the uncoated portions (26) of the first electrode (21) and the second electrode (22) may be configured to face opposite directions in the winding axis direction (Z). The uncoated portion (26) of the first electrode (21) may be housed inside the battery can (10) so that it is located at one end in the winding axis direction (Z), and the uncoated portion (26) of the second electrode (22) may be located at the other end in the winding axis direction (Z). Here, the positive active material coated on the positive plate and the negative active material coated on the negative plate may be used without limitation as long as they are active materials known in the art.

[0081] Also, the separator (28) may be a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., used alone or in a laminated form. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0082] At least one surface of the separator (28) may include a coating layer of inorganic particles. Additionally, it is possible for the separator (28) itself to be composed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure combined with a binder such that interstitial volume exists between adjacent particles.

[0083] This non-removable part (26) can itself function as an electrode tab.

[0084] The unwound portion (26) can form multiple flag-shaped notching tabs (27) by forming notches at predetermined intervals along the winding direction (X). The multiple notching tabs (27) may be in the shape of an isosceles trapezoid arranged along the winding direction (X). However, they are not limited thereto and may be in various shapes such as semicircles, semi-ellipses, triangles, rectangles, parallelograms, etc.

[0085] Additionally, a plurality of notching tabs (27) can be flattened by bending them radially in the electrode assembly (20). Additionally, the notching tabs (27) can be bent radially inward or outward in the electrode assembly (20).

[0086] Additionally, multiple notching tabs (27) may be folded one by one during the process of forming a jelly-roll type electrode assembly (20). Alternatively, the notching tabs (27) may be folded all at once after forming the jelly-roll type electrode assembly (20).

[0087] In this way, the notching tabs (27) of the first electrode (21) and the notching tabs (27) of the second electrode (22), which are folded and stacked in the radial direction, can each provide a plane that is substantially perpendicular to the winding axis direction (Z) at both ends of the winding axis direction (Z) of the electrode assembly (20).

[0088]

[0089] FIG. 4 is a drawing for explaining the process of combining the electrode assembly (20) and the current collector plate (30) of the battery cell (1) according to FIG. 1.

[0090] The battery cell (1) according to the present embodiment may have a current collector plate (30) electrically connected to at least one end in the axial direction with respect to the axis (A) of the electrode assembly (20). At this time, the current collector plate (30) may be electrically connected to the first electrode (21).

[0091] Additionally, the battery cell (1) may be provided with a current collector plate (40) electrically connected to at least the other end in the axial direction of the electrode assembly (20). At this time, the current collector plate (40) may be electrically connected to the second electrode (22). However, the battery cell (1) according to the present embodiment may omit the current collector plate (40) connected to the second electrode (22).

[0092] Each of the current collector plates (30, 40) can be bonded to a substantially flat surface provided by bending a plurality of electrode tabs exposed at both ends of the winding axis direction (Z) of the electrode assembly (20).

[0093] For example, the current collector plate (30) may be an anode current collector plate made of aluminum, and the current collector plate (40) may be a cathode current collector plate made of copper. Also, the opposite may be true, and the materials are not limited thereto. Additionally, the current collector plates (30, 40) may be manufactured by punching, trimming, piercing, and folding a metal sheet, and the manufacturing method is not limited thereto.

[0094] Hereinafter, the current collector plate described below in this specification is described as being limited to the current collector plate (30) connected to the first electrode (21), but any description applicable to both the current collector plate (30) and the current collector plate (40) may also be applied to the current collector plate (40), and any redundant descriptions below are omitted.

[0095]

[0096] FIG. 5 is a schematic diagram showing the state before the multiple tabs of the current collector plate (30) of the battery cell (1) according to FIG. 1 are folded, FIG. 6 is a diagram for explaining the current collector plate (30) according to FIG. 5, and FIG. 7 is an enlarged view of area Q of FIG. 6.

[0097] Referring to FIGS. 5 to 7, the current collector plate (30) according to the present embodiment may have a plurality of taps.

[0098] Multiple taps can perform the function of transmitting current through the current collector plate (30) to the outside or distributing it appropriately. Each tap can efficiently transmit the current generated inside the battery cell (1).

[0099] A plurality of tabs may include a first tab (32) and a second tab (33) having different lengths in the extension direction. For example, the length (L1) of the first tab (32) may be formed to be relatively longer than the length (L2) of the second tab (33).

[0100] That is, the battery cell (1) can optimize current distribution by having multiple taps of different lengths. For example, a second tap (33), which is shorter in the extension direction, may be configured to act as a main current path and handle most of the current, as it has a relatively lower resistance than the first tap (32). On the other hand, a first tap (32), which is longer in the extension direction, may be designed to have a relatively higher resistance than the second tap (33) and may act as an auxiliary current path. This prevents the current from being excessively concentrated in a specific path and contributes to increasing the electrical efficiency of the entire system.

[0101] Additionally, the battery cell (1) can improve heat generation performance by having multiple tabs of different lengths. For example, the first tab (32), which is longer in the extension direction compared to the first tab (31), can generate relatively less heat because the amount of current flowing is limited due to its relatively high resistance. Also, the second tab (33), which is shorter in length compared to the first tab (31), can avoid heat concentration while operating as the main current path, thereby enabling stable overall heat management. In this way, the thermal balance between the multiple tabs within the battery cell (1) can be maintained, and performance degradation or damage caused by overheating can be prevented.

[0102] In addition, the difference in length of such multiple taps can contribute to the structural stability and fault-tolerant design of the battery cell (1). For example, the first tap (32), which is relatively long, acts as an auxiliary path and diverts mechanical stress and electrical load from the main current path. As a result, the first tap (32) can maintain durability even during long-term use, and since the second tap (33) acts as the main current path, the function of the battery cell (1) can be maintained even if a problem occurs with the first tap (32).

[0103] Accordingly, the battery cell (1) according to the present embodiment can improve the heat generation characteristics of the battery cell (1) by dispersing the flow of current compared to a single tap structure and preventing the concentration of current density at a specific point.

[0104] Multiple tabs can be formed integrally with the current collector plate (30) through a press molding process. By doing so, electrical connections between the current collector plate (30) and the multiple tabs can be implemented without a separate attachment process, thereby simplifying the manufacturing process, minimizing electrical resistance, and increasing reliability.

[0105] Multiple taps can be positioned at mutually opposite locations based on the center (M) of the current collector plate (30), that is, the center (M) of the main body (31). In this way, the structure of multiple taps positioned oppositely based on the center (M) of the main body (31) prevents the current flow of the current collector plate (30) from being biased in a specific direction, thereby minimizing current concentration or heat concentration phenomena and contributing to increasing the stability of the battery cell (1).

[0106] The first tab (32) and the second tab (33) may be spaced apart from the center (M) of the current collector plate (30) by a predetermined distance, either the same or different. For example, the first tab (32) may be spaced apart from the center (M) of the current collector plate (30) by a predetermined distance (L3). Additionally, the second tab (33) may be spaced apart from the center (M) of the current collector plate (30) by a predetermined distance (L4) from the center (M) of the current collector plate (30) at a position facing the first tab (32) relative to the center (M) of the current collector plate (30). Thus, the battery cell (1) can ensure flexible placement of each tab according to the design structure while securing connection strength with a plurality of tabs and the current collector plate (30).

[0107] According to one embodiment, at least one of the first tab (32) and the second tab (33) may be formed along each cut portion (321, 331) that is cut inwardly for a predetermined length toward the center (M) from the edge of the collector plate (30), that is, the edge of the main body portion (31).

[0108] For example, the first tab (32) may be formed along each cut portion (321) that is cut inwardly for a predetermined length (L6) from the edge of the collector plate (30), that is, the edge of the main body part (31), toward the center (M). At this time, the length (L6) of the cut portion (321) may be formed to be smaller than the length (L5) from the center (M) of the main body part (31) of the collector plate (30) to the edge of the main body part (31).

[0109] Additionally, the cut portion (321) may be formed in the main body portion (31) of the collector plate (30), excluding the area of ​​the center portion (311) where the center hole is formed. That is, the length (L6) of the cut portion (321) may be provided as a length within the range excluding the length (L7) from the edge of the center portion (311) to the center (M) of the main body portion (31) from the length (L5) from the edge of the main body portion (31) to the center (M).

[0110] In this way, the area of ​​the collector plate (30) formed by the cut portions (321, 331) can define a part of the first tab (32) and the second tab (33), respectively. As a result, the first tab (32) and the second tab (33) can be designed to extend or fold in a desired direction while maintaining an integrated structure with the main body (31).

[0111] As a result, the battery cell (1) can secure an additional length of each tab equal to the area cut to a predetermined length. This contributes to increasing the utilization of the internal space of the battery cell (1) and enables a more efficient design within the same external dimensions.

[0112] Accordingly, the battery cell (1) according to the present embodiment can maximize space efficiency and improve performance in terms of current flow and heat management by providing a region formed along the cut portions (321, 331) at the edge of the current collector plate (30) as a part of the region of a plurality of tabs.

[0113]

[0114] FIGS. 8 and 9 are schematic drawings illustrating other embodiments of the current collector plate according to FIG. 5.

[0115] The description of the current collector plate (30) according to the above-described embodiment with reference to FIGS. 5 to 7 is applicable to matters common to the current collector plate (30) in other embodiments of the present invention (30a, 30b), and redundant descriptions are omitted below.

[0116] Referring to FIG. 8, a current collector plate (30a) according to one embodiment may have a plurality of tabs including a first tab (32) and a second tab (33) having different lengths in the extension direction. For example, the length (L8) of the first tab (32) may be formed to be relatively longer than the length (L9) of the second tab (33).

[0117] According to the present embodiment, at least one of the first tap (32) and the second tap (33) may be formed by extending from the edge of the current collector plate (30a), that is, from the edge of the main body part (31). This structure allows the current collector plate (30a) and the plurality of taps to be designed as a single unit, thereby increasing the reliability of the electrical connection and simplifying the manufacturing process.

[0118] For example, the first tap (32) and the second tap (33) can both be formed by extending from the edge of the main body (31). Thus, the distances (L10, L11) spaced from the center (M) of the main body (31) can be equal to each other. By maintaining symmetry between the two taps, the current distribution is made more uniform, preventing the phenomenon where the current density is biased in a specific direction, thereby reducing heat generation and increasing the stability of the battery cell (1).

[0119] Accordingly, the battery cell (1) according to the present embodiment has high durability as there is no stress concentration due to cutting, and can reduce electrical resistance and heat generation by simplifying the manufacturing process and making the current flow more natural.

[0120] Referring to FIG. 9, a current collector plate (30b) according to one embodiment may have a plurality of tabs including a first tab (32) and a second tab (33) having different lengths in the extension direction. For example, the length (L12) of the first tab (32) may be formed to be relatively longer than the length (L14) of the second tab (33).

[0121] According to the present embodiment, the first tab (32) is formed in at least a portion of the area along an incision (321) that is cut inwardly for a predetermined length (L13) from the edge of the current collector plate (30b), and the second tab (33) can be formed extending from the edge of the current collector plate (30b).

[0122] That is, the distance (L15) between the first tap (32) and the center (M) of the main body (31) may be shorter than the distance (L16) between the second tap (33) and the center (M) of the main body (31) by the length (L13) of the cut portion (321). This configuration can optimize current flow while compensating for the difference in physical length between the two taps.

[0123] Thus, when multiple tabs are not folded, the distance (L12+L15, L14+L16) from the center (M) of the main body (31) of the collector plate (30b) to one end in the extension direction of each tab can be designed to be the same.

[0124] Accordingly, the battery cell (1) according to the present embodiment can maintain a symmetrical arrangement with respect to the center (M) of the main body (31) even if there is a difference in the length of the multiple tabs, thereby ensuring uniform current distribution and stability of electrical performance.

[0125]

[0126] FIG. 10 is a drawing for explaining the state in which a plurality of tabs of a current collector plate (30) according to FIG. 5 are in contact with each other, FIG. 11 is a drawing for explaining the state in which a plurality of tabs of a current collector plate (30a) according to FIG. 8 are in contact with each other, and FIG. 12 is a drawing for explaining the state in which a plurality of tabs of a current collector plate (30b) according to FIG. 9 are in contact with each other.

[0127] Referring to FIGS. 10 to 12, the first tab (32) and the second tab (33) may each have a folding portion (322, 332) configured to be folded axially from the main body portion (31) of the collector plate (30), and a joining portion (326, 336) configured so that one end of each extension direction contacts each other.

[0128] These folding portions (322, 332) can be designed to maximize space efficiency and reduce interference with other components in the battery cell (1). Additionally, by configuring each tab to be folded axially through the folding portions (322, 332), multiple tabs can be formed integrally with the current collector plate (30), thereby simplifying the manufacturing process.

[0129] The joints (326, 336) are designed to be in contact face-to-face with each other and can be arranged in a mutually facing manner. This allows the first tab (32) and the second tab (33) to be stably joined, thereby increasing the reliability of the electrical connection and ensuring mechanical strength.

[0130] The first tap (32) and the second tap (33) can be formed with a thickness (T2, T3) equal to the thickness (T1) of the current collector plate (30), i.e., the main body (31). This configuration enables an integrated design between the multiple taps and the main body (31), thereby simplifying the manufacturing process and improving the reliability of the electrical connection.

[0131] Accordingly, the battery cell (1) according to the present embodiment has a plurality of tabs and a current collector plate (30) formed as a single unit, which can prevent localized resistance increase or excessive heat generation. In addition, since there is minimal deformation of the material during the molding process, a desired shape can be easily realized without post-processing, thereby increasing productivity and reducing costs.

[0132]

[0133] In one embodiment, the collector plate (30) can be joined with the second tab (33) by bending the first tab (32), which is relatively long, toward the second tab (33), which is relatively short, as shown in FIG. 10.

[0134] Specifically, the first tab (32) may be provided with a first bending portion (323) configured to extend axially from the folding portion (322) and be bent at a certain angle toward the second tab (33). The first bending portion (323) changes the path of the first tab (32) extended axially toward the second tab (33), thereby providing a position for coupling with the second tab (33) and optimizing space utilization.

[0135] Additionally, the first tab (32) may include an extension (324) that is connected to the first bend (323) and extends toward the second tab (33). The extension (324) can serve as a basis for stable coupling between the two tabs while maintaining a current flow path extending from the first bend (323).

[0136] The second bending portion (325), which is connected to the extension portion (324), can be configured to be bent again at a certain angle in the axial direction. The second bending portion (325) can more precisely adjust the connection direction and position of the first tab (32) to ensure a stable connection with the second tab (33). These first bending portion (323) and second bending portion (325) can increase assembly efficiency within the limited space of the battery cell (1) and maintain structural stability.

[0137] At this time, the joint (326) can be connected to the second bend (325) and extended in the axial direction, and can be designed to have a structure that can be stably combined with the second tab (33). In addition, by extending the joint (326) in the axial direction, sufficient area of ​​the electrical connection part can be secured to minimize contact resistance and maximize the efficiency of current flow.

[0138] At this time, the first bend portion (323) and the second bend portion (325) may be configured to be bent in opposite directions from each other in the axial direction.

[0139] In other words, the first bend (323), extension (324), and second bend (325) of the first tap (32) can effectively adjust the position and shape of the first tap (32) to optimize the current flow path and provide mechanical stability.

[0140] Accordingly, in the battery cell (1) according to the present embodiment, the first tab (32), which is longer in the extension direction, is bent and joined with the second tab (33), which is shorter in the extension direction, thereby allowing for efficient use of the limited space inside the battery cell (1), and increasing the contact area between the two tabs and reducing the contact resistance, thereby increasing the current transfer efficiency.

[0141] The description of the current collector plate (30) according to the above-described embodiment with reference to FIG. 10 is applicable to matters common to the current collector plate (30) in other embodiments of the present invention (30a, 30b), and redundant descriptions are omitted below.

[0142] According to one embodiment, the current collector plate (30a) can be joined together by having a plurality of tabs each bent toward opposing tabs, as shown in FIG. 11.

[0143] Specifically, the first tab (32), which is longer in the extension direction, is bent toward the second tab (33), and the second tab (33), which is shorter in the extension direction, can also be bent toward the first tab (32).

[0144] The second tab (33) may have a first bending portion (333) configured to extend axially from the folding portion (332) and be bent at a certain angle toward the first tab (32). Additionally, the second tab (33) may include an extension portion (334) connected to the first bending portion (333) and extending toward the first tab (32), and may have a second bending portion (335) connected to the extension portion (334) and configured to be bent again axially at a certain angle.

[0145] At this time, the joint portion (336) can be connected to the second bend portion (335) and extended in the axial direction. Thus, the joint portion (336) of the second tab (33) can be stably combined with the joint portion (326) of the first tab (32).

[0146] At this time, the first bend portion (333) and the second bend portion (335) may be configured to be bent in opposite directions from each other in the axial direction.

[0147] Accordingly, the battery cell (1) according to the present embodiment can facilitate positional alignment between multiple tabs and improve the quality of face-to-face contact at the joint portions (326, 336) by bending the first tab (32) and the second tab (33) toward each other. In addition, such a bending structure between multiple tabs can further strengthen the mechanical bonding strength and further improve durability against physical stresses such as external shocks or vibrations.

[0148] In one embodiment, the current collector plate (30b) according to FIG. 12 has a first tab (32) that is longer in the extension direction and is bent toward a second tab (33) so as to be joined with a second tab (33) that is shorter.

[0149] Specifically, the first tab (32), which is longer in the extension direction, has at least a portion formed along an incision (321) that is cut inwardly for a predetermined length from the edge of the current collector plate (30b), and can be bent toward the second tab (33). Additionally, the second tab (33), which is shorter in the extension direction, is formed extending from the edge of the current collector plate (30b) and can come into contact with the bent first tab (32). Thus, a structure in which the second tab (33) simply extends from the edge without a separate cutting process can be advantageous for simplifying the manufacturing process and maintaining the mechanical strength of the second tab (33).

[0150] Accordingly, the battery cell (1) according to the present embodiment can maximize electrical performance, manufacturing efficiency, and space utilization through a mutually complementary design of two tabs with different lengths and structures in the extension direction.

[0151]

[0152] FIG. 13 is a drawing for explaining the different width-direction lengths of a plurality of tabs of a current collector plate (30, 30a, 30b) of a battery cell (1) according to FIG. 1, and FIG. 14 is a schematic drawing showing the protrusions (3260, 3360) of a plurality of tabs of a current collector plate (30, 30a, 30b) of a battery cell (1) according to FIG. 1.

[0153] Referring to FIG. 13, the first tab (32) and the second tab (33) according to the present embodiment may be designed to have different lengths in the width direction. This increases the positional alignment and the stability of face-to-face contact of each tab during the process of joining multiple tabs, thereby providing a more reliable joining structure.

[0154] In addition, by adjusting the width direction length of each tab, the electrical resistance characteristics of the current collector plates (30, 30a, 30b) can be intentionally designed.

[0155] As an example, the width direction length (L15) of the first tap (32), which is longer in the extension direction, may be formed to be smaller than the width direction length (L16) of the second tap (33), which is shorter. For example, the difference in width direction length of each tap may be approximately 1 mm to 3 mm. That is, by reducing the width of the first tap (32) to provide a narrower cross-sectional area, it may be intentionally configured so that the electrical resistance to current flow is relatively increased.

[0156] Such a design can induce tab fusing under abnormal operating conditions, such as external short circuits or overcurrent situations.

[0157] Specifically, the high resistance characteristic of the first tap (32) causes heat to concentrate when an overcurrent flows, so that the first tap (32) can melt preferentially. As a result, the current path through the first tap (32) is quickly cut off, preventing excessive current from flowing into the battery cell (1), thereby maximizing safety.

[0158] In addition, by creating a difference in the width direction lengths of the first tap (32) and the second tap (33), the distribution of electrical resistance can be optimized, and flexibility can be provided to adjust the position and current path of each tap to suit design requirements if necessary.

[0159] Accordingly, the battery cell (1) according to the present embodiment can effectively block the risk of overheating, fire, or explosion that may occur due to a short circuit, and can support the stable operation of the battery cell (1).

[0160] Referring to FIG. 14, at least one of the first tab (32) and the second tab (33) may have a protrusion (3260, 3360) formed with a plurality of protrusions in at least a portion of one end in the extension direction.

[0161] The protrusions (3260, 3360) can be formed on the joint (326) of the first tab (32) or the joint (336) of the second tab (33), respectively, which can optimize electrical and mechanical connections in the welding process.

[0162] The protrusions (3260, 3360) can provide a shape advantageous for resistance welding. Resistance welding is a method of performing welding through resistance heat generated at each joint (326, 336) by passing an electric current.

[0163] When such protrusions (3260, 3360) are present, the contact area is locally concentrated, allowing resistance heat to be generated more effectively. This improves welding quality and increases the mechanical strength and electrical connection reliability of the joint (326, 336). Additionally, the protrusions (3260, 3360) can help ensure alignment and contact stability of the joint (326, 336).

[0164] However, if a welding method such as laser welding is used, shapes such as protrusions (3260, 3360) can be omitted. Since laser welding performs welding by concentrating high-output energy in a narrow area, uniform welding quality can be secured even without protrusions (3260, 3360).

[0165] That is, multiple tabs can be welded together by various welding methods, and whether or not protrusions (3260, 3360) are formed can be determined according to the welding method and design requirements.

[0166] Accordingly, the battery cell (1) according to the present embodiment can maximize welding quality and efficiency in a specific welding process, such as resistance welding, by having a protrusion (3260, 3360) with a plurality of protrusions formed thereon.

[0167]

[0168] FIG. 15 is a drawing for explaining how a plurality of tabs of the current collector plates (30, 30a, 30b) of the battery cell (1) according to FIG. 1 are combined with the cap (50), and FIG. 16 is a schematic drawing showing a longitudinal cross-sectional view of the battery cell (1) according to FIG. 1.

[0169] The battery cell (1) according to the present embodiment may include a cap (50) that covers the opening of the battery can (10).

[0170] The cap (50) may be configured as a cover structure that effectively seals the opening of the battery can (10). By doing so, the battery cell (1) is sealed, the internal electrolyte and electrode assembly (20) are protected from the external environment, and the long-term performance of the battery cell (1) can be maintained.

[0171] The joint point between the opening of the battery can (10) and the cap (50) can be joined by welding. For example, the cap (50) can be joined to the battery can (10) using butt welding. In this way, the battery cell (1) can have a larger internal capacity than a battery cell (1) using beading and crimping methods, while maintaining the same external shape. However, the battery can (10) and the cap (50) can be joined by other joining methods other than welding, and the joining method is not limited to this.

[0172] The cap (50) may be made of a metallic material for electrical connection with the current collector plates (30, 30a, 30b). Thus, the cap (50) may be conductive. For example, the cap (50) may include aluminum material.

[0173] The cap (50) may be disc-shaped so as to be fixed to the opening of the battery can (10) or to seal the opening, but its shape is not limited thereto. Additionally, the thickness of the cap (50) may be designed to provide sufficient strength to prevent deformation in high temperature or high pressure environments and to ensure durability to prevent leakage of the internal electrolyte.

[0174] The main body (31) of the collector plate (30, 30a, 30b) can be electrically connected and fixed by welding it to one end of the electrode assembly (20).

[0175] The second tab (33) can be interposed between the cap (50) and the first tab (32) and welded (W). Here, the second tab (33) may have a shorter length in the extension direction than the first tab (32). This welding can be performed, for example, with the cap (50) and the plurality of tabs arranged parallel to the winding axis direction (Z). By doing so, the contact area between the plurality of tabs and the cap (50) is kept constant, thereby ensuring uniform welding quality.

[0176] Welding (W) can proceed from multiple tabs toward the cap (50). This induces the welding heat to concentrate in a specific area where the multiple tabs and the cap (50) are joined, thereby contributing to minimizing contact resistance and maintaining an efficient current flow. Additionally, the design process can be simplified so that the cap (50) and the multiple tabs can be stably joined to the battery can (10) after welding.

[0177] The welded cap (50) and a plurality of tabs can be fixed to the opening of the battery can (10). This ensures the airtightness of the battery cell (1) and guarantees the efficiency of current transmission. The stable fixation of the cap (50) and the plurality of tabs can be designed to maintain the structural integrity of the battery even against external shocks or vibrations.

[0178] The welding (W) may be limited to a portion of the area where multiple tabs and the cap (50) are joined. As a result, even if the length of the second tab (33) does not reach the entire edge of the cap (50), the welding is concentrated in the center or a portion of the cap (50), thereby ensuring sufficient electrical connection and mechanical fixation.

[0179] Accordingly, the battery cell (1) according to the present embodiment can increase the flexibility of the welding process and optimize material usage. In addition, since only a portion of the cap (50) is welded, unnecessary heat loss in the welding process can be reduced and welding quality can be improved. This contributes to minimizing contact resistance between the multiple tabs and the cap (50), increasing the efficiency of current transmission, and simultaneously improving the performance and reliability of the battery cell (1).

[0180] However, the present specification is not limited to exemplary forms, and the current collector plates (30, 30a, 30b) may be interposed between the electrode assembly (20) and the bottom member (12) and electrically connected.

[0181] As described above, a single-tap structure of a current collector plate is likely to have limitations in handling sufficient discharge current or withstanding heat generation. Accordingly, the battery cell (1) according to the present embodiment includes a plurality of taps of different lengths to distribute the current flow into multiple paths, thereby preventing the phenomenon of current concentration in a specific area, improving heat generation characteristics, and simultaneously improving the stability and performance of the battery cell (1).

[0182]

[0183] FIG. 17 is a schematic diagram showing a battery pack (P) equipped with a battery cell (1) according to one embodiment of the present invention, and FIG. 18 is a schematic diagram showing a vehicle (V) equipped with a battery pack (P) according to one embodiment of the present invention.

[0184] Referring to FIG. 17, a battery pack (P) according to one embodiment of the present invention may include at least one battery cell (1) according to a prior embodiment and a pack case (C) that accommodates the same.

[0185] A battery pack (P) according to one embodiment of the present invention may further include various other components of a battery pack (P) known at the time of filing the present invention. For example, a battery pack (P) according to one embodiment of the present invention may further include components such as a current sensor, a fuse, and a service plug.

[0186] The battery pack (P) has no significant restrictions on the application of cooling methods, such as bottom cooling and side cooling, regardless of the arrangement direction of the battery cell (1), and can be freely adopted according to desired design requirements. As a result, the battery pack (P) allows for a combination of various structural designs and thermal management systems, thereby optimizing the performance of the battery cell (1) and configuring it to be suitable for various application environments.

[0187] Referring to FIG. 18, a vehicle (V) according to one embodiment of the present invention may include one or more battery packs (P) according to the present invention. In addition, a vehicle (V) according to one embodiment of the present invention may include various other components included in the vehicle in addition to the battery packs (P). For example, a vehicle (V) according to one embodiment of the present invention may include, in addition to the battery packs (P) according to one embodiment of the present invention, a vehicle body, a motor, an electronic control unit (ECU), or other control devices.

[0188] In addition, it is obvious that the battery pack (P) according to one embodiment of the present invention may also be provided in other devices, mechanisms, and facilities, such as an energy storage system using a secondary battery, in addition to the vehicle (V).

[0189] According to the various embodiments described above, a current collector plate (30, 30a, 30b) capable of further improving heat generation performance, a battery cell (1) including the same, a battery pack (P), and a vehicle (V) can be provided.

[0190]

[0191] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0192] [Explanation of the symbol]

[0193] 1: Battery cell

[0194] 10: Battery can

[0195] 11: Sidewall member

[0196] 12: Floor member

[0197] 20: Electrode assembly

[0198] 21: First electrode

[0199] 22: Second electrode

[0200] 23: Metal foil

[0201] 24: Maintenance Department

[0202] 25: Active material layer

[0203] 26: Mujibu

[0204] 27: Notching Tab

[0205] 28: Separator

[0206] 30, 30a, 30b: Collector's plate

[0207] 31: Main body

[0208] 310: Center Department

[0209] 32: 1st tab

[0210] 321: Incision

[0211] 322: Fold

[0212] 323: First bend

[0213] 324: Extension part

[0214] 325: Second bend

[0215] 326: Joint

[0216] 3260: Joint

[0217] 33: 2nd tab

[0218] 331: Incision

[0219] 332: Fold

[0220] 333: First bend

[0221] 334: Extension part

[0222] 335: Second bend

[0223] 336: Joint

[0224] 3360: Protrusion

[0225] 40: Household board

[0226] 50: Cap

[0227] M: Center

[0228] W: Welding

[0229] A: Congratulations

[0230] P: Battery pack

[0231] C: Pack case

[0232] V: Car

Claims

1. A battery can comprising a bottom member and a side wall member connected to the bottom member and extended axially, having an opening with one end open; An electrode assembly accommodated inside the battery can through an opening of the battery can; and It is equipped with a plurality of tabs and includes a current collector plate connected to one end of the electrode assembly, and The above plurality of tabs are, A battery cell characterized by including a first tab and a second tab formed to be shorter in length in the extension direction than the first tab.

2. In Paragraph 1, The above first tab and the above second tab are, A battery cell characterized by being positioned at mutually opposite locations based on the center of the above-mentioned current collector plate.

3. In Paragraph 1, At least one of the first tab and the second tab is, A battery cell characterized by having at least a portion of the area formed along an incision portion cut inwardly from the edge of the above-mentioned current collector plate for a predetermined length.

4. In Paragraph 1, At least one of the first tab and the second tab is, A battery cell characterized by being formed extending from the edge of the above-mentioned current collector plate.

5. In Paragraph 1, The above first tab is, At least a portion of the area is formed along an incision of a predetermined length cut inward from the edge of the above-mentioned collector plate, and The above second tab is, A battery cell characterized by being formed extending from the edge of the above-mentioned current collector plate.

6. In Paragraph 5, The above second tab is, A battery cell characterized by being formed with a length equal to the length of the first tab, excluding the length of the incision portion, in the extension direction.

7. In Paragraph 1, The first tab and the second tab are, respectively, A battery cell characterized by being configured to protrude axially at a predetermined distance equal to or different from the center of the above-mentioned current collector plate.

8. In Paragraph 1, The first tab and the second tab are, respectively, A battery cell characterized by being formed with the same thickness as the above-mentioned current collector plate.

9. In Paragraph 1, The above first tab and the above second tab are, A folding portion configured to be folded axially from the main body portion of the above-mentioned current collector plate; and Each is provided with a joint configured such that one end of each extension direction contacts each other, and The above joints are, respectively, A battery cell characterized by being arranged facing each other so as to be in contact face-to-face.

10. In Paragraph 9, The above first tab is, A first bending portion extending axially from the above-mentioned folding portion and configured to be bent at a certain angle toward a second tab; An extension portion connected to the first bend portion and extending toward the second tab; and A battery cell characterized by having a second bend portion that is connected to the extension portion and is bent at a certain angle toward the axial direction to be connected to the joint portion.

11. In Paragraph 10, The above second tab is, A first bending portion extending axially from the above-mentioned folding portion and configured to be bent at a certain angle toward the first tab; An extension portion connected to the first bend portion and extending toward the first tab; and A battery cell characterized by having a second bend portion that is connected to the extension portion and is bent at a certain angle toward the axial direction to be connected to the joint portion.

12. In Paragraph 1, The above first tab and the above second tab are, A battery cell characterized by being formed with different lengths in the width direction.

13. In Paragraph 12, The above first tab is, A battery cell characterized by being formed with a length shorter than the second tab in the width direction.

14. In Paragraph 1, The above battery cell is, It further includes a cap covering the opening of the battery can, and The above current collector plate is, A battery cell characterized by being electrically connected and interposed between the electrode assembly and the cap.

15. In Paragraph 14, The above second tab is, A battery cell characterized by being welded and interposed between the above cap and the above first tab.

16. In Paragraph 1, The above first tab and the above second tab are, A battery cell characterized by having a protrusion formed with a plurality of protrusions.

17. In Paragraph 16, The above first tab and the above second tab are, A battery cell characterized by being welded in contact with one another in an area including the above-mentioned protrusion.

18. In Paragraph 1, The above current collector plate is, A battery cell characterized by being interposed between the electrode assembly and the bottom member and electrically connected.

19. A battery pack characterized by including a battery cell according to any one of claims 1 to 18.

20. An automobile equipped with at least one battery pack according to claim 19.

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