Battery cell, and battery pack and vehicle including same

Abstract

A battery cell of the present invention may comprise: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis; a can configured to accommodate the electrode assembly through an open end formed on one side; a current collector configured to be electrically connected to the can; and a conductive member disposed between the electrode assembly and the can and configured to have a higher conductivity than the can.

Description

Battery cells, and battery packs containing these battery cells and automobiles

[0001] The present invention relates to a battery cell, a battery pack including the battery cell, and an automobile.

[0002] This application is a priority application for Korean Patent Application No. 10-2024-0155203 filed on November 05, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003]

[0004] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product categories, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources.

[0005] These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, not only for the primary advantage of being able to drastically reduce the use of fossil fuels, but also because they do not generate any by-products from the use of energy.

[0006] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. When a high output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Additionally, to increase charge / discharge capacity, multiple battery cells are connected in parallel to form a battery module or battery pack. Therefore, the number of battery cells included in the above battery module or pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0007] There is increasing demand for metal can-type cells as battery cells for automotive battery packs. Metal cans can be prismatic or cylindrical; cylindrical battery cells feature a structure that accommodates a jelly-roll type electrode assembly inside a cylindrical can, offering the advantage of being more robust against shock and temperature than pouch-type battery cells.

[0008] Battery cells arranged within a battery pack can be arranged so that both the electrode terminal having a first polarity and the electrode terminal having a second polarity are positioned on one side of the electrode assembly. Accordingly, when electrically connecting multiple battery cells, both the positive and negative electrodes can be connected in one direction, thereby simplifying the electrical connection structure.

[0009] However, if the current collector (e.g., negative current collector) and the terminal (e.g., negative terminal) are located in different directions relative to the electrode assembly, the electron travel distance increases, and resistance may increase. Electrons from the negative electrode can travel along the can between the negative current collector and the negative terminal located at the bottom of the can. In this case, the electron travel distance of the negative electrode increases, which may lead to increased resistance.

[0010] Therefore, there is a need to develop a battery cell structure that can reduce the resistance of the battery cell by extending the electron movement path and lowering the electron movement speed.

[0011]

[0012] The present invention was conceived against the background of the prior art described above, and aims to provide a battery cell with reduced resistance by adding an electron transport path connecting the current collector and the can.

[0013] Another technical objective of the present invention is to provide a battery pack including a battery cell of an improved structure, and a vehicle including the battery pack.

[0014] 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 a person skilled in the art from the description of the invention below.

[0015]

[0016] To solve the above problem, the battery cell of the present invention may include an electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound along a winding axis, a can configured to accommodate the electrode assembly through an open end formed on one side, and a conductive member disposed between the electrode assembly and the can, in contact with the can, and configured to have higher conductivity than the can.

[0017] One end of the conductive member may be connected to the can, and the other end of the conductive member may be connected to the current collector.

[0018] At least a portion of the conductive member may be configured to be in contact with the can.

[0019] The above can may be characterized by including a bottom portion and a side wall portion connected to the bottom portion and extending in the direction of the winding axis, and the conductive member may be connected to the bottom portion.

[0020] The above conductive member may be characterized as having multiple individuals.

[0021] The conductive member may be characterized by having a body portion extended in the direction of the winding axis, a first connecting portion extended from one end of the body portion, and a second connecting portion extended from the other end of the body portion.

[0022] At least a portion of the body part of the above-mentioned conductive member may be characterized by being inclined at a specified angle with respect to the winding axis direction.

[0023] The above plurality of conductive members may be characterized by forming a grid pattern.

[0024] The plurality of conductive members may be characterized by comprising a conductive member that is tilted at a first angle with respect to the winding axis direction and spaced apart at a constant interval, and a conductive member that is tilted at a second angle different from the first angle with respect to the winding axis direction and spaced apart at a constant interval.

[0025] The conductive member and the can, and the conductive member and the cathode current collector may be characterized by being joined by welding.

[0026] The above conductive member may be characterized by including at least one of copper (Cu) and nickel (Ni).

[0027] The above can may be characterized by having a groove formed therein configured to insert the above conductive member.

[0028] In addition, the present invention provides a battery pack characterized by including a battery according to the present invention.

[0029] And, the present invention provides an automobile characterized by including a battery pack according to the present invention.

[0030]

[0031] According to one embodiment of the present invention, the electron movement path can be expanded by adding a conductive member. This allows for the provision of a battery cell with reduced resistance. Consequently, the performance and lifespan of the battery are improved.

[0032] In addition to the above, the present invention may have various other effects, which are described in each embodiment, or effects that can be easily inferred by those skilled in the art, etc., will be omitted.

[0033]

[0034] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0035] FIG. 1 is a perspective view showing the appearance of a battery cell according to one embodiment of the present invention.

[0036] Figure 2 is a cross-sectional view of the battery cell of Figure 1 cut along II-II'.

[0037] FIG. 3 is an enlarged view showing an upper cross-sectional view of a battery cell and the arrangement of a conductive member according to one embodiment of the present invention.

[0038] FIG. 4 is an enlarged view showing a lower cross-sectional view of a battery cell and the arrangement of a conductive member according to one embodiment of the present invention.

[0039] FIG. 5 is an exploded perspective view of a battery cell showing a conductive member according to one embodiment of the present invention.

[0040] FIG. 6 is a schematic perspective view showing a portion of a battery cell including a conductive member according to another embodiment of the present invention.

[0041] FIG. 7 is a schematic perspective view showing a portion of a battery cell including a conductive member according to another embodiment of the present invention.

[0042] FIG. 8 is a drawing of a conductive member and a can according to another embodiment of the present invention, viewed from the upper direction.

[0043] FIG. 9 is a drawing of a conductive member and a can according to another embodiment of the present invention, viewed from the upper direction.

[0044] FIG. 10 is a schematic diagram showing the configuration of a battery pack according to an embodiment of the present invention.

[0045] FIG. 11 is a drawing for explaining a vehicle including the battery pack of FIG. 10.

[0046]

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0057] For convenience of explanation, in this specification, the direction following the longitudinal direction of the winding axis of the electrode assembly (10) wound in a jelly roll shape is referred to as the axial direction (Y). The direction surrounding the winding axis is referred to as the circumferential direction or periphery direction (X). The direction approaching the winding axis or moving away from the winding axis is referred to as the radial direction or radial direction (Z). In particular, the direction approaching the winding axis is referred to as the centripetal direction, and the direction moving away from the winding axis is referred to as the centrifugal direction.

[0058] First, an electrode assembly (10) according to an embodiment of the present invention will be described. The electrode assembly (10) is a jellyroll type electrode assembly (10) having a structure in which an anode and a cathode having sheet shapes and a separator interposed between them are wound in one direction.

[0059] Preferably, at least one of the anode and the cathode includes an uncoated portion at the long end of the winding direction in which the active material is not coated. At least a portion of the uncoated portion can be used as an electrode tab itself.

[0060] FIG. 1 is a perspective view showing the exterior of a battery cell (1) according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the battery cell (1) of FIG. 1 taken along II-II'.

[0061] Referring to FIGS. 1 and 2, the battery cell (1) may include an electrode assembly (10), a can (20), a current collector (e.g., a second current collector (80)), and a conductive member (100). In addition to the components described above, the battery cell (1) may further include a lead (30), a first electrode terminal (40), an insulating gasket (50), a current collector (e.g., a first current collector (60)), an insulator (70), and / or a sealing gasket (90).

[0062] A battery cell (1) according to one embodiment of the present invention may be, for example, a cylindrical battery. Preferably, the battery cell (1) may be, for example, a cylindrical secondary battery with a form factor ratio (ratio of height to diameter) greater than approximately 0.4. Preferably, 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. However, the present invention is not limited by the shape of the battery and is applicable to batteries of other shapes, such as prismatic batteries.

[0063] The electrode assembly (10) may be wound with respect to a winding axis, with the first electrode and the second electrode and the separator interposed between them. Referring to FIG. 3, the electrode assembly (10) may have a first unwound portion (11) and a second unwound portion (12). More specifically, the electrode assembly (10) may be in the form of a jelly-roll wound with the first electrode and the second electrode interposed between them and the separator interposed between them, centered on a winding axis. Here, the first electrode and the second electrode may be formed in a sheet shape. An additional separator may be provided on the outer surface of the electrode assembly (10) for insulation from the can (20). The structure of the electrode assembly (10) is not limited by the embodiment and may have a winding structure well known in the art.

[0064] The first electrode may be an anode plate and the second electrode may be a cathode plate. An anode active material may be coated on one or both sides of the anode plate, and a first uncoated portion (11) on which the anode active material is not coated may be formed at the end of the anode plate. The first uncoated portion (11) may be exposed to the outside of the separator while forming a plurality of wound turns based on the center of the electrode assembly (10), and may be used as an electrode tab itself. An anode active material may be coated on one or both sides of the cathode plate, and a second uncoated portion (12) on which the anode active material is not coated may be formed at the end of the cathode plate. The second uncoated portion (12) may be exposed to the outside of the separator while forming a plurality of wound turns based on the center of the electrode assembly (10), and may be used as an electrode tab itself.

[0065] That is, the positive plate and the negative plate may each include an uncoated portion along the winding direction at the long side end where the active material is not coated. Additionally, the first uncoated portion (11) and the second uncoated portion (12) may be configured to face in opposite directions. The first uncoated portion (11) may be housed inside the can (20) so as to be located at one end in the winding axis direction and the second uncoated portion (12) at the other end in the winding axis direction. 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.

[0066] In addition, the separator may be a porous polymer film, such as a polyolefin-based polymer like ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, etc., used alone or in a laminated form. As another example, the separator may be a conventional porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0067] At least one surface of the separation membrane may include a coating layer of inorganic particles. It is also possible for the separation membrane itself to consist of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure bonded with a binder such that interstitial volume exists between adjacent particles.

[0068] For example, notches may be formed at a predetermined interval in the first blank section (11) and the second blank section (12) to form flag-shaped notching tabs. In the jelly-roll type electrode assembly (10), the notching tabs may be folded radially and flattened. The notching tabs may be folded radially inward or outward. The notching tabs may be folded one by one during the process of winding the laminate to form the jelly-roll type electrode assembly (10). Alternatively, the notching tabs may be folded all at once after winding the laminate to form the jelly-roll type electrode assembly (10). The notching tabs of the first blank section (11) and the notching tabs of the second blank section (12), which are folded radially and overlapped in this way, may each provide a plane that is substantially perpendicular to the axial direction at both axial ends of the electrode assembly (10).

[0069] A can (20) may be configured to accommodate an electrode assembly (10) through an open end formed on one side. The can (20) includes a side wall portion (21), a bottom portion (22) connected to one axial end of the side wall portion (21), and an open end provided at the other axial end of the side wall portion (21). The bottom portion (22) has a roughly flat shape. The side wall portion (21) may be cylindrical, connected to the bottom portion (22), and extends axially. The side of the side wall portion (21) that is not connected to the bottom portion (22) may define the open end of the can (20).

[0070] In FIGS. 1 and 2, the bottom portion (22) is shown as being included at the top of the can (20), and the open end is shown as being included at the bottom of the can (20). The open end may be formed in a portion facing the bottom portion (22) of the can (20). An electrode assembly (10) may be received through the open end formed in the can (20). A lid (30) may be covered over the open end.

[0071] The bottom portion (22) and the side wall portion (21) can be manufactured by forming a metal sheet with nickel plated on the surface of steel using a deep drawing process, and then trimming the front end of the side wall portion (21) with a punch while holding it with a blank holder. Of course, the material of the can (20) is not limited to this. The material of the can (20) can be made of a conductive metal, such as aluminum, steel, stainless steel, etc., but is not limited to this.

[0072] Referring to FIGS. 1 and 2, the can (20) may have a beading portion (23) and a crimping portion (24) formed at the bottom. The beading portion (23) may be located at the bottom of the electrode assembly (10). The beading portion (23) may be formed by pressing the outer circumference of the can (20). Specifically, the beading portion (23) may have a shape that is pressed inward in the area between the open end formed on one side of the can (20) and the receiving portion that accommodates the electrode assembly (10). The upper beading portion (23a) and the lower beading portion (23b), which are located above and below respectively with respect to the innermost portion (23c) of the beading portion (23) located at the innermost side along the pressing direction, may have an asymmetrical shape relative to each other. This asymmetrical shape may be formed during the process in which the can (20) is compressed along the winding axis direction through a sizing process. The sizing process may be a process of applying pressure to the can (20) along the winding axis direction of the electrode assembly (10) to adjust the height of the battery cell (1) to the design form factor.

[0073] The lower beading portion (23b) may have a flat portion parallel in the horizontal direction. On the other hand, due to the asymmetrical shape, the upper beading portion (23a) may have a shape that is at least partially inclined along the direction toward the innermost portion (23c). The beading portion (23) prevents the electrode assembly (10), which has a size approximately corresponding to the inner diameter of the can (20), from coming out through the open end formed at the bottom of the can (20), and can function as a support portion on which the lead (30) is seated. The lower beading portion (23b) can function as a support portion for fixing the lead (30), which will be described later, as well as the contact portion of the second current collector (80), the sealing gasket (90), etc.

[0074] The clamping portion (24) may be formed at the lower part of the beading portion (23). The clamping portion (24) may extend from the lower beading portion (23b). The clamping portion (24) may have an extended and bent shape to wrap around the outer surface of the lead (30) positioned below the beading portion (23) and a part of the lower surface of the lead (30). The clamping portion (24) may also secure the sealing gasket (90) in addition to the lead (30).

[0075] The lid (30) can be supported by the lower surface of the beading portion (23) formed on the can (20). Additionally, the lid (30) can be fixed by the clamping portion (24). That is, the upper surface of the lid (30) can be supported by the beading portion (23), and the outer surface and lower surface can be supported by the clamping portion (24). A sealing gasket (90) may be interposed between the lid (30) and the clamping portion (24) to ensure airtightness of the can (20).

[0076] However, the lead (30) may be joined to the can (20) using butt welding. That is, according to another embodiment, although not shown in the drawing, the can (20) may not have a beading portion (23) and / or a crimping portion (24). In this case, the battery cell (1) can have a larger internal capacity while maintaining the same external shape. Thus, the energy density can be increased.

[0077] The first electrode terminal (40) can be coupled with the bottom portion (22). The bottom portion (22) forms the closed surface of the can (20). A through hole is formed in the bottom portion (22), and the first electrode terminal (40) can pass through the through hole. The first electrode terminal (40) may be fitted into the bottom portion (22). The first electrode terminal (40) may be fixed by riveting to the bottom portion (22) with an insulating gasket (50) interposed therebetween. The insulating gasket (50) is interposed between the first electrode terminal (40) and the bottom portion (22) to seal the inside and outside of the can (20) to prevent leakage of the electrolyte and to electrically insulate the first electrode terminal (40) and the bottom portion (22). The insulating gasket (50) may be in close contact between the first electrode terminal (40) and the can (20). A portion of the first electrode terminal (40) is inserted inside the can (20), and another portion is exposed outside the can (20).

[0078] The first electrode terminal (40) may be made of metal. The first electrode terminal (40) may be made of aluminum. During the process of riveting the first electrode terminal (40) to the can (20), the first electrode terminal (40) may be fixed on the outside of the can (20). The first electrode terminal (40) is electrically connected to the electrode assembly (10). The first electrode terminal (40) may be electrically connected to the first electrode of the electrode assembly (10) by passing through a through hole.

[0079] A current collector (e.g., a second current collector (80)) may be configured to be electrically connected to the can (20). The battery cell (1) may further include a first current collector (60) configured to be electrically connected to a first electrode and a second current collector (80) configured to be electrically connected to a second electrode. The first current collector (60) and the second current collector (80) may each be joined to a substantially flat surface provided by bending notching tabs exposed at both ends of the winding axis direction of the electrode assembly (10). Methods such as resistance welding, ultrasonic welding, or laser welding may be used for joining.

[0080] Additionally, the battery cell (1) may further include an insulator (70). The insulator (70) may be provided between the first current collector (60) and the inner surface of the bottom portion (22). The insulator (70) prevents contact between the first current collector (60) and the can (20). The insulator (70) may also be interposed between the inner surface of the side wall portion (21) and the electrode assembly (10). That is, the insulator (70) may also be interposed between the first non-contact portion (11) and the can (20). This is to prevent contact between the first non-contact portion (11), which extends toward the bottom portion (22) of the can (20), and the inner surface of the can (20).

[0081] The can (20) can be electrically connected to the second current collector (80). Accordingly, the first electrode terminal (40) may have a first polarity, and the can (20) may have a second polarity. In particular, the bottom portion (22) of the can (20) and the side wall portion (21) connected thereto may both have a second polarity. Accordingly, the can (20) may have both the first electrode terminal (40) and the second electrode terminal (25) positioned at one end in the winding axis direction, for example, at the bottom portion (22). Then, the bus bar connected to the first electrode terminal (40) and the bus bar connected to the second electrode terminal (25) may both be located at one end in the axial direction of the can (20). In one example, the first electrode terminal (40) may be a positive terminal, and the second electrode terminal (25) may be a negative terminal. Of course, the opposite may also be true. Therefore, the battery cell (1) according to the present invention can simplify the electrical connection structure by allowing both the positive and negative electrodes to be connected in one direction when electrically connecting a plurality of battery cells (1). In addition, the battery cell (1) according to the present invention has the advantage of securing a sufficient surface area for welding components for electrical connection, as most of the bottom portion (22) of the can (20) can be used as a second electrode terminal (25).

[0082] However, since the second current collector (80) is located on the lower side of the electrode assembly (10) and the second electrode terminal (25), which is electrically connected to the busbar, is located on the upper side of the electrode assembly (10), the electron travel distance is long, which may cause the resistance to increase.

[0083] The battery cell (1) according to the present invention may further include a conductive member (100) disposed between an electrode assembly (10) and a can (20). The conductivity of the conductive member (100) may be formed to be higher than the conductivity of the can (20). For example, the conductive member (100) may include at least one of copper (Cu) and nickel (Ni).

[0084] According to an embodiment of the present invention, a conductive member (100) with higher conductivity than the can (20) can be added to expand the electron movement path while simultaneously reducing the resistance of the battery cell (1). The resistance of the battery cell (1) may be an important factor affecting the performance and output of the battery cell (1) and the design of the battery pack (3). Consequently, the stability of use of the battery cell (1) can be improved. By reducing the resistance of the battery cell (1) in this way through the application of the conductive member (100) of the present invention, rapid charging and / or rapid discharging can be made possible. Furthermore, even in an environment where such rapid charging and / or rapid discharging occurs, the heat generation of the battery cell (1) can be reduced, thereby improving the performance of the battery and enhancing safety in battery usage. The structure and shape of the conductive member (100) will be described in detail below.

[0085] FIG. 3 is an enlarged view showing an upper cross-sectional view of a battery cell (1) and an arrangement of a conductive member (100) according to an embodiment of the present invention. FIG. 4 is an enlarged view showing a lower cross-sectional view of a battery cell (1) and an arrangement of a conductive member (100) according to an embodiment of the present invention.

[0086] According to one embodiment, one end of the conductive member (100) may be connected to a can (20), and the other end may be connected to a current collector (e.g., a second current collector (80)). Referring to FIG. 3, one end of the conductive member (100) may be connected to the bottom portion (22) of the can (20). One end of the conductive member (100) may be in direct contact with the inner surface of the bottom portion (22) of the can (20). At this time, the conductive member (100) must not be in contact with the first electrode terminal (40).

[0087] Referring to FIG. 4, the other end of the conductive member (100) can be directly connected to the second current collector (80). For example, the other end of the conductive member (100) can be in contact with the part where the second current collector (80) and the beading part (23) of the can (20) come into contact.

[0088] The conductive member (100) and the can (20), and the conductive member (100) and the second current collector (80) can be joined by welding (e.g., laser welding). Referring to FIG. 3, the conductive member (100) and the can (20) (e.g., bottom part (22)) can be welded (welded part (W) in FIG. 3). Referring to FIG. 4, the conductive member (100) and the second current collector (80) can be welded (welded part (W) in FIG. 4). Methods such as resistance welding, ultrasonic welding, or laser welding may be used for welding. Meanwhile, the conductive member (100) and the can (20), and the conductive member (100) and the second current collector (80) can be joined by other joining methods other than welding, and the joining methods are not limited thereto.

[0089] According to an embodiment of the present invention, the bottom portion (22) of the can (20) which is the actual part used and the second current collector (80) that collects and supplies current are directly connected to expand the electron connection path and reduce the electron movement speed while simultaneously reducing resistance.

[0090] According to one embodiment, at least a portion of the conductive member (100) may come into contact with the can (20). That is, at least a portion of the conductive member (100) may come into direct contact with the inner surface of the can (20). For example, the conductive member (100) and the inner surface of the can (20) may be positioned to face each other. For example, the conductive member (100) and the can (20) may be joined by an adhesive or by a snap-fit ​​connection.

[0091] According to an embodiment of the present invention, the conductive member (100) is brought into contact with a can (20), which is an electron transport path, thereby increasing the contact area with the can (20) and reducing the resistance of the battery cell (1).

[0092] With reference primarily to FIG. 4, the shape of the conductive member (100) may be substantially the same as the shape of the side wall portion (21) of the can (20) extended in the direction of the winding axis. At least a portion of the conductive member (100) may be extended in the direction of the winding axis along the side wall portion (21), and a portion of the conductive member (100) may be in a form pressed inward along the beading portion (23). That is, the conductive member (100) may be fixed to the can (20), and a portion of it may be compressed along the direction of the winding axis through a sizing process together with the can (20).

[0093] FIG. 5 is an exploded perspective view of a battery cell (1) showing a conductive member (100) according to one embodiment of the present invention.

[0094] The conductive member (100) may have a body portion (101) extended in the direction of the winding axis, a first connecting portion (102) extended from one end of the body portion (101), and a second connecting portion (103) extended from the other end of the body portion (101).

[0095] The conductive member (100) may be thin and long. For example, it may be defined as a member such as a metal wire. The conductive member (100) can be easily bent and its shape can be easily changed during the manufacturing process.

[0096] The first connecting part (102) may be a part connected to the can (20). At least a portion of the first connecting part (102) may be vertically connected to the body part (101). At least a portion of the first connecting part (102) may extend in a horizontal direction. At least a portion of the first connecting part (102) may be in direct contact with the lower surface of the bottom part (22) of the can (20). At least a portion of the first connecting part (102) may be welded to the can (20). However, the first connecting part (102) may be omitted depending on the manufacturing process.

[0097] The second connecting portion (103) may be a part connected to the second current collector (80). At least a portion of the second connecting portion (103) may be in a press-fit form corresponding to the beading portion (23). At least a portion of the second connecting portion (103) may be a part extending in a horizontal direction perpendicular to the body portion (101). At least a portion of the second connecting portion (103) may be in direct contact with the upper surface of the second current collector (80). At least a portion of the second connecting portion (103) may be directly welded to the second current collector (80). However, the second connecting portion (103) may be omitted depending on the manufacturing process.

[0098] The body portion (101) may be located between the can (20) and the electrode assembly (10). The body portion (101) may be in contact with the can (20). The body portion (101) may be fixed in direct contact with the can (20). Referring to FIG. 5, the body portion (101) may be a portion extended in the direction of the winding axis, that is, in the vertical direction. However, the shape of the body portion (101) is not limited by the embodiment and may be modified in various ways.

[0099] When the body part (101) is extended in the direction of the winding axis, the electron movement path is extended while the electron movement distance is minimized, thereby reducing the resistance of the battery cell (1).

[0100] There may be multiple conductive members (100). Multiple conductive members (100) may be arranged at regular intervals. Multiple conductive members (100) may be arranged radially symmetrically. For example, referring to FIG. 5, there may be four conductive members (100). In this case, the conductive members (100) may each be arranged at 90-degree intervals in a direction rotating relative to the radial direction. According to an embodiment of the present invention, by arranging multiple conductive members (100), the electron movement path can be extended and the electron movement speed can be lowered evenly, thereby evenly reducing resistance. However, the number and structure of the conductive members (100) are not limited to the above embodiment and can be designed in various ways.

[0101] FIG. 6 is a schematic perspective view showing a portion of a battery cell (1) including a conductive member (100) according to another embodiment of the present invention. All or part of the conductive members (100) of FIG. 6 may be substantially identical to the conductive members (100) of FIG. 1 to FIG. 5.

[0102] At least some of the plurality of conductive members (100) (specifically, the body portion (101) of the conductive member (100)) may be tilted at a specified angle (e.g., a first angle (θ1)) with respect to the winding axis direction. For example, at least some of the conductive members (100) may be tilted at a first angle (θ1) with respect to the winding axis direction and spaced apart at a constant interval.

[0103] According to one embodiment, the first angle (θ1) may be an acute angle. For example, the first angle (θ1) may be between 0 degrees and 90 degrees. The angles at which the plurality of conductive members (100) are tilted may be constant to each other. However, the range of the angles at which each conductive member (100) is tilted may not be limited by the above embodiment, the first angle (θ1) may be an obtuse angle, and the angles of the plurality of conductive members (100a) may be different from each other.

[0104] According to one embodiment, the conductive member (100) may be arranged within the battery cell (1) together with first conductive members (100a) in which the body portion (101) extends in the direction of the winding axis and second conductive members (100b) in which the body portion (101) is tilted at a first angle (θ1) with respect to the direction of the winding axis. At this time, the first conductive members (100a) and the second conductive members (100b) may be formed integrally.

[0105] According to an embodiment of the present invention, the first conductive members (100a) and the second conductive members (100b) intersect at least once, so the electron movement path can be varied and the electron movement speed can be reduced. Thus, the resistance of the battery cell (1) can be reduced.

[0106] However, although not shown in the drawing, a battery cell (1) consisting only of second conductive members (100b) may also be applied.

[0107] FIG. 7 is a schematic perspective view showing a portion of a battery cell (1) including a conductive member (100) according to another embodiment of the present invention. All or part of the conductive members (100) of FIG. 7 may be substantially the same as the conductive member (100) of FIG. 6.

[0108] Multiple conductive members (100) can form a grid pattern. For example, two types of conductive members (100) extending in different directions may intersect at equal intervals. According to an embodiment of the present invention, as the conductive members (100) intersect multiple times, the electron movement paths become more diverse and the movement paths can be expanded. Accordingly, the resistance of the battery cell (1) can be reduced. In addition, the resistance of the battery cell (1) can be reduced by increasing the total surface area of ​​the conductive members (100) while simplifying the arrangement and fabrication of the conductive members (100).

[0109] Referring to FIG. 7, a plurality of conductive members (100) may include a second conductive member (100b) that is tilted at a first angle (θ1) with respect to the winding axis direction and spaced apart at a constant interval, and a third conductive member (100c) that is tilted at a second angle (θ2) different from the first angle (θ1) with respect to the winding axis direction and spaced apart at a constant interval.

[0110] For example, the first angle (θ1) may be an acute angle and the second angle (θ2) may be an obtuse angle. For example, the first angle (θ1) may be between 0 degrees and 90 degrees. For example, the second angle (θ2) may be between 90 degrees and 180 degrees. However, it is sufficient for the first angle (θ1) and the second angle (θ2) to intersect each other, and they do not necessarily have to intersect perpendicularly.

[0111] According to one embodiment, first conductive members (100a) that are extended vertically in the direction of the winding axis as shown in FIG. 7 may be additionally arranged.

[0112] According to an embodiment of the present invention, the conductive members (100) can be arranged more densely to maximize the total area occupied by the conductive members (100). Additionally, as the conductive members (100) intersect multiple times, the electron movement path becomes more diverse and the electron movement area can be expanded. Accordingly, the resistance of the battery cell (1) can be drastically reduced.

[0113] FIG. 8 is a drawing of a conductive member (100) and a can (20) according to another embodiment of the present invention viewed from an upward direction.

[0114] A groove (26) configured to allow a conductive member (100) to be inserted may be formed in the can (20). The groove (26) may be formed in the side wall (21) of the can (20).

[0115] For example, referring to FIG. 8, the groove (26) formed in the can (20) may be in the form of a recess from the inner side to the outer side. The groove (26) may be composed of multiple grooves and may be arranged at regular intervals. Each of the multiple grooves (26) may be formed to extend in the direction of the winding axis. The size and shape of the groove (26) may be formed substantially identical to the size and shape of the conductive member (100). However, the size, number, arrangement, and shape of the groove (26) are not limited by the above embodiment and may be designed in various ways. The size, number, arrangement, and shape of the groove (26) may be designed in various ways depending on the size, number, arrangement, and shape of the conductive member (100).

[0116] The conductive member (100) can be inserted into the groove (26) of the can (20). The conductive member (100) can be fitted into the groove (26) of the can (20). Alternatively, the conductive member (100) can be bonded to the can (20) by an adhesive. According to one embodiment, after the conductive member (100) is inserted into the groove (26) of the can (20), the electrode assembly (10) can be accommodated inside the can (20). However, the bonding method of the conductive member (100) is not limited by the above embodiment and can be modified in various ways.

[0117] According to an embodiment of the present invention, additional space for a conductive member (100) between the can (20) and the electrode assembly (10) may not be required, and the total resistance may be reduced by adding a conductive member (100) while maintaining the size of the entire battery cell (1) and the size of the electrode assembly (10).

[0118] FIG. 9 is a drawing of a conductive member (100) and a can (20) according to another embodiment of the present invention, viewed from an upward direction.

[0119] A hole (27) configured to allow a conductive member (100) to be inserted may be formed in the can (20). The hole (27) may be formed in the side wall (21) of the can (20). The radial size of the hole (27) may be formed to be smaller than the thickness of the side wall (21) of the can (20).

[0120] For example, referring to FIG. 9, the holes (27) may be composed of a plurality of holes and may be arranged at regular intervals. The plurality of holes (27) may each be formed to extend in the direction of the winding axis. The size and shape of the holes (27) may be formed substantially identical to the size and shape of the conductive member (100). However, the size, number, arrangement, and shape of the holes (27) are not limited by the above embodiment and may be designed in various ways. The size, number, arrangement, and shape of the holes (27) may be designed in various ways depending on the size, number, arrangement, and shape of the conductive member (100).

[0121] A conductive member (100) can be inserted into a hole (27) of a can (20). A conductive member (100) can be fitted into a hole (27) of a can (20). Alternatively, a conductive member (100) can be bonded to the can (20) by an adhesive. According to one embodiment, after the conductive member (100) is inserted into the hole (27) of the can (20), an electrode assembly (10) can be accommodated inside the can (20). However, the bonding method of the conductive member (100) is not limited by the above embodiment and can be modified in various ways.

[0122] According to an embodiment of the present invention, additional space for a conductive member (100) between the can (20) and the electrode assembly (10) may not be required, and the total resistance may be reduced by adding a conductive member (100) while maintaining the size of the entire battery cell (1) and the size of the electrode assembly (10).

[0123] FIG. 10 is a drawing for explaining a battery pack according to an embodiment of the present invention. FIG. 11 is a drawing for explaining a vehicle including the battery pack of FIG. 10.

[0124] Referring to FIG. 10, the battery pack (3) according to the present invention may include at least one battery cell (1) according to the present invention as described above. Additionally, the battery pack (3) according to the present invention may include a pack housing (2) capable of accommodating the at least one battery cell (1). The battery pack (3) may be constructed using a battery module, which is an intermediate form of assembly, or the battery pack (3) may be constructed directly without a battery module as illustrated. Since the battery cell (1) itself has a large volume, there may be no particular difficulty in implementing the battery pack (3) even without using an intermediate structure called a battery module.

[0125] In addition, the battery pack (3) may further include various other components in addition to the battery cell (1), such as a BMS, a pack case, a relay, a current sensor, etc., components of the battery pack (3) known at the time of filing the present invention.

[0126] A battery pack (3) may include a plurality of battery cells (1). The battery cells (1) may be arranged in a predetermined number of rows, and each battery cell (1) may be arranged such that a first electrode terminal (40) having a first polarity and a second electrode terminal (25) having a second polarity are both positioned on the upper side. Therefore, when electrically connecting a plurality of battery cells (1), both positive and negative electrodes can be connected in one direction, thereby simplifying the electrical connection structure. Through this, the number of battery cells (1) that can be mounted in the same space can be increased to improve energy density, and electrical wiring work can be performed easily. Therefore, space efficiency is good and electrical wiring efficiency is high, resulting in significant work improvement effects during the assembly process of an electric vehicle and during the assembly and maintenance of the battery pack (3). Additionally, as previously explained, each battery cell (1) may have a higher energy density than conventional ones. A battery pack (3) with such increased energy density can store the same amount of energy while reducing its volume and load.

[0127] Therefore, if a battery pack (3) with such battery cells (1) is installed in a vehicle such as a car (V) that uses electricity as an energy source as shown in FIG. 11, the vehicle's mileage relative to energy can be further increased.

[0128] In addition, since electrical wiring is performed on the bottom of the battery housing (200) and on the side where the electrode terminal (210) is located, and electrical wiring may not be placed on the cap (300) located on the opposite side, the effect of the vent can be maximized if a vent portion is configured in the cap (300) so that it can be vented toward the cap (300). Also, if a heat sink, cooling plate, or tray is placed on the side of the cap (300), the purpose of assembly and cooling can be effectively achieved regardless of the electrical wiring connection area. Furthermore, by assembling the vent portion so that it is positioned downward, the gas discharged from inside the secondary battery is discharged downward. Since secondary batteries are usually mounted at a position lower than the occupants of a vehicle such as an EV, if gas is discharged upward from the secondary battery, it can cause harm to the occupants. The battery cell (1) of the present invention is not only capable of effectively discharging high-pressure gas inside the secondary battery, but is also safe as it is independent of the upper electrical wiring connection part, and furthermore, since the gas is discharged downward when the vent part breaks and does not cause harm to the occupant, the safety is greatly improved.

[0129] Referring to FIG. 11, the automobile (V) according to the present invention may include at least one battery pack (3) according to the present invention.

[0130] The battery cell (1) according to the present invention can be applied to a vehicle such as an electric vehicle or a hybrid vehicle. That is, the vehicle (V) according to the present invention may include the battery cell (1) according to the present invention or the battery pack (3) according to the present invention. In addition, the vehicle (V) according to the present invention may further include various other components included in the vehicle in addition to the battery cell (1) or the battery pack (3). For example, the vehicle (V) according to the present invention may further include a vehicle body, a motor, a control device such as an ECU (electronic control unit), in addition to the battery cell (1) according to the present invention. The vehicle (V) includes four-wheeled vehicles and two-wheeled vehicles. The vehicle (V) may operate by receiving power from the battery pack (3) according to one embodiment of the present invention.

[0131] Although the present invention has been described above 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.

Claims

1. An electrode assembly comprising a first electrode and a second electrode and a separator interposed between them, wound along a winding axis; A can configured to accommodate the electrode assembly through an open end formed on one side; A current collector configured to be electrically connected to the above can; and A battery cell comprising a conductive member, at least a portion thereof disposed between the electrode assembly and the can and in contact with the can, and configured to have higher conductivity than the can.

2. In Paragraph 1, A battery cell characterized in that one end of the conductive member is connected to the can, and the other end of the conductive member is connected to the current collector.

3. In Paragraph 1, The above can includes a bottom portion and a side wall portion connected to the bottom portion and extending in the direction of the winding axis, and A battery cell characterized in that the conductive member is connected to the bottom portion.

4. In Paragraph 1, A battery cell characterized by the above conductive member being a plurality of individuals.

5. In Paragraph 1, A battery cell characterized in that the conductive member comprises a body portion extended in the direction of the winding axis, a first connecting portion extended from one end of the body portion, and a second connecting portion extended from the other end of the body portion.

6. In Paragraph 5, A battery cell characterized in that at least a portion of the body portion of the conductive member is inclined at a specified angle with respect to the winding axis direction.

7. In Paragraph 1, A battery cell characterized in that the plurality of conductive members form a grid pattern.

8. In Paragraph 7, A battery cell characterized by comprising a plurality of conductive members, wherein the conductive members are inclined at a first angle with respect to the winding axis direction and spaced apart at a constant interval, and conductive members are inclined at a second angle different from the first angle with respect to the winding axis direction and spaced apart at a constant interval.

9. In Paragraph 1, A battery cell characterized in that the conductive member and the can, and the conductive member and the current collector are joined by welding.

10. In Paragraph 1, A battery cell characterized in that the conductive member comprises at least one of copper (Cu) and nickel (Ni).

11. In Paragraph 1, A battery cell characterized by having a groove formed in the can configured to insert the conductive member.

12. A battery pack characterized by comprising at least one battery cell described in any one of claims 1 to 11.

13. An automobile characterized by comprising at least one battery cell described in any one of claims 1 to 11.

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