Battery cell, and battery pack and vehicle including battery cell

Abstract

A battery cell of the present invention comprises: an electrode assembly in which a first electrode, a second electrode and a separator interposed therebetween are wound about a winding axis, each of the first electrode and the second electrode including a first uncoated part and a second uncoated part, which are not coated with an active material layer; a can for accommodating the electrode assembly; and an electrode terminal, which covers a through-hole formed in the can and is electrically connected to the first uncoated part, wherein the first uncoated part and the second uncoated part can be arranged to face the same direction with respect to a winding axis direction.

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. 10-2025-0016833 filed on February 10, 2025, 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 driving 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 battery module or pack can be varied 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] In this case, if the electrode terminals having a first polarity and a second polarity are positioned in different directions relative to the winding axis, the electron travel distance increases, and the resistance within the battery cell may increase. Specifically, 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, 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.

[0009] Therefore, there is a need to develop a battery cell structure that can reduce the resistance of the battery cell by shortening the electron travel distance.

[0010]

[0011] The present invention was conceived against the background of the prior art described above, and aims to provide a battery cell capable of reducing the resistance of the battery cell by shortening the travel distance of electrons.

[0012] 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.

[0013] 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.

[0014]

[0015] To solve the above problem, the battery cell of the present invention comprises an electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound with respect to a winding axis, wherein the first electrode and the second electrode each comprise an electrode assembly including a first uncoated portion and a second uncoated portion in which an active material layer is not coated, a can configured to accommodate the electrode assembly, and an electrode terminal that covers a through hole formed in the can and is electrically connected to the first uncoated portion, and wherein the first uncoated portion and the second uncoated portion may be arranged to face in the same direction with respect to the winding axis direction.

[0016] The above can may be directly coupled to the above second non-removable part and electrically connected.

[0017] The first electrode and the second electrode are wound and divided into a core portion positioned inwardly with respect to the radial direction and an outer portion positioned outwardly with respect to the radial direction, and the first unwound portion may protrude in the direction of the winding axis from the core portion of the first electrode, and the second unwound portion may protrude in the direction of the winding axis from the outer portion of the second electrode.

[0018] The above core portion and the above outer portion may be configured to be spaced apart by a first distance.

[0019] The above-mentioned second non-removable portion may be configured to be bent outward in the radial direction.

[0020] It may further include a current collector positioned between the electrode assembly and the electrode terminal and configured to electrically connect the first non-electrical portion and the electrode terminal.

[0021] The diameter of the above-mentioned collector may correspond to the winding diameter of the above-mentioned first unwound portion.

[0022] The above-mentioned first non-removable portion may be directly coupled to the electrode terminal.

[0023] The height of the second non-removable portion may become shorter as it extends outward in the radial direction.

[0024] The first electrode may be an anode and the second electrode may be a cathode.

[0025] In addition, the present invention provides a battery pack characterized by including a battery according to the present invention.

[0026] And, the present invention provides an automobile characterized by including a battery pack according to the present invention.

[0027]

[0028] According to one embodiment of the present invention, the shape of the first electrode and the second electrode can be changed, and the position of the first non-restricted portion and the second non-restricted portion can be changed to shorten the travel distance of electrons. By doing so, a battery cell with reduced resistance can be provided. As a result, the performance and lifespan of the battery can be improved.

[0029] 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.

[0030]

[0031] 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.

[0032] FIG. 1 is a perspective view showing the appearance of a battery cell according to one embodiment of the present invention.

[0033] Figure 2 is a cross-sectional perspective view of the battery cell of Figure 1 cut along II-II'.

[0034] Fig. 3 is a cross-sectional view of the battery cell of Fig. 1 cut along II-II'.

[0035] FIG. 4 is a drawing showing the unfolded state of an electrode assembly of a battery cell according to one embodiment of the present invention before being wound.

[0036] Figure 5 is an exploded perspective view of the electrode assembly of Figure 4.

[0037] FIG. 6 is a schematic perspective view showing the electrode assembly of a battery cell according to one embodiment of the present invention wound.

[0038] Figure 7 is an enlarged view of part A of Figure 3.

[0039] Figure 8 is an enlarged view of part B of Figure 3.

[0040] FIG. 9 is an enlarged cross-sectional view showing a part of a battery cell according to another embodiment of the present invention.

[0041] FIG. 10 is an exploded view of an electrode assembly of a battery cell according to another embodiment of the present invention.

[0042] FIG. 11 is a drawing for explaining a battery pack according to one embodiment of the present invention.

[0043] FIG. 12 is a drawing for explaining a vehicle including the battery pack of FIG. 11.

[0044]

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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 a sheet shape and a separator interposed between them are wound in one direction.

[0057] 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.

[0058] FIG. 1 is a perspective view showing the external appearance of a battery cell according to one embodiment of the present invention. FIG. 2 is a cross-sectional perspective view of the battery cell of FIG. 1 taken along II-II'. FIG. 3 is a cross-sectional view of the battery cell of FIG. 1 taken along II-II'.

[0059] Referring to FIGS. 1 to 3, the battery cell (1) may include an electrode assembly (10), a can (20), and an electrode terminal (30). In addition to the components described above, the battery cell (1) may additionally include at least one of a current collector (40), an insulating gasket (50), a lead (60), and an insulator (70).

[0060] 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.

[0061] The electrode assembly (10) may be a laminate comprising a first electrode (11) and a second electrode (12) and a separator (13 in FIG. 5) interposed between them, which may be wound along a winding axis. For example, the first electrode (11) may be an anode and the second electrode (12) may be a cathode. More specifically, the electrode assembly (10) may be in the form of a jelly-roll wound along a winding axis with the first electrode (11) and the second electrode (12) interposed between them and a separator (13). Here, the first electrode (11) and the second electrode (12) may be formed in a sheet shape. An additional separator (13) 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.

[0062] The first electrode (11) and the second electrode (12) may each include a first uncoated portion (111) and a second uncoated portion (121) on which the active material layer is not coated.

[0063] The first electrode (11) may be an anode plate and the second electrode (12) 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 (111) may be formed at the end of the anode plate where no anode active material is coated. The first uncoated portion (111) may be exposed to the outside of the separator (13) 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 (121) may be formed at the end of the cathode plate where no anode active material is coated. The second uncoated portion (121) may be exposed to the outside of the separator (13) 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. 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.

[0064] At this time, the first unwound section (111) and the second unwound section (121) may be arranged to face in the same direction relative to the winding axis direction. For example, the first unwound section (111) and the second unwound section (121) may be arranged to face upward relative to the winding axis.

[0065] According to an embodiment of the present invention, the travel distance of electrons can be shortened by positioning the first non-removable portion (111) and the second non-removable portion (121) in the same direction. Therefore, the resistance of the cell can be effectively reduced. As a result, the performance and lifespan of the battery can be improved.

[0066] A can (20) may be configured to accommodate an electrode assembly (10). A can (20) may be configured to accommodate an electrode assembly (10) through an open end formed on one side. A can (20) may include 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).

[0067] 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 (60) may be covered over the open end.

[0068] 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.

[0069] The electrode terminal (30) can cover a through hole formed in the can (20). The electrode terminal (30) can be coupled with the bottom portion (22). At this time, the bottom portion (22) can form a closed surface of the can (20). That is, a through hole is formed in the bottom portion (22), and the electrode terminal (30) can pass through the through hole. The electrode terminal (30) may be fitted into the bottom portion (22).

[0070] The electrode terminal (30) can be electrically connected to the first non-removable portion (111). The electrode terminal (30) can be electrically connected to the first electrode (11) of the electrode assembly (10) by passing through the through hole. The electrode terminal (30) can be electrically connected to the electrode assembly (10).

[0071] The electrode terminal (30) may include metal. The electrode terminal (30) may include aluminum. During the process of riveting the electrode terminal (30) to the can (20), the electrode terminal (30) may be fixed on the inside and / or outside of the can (20).

[0072] For example, the electrode terminal (30) can be riveted and fixed to the bottom portion (22) with an insulating gasket (50) interposed therebetween. The insulating gasket (50) is interposed between the electrode terminal (30) 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 electrode terminal (30) and the bottom portion (22). The insulating gasket (50) can be in close contact between the electrode terminal (30) and the can (20). A part of the electrode terminal (30) may be inserted inside the can (20), and another part may be exposed outside the can (20).

[0073] A current collector (40) may be positioned between the electrode assembly (10) and the electrode terminal (30). The current collector (40) may be configured to electrically connect the first non-circular portion (111) and the electrode terminal (30). The current collector (40) may be a positive current collector. The current collector (40) may have a tab coupling portion coupled to the first non-circular portion (111) and a terminal coupling portion coupled to the electrode terminal (30). The terminal coupling portion may be positioned at a location corresponding to a winding center hole formed at the winding center of the electrode assembly (10). The tab coupling portion and the terminal coupling portion may be positioned so as to be spaced apart from each other without being directly connected. Thus, when an impact and / or vibration occurs in the battery cell (1), the impact applied to the tab coupling portion and the terminal coupling portion can be dispersed. For example, the tab coupling portion and the terminal coupling portion may be configured so as to be spaced apart from each other along the radial direction without being connected.

[0074] FIG. 4 is a drawing showing the unfolded state of an electrode assembly of a battery cell according to one embodiment of the present invention before being wound. FIG. 5 is an exploded perspective view of the electrode assembly of FIG. 4. FIG. 6 is a perspective view schematically showing the wound appearance of an electrode assembly of a battery cell according to one embodiment of the present invention.

[0075] The first electrode (11) and the second electrode (12) can be wound and divided into a core portion (C) positioned on the inner side based on the radial direction and an outer portion (E) positioned on the outer side based on the radial direction.

[0076] At this time, referring to FIG. 4, the first electrode (11) and the second electrode (12) may include a core portion (C) positioned on the core side and an outer portion (E) positioned relatively on the outer side when wound. The core portion (C) may be located radially inward compared to the outer portion (E).

[0077] Referring to FIG. 4, when the first electrode (11) and the second electrode (12) are unfolded before being wound, the core portion (C) may be positioned on the left and the outer portion (E) may be positioned on the right. However, the positions of the core portion (C) and the outer portion (E) are for convenience of explanation only and are not limited to the left or right.

[0078] The first unwound section (111) and the second unwound section (121) may be arranged to face the same direction, the upward direction, with respect to the winding axis direction. However, the first unwound section (111) and the second unwound section (121) may be arranged in different directions with respect to the length direction so as not to overlap.

[0079] The first unwound portion (111) may protrude in the direction of the winding axis from the core portion (C) of the first electrode (11), and the second unwound portion (121) may protrude in the direction of the winding axis from the outer portion (E) of the second electrode (12).

[0080] That is, the core portion (C) of the first electrode (11) is formed to protrude upward in the direction of the winding axis more than the outer portion (E), and the first bare portion (111) may be formed on the protruding core portion (C). At this time, the core portion (C) of the first electrode (11) is provided with the first bare portion (111) by protruding upward in the direction of the winding axis, and the outer portion (E) of the first electrode (11) may be in a recessed shape downward in the direction of the winding axis.

[0081] Additionally, the outer portion (E) of the second electrode (12) is formed to protrude upward in the direction of the winding axis more than the core portion (C), and the protruding outer portion (E) may form a second bare portion (121). At this time, the core portion (C) of the first electrode (11) protrudes upward in the direction of the winding axis to form a first bare portion (111), and the outer portion (E) of the first electrode (11) may be in a recessed shape downward in the direction of the winding axis.

[0082] At this time, in the core portion (C), the second electrode (12) is in a recessed form, and the first unoccupied portion (111) of the first electrode (11) is in a form that protrudes upward in the direction of the winding axis, so the first unoccupied portion (111) can be configured so as not to overlap with the second electrode (12). Also, in the outer portion (E), the first electrode (11) is in a recessed form, and the second unoccupied portion (121) is in a form that protrudes upward in the direction of the winding axis, so the second unoccupied portion (121) can be configured so as not to overlap with the first electrode (11).

[0083] Consequently, when the electrode assembly (10) is wound, the first bare portion (111) may be positioned only on the inner side with respect to the radial direction, and the second bare portion (121) may be positioned only on the outer side with respect to the radial direction. Additionally, the first bare portion (111) and the second bare portion (121) may not overlap.

[0084] The recessed shape of the first electrode (11) and the second electrode (12) can be created, for example, by partially cutting and removing the unwound portion (111, 112) formed along the winding direction at one end of the first electrode (11) and the second electrode (12).

[0085] According to an embodiment of the present invention, the first non-removable portion (111) and the second non-removable portion (121) may be located in the same direction but may not overlap each other, thereby preventing the risk of a short circuit occurring between the first electrode (11) and the second electrode (12).

[0086] Referring to FIG. 4, the core portion (C) and the outer portion (E) may be configured to be spaced apart by a first distance (l). A gap of the first distance (l) may be required between the core portion (C) and the outer portion (E). The core portion (C) and the outer portion (E) are spaced apart, and the central portion formed between the core portion (C) and the outer portion (E) may mean a portion without a blank area.

[0087] For example, the first distance (l) may be approximately 7 mm or more and 11 mm or less. For example, the first distance (l) may be approximately 9 mm.

[0088] If the first unstable portion (111) and the second unstable portion (121) are located in the same direction with respect to the winding axis direction, there is a high possibility that a short circuit may occur. Therefore, as in the exemplary embodiment of the present invention, a separation distance of the first distance (l) is provided to prevent the risk of a short circuit occurring between the first electrode (11) and the second electrode (12).

[0089]

[0090] Figure 7 is an enlarged view of part A of Figure 3.

[0091] The can (20) can be directly coupled to the second non-reinforced portion (121) and electrically connected. The second non-reinforced portion (121) can be directly joined to the can (20). For example, methods such as resistance welding, ultrasonic welding, or laser welding may be used for joining. For example, ultrasonic welding may be mainly used for joining.

[0092] According to the present invention, a current collector for electrical connection between the electrode assembly (10) and the can (20) may not be provided. That is, the current collector configuration for electrical connection between the electrode assembly (10) and the can (20) is omitted, and the second electrode (12) may be directly connected to the can.

[0093] According to an embodiment of the present invention, the length or volume of the electrode assembly (10) can be increased by the amount by which the current collector for electrical connection between the electrode assembly (10) and the can (20) is omitted, thereby improving the energy density of the battery cell. In addition, the overall weight of the battery cell is reduced, which can be useful for making the battery cell lighter. Furthermore, since the current collector is often made of expensive materials, omitting it can reduce costs.

[0094] The second bare section (121) may be configured to be folded outward in a radial direction. The second bare section (121) may be folded and overlapped. The folded second bare section may overlap to form a substantially flat folded surface. The folded second bare section (121) may be joined together. Additionally, the folded second bare section (121) may be directly joined to the side wall (21) of the can (20).

[0095] The second unbonded portion (121) can be directly attached to the side wall portion (21) of the can (20). Specifically, the second unbonded portion (121) can be attached to the upper side of the side wall portion (21) of the can (20). The second unbonded portion (121) can be positioned to face upward in the same way as the first unbonded portion (111).

[0096] According to an embodiment of the present invention, the second non-removable portion (121) can be folded outward in the radial direction to come into direct contact with the can (20). Additionally, the folded second non-removable portions (121) can be joined together so that the second non-removable portion (121) located relatively inward in the radial direction is also directly connected to the can (20). Furthermore, the second non-removable portion (121) can be folded so as not to come into contact with the collector (40) located above the second non-removable portion (121). That is, the second non-removable portion (121) can be spaced apart from the collector (40) in the vertical direction.

[0097]

[0098] Figure 8 is an enlarged view of part B of Figure 3.

[0099] The first non-removable part (111) can come into direct contact with the entire house (40).

[0100] The first non-removable portion (111) may be bent inward in the radial direction. Alternatively, the first non-removable portion (111) may be provided so as to face upward without being bent. Thus, the first non-removable portion (111) can be reliably separated from the second non-removable portion (121) without contact. Additionally, the risk of a short circuit occurring between the first electrode (11) and the second electrode (12) can be prevented. However, the shape of the first non-removable portion (111) is not limited by the above embodiment and can be modified in various ways as long as a short circuit does not occur with the second non-removable portion (121).

[0101] The diameter (R2) of the current collector (40) may correspond to the winding diameter (R1) of the first unwound portion (111). Here, the winding diameter of the first unwound portion (111) can be defined as the diameter of the circular structure of the first unwound portion (111) formed by winding the first electrode (11).

[0102] The diameter (R2) of the current collector (40) may not be as large as the total diameter of the electrode assembly (10), but may be arranged to cover only the winding diameter (R1) of the first unwound portion (111). That is, as the winding diameter (R1) of the first unwound portion (111) is reduced, the diameter (R2) of the current collector (40) may also be reduced to a corresponding size. Therefore, the diameter of the current collector (40) may be smaller than in the past.

[0103] The current collector (40) may face the first non-retaining portion (111) in an up-and-down direction. However, the current collector (40) may not face the second non-retaining portion (121) in an up-and-down direction. For example, the current collector (40) may correspond to the core portion (C) of the electrode in an up-and-down direction, but may not correspond to the outer portion (E) of the electrode in an up-and-down direction.

[0104] According to the embodiment of the present invention, the size of the current collector (40) can be reduced compared to conventional methods, thereby reducing the overall weight of the battery cell and making it useful for lightweighting the battery cell. Additionally, cost reduction may be possible. Furthermore, by configuring the current collector (40) so that it does not face the second non-conforming part (121) in the vertical direction, the risk of a short circuit occurring between the first electrode (11) and the second electrode (12) can be prevented.

[0105]

[0106] FIG. 9 is an enlarged cross-sectional view showing a part of a battery cell according to another embodiment of the present invention.

[0107] According to one embodiment, the first non-removable portion (111) can be directly connected to the electrode terminal (30). Therefore, the current collector (40) can be omitted.

[0108] At this time, the electrode terminal may have a column portion penetrating a through hole, a terminal portion extending radially outward from the upper side of the column portion, and a joint portion extending radially outward from the lower end of the column portion. The joint portion may be a part to which the first uninsulated portion (111) is directly joined. For example, methods such as resistance welding, ultrasonic welding, or laser welding may be used for joining. For example, ultrasonic welding may be mainly used for joining.

[0109] According to an embodiment of the present invention, the length or volume of the electrode assembly (10) can be increased by the amount by which the current collector (40) is omitted, thereby improving the energy density of the battery cell (1). In addition, the total weight of the battery cell (1) is reduced, which can be useful for making the battery cell (1) lighter. Furthermore, since the current collector (40) is often made of expensive materials, omitting it can reduce costs. According to an embodiment of the present invention, not only the current collector for electrical connection between the electrode assembly (10) and the can (20) but also the current collector (40) for electrical connection between the electrode assembly (10) and the terminal (30) can be omitted, thereby improving energy efficiency more effectively.

[0110] Meanwhile, a battery cell (1) according to one embodiment of the present invention may include an insulator (70) interposed between the bottom portion (22) of the can (20) (see FIGS. 1 to 3) and the current collector (40) and / or between the bottom portion (22) of the can (20) and the first unoccupied portion (111) to prevent the first unoccupied portion (111) and / or the current collector (40) from coming into contact with the can (20). Although not shown in the drawings, the insulator (70) may have an extended shape to be inserted into a space formed between the core portion (C) and the outer portion (E) to prevent contact between the first unoccupied portion (111) and the second unoccupied portion (121) (see FIG. 4 together with FIGS. 8 and 9).

[0111]

[0112] FIG. 10 is an unfolded view of an electrode assembly (10) of a battery cell according to another embodiment of the present invention.

[0113] The height of the second thumb section (121) may not be constant. The height of the second thumb section (121) may become shorter as it extends outward in the radial direction.

[0114] The height of the innermost part of the second non-removable section (121) in the radial direction may be the first height (h1), and the height of the outermost part of the non-removable section in the radial direction may be the second height (h2). In this case, the second height (h2) may be shorter than the first height (h1).

[0115] The second unwound section (121) is bent outward in the radial direction and joined to the can (20). The unwound section located at the outermost side is easy to reach the inner surface of the can (20), but the unwound section located at the innermost side may be difficult to reach the inner surface of the can (20). If the height of the unwound section located at the innermost side in the radial direction among the second unwound sections (121) is formed to be relatively long, the number of unwound sections that can be directly joined to the can (20) can be increased, thereby increasing the efficiency of current transmission. Accordingly, the performance and charging and discharging efficiency of the battery cell (1) can be improved.

[0116] Meanwhile, in all embodiments of the present invention, the first unworn portion (111) and / or the second unworn portion (121) may include a plurality of segmented portions formed by dividing along the winding direction. When segmented portions are formed through such division, the folding of the unworn portions (111, 121) can be facilitated.

[0117]

[0118] FIG. 11 is a drawing for explaining a battery pack according to an embodiment of the present invention. FIG. 12 is a drawing for explaining a vehicle including the battery pack of FIG. 11.

[0119] Referring to FIG. 11, 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.

[0120] 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.

[0121] 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 a can (20) configured to perform the role of a first electrode terminal (30) having a first polarity and a second electrode terminal having a second polarity in each battery cell (1) may be arranged so that both are placed on the upper side. Accordingly, 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.

[0122] 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. 12, the vehicle's mileage relative to energy can be further increased.

[0123] In addition, since electrical wiring is performed on the side where the bottom of the can (20) and the electrode terminal (30) are located, and electrical wiring may not be placed on the lead (60) located on the opposite side, the effect of the vent can be maximized when the vent portion is provided on the lead (60) in the lower direction of the can (20). Also, if a heat sink, cooling plate, or tray is placed on the lead (60), the purpose of assembly and cooling can be effectively achieved regardless of the electrical wiring connection point. 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 vehicles such as EVs, 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.

[0124] Referring to FIG. 12, the automobile (V) according to the present invention may include at least one battery pack (3) according to the present invention.

[0125] 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.

[0126] 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 in which a first electrode and a second electrode and a separator interposed between them are wound with respect to a winding axis, wherein the first electrode and the second electrode each comprise a first uncoated portion and a second uncoated portion in which an active material layer is not coated; A can configured to accommodate the above electrode assembly; and It includes an electrode terminal that covers a through hole formed in the can and is electrically connected to the first non-removable portion; A battery cell in which the first and second unoccupied portions are arranged to face in the same direction relative to the winding axis direction.

2. In Paragraph 1, A battery cell characterized in that the above-mentioned can is directly coupled to the above-mentioned second non-reinforced portion and electrically connected.

3. In Paragraph 1, The first electrode and the second electrode are wound and divided into a core portion positioned inwardly with respect to the radial direction and an outer portion positioned outwardly with respect to the radial direction, and The above-mentioned first non-removable portion protrudes in the direction of the winding axis from the core portion of the first electrode, and A battery cell characterized by the above-mentioned second non-removable portion protruding in the direction of the winding axis from the outer portion of the above-mentioned second electrode.

4. In Paragraph 3, A battery cell characterized by the above-mentioned core portion and the above-mentioned outer portion being configured to be spaced apart by a first distance.

5. In Paragraph 1, A battery cell characterized by the above-mentioned second non-removable portion being configured to be bent outward in the radial direction.

6. In Paragraph 1, A battery cell further comprising: a current collector positioned between the electrode assembly and the electrode terminal and configured to electrically connect the first non-electrical portion and the electrode terminal.

7. In Paragraph 6, A battery cell characterized in that the diameter of the above-mentioned current collector corresponds to the winding diameter of the above-mentioned first unwound portion.

8. In Paragraph 1, A battery cell characterized in that the first non-removable portion is directly coupled to the electrode terminal.

9. In Paragraph 1, A battery cell characterized in that the height of the second non-removable portion becomes shorter as it extends outward in the radial direction.

10. In Paragraph 1, A battery cell characterized in that the first electrode is a positive electrode and the second electrode is a negative electrode.

11. A battery pack characterized by comprising at least one battery cell described in any one of claims 1 to 10.

12. An automobile characterized by comprising at least one battery cell described in any one of claims 1 to 10.

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