Electrode assembly, battery cell, and battery pack and vehicle comprising same

Abstract

The present invention provides an electrode assembly, a battery cell, and a battery pack and a vehicle comprising same, the electrode assembly having a first electrode, a second electrode, and a separator interposed therebetween which are wound about a winding axis to define the core and outer circumferential surface thereof, wherein the first electrode comprises first uncoated portions on the long-side ends along the length direction of the first electrode, where no active material layer is applied, and a first coated portion which is a region, other than the first uncoated portions, where an active material layer is applied, and the second electrode has a section forming the outer circumferential surface of the electrode assembly and comprises: a second uncoated portion, which is a region including at least a part of the section, where no active material layer is applied; and a second coated portion which is a region, other than the second uncoated portion, where an active material layer is applied.

Description

Electrode assembly, battery cell, battery pack including the same, and automobile

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

[0002] This application is a priority claim application for Korean Patent Application No. 10-2024-0178733 filed on December 4, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

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

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

[0005] Meanwhile, the structure of battery cells is continuously being improved to increase energy density and enhance output characteristics. However, various issues have been pointed out regarding conventional battery cell structures. In particular, as the internal resistance of the battery cell becomes relatively high, the output characteristics of the battery cell deteriorate, leading to cases where required performance cannot be fully satisfied. Furthermore, in the case of battery cells, internal resistance can have a greater impact due to the high current generated instantaneously during discharge. This not only reduces energy efficiency but also negatively affects the stability of the battery cell, which can act as a critical disadvantage, especially in applications such as electric vehicles.

[0006] Therefore, research is needed on new battery cell structures that can effectively reduce the internal resistance of the battery cell and improve output characteristics.

[0007] Accordingly, the technical problem to be solved by the present invention is to provide an electrode assembly, a battery cell, a battery pack including the same, and an automobile for improving battery cell performance.

[0008] In addition, the invention provides an electrode assembly, a battery cell, a battery pack including the same, and a vehicle capable of reducing the internal resistance of a battery cell.

[0009] In addition, the invention provides an electrode assembly, a battery cell, a battery pack including the same, and a vehicle capable of improving the output of a battery cell.

[0010] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below.

[0011] To solve the above objective, the present invention provides an electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis to define a core and an outer surface, wherein the first electrode comprises a first uncoated portion in which an active material layer is not applied along the longitudinal direction of the first electrode at each of the two long side ends, and a first retaining portion in which an active material layer is applied in an area excluding the first uncoated portion, and the second electrode comprises a second uncoated portion in which an active material layer is not applied in an area including at least a portion of the outer surface, and a second retaining portion in which an active material layer is applied in an area excluding the second uncoated portion, thereby constituting the outer surface of the electrode assembly.

[0012] For example, the first non-removable portion may be formed at both ends in the direction of the winding axis of the electrode assembly.

[0013] For example, the first non-reinforced portion may be bent along the radial direction of the electrode assembly to form a bent surface at both ends in the direction of the winding axis of the electrode assembly.

[0014] For example, the second non-removable portion may include at least one of a first portion provided at one end in the longitudinal direction of the second electrode and a second portion provided at the other end in the longitudinal direction of the second electrode.

[0015] For example, the first portion may be provided with a length that is smaller than or equal to the outer circumference length of the electrode assembly in the longitudinal direction of the second electrode.

[0016] For example, the second electrode may be provided with a longer length than the first electrode in the longitudinal direction of the second electrode.

[0017] For example, the first non-reinforced portion may be bent along the radial direction of the electrode assembly to form a bent surface at both ends in the direction of the winding axis of the electrode assembly.

[0018] For example, the second non-removable portion may include at least one of a first portion provided at one end in the longitudinal direction of the second electrode and a second portion provided at the other end in the longitudinal direction of the second electrode.

[0019] For example, the first part or the second part may be provided with a length that is smaller than or equal to the outer circumference length of the electrode assembly in the longitudinal direction of the second electrode.

[0020] For example, the second electrode may be provided with a longer length than the first electrode in the longitudinal direction of the second electrode.

[0021] For example, the active material layer may not be applied to at least a portion of the section longer than the first electrode in the longitudinal direction of the second electrode.

[0022] For example, the separator may be provided with a length longer than the first electrode and shorter than the second electrode in the longitudinal direction of the separator.

[0023] For example, the first electrode may be provided with a width greater than the width of the second electrode in the direction of the winding axis of the electrode assembly.

[0024] For example, the first electrode may be arranged to have two ends of a length extended from each end of the second electrode in the direction of the winding axis of the electrode assembly.

[0025] In addition, the present invention may include, as a battery cell, a battery can comprising the aforementioned electrode assembly, a bottom member, and a side wall member extending from the bottom member in the direction of the winding axis of the electrode assembly, the battery can accommodating the electrode assembly through an opening facing the bottom member and configured such that its outer surface contacts the side wall member and is electrically connected to the second electrode, a first electrode terminal electrically connected to the electrode assembly through a through hole formed in the bottom member of the battery can, and a cap covering the opening of the battery can.

[0026] For example, the first electrode can be electrically connected to the first electrode terminal and the cap.

[0027] For example, the battery cell further includes a second electrode terminal riveted through a through hole formed in the cap, and the first electrode can be electrically connected to the first electrode terminal and the second electrode terminal.

[0028] In addition, the present invention provides a battery pack comprising at least one of the battery cells described above.

[0029] In addition, the present invention provides an automobile comprising at least one of the above-described battery packs.

[0030] The electrode assembly, battery cell, battery pack including the same, and automobile according to various embodiments of the present invention have the effect of improving the performance of the battery cell.

[0031] In addition, the electrode assembly, battery cell, battery pack including the same, and automobile according to various embodiments have the effect of improving the output of the battery cell.

[0032] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0033] FIG. 1 is a schematic diagram showing a jelly-roll type electrode assembly according to one embodiment of the present invention.

[0034] FIG. 2 is a schematic diagram showing the first electrode of the electrode assembly according to FIG. 1.

[0035] FIG. 3 is a drawing showing another embodiment of the first electrode according to FIG. 1.

[0036] FIG. 4 is a schematic diagram showing the second electrode of the electrode assembly according to FIG. 1.

[0037] FIGS. 5 and FIGS. 6 are drawings for explaining the arrangement of each component of the electrode assembly according to FIG. 1.

[0038] FIG. 7 is a schematic diagram showing a battery cell according to one embodiment of the present invention.

[0039] FIG. 8 is a cross-sectional view schematically showing a battery cell according to FIG. 7.

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

[0041] FIG. 10 is a schematic diagram showing a battery pack including a battery cell according to one embodiment of the present invention.

[0042] FIG. 11 is a schematic diagram showing a car including the battery pack of FIG. 10.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back may be used in this specification, these terms are used merely for convenience of explanation and may vary depending on the position or arrangement, rotation, or position of the observer, as is obvious to those skilled in the art of this invention.

[0053] The present invention may be implemented in the following embodiments, each independently. Furthermore, the present invention may be implemented in combination of two or more of the following embodiments. Each of the following embodiments may not only be implemented independently but may also be freely combined with one another.

[0054] For convenience of explanation, in this specification, the direction following the length direction of the winding axis of the electrode assembly wound in a jelly roll shape is referred to as the winding axis direction (Z). The direction in which the electrode assembly is wound along the winding axis is referred to as the winding direction (X). Furthermore, the direction moving away from or closer to the winding axis of the electrode assembly is referred to as the radial direction.

[0055]

[0056] FIG. 1 is a schematic diagram showing a jelly-roll type electrode assembly (20) according to one embodiment of the present invention, FIG. 2 is a schematic diagram showing a first electrode (21) of the electrode assembly (20) according to FIG. 1, FIG. 3 is a diagram showing another embodiment of the first electrode (21) according to FIG. 1, and FIG. 4 is a schematic diagram showing a second electrode (22) of the electrode assembly (20) according to FIG. 1.

[0057] Referring to FIGS. 1 to 4, an electrode assembly (20) according to one embodiment of the present invention includes a first electrode (21) and a second electrode (22), and may be in the form of a jelly-roll when wound around a winding axis. Here, the electrode assembly (20) may define a core and an outer surface around a winding axis.

[0058] When viewed from the top or bottom in the XY plane of the electrode assembly (20), the outer shape of the electrode assembly (20) along the circumferential direction may be circular. However, the structure of the electrode assembly (20) is not limited by the embodiment and may have a wound structure well known in the art.

[0059] The first electrode (21) and the second electrode (22) can each be formed to have a predetermined width along the winding axis direction (Z) and to extend a predetermined length along the winding direction (X). For example, the first electrode (21) and the second electrode (22) can be made of a sheet-shaped metal foil.

[0060] The first electrode (21) may include a first uncoated portion (212), which is an area where the active material layer (2111) is not coated, and a first retaining portion (211), which is an area where the active material layer (2111) is coated.

[0061] The first non-retaining portion (212) may be provided extending along the length direction of the first electrode (21) at each of the long side ends of the first electrode (21), and the first retaining portion (211) may be provided in an area excluding the first non-retaining portion (212).

[0062] The second electrode (22) may include a second uncoated portion (222), which is an area where the active material layer (2211) is not coated, and a second retaining portion (221), which is an area where the active material layer (2211) is coated.

[0063] The second non-retaining portion (222) may be provided in a predetermined area of ​​at least one short end of the second electrode (22), and the second retaining portion (221) may be provided in an area excluding the second non-retaining portion (222).

[0064] The first electrode (21) may be an anode plate, and the second electrode (22) may be a cathode plate. Of course, the opposite may also be true. Here, the positive active material applied to the anode plate and the negative active material applied to the cathode plate may be used without limitation as long as they are active materials known in the art.

[0065]

[0066] According to the present embodiment, the second electrode (22) may form the outer surface of the electrode assembly (20). Here, the outer surface may be a curved surface that forms the cylindrical outer shape of the electrode assembly (20).

[0067] Accordingly, the second non-porous portion (222) may be disposed in an area including at least a portion of the outer surface of the electrode assembly (20). As a result, at least a portion of the outer surface of the electrode assembly (20) is exposed in a metal foil state, and the said portion functions as a passage through which current can flow to induce potential generation.

[0068] That is, at least a portion of the outer surface of the electrode assembly (20) can be used as itself as an electrode tab of the second electrode (22).

[0069] The electrode assembly (20) according to the present embodiment has a structure in which a first electrode (21) and a second electrode (22) and a separator (23) interposed between them are wound around a winding axis, and the outermost part is not wrapped with another coating layer such as a separator (23), and the second electrode (22) can form the outer surface of the electrode assembly (20).

[0070] Accordingly, the electrode assembly (20) according to the present embodiment has a structure that is electrically connected through an outer surface, thereby shortening the current flow path. By doing so, the resistance element generated in the electrical connection with the second electrode (22) can be effectively reduced.

[0071] In addition, a relatively large area can be utilized as the electrode tab of the second electrode (22) to provide a path through which the current can be distributed uniformly, which can prevent local overheating and shortened battery life that may occur due to an imbalance in current density.

[0072]

[0073] According to one embodiment, the first electrode (21) may have a blank portion (212) formed at both ends in the winding axis direction (Z). For example, the first blank portion (212) may include an upper blank portion (2121) located at one end of the electrode assembly (20) and a lower blank portion (2122) located at the other end of the electrode assembly (20) with respect to the winding axis direction (Z).

[0074] That is, the first electrode (21) may have electrode tabs that can be electrically connected at the upper and lower ends, respectively, with respect to the winding axis direction (Z).

[0075] The first non-reinforced portion (212) may form multiple flag-shaped notching tabs (2123) by forming notches at predetermined intervals along the winding direction (X). The multiple notching tabs (2123) may be in the shape of an isosceles trapezoid arranged along the winding direction (X). However, they are not limited thereto and may be in various shapes such as a semicircle, a semi-ellipse, a triangle, a rectangle, or a parallelogram.

[0076] Additionally, a plurality of notching tabs (2123) can be flattened by bending them radially in the electrode assembly (20). Additionally, a plurality of notching tabs (2123) can be bent one by one during the process of forming the jelly-roll type electrode assembly (20). Alternatively, the notching tabs (2123) may be bent all at once after forming the jelly-roll type electrode assembly (20).

[0077] In this way, the notching tabs (2123) of the first electrode (21), which are folded and stacked in the radial direction, can each form a folded surface for electrical connection at both ends of the winding axis direction (Z) of the electrode assembly (20).

[0078] The second non-removable portion (222) may include at least one of a first portion (2221) provided at one end in the longitudinal direction of the second electrode (22) and a second portion (2222) provided at the other end in the longitudinal direction of the second electrode (22). Here, the one end may be positioned on the outer surface side, and the other end may be positioned on the core side.

[0079] The first part (2221) may form at least a portion of the outer surface of the electrode assembly (20). By doing so, the first part (2221) may function as an electrode tab of the second electrode (22) that transmits current or enables electrical connection.

[0080] In the longitudinal direction of the second electrode (22), the length (d1) of the first part (2221) may be provided with a length that is smaller than or equal to the outer circumference length (L1) of the electrode assembly (20).

[0081] For example, in the longitudinal direction of the second electrode (22), if the length (d1) of the first part (2221) is equal to the outer circumference length (L1) of the electrode assembly (20), the first part (2221) can be formed over the entire outer circumference of the electrode assembly (20). This can contribute to simplifying the structure of the electrode assembly (20) and increasing electrical connection efficiency.

[0082] For example, in the longitudinal direction of the second electrode (22), if the length (d1) of the first part (2221) is smaller than the outer circumference length (L1) of the electrode assembly (20), the first part (2221) may be formed in a portion of the outer surface of the electrode assembly (20). In this way, since the second electrode (22) in the form of a metal foil can provide an electrical connection area with the outside even if it is not exposed to the entire area of ​​the outer surface of the electrode assembly (20), the length of the first part (2221) does not need to be excessively larger than the outer circumference length (L1) of the electrode assembly (20).

[0083] Thus, by properly designing the length (d1) of the first part (2221), unnecessary materials for functional performance can be saved and the manufacturing process can be made more efficient.

[0084] Optionally, the second portion (2222) may be formed in at least a portion of the core side of the electrode assembly (20). If the active material layer (2211) is applied to the end of the core side, problems may occur where the active material layer (2211) breaks or peels off when the second electrode (22) is wound or laminated. Additionally, the active material layer (2211) undergoes repeated expansion and contraction during the charging / discharging process, and if the active material layer (2211) is applied to the end of the core side, internal stress within the battery may increase due to volume changes.

[0085] Accordingly, the second electrode (22) according to the present embodiment can reduce damage to the active material layer (2111) and increase assembly efficiency by providing a second part (2222) in at least a portion of the core side of the electrode assembly (20).

[0086] The second retaining portion (221) may have an active material layer (2211) applied to the area excluding the second non-retaining portion (222). The active material layer (2211) may be applied to the area excluding at least one end in the longitudinal direction of the second electrode (22).

[0087] The second retaining portion (221) and the second non-retaining portion (222) may be provided in various shapes along the longitudinal direction of the second electrode (22) and are not limited to the exemplary shapes illustrated in this specification.

[0088] As an example, the active material layer (2211) may be applied in a specific pattern along the longitudinal direction of the second electrode (22). In this case, the active material layer (2211) may not be applied to an area including at least a portion of the outer surface of the electrode assembly (20).

[0089] For example, the active material layer (2211) can be applied linearly at regular intervals in the winding direction (X) and winding axis direction (Z) along the length direction of the second electrode (22). This optimizes the diffusion path of lithium ions and improves the charge / discharge speed.

[0090] In this way, the active material layer (2211) can be formed in various patterns such as grid, linear, and dotted coatings. This patterned coating method can be designed to increase electrochemical reaction efficiency while simultaneously optimizing the capacity and output characteristics of the battery.

[0091]

[0092] FIGS. 5 and FIGS. 6 are drawings for explaining the arrangement of each component of the electrode assembly (20) according to FIGS. 1.

[0093] Referring to FIG. 5, the electrode assembly (20) can be wound along the winding direction (X) with the first electrode (21) and the second electrode (22) and the separator (23) interposed between them around the winding axis.

[0094] The second electrode (22) may be provided with a length that is longer than the first electrode (21) by a predetermined length (d2) in the longitudinal direction of the second electrode (22), for example, in the winding direction (X). For example, the active material layer may not be applied to at least a portion of the section (d2) that is longer than the first electrode (21) in the longitudinal direction of the second electrode (22), for example, in the winding direction (X).

[0095] Thus, the first electrode (21), the separator (23), and the second electrode (22) together form a plurality of winding turns with respect to the winding axis of the electrode assembly (20), and the second uncoated portion (222) in which the active material layer (2222) is not coated can be provided in at least a portion of the outer surface of the electrode assembly (20).

[0096] The separator (23) may be provided with a length that is longer than the first electrode (21) by a predetermined length (d3) in the longitudinal direction of the separator (23), for example, in the winding direction (X).

[0097] Thus, the electrode assembly (20) can prevent direct contact (short circuit) between the first electrode (21) and the second electrode (22) due to charging / discharging or external impact, as the end of the first electrode (21) is not directly exposed.

[0098] Additionally, the separator (23) may be provided to be shorter than the second electrode (22) in the longitudinal direction of the separator (23), for example, in the winding direction (X). This allows the second electrode (22) to be exposed to the outer surface of the electrode assembly (20) of the separator (23) without wasting material.

[0099] Here, the separator (23) may be a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., used alone or in a laminated form. As another example, the separator (23) may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0100] At least one surface of the separator (23) may include a coating layer of inorganic particles. Additionally, it is possible for the separator (28) itself to be composed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure combined with a binder such that interstitial volume exists between adjacent particles.

[0101] Referring to FIG. 6, the first electrode (21) may be provided with a width (d4) greater than the width (d5) of the second electrode (22) in the winding axis direction (Z) of the electrode assembly (20).

[0102] The first electrode (21) may be positioned to extend a certain length beyond both long side ends of the second electrode (22) in the winding axis direction (Z) of the electrode assembly (20). That is, in the winding axis direction (Z) of the first electrode (21), both ends may be positioned to have a length that is extended further than both ends of the second electrode (22).

[0103] For example, in the winding axis direction (Z) of the electrode assembly (20), the upper part (2121) of the first part (212) may be positioned on the upper part of one long side end of the second electrode (22), and the lower part (2122) of the first part (212) may be positioned on the lower part of the other long side end of the second electrode (22).

[0104] At this time, the separator (23) may be provided with a width (d6) greater than the width (d5) of the second electrode (22) in the winding axis direction (Z) of the electrode assembly (20). Thus, the metal foil exposed on the outer surface of the electrode assembly (20) may be provided only with the second electrode (22).

[0105] Accordingly, the electrode assembly (20) according to the present embodiment can prevent direct contact between the first electrode (21) and the second electrode (22) inside the electrode assembly (20) and effectively suppress electrical short circuits that may occur during the charging / discharging process. In addition, the unworn portion (212) formed at both long side ends of the first electrode (21) can be bent radially to provide a sufficient area to function as an electrode tab.

[0106]

[0107] The electrode assembly (20, 20a, 20b) described with reference to FIGS. 1 to 6 above may be a component of a battery cell (1). Hereinafter, a battery cell (1) to which the electrode assembly (20, 20a, 20b) according to an embodiment of the present invention is applied will be described.

[0108] FIG. 7 is a schematic diagram showing a battery cell (1) according to one embodiment of the present invention, and FIG. 8 are cross-sectional views schematically showing a battery cell (1) according to FIG. 7.

[0109] First, the battery cell (1) may be a cylindrical battery cell. For example, the battery cell (1) may be a cylindrical battery cell in which the ratio of the form factor (defined as the ratio of the diameter of the cylindrical battery cell to the height, i.e., the ratio of the diameter to the height) is approximately greater than 0.4.

[0110] Here, the form factor may refer to a value representing the diameter and height of a cylindrical battery cell. By applying the numerical value representing the form factor, the cylindrical battery cell may be a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell. Here, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0111] Additionally, the battery cell (1) may be a cylindrical battery cell, for example, having a form factor ratio (ratio of diameter in the radial direction to height in the core axis direction) greater than approximately 0.4. For example, the diameter of the battery cell (1) may be 40 mm to 50 mm, and the height may be 60 mm to 130 mm. The form factor of the battery cell (1) may be, for example, 46110, 4875, 48110, 4880, or 4680. However, the shape of the battery cell (1) is not limited by the above and can be applied to batteries of other shapes.

[0112] With reference to FIGS. 1 to 6 examined above, and FIGS. 7 and 8, a battery cell (1) according to one embodiment may largely include a battery can (10), the aforementioned electrode assembly (20), a first electrode terminal (30), and a cap (60).

[0113] The battery can (10) may be a cylindrical structure for a cylindrical battery cell. In this case, a side wall member (11) forms the side of the cylinder of the battery can (10), and a bottom member (12) may be connected to the side wall member (11) to form one end of the cylinder.

[0114] That is, the bottom member (12) becomes a closed part of the battery can (10), and the other end of the battery can (10) facing the bottom member (12) can become an open opening.

[0115] The battery cell (1) can accommodate an electrode assembly (20) inside the battery can (10) through an opening of the battery can (10).

[0116] The bottom member (12) may be in the shape of a disc with a through hole (H1) formed in the center, and the side wall member (11) may be in the shape of a cylinder surrounding the bottom member (12) and having a constant radius along the circumferential direction. The battery can (10) including such bottom member (12) and side wall member (11) may be a member formed by a deep drawing process of a metal sheet having nickel plated on the surface of steel. Of course, the material of the bottom member (12) and side wall member (11) is not limited to this.

[0117] At this time, a first electrode terminal (30) can be fitted into the through hole (H1) of the bottom member (12). For example, the first electrode terminal (30) can be fixed by riveting to the bottom member (12) with a gasket (31) interposed.

[0118] The gasket (31) is interposed between the first electrode terminal (30) and the bottom member (12) to seal the inside of the battery can (10) to prevent leakage of the electrolyte and to electrically insulate the first electrode terminal (30) and the bottom member (12).

[0119] However, the method of connecting the first electrode terminal (30) and the bottom member (12) is not limited to this. For example, if the structure can seal the space between the first electrode terminal (30) and the bottom member (12) and electrically insulate the first electrode terminal (30) and the bottom member (12), various other fixing methods, such as a bolt-nut connection method, a glass seal method, or a chrome plating & PP-MAH heat bonding method, can also be applied.

[0120] The first electrode terminal (30) can be connected to the first electrode (21) through a first current collector plate (40) positioned at one end in the winding axis direction (Z). The first current collector plate (40) can be joined to one of the two ends in the winding axis direction (Z) of the electrode assembly (20). For example, the first current collector plate (40) can be joined to the first non-circular portion (212) of the first electrode (21) located at the upper end in the winding axis direction (Z) of the electrode assembly (20).

[0121] The first current collector plate (40) may be a negative current collector plate made of copper. However, the material of the first current collector plate (40) is not limited to this and may be omitted.

[0122] Thus, the first electrode terminal (30) can be electrically connected to the first electrode (21) and take on the first polarity.

[0123] The side wall member (11) of the battery can (10) can be electrically connected to the second electrode (22) by directly contacting the outer surface of the electrode assembly (20) and thus can have a second polarity. For example, the side wall member (11) of the battery can (10) can be welded (W) to the second non-removable portion (222) of the second electrode (22) which constitutes at least a portion of the outer surface of the electrode assembly (20).

[0124] At this time, an insulator (70) is placed between the bottom member (12) and the electrode assembly (20) to insulate the first electrode (21) and the bottom member (12).

[0125] Thus, the bottom member (12) can also be connected to the side wall member (11) and take on a second polarity.

[0126] The cap (60) may be configured to cover the opening of the battery can (10). For example, the cap (60) may be configured as a cover structure that effectively seals the opening of the battery can (10). Thus, the battery cell (1) is sealed, the internal electrolyte and electrode assembly (20) are protected from the external environment, and the long-term performance of the battery cell (1) can be maintained.

[0127] The joint point between the opening of the battery can (10) and the cap (60) can be joined by welding. For example, the cap (60) can be joined to the battery can (10) using butt welding. However, the battery can (10) and the cap (60) can be joined by other joining methods other than welding, such as beading and crimping, and the joining method is not limited to these.

[0128] The cap (60) may be made of a metallic material for electrical connection with the second current collector plate (50). Therefore, the cap (60) may be conductive. For example, the cap (60) may include copper material.

[0129] The cap (60) may be disc-shaped so as to be fixed to the opening of the battery can (10) or to seal the opening of the can, but its shape is not limited thereto. Additionally, the thickness of the cap (60) may be designed to provide sufficient strength to prevent deformation in high temperature or high pressure environments and to ensure durability to prevent leakage of the internal electrolyte.

[0130] The cap (60) can be connected to the first electrode (21) through a second collector plate (50) positioned at the other end in the winding axis direction (Z). For example, the cap (60) can be electrically connected to the first non-removable portion (212) of the first electrode (21) positioned at the bottom in the winding axis direction (Z) through the second collector plate (50).

[0131] The cap (60) may be insulated from the side wall member (11) of the battery can (10) having a second polarity by means of a gasket (61). Alternatively, the cap (60) may be directly connected to the first electrode (21) without the second current collector plate (50). For example, the first non-contact portion (212) (see FIG. 2) of the first electrode (21) may be connected to the cap (60).

[0132] Thus, the cap (60) can be electrically connected to the first electrode (21) and take on the first polarity.

[0133] That is, the first electrode terminal (30) and the cap (60) of the battery cell (1) according to the present embodiment may have a first polarity, for example, a negative polarity, and the side wall member (11) and the bottom member (12) may have a second polarity, for example, a positive polarity. Of course, the opposite may also be true.

[0134] Accordingly, the battery cell (1) according to the present embodiment can reduce contact resistance by welding the outer surface of the electrode assembly (20) and the side wall member (11) in contact, thereby widening the welded area and increasing the electrical contact area. As contact resistance is reduced in this way, electrical loss in the current transmission path is reduced, and the output characteristics of the battery cell (1) can be improved. In addition, a stable electrical connection can be maintained even during repeated charging and discharging processes, thereby improving the performance of the battery cell (1).

[0135]

[0136] FIG. 9 is a cross-sectional view schematically showing a battery cell (1a) according to another embodiment of the present invention.

[0137] Here, with reference to FIGS. 7 and FIGS. 8, the commonalities between the battery cell (1) described above and the battery cell (1a) of the present embodiment can be understood as identical, and redundant descriptions will be omitted below.

[0138] Referring to FIG. 9, a battery cell (1a) according to one embodiment may largely include a battery can (10), the aforementioned electrode assembly (20), a first electrode terminal (30), a cap (60a), and a second electrode terminal (90).

[0139] The cap (60a) can be configured to cover the opening of the battery can (10). That is, the cap (60a) can be configured as a cover structure that effectively seals the opening of the battery can (10). Thus, the battery cell (1) is sealed, the internal electrolyte and electrode assembly (20) are protected from the external environment, and the long-term performance of the battery cell (1) can be maintained.

[0140] The joint point between the opening of the battery can (10) and the cap (60a) can be joined by welding. For example, the cap (60a) can be joined to the battery can (10) using butt welding. However, the battery can (10) and the cap (60a) can be joined by other joining methods such as beading and crimping other than welding, and the joining method is not limited to these.

[0141] The cap (60a) may be made of a mainly metallic material for electrical connection with the second current collector plate (50). Therefore, the cap (60a) may be conductive. For example, the cap (60a) may include copper material.

[0142] The cap (60a) may be in the shape of a disc with a through hole (H2) formed in the center. Thus, the second electrode terminal (30) can be fitted into the through hole (H2) of the cap (60a).

[0143] For example, the second electrode terminal (90) can be riveted and fixed to the cap (60a) with a gasket (91) interposed therebetween. The gasket (91) is interposed between the second electrode terminal (90) and the cap (60a) to seal the inside of the battery can (10) to prevent leakage of the electrolyte and to electrically insulate the second electrode terminal (90) and the cap (60a).

[0144] However, the method of connecting the second electrode terminal (90) and the cap (60a) is not limited to this. For example, if the structure can seal the space between the second electrode terminal (90) and the cap (60a) and electrically insulate the second electrode terminal (90) and the cap (60a), various other fixing methods, such as a bolt-nut connection method, a glass seal method, or a chrome plating & PP-MAH heat bonding method, can also be applied.

[0145] The second electrode terminal (90) can be connected to the first electrode (21) through a second current collector plate (50) positioned at the other end in the winding axis direction (Z). For example, the second electrode terminal (90) can be connected to the first non-circular portion (212) of the first electrode (21) through a second current collector plate (50) positioned at the lower end in the winding axis direction (Z).

[0146] Thus, the second electrode terminal (90) can be electrically connected to the first electrode (21) and take on the first polarity.

[0147] The side wall member (11) of the battery can (10) can be electrically connected to the second electrode (22) by directly contacting the outer surface of the electrode assembly (20) and thus can have a second polarity. For example, the side wall member (11) of the battery can (10) can be welded (W) to the second non-removable portion (222) of the second electrode (22) which constitutes at least a portion of the outer surface of the electrode assembly (20).

[0148] At this time, an insulator (80) is further disposed between the cap (60a) and the electrode assembly (20) so that the first electrode (21) and the side wall member (11) can be insulated.

[0149] Thus, just like the bottom member (12), the cap (60a) can also be connected to the side wall member (11) and take on a second polarity.

[0150] That is, the first electrode terminal (30) and the second electrode terminal (90) of the battery cell (1) according to the present embodiment may have a first polarity, for example, a negative electrode, and the side wall member (11), bottom member (12) and cap (60a) may have a second polarity, for example, a positive electrode. Of course, the opposite may also be true.

[0151] However, unlike what is shown in FIG. 9, it is also possible for the cap (60a) not to be electrically connected to the side wall member (11). For example, a sealing member may be interposed between the outer periphery of the cap (60a) and the side wall member (11), and the cap (60a) and the side wall member (11) may be electrically insulated from each other due to this sealing member.

[0152] As described above, the battery cell (1, 1a) according to the embodiments of the present invention can reduce contact resistance by welding (W) the outer surface of the electrode assembly (20) and the side wall member (11) in direct contact. This design can improve the output characteristics of the battery cell (1, 1a) by increasing the efficiency of the electrical connection and minimizing energy loss that may occur in the current transfer path.

[0153] In addition, by providing a stable and wide contact area, uniformity of current transmission is ensured, and since no additional connecting parts or bonding media are required, the structure can be simplified and contribute to making the manufacturing process of the battery cell (1, 1a) more efficient.

[0154]

[0155] FIG. 10 is a schematic diagram showing a battery pack (P) having battery cells (1, 1a) according to one embodiment of the present invention, and FIG. 11 is a schematic diagram showing a vehicle (V) having a battery pack (P) according to one embodiment of the present invention.

[0156] Referring to FIG. 10, a battery pack (P) according to one embodiment of the present invention may include at least one battery cell (1, 1a) according to a prior embodiment and a pack case (C) that accommodates the same.

[0157] A battery pack (P) according to one embodiment of the present invention may further include various other components of a battery pack (P) known at the time of filing the present invention. For example, a battery pack (P) according to one embodiment of the present invention may further include components such as a current sensor, a fuse, and a service plug.

[0158] The battery pack (P) has no significant restrictions on the application of cooling methods, such as bottom cooling and side cooling, regardless of the arrangement direction of the battery cells (1, 1a), and can be freely adopted according to desired design requirements. As a result, the battery pack (P) allows for a combination of various structural designs and thermal management systems, thereby optimizing the performance of the battery cells (1, 1a) and configuring it to be suitable for various application environments.

[0159] Referring to FIG. 11, a vehicle (V) according to one embodiment of the present invention may include one or more battery packs (P) according to the present invention. In addition, a vehicle (V) according to one embodiment of the present invention may include various other components included in the vehicle in addition to the battery pack (P). For example, a vehicle (V) according to one embodiment of the present invention may include, in addition to the battery pack (P) according to one embodiment of the present invention, a vehicle body, a motor, an electronic control unit (ECU), or other control devices.

[0160] In addition, it is obvious that the battery pack (P) according to one embodiment of the present invention may also be provided in other devices, mechanisms, and facilities, such as an energy storage system using a secondary battery, in addition to the vehicle (V).

[0161] According to the various embodiments described above, an electrode assembly (20) capable of further improving performance, a battery cell (1, 1a) including the same, a battery pack (P), and a vehicle (V) can be provided.

[0162]

[0163] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0164] [Explanation of symbols] 1, 1a: Battery cell

[0165] 10: Battery can

[0166] 11: Sidewall member

[0167] 12: Floor member

[0168] 20: Electrode assembly

[0169] 21: First electrode

[0170] 211: 1st Maintenance Unit

[0171] 2111: Active material layer

[0172] 212: 1st Department of Indefinite Expenses

[0173] 2121: Upper thumb area

[0174] 2122: Lower thumb area

[0175] 2123: Notching Tab

[0176] 22: Second electrode

[0177] 221: 2nd Maintenance Unit

[0178] 2211: Active material layer

[0179] 222: 2nd Department of Indefinite Service

[0180] 2221: Part 1

[0181] 2222: Part 2

[0182] 23: Separator

[0183] 30: First electrode terminal

[0184] 31: Gasket

[0185] 40: First ceremonial tablet

[0186] 50: Second tribunal

[0187] 60, 60a: Cap

[0188] 61: Gasket

[0189] 70, 80: Insulator

[0190] 90: Second electrode terminal

[0191] 91: Gasket

[0192] W: Welded part

[0193] H1, H2: Through holes

[0194] W: Welded part

[0195] P: Battery pack

[0196] C: Pack case

[0197] V: Car

[0198] L1: Outline length

Claims

1. An electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis to define a core and an outer surface, The first electrode above is, A first uncoated portion in which an active material layer is not applied along the longitudinal direction of the first electrode at each of the long side ends; and It includes a first retaining portion having an active material layer applied to an area excluding the first non-retaining portion, and The second electrode above is, A second uncoated portion constituting the outer surface of the electrode assembly, wherein an active material layer is not applied to an area including at least a portion of the outer surface; and An electrode assembly characterized by including a second retaining portion having an active material layer applied to an area excluding the second non-retaining portion.

2. In Paragraph 1, The above-mentioned first part of the non-disability section is, An electrode assembly characterized by being formed at both ends in the direction of the winding axis of the electrode assembly.

3. In Paragraph 2, The above-mentioned first part of the non-disability section is, An electrode assembly characterized by being bent along the radial direction of the electrode assembly to form bent surfaces at both ends in the winding axis direction of the electrode assembly.

4. In Paragraph 1, The above second non-removable part is, A first portion provided at one end in the longitudinal direction of the second electrode; and An electrode assembly characterized by including at least one of a second part provided at the other end in the longitudinal direction of the second electrode.

5. In Paragraph 4, The above first part is, An electrode assembly characterized by having a length in the longitudinal direction of the second electrode that is smaller than or equal to the outer circumference length of the electrode assembly.

6. In Paragraph 1, The second electrode above is, An electrode assembly characterized by having a length longer than that of the first electrode in the longitudinal direction of the second electrode.

7. In Paragraph 6, The second electrode above is, An electrode assembly characterized in that, in the longitudinal direction of the second electrode, an active material layer is not applied to at least a portion of a section longer than the first electrode.

8. In Paragraph 1, The above separator is, An electrode assembly characterized by having a length longer than the first electrode and a length shorter than the second electrode in the longitudinal direction of the separator.

9. In Paragraph 1, The first electrode above is, An electrode assembly characterized by having a width greater than the width of the second electrode in the winding axis direction of the electrode assembly.

10. In Paragraph 9, The first electrode above is, An electrode assembly characterized by being arranged such that, in the direction of the winding axis of the electrode assembly, both ends have a length extended from each end of the second electrode.

11. As a battery cell, An electrode assembly of any one of claims 1 to 10; A battery can comprising a bottom member and a side wall member extending from the bottom member in the direction of the winding axis of the electrode assembly, accommodating the electrode assembly through an opening facing the bottom member, and configured such that its outer surface contacts the side wall member and is electrically connected to the second electrode; A first electrode terminal electrically connected to the electrode assembly through a through hole formed in the bottom member of the battery can; and A battery cell comprising a cap covering the opening of the battery can.

12. In Paragraph 11, The first electrode above is, A battery cell characterized by being electrically connected to the first electrode terminal and the cap.

13. In Paragraph 11, It further includes a second electrode terminal riveted through a through hole formed in the above cap, and The first electrode above is, A battery cell characterized by being electrically connected to the first electrode terminal and the second electrode terminal.

14. A battery pack characterized by including a battery cell according to claim 11.

15. An automobile equipped with at least one battery pack according to paragraph 14.

Images