Electrode assembly, method and apparatus for manufacturing electrode assembly, battery including electrode assembly, and battery pack and vehicle including battery

Abstract

The present invention may provide an electrode assembly in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound, in which at least one of the positive electrode and the negative electrode includes an uncoated portion at a long-side end, and a winding turn portion of the uncoated portion is provided at a one-side end of the electrode assembly, and the winding turn portion includes a bending region including a plurality of uncoated portion layers configured to be bent by pressure to form a curved surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an electrode assembly, a method and apparatus for manufacturing the same, a battery including the same, and a battery pack and a vehicle including the same.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0070340, filed on May 29, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND

[0003] Secondary batteries having high applicability according to product groups and electrical characteristics such as high energy density are generally not only applied to portable devices, but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by power sources. Such secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, since they not only have a major advantage of significantly reducing the use of fossil fuels, but also have no by-products of energy generation.

[0004] Secondary batteries widely used at present include lithium ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and the like. When a higher output voltage is required, a plurality of battery cells can be connected in series to form a battery module or a battery pack. In addition, in order to increase the charge and discharge capacity, a plurality of battery cells can be connected in parallel to form a battery module or a battery pack. Accordingly, the number of battery cells included in the battery module or the battery pack can be variously set according to the required output voltage or the charge and discharge capacity.

[0005] In addition, as a type of unit secondary battery, cylindrical, prismatic, and pouch-type batteries are known. In the case of a battery, a separator as an insulator is interposed between a positive electrode and a negative electrode, and then they are wound to form a jelly-roll type electrode assembly, and the assembly is inserted into a battery case to form a battery. Also, a tab-shaped electrode lead can be connected to each uncoated portion of the positive electrode and the negative electrode, and the electrode lead electrically connects the electrode assembly and an electrode terminal exposed to the outside. For reference, the positive electrode terminal is a cap of a sealing body sealing an opening of the battery case, and the negative electrode terminal is the battery case. However, according to a conventional battery having such a structure, since current is concentrated on the tab-shaped electrode lead connected to the positive uncoated portion and / or the negative uncoated portion, there is a problem that the resistance is high, a large amount of heat is generated, and current collection efficiency is poor.

[0006] In a small battery having a form factor of 1865 or 2170, resistance and heat generation are not major problems. However, when the form factor is increased to apply the battery to an electric vehicle, there can be a problem in which the battery catches fire due to a large amount of heat generated around the electrode tab during a rapid charging process.

[0007] To solve this problem, a battery (so-called tab-less battery) having a structure in which a positive electrode uncoated portion and a negative electrode uncoated portion are designed to be located at the upper end and the lower end of a jelly-roll type electrode assembly, respectively, and a current collector plate is welded to the uncoated portions to improve current collection efficiency is proposed.

[0008] Figures 1 to 3 is a view showing a manufacturing process of a tab-less battery. Figure 1 a structure of an electrode is shown, Figure 2 a winding process of the electrode is shown, and Figure 3 a process of welding a current collector plate to a curved surface of an uncoated portion is shown.

[0009] Reference Figures 1 to 3 The positive electrode 10 and the negative electrode 11 have a structure in which an active material 21 is coated on a sheet-shaped current collector 20, and include an uncoated portion 22 on one long side in a winding direction X.

[0010] As shown in Figure 2 , an electrode assembly A is manufactured by sequentially laminating the positive electrode 10 and the negative electrode 11 with two separators 12, and then winding them in one direction X. At this time, the uncoated portions of the positive electrode 10 and the negative electrode 11 are disposed in opposite directions based on the short side direction of the separators 12. The positions of the positive electrode 10 and the negative electrode 11 can be changed in a direction opposite to the illustrated direction.

[0011] After the winding process, the uncoated portion 10a of the positive electrode 10 and the uncoated portion 11a of the negative electrode 11 are bent toward the core side. Thereafter, the current collector plates 30, 31 are welded to the uncoated portions 10a, 11a to be welded, respectively.

[0012] The separate electrode tabs are not coupled to the positive electrode uncoated portion 10a and the negative electrode uncoated portion 11a, and the current collector plates 30, 31 are connected to external electrode terminals, and a current path is formed with a large cross-sectional area along the winding axis direction (see arrow) of the electrode assembly A, thereby having an advantage of reducing the resistance of the battery. This is because the resistance is inversely proportional to the cross-sectional area of the path through which the current flows.

[0013] In the tab-less battery, in order to improve the welding characteristics of the uncoated portions 10a, 11a and the current collector plates 30, 31, a strong pressure should be applied to the welding points of the uncoated portions 10a, 11a to bend the uncoated portions 10a, 11a as flat as possible.

[0014] When the uncoated portions 10a, 11a are bent, a jig that presses the uncoated portions 10a, 11a toward the core of the electrode assembly A can be used.

[0015] When a curved surface is formed on the entire upper surface of the electrode assembly by bending the uncoated portions 10a, 11a, the electrolyte solution can not be smoothly injected, and in addition, gas generated therein can be blocked by the curved surface and be difficult to be discharged to the outside. SUMMARY

[0016] TECHNICAL PROBLEM

[0017] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure relates to providing a method and apparatus for manufacturing an electrode including a wound turn portion having at least one opening for bending an uncoated portion of a jointless battery, and an electrode assembly manufactured by the method and apparatus.

[0018] The present disclosure also relates to providing a battery including the electrode assembly manufactured by the improved method.

[0019] The present disclosure also relates to providing an electrode assembly that can improve energy density, reduce resistance, and improve electrolyte impregnation by including an electrode having a wound turn portion including at least one opening.

[0020] The present disclosure also relates to providing a battery including an electrode assembly having an improved structure, a battery pack including the same, and a vehicle including the same.

[0021] The technical problems to be solved by the present disclosure are not limited to the above-mentioned problems, and other problems not mentioned herein can be clearly understood by those of ordinary skill in the art from the following description of the present disclosure.

[0022] TECHNICAL SOLUTION

[0023] To solve the above-mentioned problems, the present disclosure can provide an electrode assembly in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound, wherein at least one of the positive electrode and the negative electrode includes an uncoated portion at a long side end portion, and a wound turn portion of the uncoated portion is provided at one end portion of the electrode assembly, wherein the wound turn portion includes a bending region including a plurality of uncoated portion layers configured to be bent by pressure to form a curved surface.

[0024] The bending region can include a curved surface and at least one opening configured to be surrounded by the curved surface.

[0025] A ratio of an area occupied by the at least one opening to an area of the bending region can be 30% or more and 50% or less.

[0026] The plurality of uncoated portion layers can be bent multiple times to overlap along the axial direction.

[0027] The bending region can be configured to be formed by pressure using a jig including at least one protrusion on one surface.

[0028] The bending region can correspond to a region pressed by the jig.

[0029] The at least one opening of the bending region can be configured to be formed in a region into which at least one protrusion of the jig is inserted.

[0030] The wound turn portion can further include a flat region that is not pressed by the jig.

[0031] The at least one opening can be configured to be formed in a region corresponding to a region in which the separator is disposed.

[0032] An axial height of the bending region can be higher than an axial height of the flat region.

[0033] To address the above-mentioned problems, the present disclosure can provide a method for manufacturing an electrode assembly, the method including: a first step of preparing a negative electrode and a positive electrode having an uncoated portion at a long side end portion; a second step of forming an electrode-separator laminate by laminating the positive electrode, the negative electrode, and a separator at least once such that the separator is interposed between the positive electrode and the negative electrode, and by disposing the positive electrode and the negative electrode such that the positive electrode uncoated portion and the negative electrode uncoated portion are exposed in opposite directions along a short side direction of the separator, to form an electrode-separator laminate; a third step of forming an electrode assembly by winding the electrode-separator laminate around an axis such that the wound turn portion of the positive electrode uncoated portion and the wound turn portion of the negative electrode uncoated portion are exposed in opposite directions along the axial direction; and a fourth step of pressing at least a portion of the wound turn portion using a jig, and forming a bending surface and at least one opening by a plurality of uncoated portion layers bent by pressure, the at least one opening being configured to be surrounded by the bending surface.

[0034] When the plurality of uncoated portion layers are pressed using the jig in the fourth step, the bending surface can be formed and the at least one opening can be formed at the same time.

[0035] The jig can include at least one protrusion on one surface, and the at least one opening can be formed in a region into which at least one protrusion of the jig is inserted.

[0036] To solve the above problems, the present disclosure can provide a battery including: an electrode assembly; a battery case including an open end through which the electrode assembly is received and a closed end opposite thereto, and electrically connected to the electrode assembly; a sealing body sealing the open end of the battery case; a terminal electrically connected to the electrode assembly and having a surface exposed to the outside; and a current collector plate welded to the curved surface and electrically connected to the battery case or the terminal.

[0037] In addition, the present disclosure provides a battery pack including the battery according to the present disclosure.

[0038] Also, the present disclosure provides a vehicle including the battery pack according to the present disclosure.

[0039] Advantageous Effects

[0040] Since the plurality of uncoated portion layers according to the embodiments of the present disclosure are bent while overlapping in the axial direction, the electrolyte injection passage can not be obstructed by the bent portion or the curved surface, and electrolyte injection can be smoothly performed. In addition, since the gas generated inside the battery cell during charging and discharging of the battery is not captured by the bent portion or the curved surface, it is possible to smoothly discharge the gas.

[0041] According to one aspect of the present disclosure, a jig including at least one protrusion on one surface presses the wound turn portion of the uncoated portion from above, thereby bending the plurality of uncoated portion layers and simultaneously forming at least one opening, and thus the at least one opening can be used as an electrolyte injection passage to improve electrolyte impregnation.

[0042] According to another aspect of the present disclosure, the bent region of the wound turn portion of the uncoated portion can include at least one opening, thereby smoothly discharging the gas generated inside the battery to the outside.

[0043] According to still another aspect of the present disclosure, by bending the bent region of the wound turn portion of the uncoated portion, a curved surface in which the plurality of uncoated portion layers overlap in a plurality of layers can be formed, and then a current collector plate can be welded to the corresponding region, thereby reducing the resistance of the battery.

[0044] In manufacturing a conventional uncoated portion, a slitting process is included to form a specific pattern in the uncoated portion, but the uncoated portion according to the embodiments of the present disclosure can be manufactured without a separate slitting process. According to the embodiments of the present disclosure, performance degradation caused by metal foreign matter generated during the slitting process can be prevented, and gas can be smoothly discharged. According to the embodiments of the present disclosure, process time can be shortened, and process unit cost can be improved by omitting the slitting process.

[0045] According to still another aspect of the present disclosure, by providing a large-capacity battery pack manufactured using a battery having a high energy density and a low resistance and a vehicle including the same, the safety of fast charging and the efficiency of energy use can be improved.

[0046] In addition, the present disclosure can have various other effects to be described in each embodiment, or the description of effects that can be easily inferred by those skilled in the art can be omitted. BRIEF DESCRIPTION OF DRAWINGS

[0047] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, provide further understanding of the technical features of the present disclosure, and therefore, the present disclosure is not construed as being limited to the accompanying drawings.

[0048] Figure 1 is a plan view showing the structure of an electrode used when manufacturing a conventional jointless battery.

[0049] Figure 2 is a view showing an electrode winding process of a conventional jointless battery.

[0050] Figure 3 shows a process of welding a current collector plate to a curved surface of an uncoated portion in a conventional jointless battery.

[0051] Figure 4 is a plan view showing the structure of an electrode according to an embodiment of the present disclosure.

[0052] Figure 5 is a partial perspective view showing the upper structure of an electrode assembly according to an embodiment of the present disclosure before being pressed by a jig.

[0053] Figure 6 is a cross-sectional view of a jelly-roll type electrode assembly taken along line A-A', in which an electrode of Figure 5 is applied to a positive electrode and a negative electrode according to an embodiment of the present disclosure.

[0054] Figure 7 is a partial view of a jig and an electrode assembly used when pressing a wound turn portion in an axial direction according to an embodiment of the present disclosure, taken in the axial direction.

[0055] Figure 8 is a partial view of a jig and an electrode assembly used when pressing a wound turn portion in an axial direction according to another embodiment of the present disclosure, taken in the axial direction.

[0056] Figure 9 is an enlarged view showing a jig pressing a wound turn portion according to an embodiment of the present disclosure.

[0057] Figure 10is a plan view showing a pressure surface of a jig according to an embodiment of the present disclosure, viewed from below.

[0058] Figure 11 is a view schematically showing a wound turn portion according to an embodiment of the present disclosure, viewed from above.

[0059] Figure 12 is a plan view showing a pressure surface of a jig according to another embodiment of the present disclosure, viewed from below.

[0060] Figure 13 is a view schematically showing a wound turn portion according to another embodiment of the present disclosure, viewed from above.

[0061] Figure 14 is a sectional view of a battery according to an embodiment of the present disclosure, taken along the axial direction Y.

[0062] Figure 12 is a sectional view of a battery according to another embodiment of the present disclosure, taken along the axial direction Y.

[0063] Figure 16 is a view schematically showing a configuration of a battery pack according to an embodiment of the present disclosure.

[0064] Figure 17 is a view for describing a vehicle including a battery pack according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0065] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it is to be understood that the terminology used in the specification and the appended claims should not be interpreted as limiting, but should be interpreted based on the principle that the inventor is properly defined the terminology for the best explanation, based on the meanings and concepts corresponding to the technical aspects of the present disclosure.

[0066] Therefore, the embodiments described in the present specification and the configurations shown in the accompanying drawings are only some of the most preferred embodiments of the present disclosure, and are not intended to represent all technical aspects of the present disclosure, and it should be understood that various equivalents and modifications can be made thereto at the time of filing the present application.

[0067] In addition, the present disclosure includes various embodiments. For each embodiment, repeated description of substantially the same or similar configurations will be omitted, and differences will be mainly described.

[0068] In addition, in order to help understanding of the present disclosure, the accompanying drawings are not shown in actual scale, but the size of some components can be exaggerated. In addition, the same reference numerals can be assigned to the same components in different embodiments.

[0069] Although the first, second, etc. are used to describe various components, it is apparent that the components are not limited by these terms. The terms are used only to distinguish one component from another component, and it is obvious that the first component can be the second component unless there is an explicit opposite indication.

[0070] Throughout the specification, each component can be singular or plural unless there is an explicit opposite indication.

[0071] Hereinafter, when any configuration is disposed on the "upper (or lower) portion" of a component or the "top (or bottom) portion" of a component, it can not only mean that the configuration is disposed to be in contact with the upper surface (or lower surface) of the component, but also mean that other configurations can be interposed between the component and any structure disposed above (or below) the component.

[0072] In addition, when one component is described as being "connected", "coupled", or "contacted" to another component, the components can be directly connected or contacted to each other, but it should be understood that other components can be "interposed" between each component, or each component can be "connected", "coupled", or "contacted" through another component.

[0073] As used herein, the singular expression includes the plural expression unless the context clearly dictates the opposite. In this application, the term "include" or "comprise" should not be interpreted as necessarily including all various components or various steps described in the specification, but should be interpreted as including some components or steps, or further including additional components or steps.

[0074] Throughout the specification, unless there is an explicit opposite indication, when A and / or B is referred to, it refers to A, B, or A and B, and unless there is an explicit opposite indication, when C to D is referred to, it refers to C or more and D or less.

[0075] For ease of description, in this specification, the direction along the length direction of the winding axis of the electrode assembly wound in the form of a jelly-roll is referred to as the axial direction Y. Also, the direction around the winding axis is referred to as the circumferential direction or the circumferential direction X. Also, the direction close to or away from the winding axis is referred to as the radial direction or the radial direction Z. Among them, in particular, the direction close to the winding axis is referred to as the centripetal direction, and the direction away from the winding axis is referred to as the centrifugal direction.

[0076] First, an electrode assembly according to an embodiment of the disclosure will be described. The electrode assembly is a jelly-roll type electrode assembly having a structure in which sheet-shaped positive and negative electrodes and a separator interposed between the positive and negative electrodes are wound in one direction.

[0077] Preferably, at least one of the positive and negative electrodes includes an uncoated portion in which the active material is not coated on the long side end in the winding direction. At least a portion of the uncoated portion itself serves as an electrode connector.

[0078] Figure 4 This is a plan view showing the structure of an electrode according to an embodiment of the present disclosure.

[0079] refer to Figure 4 The electrode 40 according to an embodiment of the present disclosure includes a current collector 41 and an active material layer 42. Figure 4 The configuration of the current collector 41, the active material layer 42, and the uncoated portion 43 can be consistent with... Figures 1 to 3 The current collector 20, the active material layer 21, and the uncoated portion 22 are all or partly identical in configuration. Figure 4 The implementation method can be partially related to Figures 1 to 3 The combination of components shown.

[0080] In the electrode 40 according to an embodiment of the present disclosure, the current collector 41 may be formed of a metal foil. The metal foil may include a conductive metal. The metal foil may be aluminum or copper, and is appropriately selected according to the polarity of the electrode 40. An active material layer 42 is formed on at least one surface of the current collector 41, and the electrode 40 includes an uncoated portion 43 at its long side end in the winding direction X. The uncoated portion 43 is a region where the active material is not coated. An insulating coating 44 may be formed at the boundary between the active material layer 42 and the uncoated portion 43. At least a portion of the insulating coating 44 is formed to overlap with the boundary between the active material layer 42 and the uncoated portion 43. The insulating coating 44 may include a polymer resin and may include materials such as... or Inorganic fillers. The polymer resin can have a porous structure. There are no particular limitations on the polymer resin, as long as it is an insulating material. Examples of polymer resins may include polyolefins, polyimides, polyethylene terephthalate, polyfluorobutylene, etc., but this disclosure is not limited thereto.

[0081] The electrode 40 of the above embodiments can be applied to a core-type electrode assembly (e.g., Figure 6 The positive electrode (e.g., in electrode assembly 50) in the electrode assembly 50) Figure 6 The positive electrode 40a) and / or the negative electrode (e.g., Figure 6 The negative electrode 40b). Furthermore, when the electrode structure of the embodiment is applied to either the positive or negative electrode, the conventional electrode structure ( Figure 1 It can be applied to the other. In addition, the electrode structures applied to the positive and negative electrodes can not be the same, but can be different from each other.

[0082] In the present disclosure, positive electrode active materials coated on a positive electrode and negative electrode active materials coated on a negative electrode can be used without limitation, as long as they are active materials known in the art. In one example, the positive electrode active material can include an alkali metal compound represented by a chemical general formula (A includes at least one of Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x ≥ 0, 1 ≤ x+ y ≤ 2, -0.1 ≤ z ≤ 2; and stoichiometric coefficients x, y, and z are selected so that the compound remains electrically neutral).

[0083] In another example, the positive electrode active material can be an alkali metal compound disclosed in US 6,677,082, US 6,680,143, etc. (M1 includes at least one element having an average oxidation state of 3; M2 includes at least one element having an average oxidation state of 4, 0 ).

[0084] In yet another example, the positive electrode active material can be an alkali metal compound represented by a chemical general formula (M1 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M2 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M3 includes an element of a halogen family optionally containing F; ; and stoichiometric coefficients a, x, y, and z are selected so that the compound remains electrically neutral) or (M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al) represented by a lithium metal phosphate.

[0085] Preferably, the positive electrode active material can include primary particles and / or secondary particles in which the primary particles are aggregated.

[0086] In one example, the negative electrode active material can use a carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides having a potential of less than 2V, such as or ) can be used as the negative electrode active material. As the carbon material, low-crystalline carbon and high-crystalline carbon can be used.

[0087] The separator can be a porous polymer film made of, for example, a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, or an ethylene / methacrylate copolymer, alone or in a multi-layer structure. In another example, the separator can be a common porous nonwoven fabric such as one made of glass fibers or polyethylene terephthalate fibers having a high melting point.

[0088] The uncoated portion 43 according to the embodiment of the present disclosure can be defined as a region in which at least one of the long edge end portions of the positive and negative electrodes is not coated with an active material. In manufacturing a conventional uncoated portion, a slotting process for forming a specific pattern in the uncoated portion is included, but the uncoated portion 43 according to the embodiment of the present disclosure can be manufactured without a separate slotting process. According to the embodiment of the present disclosure, performance degradation caused by metal foreign matter generated during the slotting process can be prevented, and smooth gas discharge can be induced. According to the embodiment of the present disclosure, process time can be shortened, and process unit cost can be improved by omitting the slotting process, thereby improving current collection efficiency.

[0089] Figure 5 FIG. 1 is a partial perspective view showing an upper structure of an electrode assembly according to an embodiment of the present disclosure before being pressed by a jig. Figure 6 FIG. 2 is a cross-sectional view of a jelly-roll type electrode assembly taken along line A-A' of FIG. 1, in which an uncoated portion according to an embodiment of the present disclosure is included in at least one of a positive electrode and a negative electrode. Figure 5 The electrode of FIG. 1 is applied to a positive electrode and a negative electrode.

[0090] Referring to Figure 5 and Figure 6 , the electrode assembly 50 according to the embodiment of the present disclosure can include an uncoated portion 51 included in at least one of a positive electrode and a negative electrode. Figure 5 and Figure 6 The configuration of the uncoated portion 51 of FIGS. 1 and 2 can be the same as all or a part of the configuration of the uncoated portion 43 of FIGS. 1 and 2. Figure 4 The embodiments of FIGS. 1 and 2 can be partially combined with the embodiments of FIGS. 1 and 2. Figure 5 and Figure 6 The embodiments of FIGS. 1 and 2 can be partially combined with the embodiments of FIGS. 1 and 2. Figure 4 The electrode assembly 50 can be defined as an assembly in which the positive electrode 40a, the negative electrode 40b, and the separator 45 interposed therebetween are wound. The electrode assembly 50 can be manufactured by referring to the winding method described with reference to FIG. 3.

[0091] The electrode assembly 50 can be defined as an assembly in which the positive electrode 40a, the negative electrode 40b, and the separator 45 interposed therebetween are wound. The electrode assembly 50 can be manufactured by referring to the winding method described with reference to Figure 2 FIG. 3.

[0092] For example, the positive electrode 40a can include a current collector (for example, the current collector 41 of FIG. 1) and an active material coating layer (for example, the active material coating layer 42 of FIG. 1) formed on at least one surface thereof. Figure 4 The negative electrode 40b can include a current collector (for example, the current collector 41 of FIG. 1) and an active material coating layer (for example, the active material coating layer 42 of FIG. 1) formed on at least one surface thereof. Figure 4The active material layer 42), and the thickness of the current collector can be approximately 180 μm to 220 μm. The negative electrode 40b may include a current collector (e.g., Figure 4 The current collector 41) and the active material coating formed on at least one of its surfaces (e.g., Figure 4 The active material layer 42 of the positive electrode 40a has a thickness of 140 μm to 180 μm. A separator 45 is interposed between the positive electrode 40a and the negative electrode 40b, and can have a thickness ranging from approximately 8 μm to 18 μm. For example, the length of the active material layer of the positive electrode 40a in the Y-axis direction can be shorter than the length of the active material layer of the negative electrode 40b in the Y-axis direction. Therefore, the active material layer of the negative electrode 40b can extend longer in the Y-axis direction than the active material layer of the positive electrode 40a. For example, in the electrode assembly 50, the number of turns of the positive electrode 40a varies depending on the form factor of the battery and can be approximately 48 to 56. The number of turns of the negative electrode 40b also varies depending on the form factor of the battery and can be approximately 48 to 56.

[0093] A separator 45 can be inserted between the positive electrode 40a and the negative electrode 40b. At least one surface of the separator 45 may include a coating of inorganic particles. Alternatively, the separator 45 itself may be formed of a coating of inorganic particles. The particles constituting the coating may have a structure in which they are bonded to a binder, such that there is a gap volume between adjacent particles. For example, the inorganic particles may be formed of an inorganic material with a dielectric constant of 5 or greater. As a non-limiting example, the inorganic particles may include selected... , , , Hafnium dioxide , , , , , , MgO, CaO, ZnO and At least one material in the group.

[0094] At least one of the positive electrode 40a and the negative electrode 40b of the electrode assembly 50 may include an uncoated portion 51 at its long side end. The uncoated portion 51 may include a positive uncoated portion 51a extending from the positive electrode 40a and a negative uncoated portion 51b extending from the negative electrode 40b. For example, the positive uncoated portion 51a may be in the upward direction of the electrode assembly 50 (e.g., Figure 5 The uncoated portion 51b of the negative electrode protrudes in the +Y axis direction, and the uncoated portion of the negative electrode can protrude in the downward direction of the electrode assembly 50 (e.g., in the downward direction). Figure 5 It protrudes in the Y-axis direction.

[0095] For example, in the winding structure of the positive electrode 40a, the spacing between the uncoated portions 51a of the positive electrode located at radially adjacent winding turns can be approximately 350 μm to 380 μm. Similarly, in the winding structure of the negative electrode 40b, the spacing between the uncoated portions 51b of the negative electrode located at radially adjacent winding turns can be 350 μm to 380 μm.

[0096] The uncoated portion 51 may be formed to be longer than the uncoated portion used in designs for small batteries. Preferably, the uncoated portion 51 may be 6 mm or longer, optionally 7 mm or longer, optionally 8 mm or longer, optionally 9 mm or longer, optionally 10 mm or longer, optionally 11 mm or longer, and optionally 12 mm or longer.

[0097] Preferably, in the active material layers of the positive electrode 40a and the negative electrode 40b (e.g., Figure 4 An insulating coating 44 formed at the boundary between the active material layer 42 and the uncoated portion 51 can extend to or be exposed to the outside from the end of the diaphragm 45. When the insulating coating 44 is exposed to the outside of the diaphragm 45, it can be used to support the bending point when the uncoated portion 51 is bent. When supporting the bending point, it releases the stress applied to the active material layer 42 and the diaphragm 45 when the uncoated portion 51 is bent. In addition, the insulating coating 44 can prevent the positive electrode 40a and the negative electrode 40b from contacting each other and causing a short circuit.

[0098] A winding portion 52 of the uncoated portion 51 may be disposed at one end of the electrode assembly 50. The winding portion 52 may refer to the portion formed when the uncoated portion 51 is wound. The winding portion 52 is exposed to the outside of the diaphragm 45 along the axial direction Y. The positive electrode winding portion 52a formed when the positive electrode uncoated portion 51a is wound may be disposed at the upper part of the electrode assembly 50. Similarly, the negative electrode winding portion 52b formed when the negative electrode uncoated portion 51b is wound may be disposed at the lower part of the electrode assembly 50.

[0099] Figure 7 This is a partial view of the clamp 60 and electrode assembly 50 used when pressing the winding portion 52 in the axial direction Y, according to an embodiment of the present disclosure, taken along the axial direction. Figure 8 This is a partial view of the clamp 60 and electrode assembly 50 used when pressing the winding portion 52 in the axial direction Y, according to another embodiment of the present disclosure, taken along the axial direction. Figure 9 This is an enlarged view showing the clamp 60 pressing the winding portion 52 according to an embodiment of the present disclosure.

[0100] refer to Figures 7 to 9The electrode assembly 50 according to embodiments of the present disclosure may include an uncoated portion 51 of at least one of the positive and negative electrodes. Figures 7 to 9 The configuration of the uncoated portion 51 can be with Figure 5 and Figure 6 The configuration of the uncoated portion 51 is wholly or partially the same. Figures 7 to 9 The implementation method can be partially related to Figure 5 and Figure 6 The combination of implementation methods.

[0101] According to one implementation method, reference Figure 7 The wound portion 52 may include a bent region 53 pressed by the clamp 60. According to another embodiment, see reference... Figure 8 The wound portion 52 may also include a flat region 54 that is not pressed by the clamp 60, as a region excluding the curved region 53. The shape and / or size of the curved region 53 may substantially correspond to the shape and / or size of the pressure surface 62 of the clamp 60. The arrangement and ratio of the curved region 53 and the flat region 54 may be designed and varied according to the embodiments. Additionally, as shown in the accompanying drawings of this disclosure, the flat region 54 may be a region formed by removing part or all of the uncoated portion 51, with the length of the uncoated portion 51 being shorter than the length of the surrounding environment. However, this disclosure is not limited to this, and the length of the uncoated portion 51 in the flat region 54 may be formed to be substantially the same as the length of the uncoated portion 51 near the flat region 54 (the length before bending). In this case, the clamp 60 may be configured not to press the region corresponding to the flat region 54.

[0102] According to one embodiment, the curved region 53 may include a plurality of uncoated portion layers 55 arranged along the radial direction Z. The plurality of uncoated portion layers 55 may be defined in the upward direction (e.g., Figure 7 The uncoated portion protrudes from the end of the coiled portion in the +Y axis direction. The plurality of uncoated portion layers 55 may have a width in the radial direction Z that is substantially the same from the core C side to the outer peripheral surface side of the electrode assembly 50. Alternatively, the plurality of uncoated portion layers 55 may have a circumferential width that gradually increases from the core side to the outer peripheral surface side of the electrode assembly 50.

[0103] Multiple uncoated portion layers 55 can be configured to be bent under pressure. Multiple uncoated portion layers 55 can be configured to be bent under pressure multiple times. Multiple uncoated portion layers 55 can be along the axial direction Y (e.g., Figure 7The uncoated portion layers 55 are pressed from top to bottom along the Y-axis direction. Multiple uncoated portion layers 55 can be bent multiple times while overlapping along the axial direction Y. The multiple uncoated portion layers 55 can be bent irregularly. For example, the bending shape of the multiple uncoated portion layers 55 can be wavy. For example, the bending shape of the multiple uncoated portion layers 55 can be irregular serrated.

[0104] Since the multiple uncoated portion layers 55 of the embodiments of this disclosure are bent while overlapping along the axial direction Y, the electrolyte injection channel can be unobstructed by the bent portions or bent surfaces 56. Furthermore, since the gas generated inside the cell during battery charging and discharging is not captured by the bent portions or bent surfaces 56, the gas can be smoothly discharged.

[0105] Because the multiple uncoated portion layers 55 of the embodiments of this disclosure bend while overlapping along the axial direction Y, the core C of the electrode assembly 50 is not obstructed even when bent. Since the electrode assembly 50 does not obstruct the core C, the electrolyte injection channel is not obstructed, and electrolyte injection can be performed smoothly.

[0106] According to an embodiment, the bending region 53 may include a bending surface 56 and at least one opening 57, the bending surface 56 being formed by bending a plurality of uncoated partial layers 55 under pressure, and the at least one opening 57 being configured to be surrounded by the bending surface 56.

[0107] Multiple uncoated partial layers 55 can be bent multiple times while overlapping along the axial direction Y to form a flat curved surface 56 substantially perpendicular to the axial direction Y. The curved surface 56 can be an upward-facing surface formed by the multiple uncoated partial layers 55 (e.g., Figure 7 A basically flat surface (in the +Y axis direction). The curved surface 56 can be used as a collector plate (e.g., Figure 14 The welding area of ​​the first manifold 144. The curved surface 56 may include multiple uncoated partial layers 55 in areas where the multiple layers overlap along the axial direction Y to achieve sufficient weld strength.

[0108] According to an embodiment, a clamp 60 including at least one protrusion 63 on one surface can press down on the bending region 53 from above, thereby bending multiple uncoated partial layers 55 and simultaneously forming at least one opening 57.

[0109] At least one opening 57 formed in the curved region 53 can be used as an electrolyte injection channel. In other words, electrolyte injection can be smoothly performed by forming at least one opening 57 in the curved region 53. In addition, at least one opening 57 formed in the curved region 53 can be used as a channel through which gas generated inside the battery can be discharged to the outside.

[0110] The curved region 53 may substantially correspond to the shape and / or size of the pressure surface 62 of the clamp 60. According to an embodiment, at least one opening 57 may be formed in the region corresponding to the location where at least one protrusion 63 is formed in the clamp 60.

[0111] According to an embodiment, the clamp 60 may include a pressure portion 61 and a gripping portion extending from the pressure portion 61 in an upward direction (+Y-axis direction). The pressure portion 61 may include a pressure surface 62, which is a surface facing downward in a downward direction (-Y-axis direction). The pressure surface 62 may be a surface that directly faces and presses against a pressure target. For example, the pressure surface 62 may be positioned above the electrode assembly 50 and configured to press against the winding portion 52 of the electrode assembly 50 in a downward direction. For example, the pressure surface 62 may face the winding portion 52 substantially parallel to it. The gripping portion may be a portion that contacts the user's body. The shape and / or structure of the pressure portion 61 and the gripping portion may be designed and varied differently.

[0112] According to one embodiment, the clamp 60 may include at least one protrusion 63 projecting vertically from the pressure surface 62. According to another embodiment, the at least one protrusion 63 may be formed extending from the pressure surface 62 of the clamp 60 in a downward direction (e.g., Figure 7 (The Y-axis direction) is prominent.

[0113] According to an embodiment, at least one protrusion 63 may be formed on a portion of the pressure surface 62 facing the bending region 53. For example, at least one protrusion 63 may not be provided on the pressure surface 62 corresponding to the core C region of the electrode assembly 50. For example, refer to... Figure 8 At least one protrusion 63 may not be provided on the pressure surface 62 corresponding to the flat area 54.

[0114] Figure 10 This is a plan view showing the pressure surface of the clamp 60 according to an embodiment of the present disclosure, viewed from below. Figure 11 This is a schematic diagram showing the wound portion 52 as viewed from above according to an embodiment of the present disclosure. Figure 12 This is a plan view showing the pressure surface of a clamp 60 according to another embodiment of the present disclosure, viewed from below. Figure 13 This is a schematic diagram showing the wound portion 52 according to another embodiment of the present disclosure, viewed from above.

[0115] refer to Figures 10 to 13 The electrode assembly 50 and the clamp 60 according to embodiments of the present disclosure will be described. Figures 10 to 13 The configuration of the electrode assembly 50 and the clamp 60 can be with Figures 7 to 9 The electrode assembly 50 and the clamp 60 are configured in all or part the same way.Figures 10 to 13 The implementation method can be partially related to Figures 7 to 9 The combination of implementation methods.

[0116] According to an embodiment, the ratio of the area occupied by at least one opening 57 to the area of ​​the curved region 53 can be approximately 30% or greater. For example, the ratio of the area occupied by at least one opening 57 to the area of ​​the curved region 53 (hereinafter defined as the "opening ratio") can be approximately 30% or greater and 50% or less. For example, when the opening ratio is less than 30%, the opening may not function smoothly as an electrolyte injection channel and / or an internal gas venting channel. For example, when the opening ratio is greater than 50%, the welding area to the manifold may be reduced, thus welding to the manifold may be difficult. However, the ratio of the area occupied by at least one opening 57 to the area of ​​the curved region 53 is not limited to the above embodiment and can be designed and changed differently.

[0117] According to one embodiment, at least one protrusion 63 may be formed at a location corresponding to the space between the plurality of uncoated portion layers 55. In other words, at least one protrusion 63 may be configured to be inserted between the plurality of uncoated portion layers 55.

[0118] According to an embodiment, at least one protrusion 63 formed on the jig 60 can be inserted between a plurality of uncoated portion layers 55 to form at least one opening 57 between the curved surfaces 56. In this disclosure, the uncoated portion 51 (see...) Figure 8 The uncoated portions 55 can be pressed and irregularly bent by the clamp 60 without undergoing processes such as grooving for smooth bending. In this way, the uncoated portions 55 can overlap each other in the process of bending the uncoated portions 51, and therefore, spaces through which the electrolyte can pass can not be formed on the bent surface of the uncoated portions 51. However, in this disclosure, openings 57 surrounded by the uncoated portions 55 can be formed by applying pressure to form a bent surface while using protrusions 63 provided on the clamp 60 to obtain space. At least one opening 57 can be formed at a location corresponding to the space between the plurality of uncoated portions 55.

[0119] According to an embodiment, the size of at least one protrusion 63 may be substantially equal to or smaller than the width (g) in the radial direction Z between the plurality of uncoated partial layers 55. For example, refer to Figure 10 The diameter l1 of at least one protrusion 63 may be substantially equal to or less than the width (g) in the radial direction Z between the plurality of uncoated partial layers 55.

[0120] Similarly, the size of at least one opening 57 may be substantially equal to or smaller than the width (g) in the radial direction Z between the plurality of uncoated partial layers 55. For example, see reference. Figure 11The diameter l2 of at least one opening 57 may be substantially equal to or less than the width (g) in the radial direction Z between the plurality of uncoated partial layers 55.

[0121] According to an embodiment, at least one protrusion 63 may be one or more. At least one protrusion 63 may be a plurality of protrusions arranged in a regular pattern. For example, refer to... Figure 10 At least one protrusion 63 may include a plurality of protrusions arranged at regular intervals along the circumferential direction X. For example, at least one protrusion 63 may include a plurality of protrusions arranged at regular intervals along the radial direction Z. According to an embodiment, at least one protrusion 63 may be formed to extend in the circumferential direction X along the space between a plurality of uncoated partial layers 55.

[0122] For example, refer to Figure 10 At least one protrusion 63 may include a plurality of protrusions arranged to be sequentially spaced at regular intervals from the central portion of the pressure surface 62 in the outward direction along the circumferential direction X. Similarly, refer to Figure 11 At least one opening 57 may include a plurality of openings 57, which are arranged to be sequentially spaced from the core C of the curved region 53 at regular intervals along the circumferential direction X in the outward direction.

[0123] For example, refer to Figure 12 At least one protrusion 63 may include a protrusion 63 having a curved surface extending in the circumferential direction X along the pressure surface 62. In this way, a plurality of protrusions having curved surfaces extending in the circumferential direction X can be sequentially arranged from the central portion of the pressure surface 62 in an outward direction. Similarly, refer to... Figure 13 At least one opening 57 may include an opening 57 having a curved surface extending along the circumferential direction X of the curved region 53. In this way, a plurality of openings having a curved surface extending along the circumferential direction X may be sequentially arranged from the central portion of the curved region 53 in an outward direction.

[0124] The electrode assembly 50 according to embodiments of this disclosure can be applied to wound-cell batteries.

[0125] Preferably, the battery can be, for example, a battery with a shape factor ratio (the shape factor ratio is defined as the value obtained by dividing the diameter of the battery by its height, i.e., the ratio of diameter Φ to height H) greater than about 0.4.

[0126] Here, the shape factor refers to the values ​​indicating the diameter and height of the battery. Batteries according to embodiments of this disclosure can be, for example, 46110, 4875, 48110, 4880, or 4680 batteries. In the shape factor values, the first two digits indicate the diameter of the battery, and the remaining digits indicate the height of the battery.

[0127] When an electrode assembly with a jointless structure is applied to a battery with a form factor ratio exceeding 0.4, the stress applied in the radial direction when the uncoated portion is bent is relatively large, making the uncoated portion prone to tearing. Furthermore, to ensure sufficient weld strength and reduce resistance when welding the current collector to the bent surface 56 region of the uncoated portion 51, the number of overlapping layers in the uncoated portion should be sufficiently increased. This requirement can be achieved by the electrode and electrode assembly 50 according to an embodiment (modified example) of this disclosure.

[0128] According to embodiments of the present disclosure, the battery may be a generally cylindrical battery having a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0129] According to another embodiment, the battery can be a generally cylindrical battery with a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0130] According to another embodiment, the battery can be a generally cylindrical battery with a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.436.

[0131] According to another embodiment, the battery can be a generally cylindrical battery with a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0132] According to another embodiment, the battery can be a generally cylindrical battery with a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0133] Typically, batteries with a form factor ratio of approximately 0.4 or less are already in use. That is, traditionally, for example, 1865 batteries and 2170 batteries have been used. An 1865 battery has a diameter of approximately 18 mm, a height of approximately 65 mm, and a form factor ratio of 0.277. A 2170 battery has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300.

[0134] The battery according to embodiments of the present disclosure will be described in detail below.

[0135] Figure 14 It is a cross-sectional view of the battery according to an embodiment of the present disclosure, taken along the axial direction Y.

[0136] refer to Figure 14According to an embodiment of the present disclosure, the battery 190 includes: an electrode assembly 110, which includes a positive electrode, a separator, and a negative electrode wound in a core-like manner; a battery housing 142 that houses the electrode assembly 110; and a sealing body 143 that seals the open end of the battery housing 142. The electrode assembly 110 has the structure described in the above embodiment. Figure 14 The configuration of the electrode assembly 110 can be with Figures 10 to 13 The configuration of the electrode assembly 50 is wholly or partially the same. Figure 14 The implementation method can be partially related to Figures 10 to 13 The combination of implementation methods.

[0137] The battery housing 142 is a cylindrical container with an opening formed at the top. The battery housing 142 is made of a conductive metallic material such as aluminum, steel, or stainless steel. The battery housing 142 houses the electrode assembly 110 within its internal space through the top opening and also contains the electrolyte. A Ni coating may be formed on the outer and / or inner surfaces of the battery housing 142.

[0138] The electrolyte can be characterized by, for example, Salts with a structure of . Here, Including alkali metal cations, for example , or Or a combination thereof. And, Including freedom of choice , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and One or more anions in a group.

[0139] Electrolytes can also be used by dissolving them in organic solvents. Examples of organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methylcarbonate (EMC), γ-butyrolactone, and mixtures thereof.

[0140] The electrode assembly 110 can have a core shape. For example... Figure 2 As shown, the electrode assembly 110 can be manufactured by winding an electrode-separator laminate around a winding center C, the electrode-separator laminate being formed by sequentially laminating a lower separator, a positive electrode, an upper separator, and a negative electrode at least once.

[0141] The uncoated positive electrode portion 51a and the uncoated negative electrode portion 51b may each protrude from the upper and lower portions of the electrode assembly 110, respectively. The uncoated positive electrode portion 51a may form a positive electrode winding portion (e.g., ...) on the upper portion of the electrode assembly 110. Figure 6 The positive electrode winding portion 52a), and the negative electrode uncoated portion 51b can be formed in the lower part of the electrode assembly 110 as a negative electrode winding portion (e.g., Figure 6 (52b, the negative electrode winding portion).

[0142] The sealing body 143 may include a cover 143a, a sealing gasket 143b that provides airtightness and has insulating properties between the cover 143a and the battery housing 142, and a connecting plate 143c that is electrically and mechanically connected to the cover 143a.

[0143] The cover 143a may include a conductive metallic material. The cover 143a may cover the upper opening of the battery casing 142. The cover 143a may be electrically connected to the positive electrode winding portion 52a and may be electrically insulated from the battery casing 142 by a sealing gasket 143b. Therefore, the cover 143a may serve as the positive terminal of the battery 140.

[0144] The cover 143a can be disposed on the pressing edge portion 147 formed in the battery housing 142 and can be secured by the crimped edge portion 148. A sealing gasket 143b can be inserted between the cover 143a and the crimped edge portion 148 to ensure the airtightness of the battery housing 142 and to provide electrical insulation between the battery housing 142 and the cover 143a. The cover 143a may have a protrusion 143d formed to project upwards from its center.

[0145] The battery casing 142 can be electrically connected to the negative electrode winding portion 52b. Therefore, the battery casing 142 can have the same polarity as the negative electrode.

[0146] The battery housing 142 may have a pressed edge portion 147 and a rolled edge portion 148 at its upper end. The pressed edge portion 147 can be formed by pressing the periphery of the outer peripheral surface of the battery housing 142. The pressed edge portion 147 can prevent the electrode assembly 110 housed inside the battery housing 142 from escaping through the upper opening of the battery housing 142, and can also serve as a support for the sealing body 143 to be mounted thereon.

[0147] A rolled edge portion 148 may be formed on the upper part of the pressing edge portion 147. The rolled edge portion 148 may have an extended and curved shape to roll around a portion of the outer peripheral surface and the upper surface of the cover 143a provided on the pressing edge portion 147.

[0148] The battery 190 may also include a first current collector 144 and / or a second current collector 145 and / or an insulator 146.

[0149] The first current collector 144 can be connected to the upper part of the electrode assembly 110. The first current collector 144 may include a conductive metal material, such as aluminum, copper, nickel, etc.

[0150] The first current collector 144 can be welded to a welding target area of ​​a curved surface 56, which is formed by bending a plurality of uncoated portion layers 55 in a curved region 53 of the positive electrode winding portion 52a. For example, the welding target area can be an area of ​​the plurality of uncoated portion layers 55 of the electrode assembly 110 with an average number of bends of five or more. Alternatively, the welding target area can be an area of ​​the plurality of uncoated portion layers 55 with an average stack thickness of 50 μm or greater.

[0151] According to one embodiment, at least one hole (not shown) may be formed at the center of the first current collector 144. Electrolyte can be injected through the hole. According to one embodiment, the diameter of the hole may be at least 0.5 times the diameter of the cavity in the core of the electrode assembly 110. If the diameter of the hole is smaller than the diameter of the cavity in the core, the electrode or separator can be prevented from escaping through the cavity in the core when venting occurs in the battery 190. Alternatively, if the diameter of the hole is equal to or greater than the diameter of the cavity in the core, the welding jig can be easily inserted during the process of welding the second current collector 145 to the bottom of the battery housing 142, and the electrolyte can be injected smoothly.

[0152] Although not shown in the accompanying drawings, the second current collector 145 may have holes disposed at locations corresponding to the opening 57 of the electrode assembly 50 described above. In this case, even in the area covered by the second current collector 145 over the entire area of ​​one surface of the electrode assembly 50, the circulation of electrolyte can be ensured.

[0153] The lead portion 149 can extend upward from the electrode assembly 110 to connect to the connecting plate 143c, or it can be directly connected to the lower surface of the cover 143a. The connecting plate 143c can be connected to the lower surface of the cover 143a. The lead portion 149 and other portions can be connected by soldering.

[0154] The curved surface 56 formed by bending multiple uncoated partial layers 55 and the first current collector 144 can be joined by laser welding. Laser welding can be replaced by resistance welding, ultrasonic welding, etc.

[0155] A plate-shaped second current collector 145 can be attached to the lower surface of the electrode assembly 110. The second current collector 145 may include a conductive metal material, such as aluminum, copper, nickel, etc. The second current collector 145 can be electrically connected to the battery housing 142. A first surface of the second current collector 145 can be attached to the electrode assembly 110, and a second surface opposite to the first surface can be attached to the battery housing 142.

[0156] Insulator 146 may cover the first current collector 144. Insulator 146 can prevent direct contact between the first current collector 144 and the inner peripheral surface of the battery casing 142 by covering the upper surface of the first current collector 144.

[0157] The insulator 146 may have a lead hole 151, allowing a lead portion 149 extending upward from the first current collector 144 to be pulled out. The lead portion 149 can be pulled upward through the lead hole 151 and connected to the lower surface of the connecting plate 143c or the lower surface of the cover 143a.

[0158] The peripheral region of the insulator 146 can be inserted between the first current collector 144 and the pressing portion 147 to fix the combination of the electrode assembly 110 and the first current collector 144. Therefore, the combination of the electrode assembly 110 and the first current collector 144 can be restricted from moving in the axial direction Y, thereby improving the assembly stability of the battery 190.

[0159] Insulator 146 may be made of an insulating polymer resin. In one example, insulator 146 may be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0160] The battery casing 142 may also have a venting portion 152 formed on its lower surface. The venting portion 152 may correspond to a region on the lower surface of the battery casing 142 that is thinner than the surrounding region. The venting portion 152 may be configured to be structurally weaker than the surrounding region. Therefore, when an anomaly occurs in the battery 190 and the internal pressure increases to a certain level or greater, the venting portion 152 may rupture and the gas generated inside the battery casing 142 may be released to the outside.

[0161] The vent portion 152 may be formed in a circular shape, either continuously or discontinuously, on the lower surface of the battery casing 142. In a modified example, the vent portion 152 may be formed in a linear pattern or other patterns.

[0162] Figure 15 This is a cross-sectional view of a battery according to another embodiment of the present disclosure, taken along the axial direction Y.

[0163] refer to Figure 15 Battery 200 has the same Figure 14 The battery 190 shown has a basically the same electrode assembly structure, except that the rest of the structure, excluding the electrode assembly, has been changed.

[0164] Specifically, the battery 200 includes a battery housing 171 through which terminals 172 are mounted. Terminals 172 may be riveted terminals, in which one end of the edge is riveted to the inner surface of a closed portion of the battery housing 171. Terminals 172 are mounted in the closed portion of the battery housing 171 (upper part of the drawing). Terminals 172 are riveted to a through-hole in the battery housing 171, with an insulating gasket 173 inserted therebetween. Terminals 172 are exposed to the outside in a direction opposite to the direction of gravity.

[0165] Terminal 172 may include a terminal exposure portion 172a and a terminal insertion portion 172b. The terminal exposure portion 172a may be exposed to the outside of the closed portion of the battery housing 171. The terminal exposure portion 172a may be positioned approximately at the center of the closed portion of the battery housing 171. The maximum diameter of the terminal exposure portion 172a may be larger than the maximum diameter of the through-hole formed in the battery housing 171. The terminal insertion portion 172b may be electrically connected to the positive electrode winding portion 52a by penetrating approximately the center of the closed portion of the battery housing 171. The portion forming the electrical connection may be a curved surface 56 formed by bending multiple uncoated portions 55 of the positive electrode winding portion 52a. The terminal insertion portion 172b may be riveted to the inner surface of the closed portion of the battery housing 171. That is, the end edge of the terminal insertion portion 172b may be pressed by a sealing clamp to have a shape bent towards the inner surface of the battery housing 171. The maximum diameter of the end of the terminal insertion portion 172b may be larger than the maximum diameter of the through-hole in the battery housing 171.

[0166] The lower end surface of the terminal insertion portion 172b is substantially flat and can be soldered to the first current collector 144', which is connected to the bent portion of the positive electrode winding portion 52a.

[0167] The first collector plate 144' can have the same... Figure 14 The manifold 145 shown has a basically the same structure.

[0168] An insulator 174, made of insulating material, can be inserted between the first current collector 144' and the inner surface of the battery housing 171. The insulator 174 can cover the upper portion of the first current collector 144' and the upper edge portion of the electrode assembly 110. This prevents the first current collector 144' from contacting the inner surfaces of the battery housing 171, which have different polarities, thus preventing a short circuit. Preferably, the terminal insertion portion 172b of the terminal 172 can be soldered to the first current collector 144' through the insulator 174. The insulator 174 may comprise an insulating polymer resin.

[0169] An insulating gasket 173 can be configured to be inserted between the battery housing 171 and the terminal 172 to prevent the battery housing 171 and the terminal 172, which have opposite polarities, from making electrical contact with each other. This allows the upper surface of the battery housing 171, which has a generally flat shape, to serve as the negative terminal of the battery 200.

[0170] The insulating gasket 173 may include a gasket exposed portion 173a and a gasket inserted portion 173b. The gasket exposed portion 173a may be inserted between the terminal exposed portion 172a of the terminal 172 and the battery housing 171. The gasket inserted portion 173b may be inserted between the terminal inserted portion 172b of the terminal 172 and the battery housing 171. The gasket inserted portion 173b may deform together with the terminal inserted portion 172b during riveting to make tight contact with the inner surface of the battery housing 171. The insulating gasket 173 may be made of, for example, an insulating polymer resin.

[0171] The exposed portion 173a of the insulating pad 173 may have an extended shape to cover the outer peripheral surface of the exposed portion 172a of the terminal 172. When the insulating pad 173 covers the outer peripheral surface of the terminal 172, short circuits can be prevented during the process of attaching electrical connection components such as busbars to the upper surface of the battery housing 171 and / or the terminal 172. Although not shown in the figures, the exposed portion 173a may have an extended shape to cover not only the outer peripheral surface of the exposed portion 172a of the terminal but also a portion of the upper surface.

[0172] When the insulating gasket 173 is made of polymer resin, it can be heat-fused to the battery housing 171 and the terminal 172. This enhances the airtightness at the interface between the insulating gasket 173 and the terminal 172, as well as at the interface between the insulating gasket 173 and the battery housing 171. Furthermore, when the exposed portion 173a of the insulating gasket 173 has a shape extending to the upper surface of the exposed portion 172a of the terminal, the terminal 172 can be integrally coupled to the insulating gasket 173 via insertion injection.

[0173] The remaining area 175 of the upper surface of the battery housing 171, excluding the area occupied by the terminal 172 and the insulating pad 173, can correspond to an electrode terminal with the opposite polarity to the terminal 172.

[0174] The second current collector 176 can be connected to the lower part of the electrode assembly 110. The second current collector 176 may include a conductive metallic material, such as aluminum, steel, copper, nickel, etc. The second current collector 176 can be welded to a welding target area of ​​the curved surface 56 formed in the negative electrode winding portion 52b. The welding target area may refer to the area along the radial direction of the electrode assembly 110 according to the uncoated portion layer 55 (see...). Figure 8 The number of overlapping curved layers remains in the maximum range.

[0175] Preferably, at least a portion of the second current collector 176 can be electrically connected to the battery housing 171. In one example, at least a portion of the edge portion of the second current collector 176 can be inserted and secured between the inner surface of the battery housing 171 and the sealing gasket 178b. Preferably, the welding target area included in the second current collector 176 and the curved surface 56 formed on the negative electrode winding portion 52b can be joined by laser welding. In this case, welding is performed in areas where the average number of uncoated partial layers 55 stacked in the axial direction Y of the curved surface 56 is 5 or greater, or in areas where the average stack thickness of the multiple uncoated partial layers 55 is 25 μm or greater. Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0176] Additionally, although not shown in the accompanying drawings, the second current collector 176 may have holes provided at positions corresponding to the openings 57 of the electrode assembly 50. In this case, even in areas where the entire area of ​​one surface of the electrode assembly 50 is covered by the second current collector 176, an area where electrolyte circulation can be ensured can be achieved.

[0177] The sealing body 178 at the lower opening end of the sealed battery housing 171 may include a cover 178a and a sealing gasket 178b. The sealing gasket 178b allows the cover 178a to be electrically separated from the battery housing 171. The rolled edge portion 181 secures the edge of the cover 178a and the sealing gasket 178b together. The cover 178a is provided with a venting portion 179. The construction of the venting portion 179 is substantially the same as that of the embodiment described above.

[0178] Preferably, the cover 178a may comprise a conductive metallic material. However, since the sealing gasket 178b is inserted between the cover 178a and the battery housing 171, the cover 178a may not be polarized. The seal 178 may be configured to seal the opening at the bottom of the battery housing 171 and to release gas when the internal pressure of the battery 200 increases above a critical value. The cover 178a may include a venting portion 179 in the edge region of the flat portion. The venting portion 179 is constructed substantially the same as that described in the above embodiment.

[0179] Preferably, the terminal 172, which is electrically connected to the bent portion of the positive electrode winding portion 52a via the first current collector 144', can be used as the first electrode terminal. Alternatively, the portion 175, excluding the terminal 172, on the upper surface of the battery housing 171, which is electrically connected to the bent portion of the negative electrode winding portion 52b via the second current collector 176, can be used as a second electrode terminal having a polarity different from the first electrode terminal. Thus, when the two electrode terminals are positioned on the upper part of the battery 200, electrical connection components such as busbars can be provided only on one side of the battery 200. This simplifies the battery pack structure and increases energy density. Furthermore, since the portion 175 used as the second electrode terminal has a generally flat shape, sufficient bonding area can be ensured for bonding electrical connection components such as busbars. Therefore, the battery 200 can reduce the resistance at the bonding portion of the electrical connection components to a desired level.

[0180] The battery according to the above-described embodiment (modified example) can be used to manufacture battery packs.

[0181] Figure 16 This is a diagram schematically illustrating the configuration of a battery pack according to an embodiment of the present disclosure.

[0182] refer to Figure 16 According to an embodiment of the present disclosure, the battery pack 300 includes an assembly for electrically connecting a battery 301 and a battery pack housing 302 for housing the assembly. The battery 301 can be any of the batteries described in the above embodiment (modified example). In the accompanying drawings, for ease of explanation, components such as busbars for electrically connecting the battery 301, cooling units, and external terminals are omitted.

[0183] The battery pack 300 can be installed in a vehicle. The vehicle can be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. Examples of vehicles include four-wheeled vehicles and two-wheeled vehicles.

[0184] Figure 17 It is used to describe including Figure 16 Image of a vehicle with a 300 battery pack.

[0185] refer to Figure 17 The vehicle V according to an embodiment of the present disclosure may include a battery pack 300 according to an embodiment of the present disclosure. According to an embodiment of the present disclosure, the vehicle V can operate by receiving power from the battery pack 300.

[0186] According to one aspect of this disclosure, a clamp comprising at least one protrusion on a surface presses down on a bending region from above, thereby bending a plurality of uncoated partial layers and simultaneously forming at least one opening, and thus the at least one opening can be used as an electrolyte injection channel to improve electrolyte impregnation.

[0187] According to another aspect of this disclosure, the curved region may include at least one opening, thereby allowing gas generated inside the battery to be smoothly discharged to the outside.

[0188] According to another aspect of this disclosure, by bending the curved region of the uncoated portion of the winding turn portion, a curved surface in which multiple uncoated portion layers overlap in multiple layers can be formed, and then the current collector can be welded to the corresponding region, thereby reducing the resistance of the battery.

[0189] According to another aspect of this disclosure, uncoated portions can be manufactured without a separate grooving process, thereby preventing performance degradation caused by metallic foreign matter generated during the grooving process and ensuring smooth gas venting. According to embodiments of this disclosure, process time can be shortened, and unit process cost can be increased by omitting the grooving process.

[0190] According to another aspect of this disclosure, by providing a large-capacity battery pack manufactured using batteries with high energy density and low resistance, and a vehicle including the large-capacity battery pack, the safety of fast charging and the efficiency of energy use can be improved.

[0191] The present disclosure has been described above with reference to a limited number of embodiments and accompanying drawings, but the present disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations can be made to it within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents.

Claims

1. An electrode assembly in which a positive electrode, a negative electrode, and a diaphragm inserted between the positive electrode and the negative electrode are wound together. in, At least one of the positive and negative electrodes includes an uncoated portion at the long side end, and The uncoated portion of the winding is located at one end of the electrode assembly. The wound portion includes a curved region comprising multiple uncoated portion layers configured to bend by applying pressure to form a curved surface. The curved region includes at least one opening configured to be surrounded by the curved surface.

2. The electrode assembly according to claim 1, in, The ratio of the area occupied by the at least one opening to the area of ​​the curved region is 30% or greater and 50% or less.

3. The electrode assembly according to claim 1, in, The multiple uncoated portions are bent to overlap along the axial direction.

4. The electrode assembly according to claim 1, in, The curved area is configured to be formed by pressing with a clamp that includes at least one protrusion on one surface.

5. The electrode assembly according to claim 4, in, The curved area corresponds to the area pressed by the clamp.

6. The electrode assembly according to claim 4, in, The at least one opening in the curved region is configured to be formed in the region where the at least one protrusion of the clamp is inserted.

7. The electrode assembly according to claim 4, in, The wound portion also includes a flat area that is not pressed down by the clamp.

8. The electrode assembly according to claim 1, in, The at least one opening is configured to be formed in a region corresponding to the region where the diaphragm is disposed.

9. The electrode assembly according to claim 1, in, The axial height of the curved region is higher than that of the flat region.

10. A method for manufacturing an electrode assembly, the method comprising: The first step is to prepare a negative electrode and a positive electrode with uncoated portions at the long side ends; The second step involves laminating the positive electrode, the negative electrode, and the separator at least once to insert the separator between the positive electrode and the negative electrode, and setting the positive electrode and the negative electrode so that the uncoated portions of the positive electrode and the negative electrode are exposed in opposite directions along the long side of the separator, thereby forming an electrode-separator laminate. The third step is to form an electrode assembly by winding the electrode-separator laminate around an axis such that the winding portions of the uncoated positive electrode and the winding portions of the uncoated negative electrode are exposed in opposite directions along the axial direction. as well as The fourth step involves pressing at least a portion of the wound portion using a clamp, and forming a curved surface and at least one opening through multiple uncoated portion layers bent by the pressing, the at least one opening being configured to be surrounded by the curved surface.

11. The method for manufacturing an electrode assembly according to claim 10, in, When the clamp is used to press the plurality of uncoated partial layers in the fourth step, the curved surface is formed and at least one opening is formed simultaneously.

12. The method for manufacturing an electrode assembly according to claim 10, in, The clamp includes at least one protrusion on one surface, and The at least one opening is formed in the area where the at least one protrusion of the clamp is inserted.

13. A battery, the battery comprising: Electrode assembly according to any one of claims 1 to 12; A battery housing, the battery housing including an open end and an opposite closed end, the battery housing accommodating the electrode assembly through the open end, and the battery housing being electrically connected to the electrode assembly; A sealing body that seals the opening end of the battery housing; Terminals, which are electrically connected to the electrode assembly and have surfaces exposed to the outside; as well as A current collector plate, which is welded to the curved surface and electrically connected to the battery housing or the terminal.

14. A battery pack comprising a battery according to any one of claims 1 to 13.

15. A vehicle comprising the battery pack according to claim 14.

Images