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

Abstract

The present invention may provide an electrode assembly in which a positive electrode, a negative electrode, and a separator interposed therebetween are wound, wherein at least one of the positive electrode and the negative electrode includes an uncoated portion at a long side end portion, a winding turn portion of the uncoated portion is provided at one side end portion 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 bent surface.

Description

Electrode assembly and manufacturing method and device thereof, battery including electrode assembly and battery pack and vehicle including same

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

[0002] This application claims priority to Korean Patent Application No. 10-2024-0070340, filed on May 29, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0003]

[0004] Secondary batteries, with their high applicability across product categories and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical power sources. These batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0005] Commonly used secondary batteries today include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. When high output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Furthermore, to increase charge / discharge capacity, multiple battery cells are connected in parallel to form a battery module or pack. Therefore, the number of battery cells included in a battery module or pack can vary depending on the required output voltage or charge / discharge capacity.

[0006] Meanwhile, as types of unit secondary batteries, cylindrical, prismatic, and pouch-shaped batteries are known. In the case of batteries, a separator, which is an insulator, is interposed between the positive and negative electrodes, and this is wound to form a jelly-roll-shaped electrode assembly, which is then inserted into the battery housing to constitute the battery. In addition, a strip-shaped electrode tab may be connected to each of the non-coated portions of the positive and negative electrodes, and the electrode tab electrically connects the electrode assembly and the electrode terminal exposed to the outside. For reference, the positive terminal is a cap of a sealing body that seals the opening of the battery housing, and the negative terminal is the battery housing. However, according to a conventional battery having such a structure, since the current is concentrated on the strip-shaped electrode tab connected to the positive non-coated portion and / or the negative non-coated portion, there was a problem that the resistance was high, a lot of heat was generated, and the current collection efficiency was poor.

[0007] Resistance and heat generation are not major issues for small batteries with form factors such as 1865 or 2170. However, if the form factor is increased for use in electric vehicles, excessive heat generated around the electrode tabs during rapid charging can lead to battery fires.

[0008] To solve these problems, a battery having a structure in which a positive electrode non-conducting portion and a negative electrode non-conducting portion are respectively located at the top and bottom of a jelly roll type electrode assembly and a current collecting plate is welded to these non-conducting portions to improve current collection efficiency (a so-called tab-less battery) has been proposed.

[0009] Figures 1 to 3 are drawings showing the manufacturing process of a tab-less battery. Figure 1 shows the structure of an electrode, Figure 2 shows the winding process of the electrode, and Figure 3 shows the process of welding a current collecting plate to the folded surface of the non-conductive portion.

[0010] Referring to FIGS. 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 includes a non-conductive portion (22) on one long side along the winding direction (X).

[0011] The electrode assembly (A) is manufactured by sequentially stacking a positive electrode (10) and a negative electrode (11) together with two separators (12) as illustrated in Fig. 2, and then winding them in one direction (X). At this time, the non-coated portions of the positive electrode (10) and the negative electrode (11) are arranged in opposite directions based on the short side direction of the separator (12). The positions of the positive electrode (10) and the negative electrode (11) may be changed to the opposite of what is illustrated.

[0012] After the winding process, the non-coated portion (10a) of the positive electrode (10) and the non-coated portion (11a) of the negative electrode (11) are folded toward the core side. Thereafter, the non-coated portions (10a, 11a) are joined by welding the current collecting plates (30, 31), respectively.

[0013] The positive electrode uncharged portion (10a) and the negative electrode uncharged portion (11a) are not connected with separate electrode tabs, the current collecting plates (30, 31) are connected to external electrode terminals, and the current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly (A) (see arrow), so there is an advantage in that the resistance of the battery can be reduced. This is because the resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0014] In a tab-less battery, in order to improve the welding characteristics of the non-conductive portion (10a, 11a) and the current collecting plate (30, 31), strong pressure must be applied to the welding point of the non-conductive portion (10a, 11a) to bend the non-conductive portion (10a, 11a) as flat as possible.

[0015] When bending the non-conductive portion (10a, 11a), a jig that presses the non-conductive portion (10a, 11a) toward the core of the electrode assembly (A) can be used.

[0016] When a folded surface is formed on the entire upper surface of the electrode assembly by bending the non-conductive portion (10a, 11a), not only is the injection of the electrolyte difficult, but gas generated internally may be blocked by the folded surface and difficult to discharge to the outside.

[0017]

[0018] The present invention was created under the background of the above-described prior art, and its purpose is to provide a method and device for manufacturing an electrode including a winding turn portion including at least one opening when bending a non-conductive portion of a tab-less battery, and an electrode assembly manufactured by the method and device.

[0019] Another technical object of the present invention is to provide a battery including an electrode assembly manufactured by an improved method.

[0020] Another technical object of the present invention is to provide an electrode assembly having an electrode having a winding turn portion including at least one opening, which can improve energy density, reduce resistance, and improve electrolyte impregnation.

[0021] Another technical object of the present invention is to provide a battery including an electrode assembly of an improved structure, a battery pack including the same, and a vehicle including the battery pack.

[0022] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0023]

[0024] In order to solve the above problem, the present invention can provide an electrode assembly in which a positive electrode and a negative electrode and a separator interposed therebetween are wound, wherein at least one of the positive electrode and the negative electrode includes a non-coated portion at a long end, a winding turn portion of the non-coated portion is provided at one end of the electrode assembly, and the winding turn portion includes a bending region including a plurality of non-coated portion layers configured to be bent by pressure to form a bending surface.

[0025] The bending region may include the bending surface and at least one opening configured to be surrounded by the bending surface.

[0026] The ratio of the area occupied by the at least one opening to the area of ​​the bending region may be 30% or more and 50% or less.

[0027] The above multiple layers of the non-woven fabric can be folded multiple times so as to overlap along the axial direction.

[0028] The above bending region may be configured to be formed by pressing using a jig including at least one protrusion on one surface.

[0029] The above bending area may correspond to the area pressed by the jig.

[0030] The jig may be configured such that at least one opening of the bending region is formed in an area where at least one protrusion is inserted.

[0031] The above-mentioned winding turn portion may further include a flat area that is not pressurized by the jig.

[0032] The at least one opening may be configured to be formed in an area corresponding to the area where the separator is arranged.

[0033] The axial height of the above bending region may be higher than the axial height of the above flat region.

[0034] In order to solve the above problem, the present invention can provide a method for manufacturing an electrode assembly, including a first step of preparing a positive electrode and a negative electrode having a non-coated portion at a long end; a second step of forming an electrode-separator laminate by stacking the positive electrode, the negative electrode, and the separator at least once so that a separator is interposed between the positive electrode and the negative electrode, and so that the positive non-coated portion and the negative non-coated portion are exposed in opposite directions along the short side direction of the separator; a third step of forming an electrode assembly by winding the electrode-separator laminate around one axis so that a winding turn portion of the positive electrode non-coated portion and a winding turn portion of the negative electrode non-coated portion are exposed in opposite directions along the axial direction; and a fourth step of pressing at least a portion of the winding turn portion using a jig, and forming a bending surface and at least one opening configured to be surrounded by the bending surface by a plurality of non-coated portion layers bent by the pressing.

[0035] In the fourth step, when the plurality of non-woven layers are pressed using the jig, the bending surface may be formed at the same time as the at least one opening is formed.

[0036] The jig may include at least one protrusion on one surface, and at least one opening may be formed in an area of ​​the jig into which the at least one protrusion is inserted.

[0037] In order to solve the above problem, the present invention can provide a battery including an electrode assembly; a battery housing including an open end and a closed end opposite thereto, the electrode assembly being received through the open end and electrically connected to the electrode assembly; a sealing body sealing the open end of the battery housing; a terminal electrically connected to the electrode assembly and having a surface exposed to the outside; and a current collecting plate welded to the folded surface and electrically connected to either the battery housing or the terminal.

[0038] In addition, the present invention provides a battery pack characterized by including a battery module according to the present invention.

[0039] And, the present invention provides an automobile characterized by including a battery pack according to the present invention.

[0040]

[0041] According to one embodiment of the present invention, since the plurality of non-conductive layers are folded while overlapping along the axial direction, the electrolyte injection passage is not blocked by the folded portion or the folded surface, and the electrolyte injection can be smoothly performed. In addition, since the gas generated within the cell during battery charging and discharging is not captured by the folded portion or the folded surface, smooth gas discharge can be induced.

[0042] According to one aspect of the present invention, a jig including at least one protrusion on one side presses a non-woven winding turn portion from above, thereby bending a plurality of non-woven layers and forming at least one opening so that at least one opening can be utilized as an electrolyte injection passage, thereby improving electrolyte impregnation properties.

[0043] According to another aspect of the present invention, the bending area of ​​the non-removable winding turn portion includes at least one opening so that gas generated inside the battery can be smoothly discharged to the outside.

[0044] According to another aspect of the present invention, the resistance of the battery can be lowered by bending the bending area of ​​the winding turn portion of the non-woven portion to form a bending surface in which a plurality of non-woven portion layers are overlapped in multiple layers, and then welding a current collecting plate to the area.

[0045] Conventionally, when manufacturing a non-woven part, a notching process was included to form a certain pattern in the non-woven part. However, the non-woven part according to an embodiment of the present invention can be manufactured without a separate notching process. According to an embodiment of the present invention, performance degradation due to metal foreign substances generated during the notching process can be prevented and smooth gas discharge can be induced. According to an embodiment of the present invention, by omitting the notching process, the process time can be shortened and the process cost can be improved.

[0046] According to another aspect of the present invention, by providing a large-capacity battery pack manufactured using batteries having high energy density and low resistance and a vehicle including the same, the safety of rapid charging and the efficiency of energy use can be improved.

[0047] In addition, the present invention may have various other effects, which will be described in each embodiment configuration, or the description of effects that can be easily inferred by those skilled in the art will be omitted.

[0048]

[0049] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0050] Figure 1 is a plan view showing the structure of an electrode used in the manufacture of a conventional tab-less battery.

[0051] Figure 2 is a drawing showing the electrode winding process of a conventional tab-less battery.

[0052] Figure 3 shows a process in which a current collecting plate is welded to a folded surface of a non-conductive portion in a conventional tab-less battery.

[0053] Figure 4 is a plan view showing the structure of an electrode according to an embodiment of the present invention.

[0054] FIG. 5 is a partial perspective view showing the upper structure of an electrode assembly before being pressurized by a jig according to an embodiment of the present invention.

[0055] FIG. 6 is a cross-sectional view taken along line A-A' of a jelly roll type electrode assembly in which the electrodes of FIG. 5 according to an embodiment of the present invention are applied to the positive and negative electrodes.

[0056] FIG. 7 is a partial view taken along the axial direction of a jig and electrode assembly used when pressurizing a winding turn part along the axial direction according to one embodiment of the present invention.

[0057] FIG. 8 is a partial cross-sectional view of a jig and electrode assembly used when pressurizing a winding turn part along the axial direction according to another embodiment of the present invention.

[0058] FIG. 9 is an enlarged view showing a jig pressurizing a winding turn part according to one embodiment of the present invention.

[0059] Fig. 10 is a plan view showing the pressurized surface of a jig according to one embodiment of the present invention as viewed from the downward direction.

[0060] Fig. 11 is a diagram schematically showing a top view of a winding turn part according to one embodiment of the present invention.

[0061] Fig. 12 is a plan view showing the pressurized surface of a jig according to another embodiment of the present invention as viewed from the downward direction.

[0062] Fig. 13 is a diagram schematically showing a top view of a winding turn part according to another embodiment of the present invention.

[0063] FIG. 14 is a cross-sectional view of a battery according to one embodiment of the present invention taken along the axial direction (Y).

[0064] FIG. 12 is a cross-sectional view of a battery according to another embodiment of the present invention taken along the axial direction (Y).

[0065] Fig. 16 is a drawing schematically showing the configuration of a battery pack according to an embodiment of the present invention.

[0066] FIG. 17 is a drawing for explaining a vehicle including a battery pack according to an embodiment of the present invention.

[0067]

[0068] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0069] Accordingly, 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. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0070] Furthermore, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar components will be omitted, and the differences will be described.

[0071] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and the dimensions of some components may be exaggerated. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0072] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0073] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0074] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0075] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0076] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0077] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0078] For convenience of explanation, the direction along the longitudinal 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) in this specification. In addition, the direction surrounding the winding axis is referred to as the circumferential direction or the circumferential direction (X). In addition, the direction approaching or moving away from the winding axis is referred to as the radial direction or the radial direction (Z). Among these, the direction approaching the winding axis is referred to as the centripetal direction, and the direction moving away from the winding axis is referred to as the centrifugal direction.

[0079] First, an electrode assembly according to an embodiment of the present invention will be described. The electrode assembly is a jelly roll type electrode assembly having a structure in which a positive electrode and a negative electrode in a sheet shape and a separator interposed therebetween are wound in one direction.

[0080] Preferably, at least one of the positive and negative electrodes includes a non-coated portion on the long side in the winding direction that is not coated with an active material. At least a portion of the non-coated portion is used as an electrode tab in itself.

[0081] Figure 4 is a plan view showing the structure of an electrode according to an embodiment of the present invention.

[0082] Referring to FIG. 4, an electrode (40) according to one embodiment of the present invention includes a current collector (41) and an active material layer (42). The configuration of the current collector (41), the active material layer (42), and the non-conductive portion (43) of FIG. 4 may be all or part of the same as the configuration of the current collector (20), the active material layer (21), and the non-conductive portion (22) of FIGS. 1 to 3. The embodiment of FIG. 4 may be partially combined with the element(s) illustrated in FIGS. 1 to 3.

[0083] According to one embodiment of the present invention, the electrode (40) may include a current collector (41) 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 depending on the polarity of the electrode (40). The active material layer (42) is formed on at least one surface of the current collector (41), and includes a non-coated portion (43) at a long end in the winding direction (X). The non-coated portion (43) is a region where the active material is not coated. An insulating coating layer (44) may be formed at a boundary between the active material layer (42) and the non-coated portion (43). The insulating coating layer (44) is formed so that at least a portion overlaps the boundary between the active material layer (42) and the non-coated portion (43). The insulating coating layer (44) may include a polymer resin, and may include an inorganic filler such as SiO2 or Al2O3. The polymer resin may have a porous structure. The polymer resin is not particularly limited as long as it is an insulating material. The polymer resin may be polyolefin, polyimide, polyethylene terephthalate, polybutylene fluoride, etc., but the present invention is not limited thereto.

[0084] The electrode (40) of the above-described embodiment can be applied to an anode (e.g., an anode (40a) of FIG. 6) and / or a cathode (e.g., an anode (40b) of FIG. 6) included in a jellyroll type electrode assembly (e.g., an electrode assembly (50) of FIG. 6). In addition, when the electrode structure of the embodiment is applied to one of the anode and the cathode, a conventional electrode structure (FIG. 1) can be applied to the other. In addition, the electrode structures applied to the anode and the cathode may not be identical to each other and may be different.

[0085] In the present invention, the positive electrode active material coated on the positive electrode and the negative electrode active material coated on the negative electrode may be used without limitation as long as they are active materials known in the art. In one example, the positive electrode active material may include an alkali metal compound represented by the general chemical formula A[AxMy]O2+z (A includes at least one element selected from 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; stoichiometric coefficients x, y, and z are selected such that the compound maintains electrical neutrality).

[0086] In another example, the positive electrode active material may be an alkali metal compound xLiM1O2(1x)Li2M2O3 (M1 comprises at least one element having an average oxidation state 3; M2 comprises at least one element having an average oxidation state 4; 0≤x≤1) as disclosed in US6,677,082, US6,680,143, etc.

[0087] In another example, the cathode active material has the general formula LiaM1xFe1xM2yP1yM3zO4z (M1 comprises at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M2 comprises 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 comprises a halogen element optionally including F; 0 < a ≤2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients a, x, y and z are selected such that the compound maintains electrical neutrality), or Li3M2(PO4)3 [M comprises at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al. It may be a lithium metal phosphate represented by [containing at least one selected element].

[0088] Preferably, the positive electrode active material may include primary particles and / or secondary particles formed by agglomeration of primary particles.

[0089] In one example, the negative active material may be carbon, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides such as TiO2 and SnO2 with a potential of less than 2 V can also be used as the negative active material. Carbon materials such as low-crystalline carbon and high-crystalline carbon can all be used.

[0090] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, etc., used alone or in a laminated manner. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc.

[0091] The non-coated region (43) according to an embodiment of the present invention can be defined as a region in which at least one long side end of the positive electrode and the negative electrode is not coated with an active material. In the past, when manufacturing a non-coated region, a notching process was included to form a certain pattern in the non-coated region, but the non-coated region (43) according to an embodiment of the present invention can be manufactured without a separate notching process. According to an embodiment of the present invention, it is possible to prevent performance degradation due to metal foreign substances generated during the notching process and induce smooth gas discharge. According to an embodiment of the present invention, by omitting the notching process, the process time can be shortened, the process cost can be improved, and the current collection efficiency can be improved.

[0092] Fig. 5 is a partial perspective view showing the upper structure of an electrode assembly before being pressurized by a jig according to an embodiment of the present invention. Fig. 6 is a cross-sectional view taken along line A-A' of a jelly roll type electrode assembly in which the electrode of Fig. 5 is applied to the positive and negative electrodes according to an embodiment of the present invention.

[0093] Referring to FIGS. 5 and 6, an electrode assembly (50) according to one embodiment of the present invention may include a non-conductive portion (51) including at least one of the positive electrode and the negative electrode. The configuration of the non-conductive portion (51) of FIGS. 5 and 6 may be all or part of the same as the configuration of the non-conductive portion (43) of FIG. 4. The embodiment of FIGS. 5 and 6 may be partially combined with the embodiment of FIG. 4.

[0094] An electrode assembly (50) can be defined as an assembly in which a positive electrode (40a) and a negative electrode (40b) and a separator (45) interposed therebetween are wound. The electrode assembly (50) can be manufactured using the winding method described with reference to FIG. 2.

[0095] For example, the positive electrode (40a) includes a current collector (e.g., a current collector (41) of FIG. 4) and an active material layer formed on at least one surface thereof (e.g., an active material layer (42) of FIG. 4), and the thickness of the current collector may be approximately 180 μm to 220 μm. The negative electrode (40b) includes a current collector (e.g., a current collector (41) of FIG. 4) and an active material layer formed on at least one surface thereof (e.g., an active material layer (42) of FIG. 4), and the thickness of the current collector may be approximately 140 μm to 180 μm. The separator (45) is interposed between the positive electrode (40a) and the negative electrode (40b), and the thickness may be approximately 8 μm to 18 μm. For example, the Y-axis direction length of the active material layer of the positive electrode (40a) may be smaller than the Y-axis direction length of the active material layer of the negative electrode (40b). Accordingly, the active material layer of the negative electrode (40b) can extend longer along 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 may 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 may be approximately 48 to 56.

[0096] A separator (45) may be interposed between the anode (40a) and the cathode (40b). At least one surface of the separator (45) may include a coating layer of inorganic particles. Additionally, the separator (45) itself may be formed of a coating layer of inorganic particles. The particles forming the coating layer may have a structure in which they are combined with a binder so that an interstitial volume exists between adjacent particles. For example, the inorganic particles may be formed of an inorganic material having a dielectric constant of 5 or higher. As a non-limiting example, the inorganic particles may include at least one material selected from the group consisting of Pb(Zr,Ti)O3(PZT), Pb1xLaxZr1yTiyO3(PLZT), PB(Mg3Nb2 / 3)O3PbTiO3(PMNPT), BaTiO3, hafnia(HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO, and Y2O3.

[0097] At least one of the positive electrode (40a) and the negative electrode (40b) of the electrode assembly (50) may include a non-coated portion (51) at a long end. The non-coated portion (51) may include a positive non-coated portion (51a) extending from the positive electrode (40a), and a negative non-coated portion (51b) extending from the negative electrode (40b). For example, the positive non-coated portion (51a) may protrude in an upward direction of the electrode assembly (50) (e.g., in the +Y direction of FIG. 5), and the negative non-coated portion (51b) may protrude in a downward direction of the electrode assembly (50) (e.g., in the -Y direction of FIG. 5).

[0098] For example, in the winding structure of the anode (40a), the spacing between the anode non-coated portions (51a) located in radially adjacent winding turns may be approximately 350 um to 380 um. In addition, in the winding structure of the cathode (40b), the spacing between the cathode non-coated portions (51b) located in radially adjacent winding turns may be approximately 350 um to 380 um.

[0099] The non-conductive portion (51) may be formed longer than the non-conductive portion applied to the design of a small battery. Preferably, the non-conductive 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, or optionally 12 mm or longer.

[0100] Preferably, the insulating coating layer (44) formed at the boundary between the active material layer (e.g., the active material layer (42) of FIG. 4) of the positive electrode (40a) and the negative electrode (40b) and the non-coated portion (51) may extend to the end of the separator (45) or be exposed outward from the end. When the insulating coating layer (44) is exposed to the outside of the separator (45), it may serve to support the bending point when the non-coated portion (51) is bent. When the bending point is supported, the stress applied to the active material layer (42) and the separator (45) when the non-coated portion (51) is bent is relieved. In addition, the insulating coating layer (44) may prevent the positive electrode (40a) and the negative electrode (40b) from contacting each other and causing a short circuit.

[0101] A winding turn portion (52) of the non-coated portion (51) may be provided at one end of the electrode assembly (50). The winding turn portion (52) may refer to a portion formed when the non-coated portion (51) is wound. The winding turn portion (52) is exposed to the outside of the separator (45) along the axial direction (Y). A positive winding turn portion (52a) formed when the positive non-coated portion (51a) is wound may be provided at the upper end of the electrode assembly (50). Similarly, a negative winding turn portion (52b) formed when the negative non-coated portion (51b) is wound may be provided at the lower end of the electrode assembly (50).

[0102] FIG. 7 is a partial view of a jig (60) and an electrode assembly (50) used when pressing a winding turn portion (52) along the axial direction (Y) according to one embodiment of the present invention, taken along the axial direction (Y). FIG. 8 is a partial view of a jig (60) and an electrode assembly (50) used when pressing a winding turn portion (52) along the axial direction (Y) according to another embodiment of the present invention, taken along the axial direction (Y). FIG. 9 is an enlarged view showing a state in which a jig (60) presses a winding turn portion (52) according to one embodiment of the present invention.

[0103] Referring to FIGS. 7 to 9, an electrode assembly (50) according to one embodiment of the present invention may include a non-conductive portion (51) including at least one of the positive electrode and the negative electrode. The configuration of the non-conductive portion (51) of FIGS. 7 to 9 may be all or part of the same as the configuration of the non-conductive portion (51) of FIGS. 5 and 6. The embodiment of FIGS. 7 to 9 may be partially combined with the embodiment of FIGS. 5 and 6.

[0104] According to one embodiment, referring to FIG. 7, the winding turn portion (52) may include a bending region (53) that is pressed by the jig (60). According to another embodiment, referring to FIG. 8, the winding turn portion (52) may further include a flat region (54) that is not pressed by the jig (60) as a region excluding the bending region (53). The shape and / or size of the bending region (53) may substantially correspond to the shape and / or size of the pressing surface (62) of the jig (60). The arrangement and ratio of the bending region (53) and the flat region (54) may be variously designed and changed according to the embodiment. Meanwhile, the flat region (54) may be a region in which a part or all of the plain region (51) is removed so that the length of the plain region (51) is formed to be shorter than the surrounding area, as illustrated in the drawing of the present invention. However, the present invention is not limited thereto, and the length of the uncoated portion (51) in the flat area (54) may be formed to be substantially the same as the length of the uncoated portion (51) around the flat area (54) (length before bending). In this case, the jig (60) may be configured so as not to pressurize the area corresponding to the flat area (54).

[0105] According to one embodiment, the bending region (53) may include a plurality of non-coated layers (55) arranged along the radial direction (Z). The plurality of non-coated layers (55) may be defined as ends of the rolled non-coated layers that protrude upward (e.g., the +Y-axis direction of FIG. 7). The plurality of non-coated layers (55) may have a width in the radial direction (Z) that is substantially the same from the core (c) side of the electrode assembly (50) toward the outer peripheral surface. Alternatively, the plurality of non-coated layers (55) may have a width in the circumferential direction that gradually increases from the core side of the electrode assembly (50) toward the outer peripheral surface.

[0106] The plurality of non-woven layers (55) may be configured to be bent by pressure. The plurality of non-woven layers (55) may be configured to be bent multiple times by pressure. The plurality of non-woven layers (55) may be pressed from the upper side to the lower side along the axial direction (Y) (e.g., the -Y-axis direction of FIG. 7). The plurality of non-woven layers (55) may be bent multiple times while overlapping along the axial direction (Y). The plurality of non-woven layers (55) may be bent irregularly. For example, the bending shape of the plurality of non-woven layers (55) may be a wave shape. For example, the bending shape of the plurality of non-woven layers (55) may be an irregular zigzag shape.

[0107] Since the plurality of non-conductive layers (55) according to one embodiment of the present invention are folded while overlapping along the axial direction (Y), the electrolyte injection passage may not be blocked by the folded portion or folded surface (56). In addition, since the gas generated inside the cell during battery charging and discharging is not captured by the folded portion or folded surface (56), smooth gas discharge can be induced.

[0108] Since the plurality of non-conductive layers (55) according to one embodiment of the present invention are folded while overlapping along the axial direction (Y), the core (C) of the electrode assembly (50) may not be shielded even when folded. Since the electrode assembly (50) does not shield the core (C), the electrolyte injection passage is not shielded, and the electrolyte injection can be smoothly performed.

[0109] According to one embodiment, the bending region (53) may include a bending surface (56) formed by bending a plurality of non-woven layers (55) under pressure, and at least one opening (57) configured to be surrounded by the bending surface (56).

[0110] A plurality of non-coated layers (55) can be folded multiple times while overlapping along the axial direction (Y) to form a flat folded surface (56) that is substantially perpendicular to the axial direction (Y). The folded surface (56) can be a substantially flat surface facing upward (e.g., the +Y-axis direction in FIG. 7) formed by the plurality of non-coated layers (55). The folded surface (56) can be used as a welding area of ​​a current collecting plate (e.g., the first current collecting plate (144) in FIG. 11). The folded surface (56) can include an area where the plurality of non-coated layers (55) are overlapped in multiple layers along the axial direction (Y) to achieve sufficient welding strength.

[0111] According to one embodiment, a jig (60) including at least one protrusion (63) on one side can be used to press the bending region (53) from above, thereby bending a plurality of non-woven layers (55) while forming at least one opening (57).

[0112] At least one opening (57) formed in the bending region (53) can be utilized as an electrolyte injection passage. In other words, by forming at least one opening (57) in the bending region (53), electrolyte injection can be smoothly performed. In addition, at least one opening (57) formed in the bending region (53) can be utilized as a passage through which gas generated within the battery can be discharged to the outside.

[0113] The bending area (53) may substantially correspond to the shape and / or size of the pressing surface (62) of the jig (60). According to one embodiment, at least one opening (57) may be formed in an area corresponding to a position where at least one protrusion (63) is formed in the jig (60).

[0114] According to one embodiment, the jig (60) may include a pressurizing portion (61) and a grip portion extending upward (in the +Y-axis direction) from the pressurizing portion (61). The pressurizing portion (61) may include a pressurizing surface (62), which is a surface facing downward (in the -Y-axis direction). The pressurizing surface (62) may be a surface that directly faces a pressurizing target and presses the pressurizing target. For example, the pressurizing surface (62) may be located on the upper side of the electrode assembly (50) and configured to press the winding turn portion (52) of the electrode assembly (50) from the upward direction to the downward direction. For example, the pressurizing surface (62) may face the winding turn portion (52) in a substantially parallel manner. The grip portion may be a portion that comes into contact with the user's body. The shape and / or structure of the pressurizing portion (61) and the grip portion may be designed in various ways.

[0115] According to one embodiment, the jig (60) may include at least one protrusion (63) protruding vertically from the pressing surface (62). According to one embodiment, the at least one protrusion (63) may be formed to protrude downwardly (e.g., in the -Y-axis direction of FIG. 7) from the pressing surface (62) of the jig (60).

[0116] According to one embodiment, at least one protrusion (63) may be formed in a portion of the pressing surface (62) that faces the bending region (53). For example, at least one protrusion (63) may not be positioned on the pressing surface (62) corresponding to the core (C) region of the electrode assembly (50). For example, referring to FIG. 8, at least one protrusion (63) may not be positioned on the pressing surface (62) corresponding to the flat region (54).

[0117] Fig. 10 is a plan view showing the pressurized surface of a jig (60) according to one embodiment of the present invention as viewed from the downward direction. Fig. 11 is a diagram schematically showing the winding turn part (52) according to one embodiment of the present invention as viewed from the upward direction. Fig. 12 is a plan view showing the pressurized surface of a jig (60) according to another embodiment of the present invention as viewed from the downward direction. Fig. 13 is a diagram schematically showing the winding turn part (52) according to another embodiment of the present invention as viewed from the upward direction.

[0118] Referring to FIGS. 10 to 13, an electrode assembly (50) and a jig (60) according to an embodiment of the present invention will be described. The configuration of the electrode assembly (50) and the jig (60) of FIGS. 10 to 13 may be all or part of the same as the configuration of the electrode assembly (50) and the jig (60) of FIGS. 7 to 9. The embodiment of FIGS. 10 to 13 may be partially combined with the embodiment of FIGS. 7 to 9.

[0119] According to one embodiment, the ratio of the area occupied by the at least one opening (57) to the area of ​​the bending region (53) may be approximately 30% or more. For example, the ratio of the area occupied by the at least one opening (57) to the area of ​​the bending region (53) (hereinafter, defined as the 'opening ratio') may be approximately 30% or more and 50% or less. For example, when the opening ratio is lower than 30%, the function as an electrolyte injection passage and / or an internal gas exhaust passage may not be smoothly performed. For example, when the opening ratio is higher than 50%, the welding area with the current collecting plate is reduced, so that welding with the current collecting plate may be difficult. However, the ratio of the area occupied by the at least one opening (57) to the area of ​​the bending region (53) is not limited by the above embodiment, and may be designed in various ways.

[0120] According to one embodiment, at least one protrusion (63) may be formed at a position corresponding to a space between the plurality of non-woven layers (55). In other words, at least one protrusion (63) may be configured to be inserted between the plurality of non-woven layers (55).

[0121] According to one embodiment, at least one protrusion (63) formed on the jig (60) may be inserted between a plurality of non-coated layers (55) to form at least one opening (57) between the folded surfaces (56). In the present invention, the non-coated portion (51) (see FIG. 8) may be bent irregularly by being pressed by the jig (60) without going through a process such as notching for smooth bending. In the process of bending the non-coated portion (51) in this way, the non-coated portion layers (55) may overlap each other, and thus a space through which an electrolyte may pass may not be formed on the folded surface of the non-coated portion (51). However, in the present invention, by ensuring a space by using the protrusion (63) provided on the jig (60) and applying pressure to form a folded surface, an opening (57) surrounded by the non-coated portion layers (55) may be formed. At least one opening (57) can be formed at a position corresponding to the space between the plurality of non-woven layers (55).

[0122] According to one 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 non-coated layers (55). For example, referring to FIG. 10, the diameter (l1) 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 non-coated layers (55).

[0123] Likewise, 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 non-coated layers (55). For example, referring to FIG. 11, the diameter (l2) 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 non-coated layers (55).

[0124] According to one embodiment, at least one protrusion (63) may be one or multiple. At least one protrusion (63) may be multiple protrusions arranged in a certain pattern. For example, referring to FIG. 10, at least one protrusion (63) may include multiple protrusions arranged at a certain interval along the circumferential direction (x). For example, at least one protrusion (63) may include multiple protrusions arranged at a certain interval along the radial direction (z). According to one embodiment, at least one protrusion (63) may be formed to extend in the circumferential direction (x) along the space between the multiple non-woven layers (55).

[0125] For example, referring to FIG. 10, at least one protrusion (63) may include a plurality of protrusions that are spaced apart at regular intervals sequentially in the circumferential direction (x) from the center portion of the pressurized surface (62) in the outward direction. Similarly, referring to FIG. 11, at least one opening (57) may include a plurality of openings (57) that are spaced apart at regular intervals sequentially in the circumferential direction (x) from the core portion (c) of the bending region (53) in the outward direction.

[0126] For example, referring to FIG. 12, at least one protrusion (63) may include a protrusion (63) having a curved surface formed extending along the circumferential direction (x) of the pressurizing surface (62). In this way, a plurality of protrusions having a curved surface formed extending along the circumferential direction (x) may be sequentially arranged from the center portion of the pressurizing surface (62) toward the outside. Similarly, referring to FIG. 13, at least one opening (57) may include an opening (57) having a curved surface formed extending along the circumferential direction (x) of the bending region (53). In this way, a plurality of openings having a curved surface formed extending along the circumferential direction (x) may be sequentially arranged from the center portion of the bending region (53) toward the outside.

[0127] The electrode assembly (50) according to an embodiment of the present invention can be applied to a jelly roll type battery.

[0128] Preferably, the battery may be a battery having a form factor ratio (defined as the ratio of the diameter of the battery divided by its height, i.e., the ratio of the diameter (Φ) to the height (H)) of greater than about 0.4.

[0129] Here, the form factor refers to a value indicating the diameter and height of the battery. A battery according to one embodiment of the present invention may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the numerical value indicating the form factor, the first two numbers indicate the diameter of the battery, and the remaining numbers indicate the height of the battery.

[0130] When applying an electrode assembly (50) having a tab-less structure to a battery having a form factor ratio exceeding 0.4, the stress applied in the radial direction when bending the non-coated portion (51) is large, making it easy for the non-coated portion (51) to tear. In addition, in order to sufficiently secure welding strength and reduce resistance when welding a current collecting plate to the bending surface (56) area of ​​the non-coated portion (51), the number of overlapping layers of the non-coated portion (51) must be sufficiently increased. These requirements can be achieved by the electrode and electrode assembly (50) according to embodiments (modified examples) of the present invention.

[0131] A battery according to one embodiment of the present invention may be a battery having a substantially cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0132] According to another embodiment, a battery may be a battery having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0133] According to another embodiment, a battery may be a battery having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.436.

[0134] According to another embodiment, a battery may be a battery having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0135] According to another embodiment, a battery may be a battery having a generally cylindrical shape, a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0136] Conventionally, batteries with a form factor ratio of approximately 0.4 or less have been used. That is, conventionally, for example, 1865 batteries and 2170 batteries have been used. For 1865 batteries, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. For 2170 batteries, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0137] Hereinafter, a battery according to an embodiment of the present invention will be described in detail.

[0138] FIG. 14 is a cross-sectional view of a battery according to one embodiment of the present invention taken along the axial direction (Y).

[0139] Referring to FIG. 14, a battery (190) according to one embodiment of the present invention includes an electrode assembly (110) including a positive electrode, a separator, and a negative electrode wound in a jelly roll shape, a battery housing (142) that accommodates the electrode assembly (110), and a sealing body (143) that seals an open end of the battery housing (142). The electrode assembly (110) has the structure of the embodiment described above. The configuration of the electrode assembly (110) of FIG. 14 may be all or part of the same as the configuration of the electrode assembly (50) of FIGS. 10 to 13. The embodiment of FIG. 14 may be partially combined with the embodiments of FIGS. 10 to 13.

[0140] The battery housing (142) is a cylindrical container with an opening formed at the top. The battery housing (142) is made of a conductive metal material, such as aluminum, steel, or stainless steel. The battery housing (142) accommodates an electrode assembly (110) in an inner space through the upper opening, and also accommodates an electrolyte. A nickel coating layer may be formed on the outer surface and / or inner surface of the battery housing (142).

[0141] The electrolyte may be a salt having a structure such as A+B--, where A+ comprises an alkali metal cation such as Li+, Na+, K+, or a combination thereof. And B-- is F--, Cl--, Br--, I--, NO3--, N(CN)2--, BF4--, ClO4--, AlO4--, AlCl4--, PF6--, SbF6--, AsF6--, BF2C2O4--, BC4O8--, (CF3)2PF4--, (CF3)3PF3-, (CF3)4PF2--, (CF3)5PF--, (CF3)6P--, CF3SO3--, C4F9SO3--, CF3CF2SO3--, (CF3SO2)2N--, (FSO2)2N--, CF3CF2(CF3)2CO--, (CF3SO2)2CH--, (SF5)3C--, (CF3SO2)3C--, It contains at least one anion selected from the group consisting of CF3(CF2)7SO3--, CF3CO2--, CH3CO2-, SCN--, and (CF3CF2SO2)2N--.

[0142] The electrolyte can also be used by dissolving it in an organic solvent. Examples of the organic solvent that can be used 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 methyl carbonate (EMC), gamma butyrolactone, or mixtures thereof.

[0143] The electrode assembly (110) may have a jelly roll shape. As illustrated in FIG. 2, the electrode assembly (110) may be manufactured by sequentially stacking a lower separator, an anode, an upper separator, and a cathode at least once, and winding the electrode-separator laminate around a winding center (C).

[0144] A positive electrode non-coated portion (51a) and a negative electrode non-coated portion (51b) may protrude from the upper and lower portions of the electrode assembly (110), respectively. The positive electrode non-coated portion (51a) may form a positive electrode winding turn portion (e.g., a positive electrode winding turn portion (52a) of FIG. 6) at the upper portion of the electrode assembly (110), and the negative electrode non-coated portion (51b) may form a negative electrode winding turn portion (e.g., a negative electrode winding turn portion (52b) of FIG. 6) at the lower portion of the electrode assembly (110).

[0145] The sealing body (143) may include a cap (143a), a sealing gasket (143b) that provides airtightness between the cap (143a) and the battery housing (142) and has insulating properties, and a connecting plate (143c) that is electrically and mechanically connected to the cap (143a).

[0146] The cap (143a) may include a conductive metal material. The cap (143a) may cover the upper opening of the battery housing (142). The cap (143a) may be electrically connected to the positive electrode winding turn portion (52a) and may be electrically insulated from the battery housing (142) via a sealing gasket (143b). Therefore, the cap (143a) may function as the positive electrode terminal of the battery (140).

[0147] The cap (143a) may be mounted on a beading portion (147) formed on the battery housing (142) and may be fixed by a crimping portion (148). A sealing gasket (143b) may be interposed between the cap (143a) and the crimping portion (148) to ensure airtightness of the battery housing (142) and electrical insulation between the battery housing (142) and the cap (143a). The cap (143a) may have a protrusion (143d) formed to protrude upward from its center.

[0148] The battery housing (142) can be electrically connected to the negative electrode winding turn part (52b). Therefore, the battery housing (142) can have the same polarity as the negative electrode.

[0149] The battery housing (142) may have a beading portion (147) and a crimping portion (148) at the top. The beading portion (147) may be formed by pressing the outer circumference of the battery housing (142). The beading portion (147) may prevent the electrode assembly (110) accommodated inside the battery housing (142) from coming out through the upper opening of the battery housing (142), and may function as a support portion on which the sealing body (143) is secured.

[0150] The crimping portion (148) may be formed on the upper portion of the beading portion (147). The crimping portion (148) may have an extended and bent shape so as to surround the outer surface of the cap (143a) placed on the beading portion (147) and a portion of the upper surface of the cap (143a).

[0151] The battery (190) may further include a first collector plate (144) and / or a second collector plate (145) and / or an insulator (146).

[0152] The first collector plate (144) may be coupled to the upper portion of the electrode assembly (110). The first collector plate (144) may include a conductive metal material such as aluminum, copper, nickel, etc.

[0153] The first collector plate (144) can be welded to a welding target area of ​​a bending surface (56) formed by bending a plurality of non-coated layers (55) in a bending area (53) of the positive winding turn portion (52a). For example, the welding target area may be an area in which the average number of bends of the plurality of non-coated layers (55) of the electrode assembly (110) is 5 or more. In addition, the welding target area may be an area in which the average stacking thickness of the plurality of non-coated layers (55) is 50 μm or more.

[0154] According to one embodiment, at least one hole (not shown) may be formed in the center of the first current collecting plate (144). The electrolyte may 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 may be prevented from leaking out through the cavity in the core when a vent occurs in the battery (190). In addition, if the diameter of the hole is equal to or larger than the diameter of the cavity in the core, the welding jig may be easily inserted during the process of welding the second current collecting plate (145) to the bottom of the battery housing (142), and the electrolyte may be smoothly injected.

[0155] Although not shown in the drawing, the first collector plate (145) may be provided with a hole provided at a position corresponding to the opening (57) of the electrode assembly (50) described above. In this case, an area where the electrolyte can circulate can be secured even in an area covered by the first collector plate (145) among the entire area on one side of the electrode assembly (50).

[0156] The lead portion (149) may extend upward from the electrode assembly (110) and be coupled to the connection plate (143c) or directly coupled to the lower surface of the cap (143a). The connection plate (143c) may be coupled to the lower surface of the cap (143a). The connection of the lead portion (149) to other components may be achieved through welding.

[0157] The bonding between the folded surface (56) formed by folding multiple non-conductive layers (55) and the first collector plate (144) can be achieved by laser welding. Laser welding can be replaced by resistance welding, ultrasonic welding, etc.

[0158] A plate-shaped second current collecting plate (145) may be coupled to the lower surface of the electrode assembly (110). The second current collecting plate (145) may include a conductive metal material such as aluminum, copper, nickel, etc. The second current collecting plate (145) may be electrically connected to the battery housing (142). A first surface of the second current collecting plate (145) may be coupled to the electrode assembly (110), and a second surface opposite to the first surface may be coupled to the battery housing (142).

[0159] The insulator (146) can cover the first collector plate (144). The insulator (146) can prevent direct contact between the first collector plate (144) and the inner surface of the battery housing (142) by covering the first collector plate (144) on the upper surface of the first collector plate (144).

[0160] The insulator (146) may be provided with a lead hole (151) so that a lead portion (149) extending upward from the first collector plate (144) may be drawn out. The lead portion (149) may be drawn out upward through the lead hole (151) and coupled to the lower surface of the connecting plate (143c) or the lower surface of the cap (143a).

[0161] The peripheral area of ​​the insulator (146) can be interposed between the first collector plate (144) and the beading portion (147) to fix the assembly of the electrode assembly (110) and the first collector plate (144). Accordingly, the assembly of the electrode assembly (110) and the first collector plate (144) can be restricted from moving in the axial direction (Y), thereby improving the assembly stability of the battery (190).

[0162] The insulator (146) may be made of an insulating polymer resin. In one example, the insulator (146) may be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0163] The battery housing (142) may further include a venting portion (152) formed on its lower surface. The venting portion (152) may correspond to a region of the lower surface of the battery housing (142) that has a thinner thickness than the surrounding region. The venting portion (152) may be configured to be structurally weaker than the surrounding region. Therefore, if an abnormality occurs in the battery (190) and the internal pressure increases above a certain level, the venting portion (152) may rupture, allowing gas generated inside the battery housing (142) to be discharged to the outside.

[0164] The venting portion (152) may be formed continuously or discontinuously in a circular manner on the lower surface of the battery housing (142). In a modified example, the venting portion (152) may be formed in a linear pattern or other pattern.

[0165] FIG. 15 is a cross-sectional view of a battery according to another embodiment of the present invention taken along the axial direction (Y).

[0166] Referring to FIG. 15, the battery (200) is substantially the same in structure as the battery (190) illustrated in FIG. 14 in that the structure of the electrode assembly is the same, and the remaining structure except for the electrode assembly is changed.

[0167] Specifically, the battery (200) includes a battery housing (171) through which a terminal (172) is installed. The terminal (172) may be a riveted terminal in which an edge of one end is riveted to an inner surface of a closed portion of the battery housing (171). The terminal (172) is installed in the closed portion (upper portion of the drawing) of the battery housing (171). The terminal (172) is riveted to the through hole of the battery housing (171) with an insulating gasket (173) interposed therebetween. The terminal (172) is exposed to the outside in a direction opposite to the direction of gravity.

[0168] The 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 located at approximately the center of the closed portion of the battery housing (171). The maximum diameter of the terminal exposure portion (172a) may be formed to be larger than the maximum diameter of the through hole formed in the battery housing (171). The terminal insertion portion (172b) may penetrate approximately the center of the closed portion of the battery housing (171) and be electrically connected to the positive electrode winding turn portion (52a). The portion where the electrical connection is made may be a folded surface (56) formed when a plurality of non-coated layers (55) of the positive electrode winding turn portion (52a) are folded. The terminal insertion portion (172b) may be riveted onto the inner surface of the closure portion of the battery housing (171). That is, the end edge of the terminal insertion portion (172b) may be bent toward the inner surface of the battery housing (171) by being pressed by a caulking jig. The maximum diameter of the end of the terminal insertion portion (172b) may be larger than the maximum diameter of the through hole of the battery housing (171).

[0169] The lower surface of the terminal insertion portion (172b) is substantially flat and can be welded to the first collector plate (144') connected to the bending portion of the positive winding turn portion (52a).

[0170] The first collector plate (144') may have substantially the same structure as the collector plate (145) shown in FIG. 14.

[0171] An insulator (174) made of an insulating material may be interposed between the first collector plate (144') and the inner surface of the battery housing (171). The insulator (174) may cover the upper portion of the first collector plate (144') and the upper edge portion of the electrode assembly (110). This may prevent the first collector plate (144') from contacting the inner surface of the battery housing (171) having a different polarity, thereby causing a short circuit. Preferably, the terminal insertion portion (172b) of the terminal (172) may penetrate the insulator (174) and be welded to the first collector plate (144'). The insulator (174) may include an insulating polymer resin.

[0172] An insulating gasket (173) may be interposed between the battery housing (171) and the terminal (172) to prevent the battery housing (171) and the terminal (172) having opposite polarities from electrically contacting each other. This allows the upper surface of the battery housing (171) having a roughly flat shape to function as the negative terminal of the battery (200).

[0173] The insulating gasket (173) may include a gasket exposure portion (173a) and a gasket insertion portion (173b). The gasket exposure portion (173a) may be interposed between the terminal exposure portion (172a) of the terminal (172) and the battery housing (171). The gasket insertion portion (173b) may be interposed between the terminal insertion portion (172b) of the terminal (172) and the battery housing (171). The gasket insertion portion (173b) may be deformed together with the terminal insertion portion (172b) when riveting so as to be in close contact with the inner surface of the battery housing (171). The insulating gasket (173) may be made of, for example, an insulating polymer resin.

[0174] The gasket exposure portion (173a) of the insulating gasket (173) may have an extended shape to cover the outer surface of the terminal exposure portion (172a) of the terminal (172). When the insulating gasket (173) covers the outer surface of the terminal (172), a short circuit can be prevented from occurring during the process of connecting an electrical connection component such as a bus bar to the upper surface of the battery housing (171) and / or the terminal (172). Although not shown in the drawing, the gasket exposure portion (173a) may have an extended shape to cover not only the outer surface of the terminal exposure portion (172a) but also a portion of the upper surface.

[0175] In the case where the insulating gasket (173) is made of a polymer resin, the insulating gasket (173) can be combined with the battery housing (171) and the terminal (172) by heat fusion. In this case, the sealing properties at the bonding interface between the insulating gasket (173) and the terminal (172) and at the bonding interface between the insulating gasket (173) and the battery housing (171) can be enhanced. Meanwhile, in the case where the gasket exposure portion (173a) of the insulating gasket (173) has a form that extends to the upper surface of the terminal exposure portion (172a), the terminal (172) can be integrally combined with the insulating gasket (173) by insert injection.

[0176] Among the upper surfaces of the battery housing (171), the remaining area (175) excluding the area occupied by the terminal (172) and the insulating gasket (173) may correspond to an electrode terminal having the opposite polarity to the terminal (172).

[0177] The second collector plate (176) may be coupled to the lower portion of the electrode assembly (110). The second collector plate (176) may include a conductive metal material such as aluminum, steel, copper, or nickel. The second collector plate (176) may be coupled to a welding target area of ​​a bending surface (56) formed on the negative electrode winding turn portion (52b) through welding. The welding target area may refer to a section in which the number of overlapping layers according to the bending of the non-coated layers (55) (see FIG. 8) is maintained at a maximum along the radial direction of the electrode assembly (110).

[0178] Preferably, at least a portion of the second collector plate (176) may be electrically connected to the battery housing (171). In one example, at least a portion of the edge portion of the second collector plate (176) may be interposed and fixed between the inner surface of the battery housing (171) and the sealing gasket (178b). Preferably, the welding target area included in the folded surface (56) formed on the second collector plate (176) and the negative electrode winding turn portion (52b) may be joined by laser welding. At this time, the welding is performed in an area in which the average number of stacked layers of the plurality of non-coated layers (55) in the axial direction (Y) of the folded surface (56) is 5 or more, or an area in which the average stacked thickness of the plurality of non-coated layers (55) is 25 μm or more. The laser welding may be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0179] Meanwhile, although not shown in the drawing, the second collector plate (176) may be provided with a hole provided at a position corresponding to the opening (57) of the electrode assembly (50) described above. In this case, an area where the electrolyte can circulate can be secured even in an area covered by the second collector plate (176) among the entire area on one side of the electrode assembly (50).

[0180] A sealing member (178) for sealing the lower open end of the battery housing (171) may include a cap (178a) and a sealing gasket (178b). The sealing gasket (178b) may electrically isolate the cap (178a) and the battery housing (171). A crimping member (181) may secure the edge of the cap (178a) and the sealing gasket (178b) together. The cap (178a) is provided with a vent member (179). The configuration of the vent member (179) is substantially the same as in the above-described embodiment.

[0181] Preferably, the cap (178a) may include a conductive metal material. However, since a sealing gasket (178b) is interposed between the cap (178a) and the battery housing (171), the cap (178a) may not have electrical polarity. The sealing body (178) may be configured to seal the open end of the lower portion of the battery housing (171) and discharge gas when the internal pressure of the battery (200) increases above a threshold value. The cap (178a) may include a vent portion (179) at the edge area of ​​the flat portion. The configuration of the vent portion (179) is substantially the same as that of the above-described embodiment.

[0182] Preferably, the terminal (172) electrically connected to the folded portion of the positive winding turn portion (52a) through the first current collecting plate (144') can be used as the first electrode terminal. In addition, the portion (175) of the upper surface of the battery housing (171) electrically connected to the folded portion of the negative winding turn portion (52b) through the second current collecting plate (176), excluding the terminal (172), can be used as a second electrode terminal having a different polarity from the first electrode terminal. In this way, when the two electrode terminals are positioned on the upper portion of the battery (200), it is possible to place electrical connection components such as bus bars on only one side of the battery (200). This can lead to simplification of the battery pack structure and improvement of energy density. In addition, since the portion (175) used as the second electrode terminal has a substantially flat shape, a sufficient bonding area can be secured when bonding electrical connection components such as bus bars. Accordingly, the battery (200) can lower the resistance at the joint portion of the electrical connection component to a desirable level.

[0183] The battery according to the above-described embodiments (variants) can be used to manufacture a battery pack.

[0184] Fig. 16 is a drawing schematically showing the configuration of a battery pack according to an embodiment of the present invention.

[0185] Referring to FIG. 16, a battery pack (300) according to an embodiment of the present invention includes a battery assembly (301) electrically connected thereto and a pack housing (302) accommodating the battery assembly. The battery (301) may be any of the batteries according to the embodiments (variants) described above. In the drawing, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrical connection of the batteries (301) are omitted.

[0186] The battery pack (300) may be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle or a two-wheeled vehicle.

[0187] FIG. 17 is a drawing for explaining a vehicle including the battery pack (300) of FIG. 16.

[0188] Referring to FIG. 17, a vehicle (V) according to one embodiment of the present invention may include a battery pack (300) according to one embodiment of the present invention. The vehicle (V) may operate by receiving power from the battery pack (300) according to one embodiment of the present invention.

[0189]

[0190] According to one aspect of the present invention, a jig including at least one protrusion on one side presses a bending region from above, thereby bending a plurality of non-woven layers while forming at least one opening, so that at least one opening can be utilized as an electrolyte injection passage, thereby improving electrolyte impregnation properties.

[0191] According to another aspect of the present invention, the bending region includes at least one opening so that gas generated inside the battery can be smoothly discharged to the outside.

[0192] According to another aspect of the present invention, the resistance of the battery can be lowered by bending the bending area of ​​the winding turn portion of the non-woven portion to form a bending surface in which a plurality of non-woven portion layers are overlapped in multiple layers, and then welding a current collecting plate to the area.

[0193] According to another aspect of the present invention, the non-conductive portion is manufactured without a separate notching process, thereby preventing performance degradation caused by metallic foreign substances generated during the notching process and inducing smooth gas discharge. According to an embodiment of the present invention, by omitting the notching process, the process time can be shortened and the process cost can be improved.

[0194] According to another aspect of the present invention, by providing a large-capacity battery pack manufactured using batteries having high energy density and low resistance and a vehicle including the same, the safety of rapid charging and the efficiency of energy use can be improved.

[0195] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by a person having ordinary skill in the art to which the present invention pertains within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below.

Claims

1. An electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed therebetween, At least one of the positive electrode and the negative electrode includes a non-conductive portion at the long end, A winding turn part of the non-conductive part is provided at one end of the electrode assembly, The above-mentioned winding turn portion includes a bending region including a plurality of non-woven layers configured to be bent by pressure to form a bending surface, An electrode assembly wherein the bending region comprises at least one opening configured to be surrounded by the bending surface.

2. In paragraph 1, An electrode assembly wherein the ratio of the area occupied by the at least one opening to the area of ​​the bending region is 30% or more and 50% or less.

3. In paragraph 1, An electrode assembly in which the above plurality of non-conductive layers are folded so as to overlap along the axial direction.

4. In paragraph 1, An electrode assembly configured such that the above bending region is formed by pressing using a jig including at least one protrusion on one surface.

5. In paragraph 4, The above bending area is an electrode assembly corresponding to the area pressed by the above jig.

6. In paragraph 4, An electrode assembly configured such that at least one opening is formed in the bending area in which at least one protrusion of the jig is inserted.

7. In paragraph 4, An electrode assembly wherein the above-mentioned winding turn portion further includes a flat region that is not pressed by the jig.

8. In paragraph 1, An electrode assembly configured such that at least one opening is formed in an area corresponding to an area where the separator is disposed.

9. In paragraph 1, An electrode assembly wherein the axial height of the above bending region is higher than the axial height of the above flat region.

10. Step 1: Preparing a positive electrode and a negative electrode having a non-conductive portion at the long end; A second step of forming an electrode-separator laminate by stacking the anode, the cathode, and the separator at least once so that a separator is interposed between the anode and the cathode, and arranging the anode and the cathode so that the anode non-coated portion and the cathode non-coated portion are exposed opposite to each other along the short side direction of the separator; A third step of forming an electrode assembly by winding the electrode-separator laminate around one axis so that the winding turn portion of the positive electrode non-coated portion and the winding turn portion of the negative electrode non-coated portion are exposed in opposite directions along the axis; and A method for manufacturing an electrode assembly, comprising: a fourth step of pressing at least a portion of the above-described winding turn portion using a jig, forming a bending surface by a plurality of non-woven layers bent by the pressing, and at least one opening configured to be surrounded by the bending surface; 11. In paragraph 10, A method for manufacturing an electrode assembly configured such that when the plurality of non-woven layers are pressed using the jig in the fourth step, the bending surface is formed and at least one opening is formed at the same time.

12. In paragraph 10, The above jig comprises at least one protrusion on one surface, A method for manufacturing an electrode assembly, wherein at least one opening is formed in an area where at least one protrusion of the jig is inserted.

13. An electrode assembly according to any one of claims 1 to 12; A battery housing comprising an open end and an opposite closed end, wherein the electrode assembly is received through the open end and is electrically connected to the electrode assembly; A sealing body that seals the open end of the above battery housing; A terminal electrically connected to the above electrode assembly and having a surface exposed to the outside; and A battery comprising a current collecting plate welded to the above-described bending surface and electrically connected to either 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 including a battery pack according to Article 14.

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