Secondary battery manufacturing device and battery module equipped with secondary battery manufactured thereby

Abstract

A secondary battery manufacturing apparatus according to an embodiment of the present invention may include: an unwinder for supplying a wound electrode foil; a plurality of slitters for cutting the electrode foil supplied from the unwinder at predetermined intervals; a plurality of rewinders for winding the plurality of electrode foils discharged from the slitters in one direction; and a first winding device and a second winding device for winding the electrode foil and separator wound from the rewinders and discharging a wound electrode assembly. According to an embodiment of the present invention, the process of unwinding and rewinding already wound material to align the direction of the unwound portion or the direction of the electrode plate surface can be omitted. In addition, since an electrode assembly can be produced by winding a reel with a different direction of the unwound portion or the direction of the electrode plate surface as is without rewinding, the manufacturing time and manufacturing process can be reduced.

Description

Technology Field

[0001] An embodiment of the present invention relates to a secondary battery manufacturing apparatus and a battery module having a secondary battery manufactured thereby. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries in hybrid and electric vehicles. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case housing the assembly, and electrode terminals connected to the electrode assembly.

[0003] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The problem to be solved

[0004] An embodiment of the present invention provides a secondary battery manufacturing apparatus with an improved winding structure and a battery module having a secondary battery manufactured thereby.

[0005] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0006] A secondary battery manufacturing apparatus according to an embodiment of the present invention may include: an unwinder for supplying a wound electrode foil; a plurality of slitters for cutting the electrode foil supplied from the unwinder at predetermined intervals; a plurality of rewinders for winding the plurality of electrode foils discharged from the slitters in one direction; and a first winding device and a second winding device for winding the electrode foil and separator wound from the rewinders and discharging a wound electrode assembly.

[0007] The reel of wound electrode foil discharged from the above rewinder may have the unwound portions facing in different directions.

[0008] The reel of the wound electrode foil discharged from the above rewinder may have the same side facing outward from the winding.

[0009] The above unwinder is equipped with two parts and can supply a negative electrode foil and a positive electrode foil, respectively.

[0010] The first winding device above can wind an electrode assembly in an A-reel in which the negative electrode unworn portion and the positive electrode unworn portion each face a preset direction.

[0011] The above second winding device can wind the electrode assembly with a B-reel in which the negative electrode unworn portion and the positive electrode unworn portion each face a direction opposite to a preset direction.

[0012] The electrode assembly wound on the above A reel and the electrode assembly wound on the above B reel can be wound in opposite directions.

[0013] The above negative electrode foil and the above positive electrode foil may be coated with an active material in the form of a stripe pattern along the length direction.

[0014] Either one of the above negative electrode foil and the above positive electrode foil, or the above negative electrode foil and the above positive electrode foil, may have the active material unbalancedly coated on one or both sides.

[0015] In addition, the battery module according to an embodiment of the present invention may include a plurality of secondary batteries manufactured by the aforementioned secondary battery manufacturing apparatus.

[0016] The above secondary battery may include a plurality of first secondary batteries and second secondary batteries in which the winding directions of the electrode assemblies are opposite to each other.

[0017] The above electrode assembly may include a negative plate and a positive plate.

[0018] The above-mentioned cathode plate and the above-mentioned anode plate may be coated with an active material in the form of a stripe pattern along the length direction.

[0019] Either one of the above-mentioned negative plate and the above-mentioned positive plate, or the above-mentioned negative plate and the above-mentioned positive plate, may have the active material unbalancedly coated on one or both sides. Effects of the invention

[0020] According to an embodiment of the present invention, the process of unwinding and rewinding the already wound material to align the direction of the unwound portion or the direction of the electrode plate surface can be omitted.

[0021] In addition, since the electrode assembly can be produced by winding the reel as is without rewinding the direction of the non-rewinding portion or the direction of the electrode plate surface, the manufacturing time and manufacturing process can be reduced.

[0022] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below. Brief explanation of the drawing

[0023] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a perspective view of an exemplary cylindrical secondary battery. Figure 2 is a cross-sectional view of a cylindrical secondary battery according to Figure 1. FIG. 3 is a perspective view of an exemplary cylindrical secondary battery. Figure 4 is a cross-sectional view of a cylindrical secondary battery according to Figure 3. FIG. 5 is a schematic diagram briefly illustrating the supply state of the winding material during the winding of an exemplary electrode assembly. FIG. 6 is a schematic diagram illustrating part of the winding process of an electrode assembly according to one example. FIG. 7 is a schematic diagram illustrating part of the winding process of an electrode assembly according to another example. FIG. 8 is a schematic diagram briefly illustrating a secondary battery manufacturing apparatus according to the present invention. FIG. 9 is a schematic diagram briefly illustrating an electrode assembly wound by a first winding device according to FIG. 8. FIG. 10 is a schematic diagram briefly illustrating an electrode assembly wound by a second winding device according to FIG. 8. FIGS. 11 and FIGS. 12 are perspective views illustrating a battery pack including an exemplary secondary battery according to the present invention. FIGS. 13 and FIGS. 14 are a perspective view and a side view illustrating an automobile including an exemplary battery pack according to the present invention. Specific details for implementing the invention

[0024] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0025] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0026] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0027] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0028] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0029] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0030] The fact that any configuration is placed on the upper (or lower) surface of a component or on the upper (or lower) surface of a component may mean not only that the any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or under) said component.

[0031] Furthermore, where it is stated that one component is connected, coupled, or joined to another component, it should be understood that while said components may be directly connected or joined to each other, other components may be interposed between each component, or each component may be connected, coupled, or joined through other components. Additionally, when it is stated that a part is electrically coupled to another part, this includes not only cases where they are directly connected but also cases where they are connected with other elements in between.

[0032] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise. That is, "and / or" includes any combination or any combination of the enumerated items. "C through D" means C or more and D or less, unless specifically stated otherwise.

[0033] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0034] Hereinafter, a secondary battery manufacturing apparatus according to embodiments of the present invention and a battery module equipped with a secondary battery manufactured thereby will be described in detail with reference to the attached drawings.

[0035] First, exemplary structures of a secondary battery will be described (the drawing numbers in FIGS. 1 to 4 are numbers that apply only to the components of the corresponding drawings).

[0036] FIG. 1 is a perspective view of an exemplary cylindrical secondary battery. FIG. 2 is a cross-sectional view of a cylindrical secondary battery according to FIG. 1.

[0037] Referring to FIGS. 1 and 2, an exemplary secondary battery (10) may include a cylindrical can (100), an electrode assembly (200) housed inside the can (100), a first electrode current collector (300) and a second electrode current collector (400), a terminal portion (500) provided on one side of the can (100), and a cap assembly (600) provided on the other side of the can (100).

[0038] The can (100) forms the outer shape of the secondary battery (10) and may have a cylindrical shape with one end open. The can (100) may include or be referred to as a case, housing, or outer material. The can (100) may include a disc-shaped upper surface (110) and a cylindrical side (120) extending downward from the upper surface (110). A terminal hole is formed through the upper surface (110), and a terminal portion (500) is provided in the terminal hole. A beading portion (122) may be formed adjacent to the end of the side portion (120). The beading portion (122) is formed concavely toward the inside of the side portion (120). The beading portion (122) is provided for fixing the electrode assembly (200) and seating the cap assembly (600). A crimping portion (124) is formed at the end of the side portion (120) spaced apart from the beading portion (122). The crimping portion (124) can be formed by bending the end of the side portion (120) toward the inside of the can (100). A cap assembly (600) can be seated and fixed between the beading portion (122) and the crimping portion (124). In the manufacturing process, the open bottom of the can (100) can be positioned so that it faces upward, and then the electrode assembly (200) can be inserted together with the electrolyte. Afterward, the cap assembly (600) is seated on the beading portion (122), the crimping portion (124) is formed to fix the cap assembly (600), and then the cap assembly (600) can be positioned so that it faces downward. If necessary, the cap assembly (600) may be used in a state where it faces upward. In this embodiment, the description is based on an example where the bottom of the can (100) is open, but conversely, the top of the can (100) may be open. The can (100) may be provided as a metal such as steel, nickel-plated steel, steel alloy, aluminum, aluminum alloy, or a cooling sheet for deep drawing (SPCE), or as a laminate film or plastic material constituting a pouch. An electrode assembly (200) is accommodated inside the can (100) together with an electrolyte.

[0039] The electrode assembly (200) may include or be referred to as an electrode group, an electrode body, or a jelly roll. The electrode assembly (200) may include a first electrode plate (210) and a second electrode plate (220), and a separator (230) interposed between the first electrode plate (210) and the second electrode plate (220). The electrode assembly (200) may be wound in a cylindrical shape. The first electrode plate (210) and the second electrode plate (220) are electrically connected to the first electrode current collector (250) and the second electrode current collector (260), respectively. For example, the first electrode plate (210) may act as the positive electrode and the second electrode plate (220) may act as the negative electrode. Or it may be configured in the opposite way. In some examples, a hollow cylindrical core may be provided in the center of the electrode assembly (200). Additionally, in some examples, a center pin (optional) may be inserted into the core.

[0040] The first electrode plate (210) may be either a negative electrode plate or a positive electrode plate. The first electrode plate (210) may include a first substrate which is a metal thin plate, a first active material layer provided on at least one surface of the first substrate, and a first non-active portion where the first active material is not provided. The first non-active portion may be referred to as the first substrate. The first non-active portion may be positioned toward the upper surface portion (110) of the can (100) and may be electrically connected to the first electrode current collector plate (300).

[0041] For example, the first electrode plate (210) can function as an anode. The first substrate may include an aluminum foil, and the first active material layer may include a transition metal oxide. The first substrate may be referred to as a first metal current collector or a first electrode plate foil, etc.

[0042] In some examples, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used as the positive electrode active material. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0043] The above composite oxide may be a lithium transition metal composite oxide, and specific examples include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0044] As an example, compounds represented by any one of the following chemical formulas may be used. LiaA1-bXbO2-cDc(0.90 ≈ a ≈ 1.8, ≈ b ≈ 0.5, ≈ c ≈ 0.05); LiaMn2-bXbO4-cDc(0.90 ≈ a ≈ 1.8, ≈ b ≈ 0.5, ≈ c ≈ 0.05); LiaNi1-b-cCobXcO2-D(0.90 ≈ a ≈ 1.8, ≈ b ≈ 0.5, ≈ c ≈ 0.5, 0<<2); LiaNi1-b-cMnbXcO2-D(0.90 ≈ a ≈ 1.8, ≈ b ≈ 0.5, ≈ c ≈ 0.5, 0<<2); LiaNibCocL1dGeO2(0.90?a?1.8, 0?b=0.9, 0=c=0.5, 0=d=0.5, 0=e=0.1); LiaNiGbO2(0.90=a=1.8, 0.001=b=0.1); LiaCoGbO2(0.90=a=1.8, 0.001=b=0.1); LiaMn1-bGbO2 (0.90=a=1.8, 0.001=b=0.1); LiaMn2GbO4 (0.90=a=1.8, 0.001=b=0.1); LiaMn1-gGgPO4 (0.90=a=1.8, 0=g=0.5); Li(3-f)Fe2(PO4)3(0=f=2); LiaFePO4(0.90=a=1.8).

[0045] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L1 is Mn, Al, or a combination thereof.

[0046] A positive electrode for a lithium secondary battery may include a current collector (e.g., a first substrate) and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0047] The content of the positive active material is 90% to 99.5% by weight with respect to 100% by weight of the positive active material layer, and the content of the binder and the conductive material may each be 0.5% to 5% by weight with respect to 100% by weight of the positive active material layer.

[0048] Aluminum may be used as the current collector mentioned above, but is not limited thereto.

[0049] The second electrode plate (220) may be the other of a negative electrode plate and a positive electrode plate. The second electrode plate (220) may include a second substrate which is a metal thin plate, a second active material layer provided on at least one surface of the second substrate, and a second non-active portion where the second active material layer is not provided. The second non-active portion may be positioned toward the bottom of the side (120) of the can (100) and may be electrically connected to the second electrode current collector plate (400).

[0050] For example, the second electrode plate (220) can function as a negative electrode. The second substrate may include a copper or nickel foil, and the second active material layer may include a carbon-based material, Si, Sn, tin oxide, tin alloy composite, transition metal oxide, lithium metal nitrite, or metal oxide, etc. The second substrate may be referred to as a second metal current collector or a second electrode plate foil, etc.

[0051] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0052] A material capable of reversibly intercalating / deintercalating the above lithium ions may be a carbon-based negative electrode active material, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite, such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0053] As a material capable of doping and undoping the above lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The above Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0054] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0055] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0056] A negative electrode for a lithium secondary battery may include a current collector (e.g., a second substrate) and a negative electrode active material layer formed on the current collector. The negative electrode active material layer may include a negative electrode active material and may further include a binder and / or a conductive material.

[0057] For example, the negative electrode active material layer may comprise 90% to 99% by weight of negative electrode active material, 0.5% to 5% by weight of binder, and 0% to 5% by weight of conductive material.

[0058] As the binder, a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used. When an aqueous binder is used as the cathode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0059] As the current collector mentioned above, a material selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof may be used.

[0060] A separator (230) is disposed between the first electrode plate (210) and the second electrode plate (220) to prevent a short circuit and enable the movement of lithium ions. For example, the separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0061] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic-based polymer.

[0062] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include, but is not limited to, inorganic particles selected from SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0063] The above organic and inorganic materials may exist mixed in a single coating layer, or may exist in a stacked form with a coating layer containing organic materials and a coating layer containing inorganic materials.

[0064] The electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0065] The above-mentioned non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can move. The above-mentioned non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in a mixture of two or more types.

[0066] In addition, when using carbonate-based solvents, cyclic carbonates and chain carbonates can be mixed and used.

[0067] The first electrode collector plate (300) is approximately circular in shape and can be electrically connected to the positive terminal (510) to be described later. The first electrode collector plate (300) can be joined to the positive terminal (510) by welding. Since the first electrode collector plate (300) is electrically connected to the first electrode plate (210), the first electrode plate (210) and the positive terminal (510) can be electrically connected.

[0068] The second electrode collector plate (400) is approximately circular in shape, and its edges are bent in a streamlined shape so as to come into contact with the beading portion (122). The second electrode collector plate (400) can be joined to the beading portion (122) by welding. Since the second electrode collector plate (400) is electrically connected to the second electrode plate (220), the second electrode plate (220) and the can (100) can be electrically connected.

[0069] The terminal portion (500) may include a positive terminal (510) and at least one gasket (520). The positive terminal (510) is coupled to the upper surface portion (110) of the can (100) and is electrically connected to the first electrode plate (210) through the first electrode collector plate (300). The positive terminal (510) is coupled to the upper surface portion (110) by a rivet coupling method. The positive terminal (510) can be inserted into the terminal hole from the outside of the can (100), and then its inner end can be compressed and deformed by processing such as pressing or spinning to be in close contact with the inside of the upper surface portion (110). Alternatively, the positive terminal (510) can be inserted into the terminal hole from the inside of the can (100), and then its outer end can be compressed and deformed to be in close contact with the outside of the upper surface portion (110). At this time, a gasket (520) is inserted between the positive terminal (510) and the terminal hole to insulate the can (100) and the positive terminal (130).

[0070] The gasket (520) is made of an insulating material and may include a first gasket (522), a second gasket (524), and a third gasket (526). The first gasket (522) insulates the positive terminal (510) and the upper surface (110). Therefore, the size of the first gasket (522) may be larger than the portion of the positive terminal (510) that is exposed to the outside of the upper surface (110). The second gasket (524) insulates the positive terminal (510) and the terminal hole of the upper surface (110). The third gasket (526) insulates the upper surface (110) and the first electrode collector plate (300). Therefore, the third gasket (526) may have the same or similar size and shape as the first electrode collector plate (300). Alternatively, the third gasket (526) may have the same or similar size and shape as the upper surface (110). In some embodiments, an insulating tape (530) may be attached to the first electrode current collector plate (300) instead of the third gasket (526). Also, in some embodiments, the first gasket (522), the second gasket (524), and the third gasket (526) may be provided as a single unit.

[0071] The cap assembly (600) may include a cap plate (610) and an insulator (620). The edge of the cap plate (610) is fixed to the side (120) of the can (100) by a beading portion (122) and a crimping portion (124), and is insulated from the side (120) by the insulator (620). A notch (612) may be formed on the cap plate (610) that breaks when the internal pressure exceeds a certain pressure. The notch (612) is formed to be thinner than other areas and acts as a vent through which internal gas is discharged upon breaking.

[0072] FIG. 3 is a perspective view of an exemplary cylindrical secondary battery. FIG. 4 is a cross-sectional view of the cylindrical secondary battery according to FIG. 3 (the reference numbers of each structure of the secondary battery shown in FIG. 3 and FIG. 4 apply only to the description of the configuration in the corresponding drawings. In addition, detailed descriptions of configurations and features having the same function as the aforementioned secondary battery are omitted.)

[0073] Referring to FIGS. 3 and 4, an exemplary secondary battery (10) may include a cylindrical can (100), an electrode assembly (300) inserted inside the can (100), a cap assembly (500) inserted at one end of the can (100), and an insulating gasket (700) inserted between the can (100) and the cap assembly (500). The electrode assembly (300) may be supported by a center pin (380, optional).

[0074] A can (100) includes a circular bottom portion (110) and a side portion (130) extending upward from the bottom portion (110), and the upper part of the side portion (130) is in an open shape (hereinafter referred to as the opening). A cap assembly (500) is inserted into the opening of the can (100). A beading portion (132) and a crimping portion (134) may be formed on the side portion (130) to secure the cap assembly (500). In the manufacturing process of a secondary battery (10), an electrode assembly (300) may be inserted into the can (100) together with an electrolyte through the opening of the can (100).

[0075] The electrode assembly (300) includes a negative electrode plate (310), a positive electrode plate (320), and a separator (330). A negative electrode active material (e.g., graphite, carbon, etc.) may be formed on both sides of the negative electrode plate (310). A positive electrode active material (e.g., transition metal oxide (LiCoO2, LiNiO2, LiMn2O4, etc.)) may be formed on both sides of the positive electrode plate (320). The separator (330) is placed between the negative electrode plate (310) and the positive electrode plate (320) to prevent short circuits and to allow only the movement of lithium ions. The negative electrode plate (310), the positive electrode plate (320), and the separator (330) may be wound into a roughly cylindrical shape and accommodated inside a can (100). The negative plate (310) may be a copper (Cu) or nickel (Ni) foil, the positive plate (320) may be an aluminum (Al) foil, and the separator (330) may be a polyethylene (PE) or polypropylene (PP), but the above materials are not limited in the present invention. A negative tab (340) extending a certain length protruding downward from the negative plate (310) and a positive tab (350) extending a certain length upward from the positive plate (320) may be welded, but the reverse is also possible. The negative tab (340) may be made of copper or nickel, and the positive tab (350) may be made of aluminum, but the above materials are not limited in the present invention. The negative tab (340) may be welded to the bottom portion (110) of the can (100), in which case the can (100) may operate as a negative electrode. Conversely, the positive electrode tab (350) may be welded to the bottom portion (111) of the can (100), in which case the can (100) may operate as a positive electrode. In this embodiment, the negative electrode tab (340) is shown in the drawing as an example of being welded to the bottom portion (110) of the can (100).

[0076] In this embodiment, a structure was described in which the negative plate (310) and the positive plate (320) are electrically connected to the can (100) and the cap assembly (500), respectively, through the negative tab (340) and the positive tab (350). However, a negative-free section and a positive-free section may be configured without the negative tab (340) and the positive tab (350), in which active material is not provided on the negative plate (310) and the positive plate (320), respectively. In this case, the negative-free section may be directly attached to the bottom portion (111) of the can (100) or welded to the negative collector plate and then electrically connected to the can (100) through the negative collector plate. The positive-free section may be welded to the positive collector plate and the positive collector plate may be electrically connected to the cap assembly through the positive lead.

[0077] Additionally, a first insulating plate (360) and a second insulating plate (370) may be interposed at the upper and lower portions of the electrode assembly (300). The first insulating plate (360) prevents the positive plate (320) from electrically contacting the bottom portion (110) of the can (100), and the second insulating plate (370) prevents the negative plate (310) from electrically contacting the cap assembly (500).

[0078] A first hole (362) communicating with a center pin (380) and a second hole (364) through which a negative electrode tab (340) can pass may be formed in the first insulating plate (360). The first hole (362) allows the gas to move upward through the cylindrical center pin (380) when a large amount of gas is generated due to a malfunction of the secondary battery. The negative electrode tab (340) can pass through the second hole (364) and be welded to the bottom portion (110).

[0079] A first hole (372) may be formed through the second insulating plate (370) to allow the gas to move to the cap assembly (500) when a large amount of gas is generated due to a malfunction of the secondary battery. Additionally, a second hole (374) may be formed through the second insulating plate (370) to allow the positive electrode tab (350) to pass through. The positive electrode tab (350) can be welded to the cap down (550), which will be described later, through the second hole (374). The second hole (374) may be formed in multiple numbers to serve as an inlet for the electrolyte to be injected into the electrode assembly (300) during the electrolyte injection process.

[0080] The cap assembly (500) may include a cap up (510) exposed to the outside of the can (100), a cap down (550) positioned at the bottom of the cap up (510), a vent plate (530) positioned between the cap up (510) and the cap down (550), and an insulator (570) positioned between the vent plate (530) and the cap down (550).

[0081] The cap up (510) is positioned at the uppermost part of the cap assembly (500) and may be provided with a piercing hole (512) for discharging gas generated inside the can (100) to the outside. The cap up (510) may be approximately disc-shaped, and a certain area may protrude convexly upward around a central axis (B). A vent plate (530) may be positioned at the bottom of the cap up (510).

[0082] The vent plate (530) is approximately in the shape of a disc, with its edge bent toward the edge of the cap-up (510) to contact the lower edge of the cap-up (510). The vent plate (530) can be bent again toward the interior of the can (100) with the part in contact with the cap-up (510) to contact the upper edge of the cap-up (510). At least one notch (532a) may be formed on the vent plate (530). When the internal gas pressure of the can (100) is greater than a predetermined breaking pressure, the vent plate (530) may be inverted upward and the notch (532a) may be broken. Accordingly, the internal gas of the can (100) can be rapidly released to the outside through the piercing hole (512) of the cap-up (510).

[0083] The cap down (550) is positioned at the bottom of the vent plate (530) and has a roughly disc shape. For example, the cap down (550) may be formed from aluminum, aluminum alloy, and equivalents, but the material is not limited thereto. The cap down (550) serves to support the cap up (510) and prevent deformation of the cap up (510) from external forces. The edge of the cap down (550) is bent toward the vent plate (530), and an insulator (570) is placed in the bent portion. A central portion of the cap down (550) is in contact with the vent plate (530). The contact area between the cap down (550) and the vent plate (530) can be connected by welding. Since the cap down (550) is welded to the positive tab (350), the cap down (550), the vent plate (530), and the cap up (510) can all exhibit positive polarity.

[0084] The insulator (570) is an insulator in the shape of a ring and serves to insulate the vent plate (530) and the cap down (550) from each other. For example, the insulator (570) may be formed from polyethylene (PE), polypropylene (PP), polystyrene (PS), ethylene-vinyl acetate copolymer (EVA), or an equivalent, but is not limited thereto. The insulator (570) may be joined to the vent plate (530) and the cap down (550) by methods such as ultrasonic welding, laser welding, or fusion.

[0085] The electrode assembly described in the above embodiments must wind the first electrode plate (or positive plate) and the second electrode plate (or negative plate) together with a separator. During winding, it is essential that the first unwound portion (or positive unwound portion) and the second unwound portion (or negative unwound portion) be positioned opposite to each other. Below, some processes and the manufacturing apparatus according to the manufacturing apparatus and method of a secondary battery are described.

[0086] FIG. 5 is a schematic diagram briefly illustrating the supply state of the winding material during the winding of an exemplary electrode assembly. FIG. 6 is a schematic diagram illustrating a part of the winding process of an electrode assembly according to one example. FIG. 7 is a schematic diagram illustrating a part of the winding process of an electrode assembly according to another example.

[0087] Referring to FIG. 5, when winding the cathode plate (10), the anode plate (20), and the separator (30), the direction in which each winding material is unwound from the reel and supplied to the winder (300) is direction (3). At this time, for example, the negative non-negative portion (12) of the cathode plate (10) may be supplied facing direction (1), and the positive non-negative portion (22) of the anode plate (20) may be supplied facing direction (2). A separator (30) is placed between the cathode plate (10) and the anode plate (20). Although omitted in FIG. 5 to show the placement of the non-negative portions, the separator (30) is placed on both the front and back of the anode plate (20) (see FIG. 9 and FIG. 10).

[0088] Generally, when coating an active material onto an electrode plate during the manufacturing process of a secondary battery, the coating is performed continuously. However, depending on the structure of the secondary battery, there are cases where the active material is coated in a specific pattern or stripe shape. For example, as shown in FIGS. 6 and 7, a plurality of active material layers (14) may be coated in a stripe shape along the discharge direction of the electrode plate foil on a single electrode plate foil. A plurality of uncoated portions (12) may be provided at both edges and the center along the discharge direction of the electrode plate foil. As described above, when manufacturing the active material in the form of a strip coating, an unbalanced coating may be applied by considering the movement of lithium ions and the ratio of the negative and positive electrodes according to the number of turns (the number of times the electrode assembly is wound, defined as 1 turn when wound one full turn). An unbalanced coating is a coating method in which the coating thickness is applied differently to side A (one of the two sides) and side B (the other of the two sides) of the electrode plate foil. An unbalanced coating may be applied to either the negative electrode plate or the positive electrode plate, or to both. When applying an unbalanced coating, it is essential to distinguish between side A and side B of the electrode foil when winding the electrode assembly. In addition, since the uncoated portions of the negative and positive plates must be positioned opposite to each other, it is essential to distinguish the orientation of the uncoated portions when winding the electrode assembly.

[0089] Once the coating of the active material is completed, a process of cutting the electrode plate according to the preset specifications of the secondary battery (slitting process, step S1 in FIGS. 6 and 7) is carried out. At this time, cutting is performed in the area coated with the active material (dotted line L1) and the uncoated area (dotted line L2). The electrode plate cutting and winding process will be explained in more detail. For convenience, FIGS. 6 and 7 are illustrated based on a winding material (electrode plate foil) for a negative electrode plate, but two unwinders are provided to supply the negative electrode plate foil and the positive electrode plate foil to the slitter, respectively.

[0090] Referring to FIG. 6, a negative foil (winding material) having a plurality of negative electrode unwound portions (12) and negative electrode active material portions (14) in a stripe shape is wound on an unwinder (100). As the winding material is unwound from the unwinder (100), cutting is performed along the center of the negative electrode active material portion (14) and the center of the negative electrode unwound portion (12) by a cutter (not shown). Each of the negative foils cut in this way is wound onto a rewinder (200). A bobbin (not shown) is provided on the rewinder (200), and the winding material wound on the bobbin is referred to as a reel. For example, each reel may be referred to as Reel A, Reel B, etc., in order. Reel A and Reel B are arbitrary names, but reels having the same direction of the unwound portion or the same plate surface direction of the winding material can be grouped together and classified as Reel A, Reel B, etc.

[0091] As described in FIG. 5, when the negative plate (10) is wound onto the winder (300), the negative plate (10) must have the negative-free portion (12) positioned in direction (1). Therefore, in the slitting process (S1), the direction in which the negative plate (10) discharged from the unwinder (100) is wound onto the rewinder (200) can be determined by considering the direction of the negative-free portion (12) of each reel. For convenience of explanation, only two rewinders (200a, 200b) are shown in the drawing, but multiple rewinders (200) may be provided. Also, although it is shown that only one A reel (10a) and one B reel (10b) are wound onto each rewinder (200a, 200b), multiple A reels (10a) and B reels (10b) may be wound at once.

[0092] Referring to FIG. 6, in order to align the direction of the negative electrode non-existent portion (12), reel A (10a) can be wound onto a rewinder (200a) with the B side facing outward, and reel B (10b) can be wound onto a rewinder (200b) with the A side facing outward. After the slitting process, the direction of the negative electrode non-existent portion (12) of reel A (10a) becomes oriented in direction (1) (S2). Therefore, it can be unwound as is (S3) and supplied to the winder (300). At this time, the B side of reel A is unwound with the B side facing outward and the A side facing inward. However, after the slitting process, the negative electrode non-existent portion (12) of reel B (10b) becomes oriented in direction (2) (S2). Therefore, to align the direction of the negative electrode non-existent portion (12) to be supplied to the winder (300), reel B (10b) must be flipped over (S3). When the reel is flipped over, the B reel (10b) is unwound with side A facing outward and side B facing inward. In this case, since the A and B sides of the negative plate face different directions for each reel, it is impossible to form an electrode assembly. Therefore, the B reel (10b) must be unwound and re-wound so that side B faces outward, just like the A reel (10b) (S4). That is, in order to align the direction of the negative electrode non-part (12) in the winder (300), an additional process (S4) is required to unwrap and re-wind the negative plate discharged from the slitting process and wound on the rewinder (200). This same problem occurs during the manufacture of the positive plate.

[0093] Conversely, in the slitting process (S1), the direction in which the negative plate (10) discharged from the unwinder (100) is wound onto the rewinder (200) can be determined by considering which side of each reel faces outward.

[0094] Referring to FIG. 7, in order to align the A or B side of the cathode plate (10), both A reel (10a) and B reel (10b) can be wound onto a rewinder (200a, 200b) such that the B side faces outward. After the slitting process, the direction of the cathode non-existent portion (12) of both A reel (10a) and B reel (10b) is reversed, instead of the B side facing outward. Since the direction of the cathode non-existent portion (12) of A reel (10a) is oriented in direction (1) (S2), it can be unwound as is (S3) and supplied to the winder (300). At this time, the B side of A reel is unwound with the B side facing outward and the A side facing inward. However, after the slitting process, the cathode non-existent portion (12) of B reel (10b) is oriented in direction 2. If the B reel (10b) is unwound as is, the B side faces outward (S3), but the negative electrode non-reinforced portion (12) still faces direction (2). Therefore, in order to align the direction of the negative electrode non-reinforced portion (12) to be supplied to the winder (300), the B reel (10b) must be unwound and re-wound so that the direction of the negative electrode non-reinforced portion (12) faces direction (1), just like the A reel (10a). That is, in order to align the A side and B side directions in the winder (300), an additional process of unwinding and re-winding the negative electrode plate discharged from the slitting process and wound on the rewinder (200) is required. This problem occurs in the same way when manufacturing the positive electrode plate.

[0095] Accordingly, in this embodiment, a dual winding device is provided to allow reels with different orientations of the blank portion or plate surface to be wound directly so as not to unwind and rewind the winding material (negative foil or positive foil).

[0096] FIG. 8 is a schematic diagram briefly illustrating a manufacturing apparatus for a secondary battery according to the present invention. FIG. 9 is a schematic diagram briefly illustrating an electrode assembly wound by a first winding device according to FIG. 8. FIG. 10 is a schematic diagram briefly illustrating an electrode assembly wound by a second winding device according to FIG. 8 (for convenience, the wound negative electrode foil or positive electrode foil is referred to as a negative electrode plate and a positive electrode plate, respectively).

[0097] Referring to FIG. 8, a secondary battery manufacturing apparatus (1000) according to one embodiment of the present invention may include a first winding apparatus (W1) that winds only A reel for both the negative electrode plate (10a) and the positive electrode plate (20a), and a second winding apparatus (W2) that winds only B reel for both the negative electrode plate (10) and the positive electrode plate (20). The secondary battery manufacturing apparatus (1000) may include an unwinder (100), a cutter (not shown), and a rewinder (200) for the aforementioned slitting process. The description of the unwinder (100), the cutter (not shown), and the rewinder (200) is replaced by the description above. The first winding device (W1) may include a first winder (300a) for final winding, a first reel support (310a) for supplying an A-reel negative plate (10a), a second reel support (320a) for supplying an A-reel positive plate (20a), and a pair of separator support (330a) for supplying a separator (30a). The second winding device (W2) may also include a second winder (300b) for final winding, a third reel support (310b) for supplying a B-reel negative plate (10v), a fourth reel support (320b) for supplying a B-reel positive plate (20b), and a pair of separator support (330b) for supplying a separator (30b). Here, the A-reel negative plate (10a) and the A-reel positive plate (20a) may each refer to a reel wound such that the negative non-negative portion (12) faces direction (1) and the positive non-negative portion (22) faces direction (2), as shown in FIG. 5. The A-reel may be a reel wound such that one of the A-side or B-side faces outward. Additionally, the B-reel may refer to a reel wound such that the negative non-negative portion (12b) faces direction (2) and the positive non-negative portion (22b) faces direction (1), contrary to FIG. 5. The B-reel may be a reel wound such that the same side as the A-reel faces outward.

[0098] First, we examine the process of winding the electrode assembly in the first winding device (W1).

[0099] As shown in FIG. 8, the A-reel negative plate (10a) and positive plate (20a) are supplied to the first winder (300a) together with the separator (30a). Two separators (30a) are supplied so that they are placed on the A and B sides of the positive plate (20a), respectively. The winding direction in which the first winder (300a) is wound and the arrangement of the negative plate (10a) and positive plate (20a) are illustrated in enlarged view in FIG. 9. When the first winder (300a) is wound counterclockwise, the negative plate (10a) is placed on the outside of the separator (30a), and the positive plate (20a) is placed between the two separators (30a). At this time, the substrate direction of the positive plate (20a) becomes the inner direction, and the substrate direction of the negative plate (10a) becomes the outer direction. When the negative plate (10a), separator (30a), and positive plate (20a) are wound in this state, the electrode assembly (E1) wound in a counterclockwise direction is discharged as shown in the upper right of FIG. 9. At this time, the negative electrode unwound portion (12a) of the electrode assembly (E1) may face left as shown in the lower right of FIG. 9, and the positive electrode unwound portion (22a) may face right.

[0100] Conversely, referring to FIGS. 8 and FIGS. 10, the direction of the B reel is opposite to that of the A reel. Therefore, when the second winder (300b) is wound counterclockwise in the second winding device (W2), the direction of the material of the negative plate (10b) becomes the inner direction, and the direction of the material of the positive plate (20b) becomes the outer direction. The aforementioned inner direction refers to the direction toward the winding center, and the outer direction refers to the direction toward the outside of the electrode assembly. When the negative plate (10b), separator (30b), and positive plate (20b) are wound in this state, the electrode assembly (E2) is wound clockwise as shown in the right discharge shape of FIG. 10. At this time, the discharge shape of the electrode assembly (E2) is the same as the upper right bottom of FIG. 10, depending on the direction of the B reel's unused portion. The negative unused portion (12b) faces the right direction, and the positive unused portion (22b) faces the left direction. When the electrode assembly (E2) of Fig. 10 is rotated in the same direction as the electrode assembly (E1) of Fig. 9, it exhibits a winding direction similar to the lower right side of Fig. 10. That is, the B-reel electrode assembly (E2) of Fig. 10 has a winding direction reversed from that of the A-reel electrode assembly (E1) of Fig. 9.

[0101] Therefore, when a secondary battery is manufactured by producing an A-reel electrode assembly (E1) and a B-reel electrode assembly (E2) respectively, a secondary battery is produced in which the winding directions of the electrode assemblies are opposite to each other. More specifically, the secondary battery made with the A-reel electrode assembly (E1) can be referred to as the first secondary battery, and the secondary battery made with the B-reel electrode assembly (E2) can be referred to as the second secondary battery. As described above, the first secondary battery and the second secondary battery have electrode assemblies in opposite directions. When a battery module or battery pack is constructed using such secondary batteries, multiple first and second secondary batteries with electrode assemblies in opposite winding directions are used in combination. The winding direction of the electrode assembly is irrelevant to the capacity or performance of the secondary battery. Therefore, the process of unwinding and rewinding already wound material to align the direction of the unwound portion or the direction of the electrode plate surface can be omitted. In addition, since the electrode assembly can be produced by winding the reel as is without rewinding the direction of the non-rewinding portion or the direction of the electrode plate surface, the manufacturing time and manufacturing process can be reduced.

[0102] The secondary battery according to the above-described embodiment can be used to manufacture a battery pack (the reference numbers of the components described below are reference numbers applicable only to the drawings).

[0103] FIGS. 11 and 12 are perspective views illustrating a battery pack (300) including an exemplary cylindrical secondary battery according to the present invention. Referring to FIGS. 11 and 12, the battery pack (300) may include a plurality of battery modules (200) and a housing (310) for accommodating the plurality of battery modules (200). For example, the housing (310) may include first and second housings (311, 312) that are coupled in a direction facing each other with the plurality of battery modules (200) interposed therebetween. The plurality of battery modules (210) may be electrically connected to each other using a bus bar (251), and the plurality of battery modules (200) may be electrically connected to each other in a series / parallel or mixed series / parallel manner to obtain the required electrical output. In the drawings, for convenience of illustration, components such as a bus bar for electrically connecting the battery cells, a cooling unit, and external terminals are omitted. In some examples, the battery pack (300) may be mounted in 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.

[0104] FIGS. 13 and FIGS. 14 are a perspective view and a side view illustrating an automobile (400, 500) including an exemplary battery pack (300) according to the present invention. In FIG. 13, the battery pack (300) may include a battery pack cover (311) (which may correspond to the first housing) which is part of the vehicle under body (410) and a pack frame (312) (which may correspond to the second housing) disposed at the bottom of the vehicle under body (410). The battery pack cover (311) and the pack frame (312) may be structures formed integrally with the vehicle floor portion (420). The vehicle under body (410) separates the interior and exterior of the vehicle, and the pack frame (312) may be disposed on the exterior of the vehicle.

[0105] As illustrated in FIG. 14, the vehicle (500) may be formed by combining additional parts, such as a hood (510) at the front of the vehicle and fenders (520) located at the front and rear of the vehicle, respectively, with the vehicle body (400). The vehicle (500) includes a battery pack (300) comprising a battery pack cover (311) and a pack frame (312), and the battery pack (300) may be combined with the vehicle body part (400).

[0106] The above description is merely one embodiment for implementing the present invention, and the present invention is not limited to the above-described embodiment. The technical spirit of the present invention extends to the scope in which various modifications can be made by anyone with ordinary knowledge in the field to which the invention belongs, without departing from the essence of the invention as claimed in the following patent claims. Explanation of the symbols

[0107] 1000: Secondary battery manufacturing device 100: Unwinder 200: Rewinder 300: Winder

Claims

Claim 1 A secondary battery manufacturing apparatus comprising: an unwinder for supplying a wound electrode foil; a plurality of slitters for cutting the electrode foil supplied from the unwinder at predetermined intervals; a plurality of rewinders for winding the electrode foils discharged from the slitters in one direction each; and a first winding device and a second winding device for winding the electrode foil and separator wound from the rewinders and discharging a wound electrode assembly, wherein the first winding device winds the electrode assembly in an A-reel with the negative electrode unwound portion and the positive electrode unwound portion facing a predetermined direction each. Claim 2 A secondary battery manufacturing apparatus according to claim 1, wherein the reel of wound electrode foil discharged from the rewinder has the unwound portions facing in different directions. Claim 3 A secondary battery manufacturing apparatus according to claim 2, wherein the reel of wound electrode foil discharged from the rewinder has the same side facing outward from the winding. Claim 4 A secondary battery manufacturing apparatus according to claim 3, wherein the unwinder is provided in two units to supply a negative electrode plate foil and a positive electrode plate foil, respectively. Claim 5 delete Claim 6 A secondary battery manufacturing apparatus according to claim 1, wherein the second winding device winds an electrode assembly with a B-reel in which the negative electrode unwound portion and the positive electrode unwound portion each face a direction opposite to a preset direction. Claim 7 A secondary battery manufacturing apparatus according to claim 6, wherein the electrode assembly wound on reel A and the electrode assembly wound on reel B are wound in opposite directions. Claim 8 In claim 4, the negative electrode foil and the positive electrode foil are coated with an active material in a stripe pattern along the length direction, in a secondary battery manufacturing apparatus. Claim 9 In claim 8, an apparatus for manufacturing a secondary battery, wherein either the negative electrode foil and the positive electrode foil, or the negative electrode foil and the positive electrode foil, have the active material unbalancedly coated on one or both sides. Claim 10 A battery module comprising a plurality of secondary batteries manufactured by a secondary battery manufacturing apparatus according to any one of claims 1 to 4 and claims 6 to 9. Claim 11 In claim 10, the secondary battery comprises a plurality of first secondary batteries and second secondary batteries in which the winding directions of the electrode assemblies are opposite to each other, forming a battery module. Claim 12 In claim 11, the electrode assembly comprises a negative plate and a positive plate, forming a battery module. Claim 13 In claim 12, the battery module wherein the negative plate and the positive plate are coated with an active material in a stripe pattern along the longitudinal direction. Claim 14 In claim 13, a battery module wherein either the negative electrode plate and the positive electrode plate, or the negative electrode plate and the positive electrode plate, have the active material unbalancedly coated on one or both sides.

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