Secondary battery manufacturing device, and battery module having secondary battery manufactured thereby

Abstract

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

Description

A secondary battery manufacturing device and a battery module equipped with a secondary battery manufactured thereby

[0001] An embodiment of the present invention relates to a device for manufacturing a secondary battery and a battery module including a secondary battery manufactured thereby.

[0002] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for motor drives and power storage in hybrid and electric vehicles. These secondary batteries include an electrode assembly comprising a positive and negative electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

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

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

[0005] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0006] A secondary battery manufacturing device according to an embodiment of the present invention may include an unwinder for supplying rolled 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 rolled electrode foil and separator from the rewinder and discharging a rolled electrode assembly.

[0007] The reels of wound polar foil discharged from the above rewinder may have their uncoated portions facing in different directions.

[0008] The reels of wound polar foil discharged from the above rewinder may have the same side facing the winding outer side.

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

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

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

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

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

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

[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 electrode plate and a positive electrode plate.

[0018] The above negative electrode plate and the positive electrode plate may be coated with an active material in a stripe pattern along the length direction.

[0019] Either the negative electrode plate or the positive electrode plate, or the negative electrode plate and the positive electrode plate may have the active material unbalancedly coated on one or both sides.

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

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

[0022] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0023] 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.

[0024] Figure 1 is a perspective view of an exemplary cylindrical secondary battery.

[0025] Figure 2 is a cross-sectional view of a cylindrical secondary battery according to Figure 1.

[0026] Figure 3 is a perspective view of an exemplary cylindrical secondary battery.

[0027] Fig. 4 is a cross-sectional view of a cylindrical secondary battery according to Fig. 3.

[0028] Figure 5 is a schematic diagram briefly illustrating the supply state of the winding material when winding an exemplary electrode assembly.

[0029] Figure 6 is a schematic diagram illustrating a part of a winding process of an electrode assembly according to an example.

[0030] Figure 7 is a schematic diagram illustrating part of a winding process of an electrode assembly according to another example.

[0031] Figure 8 is a schematic diagram briefly illustrating a device for manufacturing a secondary battery according to the present invention.

[0032] FIG. 9 is a schematic diagram schematically illustrating an electrode assembly wound by the first winding device according to FIG. 8.

[0033] FIG. 10 is a schematic diagram schematically illustrating an electrode assembly wound by a second winding device according to FIG. 8.

[0034] FIGS. 11 and 12 are perspective views illustrating a battery pack including an exemplary secondary battery according to the present invention.

[0035] FIGS. 13 and 14 are perspective and side views illustrating a vehicle including an exemplary battery pack according to the present invention.

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0037] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0038] Additionally, to facilitate understanding of the invention, the attached drawings may not be drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0039] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0040] 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.

[0041] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0042] Any configuration being placed on (or below) a component or above (or below) a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of the component, but also that another configuration may be interposed between the component and any configuration placed on (or below) the component.

[0043] 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 coupled to one another, but that other components may be interposed between the components, or that each component may be connected, coupled, or connected through another component. Furthermore, when it is said 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 another element in between.

[0044] When reference is made throughout the specification to A and / or B, this means A, B, or A and B, unless otherwise stated. That is, and / or includes all or any combination of the listed items. When reference is made to C through D, this means C or more and D or less, unless otherwise stated.

[0045] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0046] Hereinafter, with reference to the attached drawings, a manufacturing device for a secondary battery according to embodiments of the present invention and a battery module including a secondary battery manufactured thereby will be described in detail.

[0047] First, exemplary structures of secondary batteries are described (the drawing numbers in FIGS. 1 to 4 are numbers that apply only to the components of the corresponding drawings).

[0048] Fig. 1 is a perspective view of an exemplary cylindrical secondary battery. Fig. 2 is a cross-sectional view of the cylindrical secondary battery according to Fig. 1.

[0049] Referring to FIGS. 1 and 2, an exemplary secondary battery (10) may include a cylindrical can (100), an electrode assembly (200) accommodated 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).

[0050] The can (100) constitutes the outer shape of the secondary battery (10) and may have a cylindrical shape with one end opened. The can (100) may include or be referred to as a case, a housing, or an outer material. The can (100) may include a top surface (110) in a circular shape and a side surface (120) in a cylindrical shape extending downward from the top surface (110). A terminal hole is formed through the top surface (110), and a terminal portion (500) is provided in the terminal hole. A bead portion (122) may be formed adjacent to an end of the side surface (120). The bead portion (122) is formed to be concave toward the inside of the side surface (120). The bead portion (122) is provided for fixing the electrode assembly (200) and for settling 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) may be formed by bending the end of the side portion (120) toward the inside of the can (100). The cap assembly (600) may 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) may be placed so that it faces upwards, and then the electrode assembly (200) may be inserted together with the electrolyte. Thereafter, after the cap assembly (600) is seated on the beading portion (122), the crimping portion (124) may be formed to fix the cap assembly (600), and then the cap assembly (600) may be positioned so that it faces downwards again. If necessary, the cap assembly (600) may also be used in a state where it faces upwards. In this embodiment, the example is described based on an example in which 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 with a metal such as steel, nickel-plated steel, steel alloy, aluminum, aluminum alloy, deep drawing cooling sheet (SPCE), or a laminate film or plastic material constituting a pouch. An electrode assembly (200) is accommodated inside the can (100) together with an electrolyte.

[0051] 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 a first electrode current collector plate (250) and a second electrode current collector plate (260), respectively. For example, the first electrode plate (210) may serve as an anode, and the second electrode plate (220) may serve as a cathode. Or, the configuration may be the opposite. In some examples, a hollow cylindrical core may be provided at the center of the electrode assembly (200). Additionally, in some examples, the core may have a center pin (optional) inserted.

[0052] 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-conductive portion on which the first active material is not provided. The first non-conductive portion may be referred to as the first substrate. The first non-conductive portion may be arranged toward the upper surface (110) of the can (100) and may be electrically connected to the first electrode current collector (300).

[0053] For example, the first electrode plate (210) may function as an anode. The first substrate may include 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.

[0054] In some examples, a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) may be used as the cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from the group consisting of cobalt, manganese, nickel, and combinations thereof may be used.

[0055] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0056] As an example, a compound represented by any one of the following chemical formulas may be used. LiaA1-bXbO2-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaMn2-bXbO4-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNi1-b-cMnbXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤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).

[0057] In the 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.

[0058] 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 includes a positive electrode active material and may further include a binder and / or a conductive material.

[0059] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0060] Aluminum may be used as the current collector, but is not limited thereto.

[0061] The second electrode plate (220) may be the other of the negative electrode plate and the positive electrode plate. The second electrode plate (220) may include a second substrate which is a metal sheet, a second active material layer provided on at least one surface of the second substrate, and a second non-conductive portion where the second active material layer is not provided. The second non-conductive portion may be arranged toward the bottom of the side portion (120) of the can (100) and may be electrically connected to the second electrode current collector plate (400).

[0062] For example, the second electrode plate (220) may function as a cathode. The second substrate may include copper or nickel foil, and the second active material layer may include a carbon-based material, Si, Sn, tin oxide, a tin alloy complex, a transition metal oxide, lithium metal nitrite, or a metal oxide. The second substrate may be referred to as a second metal current collector or a second electrode plate foil.

[0063] 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.

[0064] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, 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, and the like.

[0065] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material can be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0066] The above 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.

[0067] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0068] 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 includes a negative electrode active material and may further include a binder and / or a conductive material.

[0069] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0070] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0071] The current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0072] A separator (230) is positioned between the first electrode plate (210) and the second electrode plate (220) to prevent short circuits 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 positioned on one or both sides of the porous substrate.

[0073] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic polymer.

[0074] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0075] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0076] An electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0077] The non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move. The 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 combination of two or more.

[0078] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0079] The first electrode collector plate (300) has a roughly circular shape and can be electrically connected to a positive electrode terminal (510) to be described later. The first electrode collector plate (300) can be joined to the positive electrode 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 electrode terminal (510) can be electrically connected.

[0080] The second electrode collector plate (400) has a roughly circular shape, and its edges are curved in a streamlined shape so that it can be in 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.

[0081] 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 (110) of the can (100) and is electrically connected to the first electrode plate (210) through the first electrode current collector plate (300). The positive terminal (510) is coupled to the upper surface (110) by a rivet connection. The positive terminal (510) may be inserted into a terminal hole from the outside of the can (100) and then the inner end may be compressed and deformed by processing such as pressing or spinning to adhere to the inside of the upper surface (110). Alternatively, the positive terminal (510) may be inserted into a terminal hole from the inside of the can (100) and then the outer end may be compressed and deformed to adhere to the outside of the upper surface (110). At this time, a gasket (520) can be inserted between the positive terminal (510) and the terminal hole to insulate the can (100) and the positive terminal (130).

[0082] 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 between 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) exposed to the outside of the upper surface (110). The second gasket (524) insulates between the positive terminal (510) and the terminal hole of the upper surface (110). The third gasket (526) insulates between the upper surface (110) and the first electrode current collector (300). Therefore, the third gasket (526) may have the same or similar size and shape as the first electrode current collector (300). Alternatively, the third gasket (526) may have the same or similar size and shape as the upper surface (110). In some embodiments, instead of the third gasket (526), ​​an insulating tape (530) may be attached to the first electrode current collector (300). Furthermore, in some embodiments, the first gasket (522), the second gasket (524), and the third gasket (526) may be provided as a single unit.

[0083] The cap assembly (600) may include a cap plate (610) and an insulator (620). The cap plate (610) is secured to the side (120) of the can (100) by a beading portion (122) and a crimping portion (124) at an edge, and is insulated from the side (120) by the insulator (620). A notch (612) may be formed on the cap plate (610) to be broken when the internal pressure exceeds a certain pressure. The notch (612) is formed to be thinner than other regions, and acts as a vent through which internal gas is discharged when broken.

[0084] 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 (reference numbers of each structure of the secondary battery illustrated in Figs. 3 and 4 are applied only to the description of the configuration of the corresponding drawings. In addition, a detailed description of the configuration and features that have the same function as the secondary battery described above are omitted.).

[0085] Referring to FIGS. 3 and 4, an exemplary secondary battery (10) may include a cylindrical can (100), an electrode assembly (300) inserted into the can (100), a cap assembly (500) inserted into 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).

[0086] The can (100) includes a circular bottom portion (110) and a side portion (130) extending upward from the bottom portion (110), and the upper portion of the side portion (130) is open (hereinafter, referred to as an opening portion). A cap assembly (500) is inserted into the opening portion 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 the secondary battery (10), an electrode assembly (300) may be inserted into the can (100) together with an electrolyte through the opening portion of the can (100).

[0087] The electrode assembly (300) includes a negative electrode plate (310), a positive electrode plate (320), and a separator (330). The negative electrode plate (310) may have a negative electrode active material (e.g., graphite, carbon, etc.) formed on both surfaces. The positive electrode plate (320) may have a positive electrode active material (e.g., transition metal oxide (LiCoO2, LiNiO2, LiMn2O4, etc.)) formed on both surfaces. The separator (330) is disposed between the negative electrode plate (310) and the positive electrode plate (320) to prevent short circuit and only allow 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 electrode plate (310) may be made of copper (Cu) or nickel (Ni) foil, the positive electrode plate (320) may be made of aluminum (Al) foil, and the separator (330) may be made of polyethylene (PE) or polypropylene (PP), but the present invention is not limited to the above materials. A negative electrode tab (340) that protrudes downward from the negative electrode plate (310) by a certain length may be welded to the positive electrode plate (320), and a positive electrode tab (350) that protrudes upward by a certain length may be welded to the positive electrode plate (320), but the opposite is also possible. The negative electrode tab (340) may be made of copper or nickel, and the positive electrode tab (350) may be made of aluminum, but the present invention is not limited to the above materials. The negative electrode 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 (111) of the can (100), in which case the can (100) may function as a positive electrode. In the present embodiment, the negative electrode tab (340) is welded to the bottom (110) of the can (100) as an example.

[0088] In this embodiment, a structure in which the negative electrode plate (310) and the positive electrode plate (320) are electrically connected to the can (100) and the cap assembly (500) through the negative electrode tab (340) and the positive electrode tab (350) has been described. However, a negative electrode non-conductive portion and a positive electrode non-conductive portion without an active material may be configured on each of the negative electrode plate (310) and the positive electrode plate (320) without the negative electrode tab (340) and the positive electrode tab (350). In this case, the negative electrode non-conductive portion may be directly adhered to the bottom portion (111) of the can (100) or may be welded to the negative electrode current collector and then electrically connected to the can (100) through the negative electrode current collector. The positive electrode non-conductive portion may be welded to the positive electrode current collector and the positive electrode current collector may be electrically connected to the cap assembly through the positive lead.

[0089] Additionally, a first insulating plate (360) and a second insulating plate (370) may be interposed between the upper and lower portions of the electrode assembly (300). The first insulating plate (360) prevents the positive electrode plate (320) from electrically contacting the bottom portion (110) of the can (100), and the second insulating plate (370) prevents the negative electrode plate (310) from electrically contacting the cap assembly (500).

[0090] A first hole (362) communicating with a center pin (380) and a second hole (364) allowing a negative electrode tab (340) to pass through 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 an abnormality in the secondary battery. The negative electrode tab (340) may be welded to the bottom portion (110) through the second hole (364).

[0091] A first hole (372) may be formed through the second insulating plate (370) to allow gas to move to the cap assembly (500) when a large amount of gas is generated due to an abnormality in the secondary battery. In addition, 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) may be welded to the cap down (550) described below through the second hole (374). A plurality of second holes (374) may be formed to serve as inlets through which electrolyte is injected into the electrode assembly (300) during the electrolyte injection process.

[0092] The cap assembly (500) may include a cap up (510) exposed to the outside of the can (100), a cap down (550) positioned below 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).

[0093] 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 have a roughly circular shape, and a predetermined area may protrude upward in a convex manner around a central axis (B). A vent plate (530) may be positioned at the bottom of the cap up (510).

[0094] The vent plate (530) is roughly circular in shape, and its edge is bent toward the edge of the cap up (510) to contact the lower edge of the cap up (510). The vent plate (530) may be bent again toward the inside of the can (100) around the portion 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 gas pressure inside the can (100) is greater than a predetermined breaking pressure, the notch (532a) may be broken as the vent plate (530) is reversed upward. Accordingly, the gas inside the can (100) may be quickly released to the outside through the piercing hole (512) of the cap up (510).

[0095] The cap down (550) is positioned below the vent plate (530) and has a roughly circular shape. For example, the cap down (550) may be formed of aluminum, an aluminum alloy, and an equivalent thereof, but the material is not limited thereto. The cap down (550) supports the cap up (510) and prevents deformation of the cap up (510) due to external force. The edge of the cap down (550) is bent toward the vent plate (530), and an insulator (570) is positioned at the bent portion. A central portion of the cap down (550) is in contact with the vent plate (530). The contact area of ​​the cap down (550) and the vent plate (530) may 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) may all exhibit positive polarity.

[0096] The insulator (570) is a roughly ring-shaped insulator that serves to insulate the vent plate (530) and the cap down (550) from each other. For example, the insulator (570) may be formed of, but is not limited to, polyethylene (PE), polypropylene (PP), polystyrene (PS), ethylene-vinyl acetate copolymer (EVA), or an equivalent thereof. The insulator (570) may be joined to the vent plate (530) and the cap down (550) by means of ultrasonic welding, laser welding, fusion, or the like.

[0097] The electrode assembly described in the above embodiments requires winding a first electrode plate (or positive electrode plate) and a second electrode plate (or negative electrode plate) together with a separator. During winding, it is essential that the first uncoated portion (or positive electrode uncoated portion) and the second uncoated portion (or negative electrode uncoated portion) are arranged opposite each other. Below, some processes and manufacturing devices for secondary batteries and manufacturing methods are described.

[0098] Fig. 5 is a schematic diagram schematically illustrating the supply state of the winding material during the winding of an exemplary electrode assembly. Fig. 6 is a schematic diagram illustrating a portion of the winding process of an electrode assembly according to an example. Fig. 7 is a schematic diagram schematically illustrating a portion of the winding process of an electrode assembly according to another example.

[0099] Referring to Fig. 5, when winding the negative plate (10), the positive 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 electrode non-coated portion (12) of the negative electrode plate (10) may be supplied facing direction (1), and the positive electrode non-coated portion (22) of the positive electrode plate (20) may be supplied facing direction (2). The separator (30) is arranged between the negative electrode plate (10) and the positive electrode plate (20). Although it is omitted in Fig. 5 to show the arrangement of the non-coated portion, the separator (30) is arranged on both the front and back of the positive electrode plate (20) (see Figs. 9 and 10).

[0100] In general, when coating an active material on an electrode plate in 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) can be coated in a stripe shape on one electrode plate foil along the discharge direction of the electrode plate foil. A plurality of non-coated regions (12) can 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 can be applied considering the ratio of the negative and positive electrodes according to the movement of lithium ions and the number of turns (the number of turns of the electrode assembly, where one turn is defined as one turn). An unbalanced coating is a coating method that applies different coating thicknesses to the A side (one of the two sides) and the B side (the other of the two sides) of the electrode plate foil. An unbalanced coating can be applied to either or both of the negative and positive electrode plates. When applying an unbalanced coating, it is essential to distinguish between the A and B sides of the electrode foil when winding the electrode assembly. Furthermore, since the uncoated portions of the negative and positive plates must be arranged opposite each other, it is essential to distinguish the orientation of the uncoated portions when winding the electrode assembly.

[0101] 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 of FIGS. 6 and 7) is performed. 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 described in more detail. For convenience, FIGS. 6 and 7 illustrate the winding material (electrode plate foil) for the 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.

[0102] Referring to Fig. 6, a negative electrode foil (winding material) having a plurality of negative electrode non-woven portions (12) and negative electrode active material portions (14) in a stripe shape is wound around an unwinder (100). As the winding material is unwound from the unwinder (100), a cutter (not shown) cuts the negative electrode active material portion (14) along the center of the negative electrode non-woven portion (12). Each of the cut negative electrode foils is wound around a rewinder (200). The rewinder (200) is equipped with a bobbin (not shown), and the winding material wound around the bobbin is referred to as a reel. For example, each reel may be referred to as an A reel and a B reel in order. A reel and a B reel may be any name, but reels having the same non-woven portion direction or the same plate direction of the winding material may be grouped together and distinguished as A reel and B reel, etc.

[0103] As described in Fig. 5, when wound on a winder (300), the negative electrode plate (10) must have its negative electrode uncoated portion (12) arranged in the direction (1). Therefore, in the slitting process (S1), the direction in which the negative electrode plate (10) discharged from the unwinder (100) is wound on the rewinder (200) can be determined by considering the direction of the negative electrode uncoated portion (12) of each reel. For convenience of explanation, only two rewinders (200a, 200b) are illustrated in the drawing, but the rewinder (200) may be provided in multiple numbers. In addition, although only one A reel (10a) and one B reel (10b) are illustrated as being wound on each rewinder (200a, 200b), multiple A reels (10a) and B reels (10b) may be wound at a time.

[0104] Referring to FIG. 6, in order to align the direction of the negative electrode non-coated portion (12), the A reel (10a) can be wound on the rewinder (200a) with the B side facing outward, and the B reel (10b) can be wound on the rewinder (200b) with the A side facing outward. After the slitting process, the direction of the negative electrode non-coated portion (12) of the A reel (10a) is oriented in direction (1) (S2). Therefore, it can be unwound as is (S3) and supplied to the winder (300). At this time, the A reel is unwound with the B side facing outward and the A side facing inward. However, after the slitting process, the negative electrode non-coated portion (12) of the B reel (10b) is oriented in direction (2) (S2). Therefore, in order to align the direction of the negative electrode non-coated portion (12) to be supplied to the winder (300), the B reel (10b) must be turned over (S3). When the reel is turned over, the B reel (10b) is unwound with the A side facing outward and the B side facing inward. In this case, since the A and B sides of the negative plate of each reel face different directions, it is impossible to manufacture an electrode assembly. Therefore, the B reel (10b) must be unwound again and rewound so that the B side faces outward like the A reel (10b) (S4). That is, in order to align the direction of the negative electrode non-coated portion (12) in the winder (300), a problem arises in which an additional process (S4) is required to unwound and rewound the negative plate discharged from the slitting process and wound on the rewinder (200). This problem also occurs when manufacturing the positive plate.

[0105] Conversely, in the slitting process (S1), the direction in which the negative plate (10) discharged from the unwinder (100) is wound on the rewinder (200) can be determined by considering which side of each reel faces outward.

[0106] Referring to Fig. 7, in order to match the arrangement of the A side or the B side of the negative plate (10), both the A reel (10a) and the B reel (10b) can be wound on the rewinder (200a, 200b) so that the B side faces outward. After the slitting process, both the A reel (10a) and the B reel (10b) have the B side facing outward, but the direction of the negative electrode non-coated portion (12) is opposite. Since the direction of the negative electrode non-coated portion (12) of the 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 the A reel faces outward and the A side faces inward. However, after the slitting process, the negative electrode non-coated portion (12) of the B reel (10b) faces in direction 2. If the B reel (10b) is unwound as it is, the B side faces outward (S3), but the negative electrode uncoated portion (12) still faces in the direction of (2). Therefore, in order to align the direction of the negative electrode uncoated portion (12) to be supplied to the winder (300), the B reel (10b) must be unwound again and rewound so that the direction of the negative electrode uncoated portion (12) faces in the direction of (1), like the A reel (10a). That is, in order to align the directions of the A and B sides in the winder (300), a problem arises in that an additional process of unwinding and rewound the negative electrode plate discharged from the slitting process and wound on the rewinder (200) is required. This problem also occurs when manufacturing the positive electrode plate.

[0107] Therefore, in this embodiment, a dual winding device is provided so that reels with different directions of the non-woven part or plate surface can be wound directly without having to unwind and rewind the winding material (negative foil or positive foil).

[0108] Fig. 8 is a schematic diagram briefly illustrating a device for manufacturing a secondary battery according to the present invention. Fig. 9 is a schematic diagram briefly illustrating an electrode assembly wound by the first winding device according to Fig. 8. Fig. 10 is a schematic diagram briefly illustrating an electrode assembly wound by the 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).

[0109] Referring to FIG. 8, a secondary battery manufacturing device (1000) according to an embodiment of the present invention may include a first winding device (W1) that winds only the A reel for both the negative electrode plate (10a) and the positive electrode plate (20a), and a second winding device (W2) that winds only the B reel for both the negative electrode plate (10) and the positive electrode plate (20). The secondary battery manufacturing device (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 with the description described above. The first winding device (W1) may include a first winder (300a) for final winding, a first reel support (310a) for supplying A reel negative plate (10a), a second reel support (320a) for supplying A reel positive plate (20a), and a pair of separator supports (330a) for supplying separators (30a). The second winding device (W2) may also include a second winder (300b) for final winding, a third reel support (310b) for supplying B reel negative plate (10v), a fourth reel support (320b) for supplying B reel positive plate (20b), and a pair of separator supports (330b) for supplying separators (30b). Here, the A-reel negative electrode plate (10a) and the A-reel positive electrode plate (20a) may each mean a reel wound such that the negative electrode non-coated portion (12) faces in direction (1) and the positive electrode non-coated portion (22) faces in direction (2), as shown in FIG. 5. The A-reel may be a reel wound such that one of the A-side or the B-side faces outward. In addition, the B-reel may mean a reel wound such that the negative electrode non-coated portion (12b) faces in direction (2) and the positive electrode non-coated portion (22b) faces in direction (1), as opposed to FIG. 5. The B-reel may be a reel wound such that the same side as the A-reel faces outward.

[0110] Let us first look at the process of winding the electrode assembly in the first winding device (W1).

[0111] As shown in Fig. 8, the A-reel negative plate (10a) and the positive plate (20a) are supplied to the first winder (300a) together with the separator (30a). The separator (30a) is supplied in two pieces so that it is arranged on the A and B sides of the positive plate (20a), respectively. The winding direction and the arrangement of the negative plate (10a) and the positive plate (20a) in the first winder (300a) are illustrated in an enlarged manner in Fig. 9. When the first winder (300a) is wound counterclockwise, the negative plate (10a) is arranged on the outside of the separator (30a), and the positive plate (20a) is arranged between the two separators (30a). At this time, the substrate direction of the positive plate (20a) becomes the inside direction, and the substrate direction of the negative plate (10a) becomes the outside direction. When the negative electrode plate (10a), separator (30a), and positive electrode plate (20a) are wound in this state, the electrode assembly (E1) wound counterclockwise is discharged as shown in the upper right of Fig. 9. At this time, the negative electrode non-conducting portion (12a) of the electrode assembly (E1) may face to the left as shown in the lower right of Fig. 9, and the positive electrode non-conducting portion (22a) may face to the right.

[0112] Conversely, referring to FIGS. 8 and 10, the direction of the uncoated portion of the B reel is opposite to that of the A reel. Therefore, in the second winder (W2), when the second winder (300b) is wound counterclockwise, the direction of the substrate of the negative electrode plate (10b) becomes inward, and the direction of the substrate of the positive electrode plate (20b) becomes outward. The aforementioned inward direction means the direction toward the winding center, and the outward direction means the direction toward the outside of the electrode assembly. When the negative electrode plate (10b), the separator (30b), and the positive electrode plate (20b) are wound in this state, the electrode assembly (E2) is wound in a clockwise direction as shown in the right discharge shape of FIG. 10. At this time, the discharge shape of the electrode assembly (E2) is as shown in the upper and lower right of FIG. 10 according to the direction of the uncoated portion of the B reel. The negative electrode uncoated portion (12b) faces the right, and the positive electrode uncoated portion (22b) faces the left. When the electrode assembly (E2) of FIG. 10 is rotated in the same direction as the electrode assembly (E1) of FIG. 9, it exhibits the same winding direction as 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.

[0113] Therefore, when a secondary battery is manufactured by manufacturing the A reel electrode assembly (E1) and the B reel electrode assembly (E2) respectively, a secondary battery is manufactured in which the winding directions of the electrode assemblies are opposite to each other. More specifically, a secondary battery manufactured with the A reel electrode assembly (E1) may be referred to as a first secondary battery, and a secondary battery manufactured with the B reel electrode assembly (E2) may be referred to as a second secondary battery. As described above, the winding directions of the electrode assemblies of the first and second secondary batteries are opposite to each other. When a battery module or battery pack is configured with these secondary batteries, a plurality of first and second secondary batteries in which the winding directions of the electrode assemblies are opposite to each other are mixed. The winding direction of the electrode assembly is unrelated to the capacity or performance of the secondary battery. Therefore, the process of unwinding and rewinding the already wound winding material to align the direction of the non-coated 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 without rewinding the reel having a different direction of the non-conductive portion or the direction of the polar plate surface, the manufacturing time and manufacturing process can be reduced.

[0114] The secondary battery according to the above-described embodiment can be used to manufacture a battery pack (reference numbers of the components described below are reference numbers that apply only to the corresponding drawing).

[0115] 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 series-parallel hybrid manner to obtain a required electrical output. In the drawings, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrically connecting battery cells are omitted. In some examples, 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.

[0116] Figures 13 and 14 are perspective views and side views illustrating a vehicle (400, 500) including an exemplary battery pack (300) according to the present invention. In Figure 13, the battery pack (300) may include a battery pack cover (311) (which may correspond to the first housing) which is a part of a vehicle underbody (410) and a pack frame (312) (which may correspond to the second housing) which is disposed at a lower portion of the vehicle underbody (410). The battery pack cover (311) and the pack frame (312) may be formed integrally with the vehicle floor (420). The vehicle underbody (410) separates the interior and exterior of the vehicle, and the pack frame (312) may be disposed at the exterior of the vehicle.

[0117] As illustrated in FIG. 14, a vehicle (500) may be formed by combining additional components, such as a hood (510) at the front of the vehicle and fenders (520) positioned at the front and rear of the vehicle, respectively, with a body (400). The vehicle (500) includes a battery pack (300) including a battery pack cover (311) and a pack frame (312), and the battery pack (300) may be combined with a body component (400).

[0118] The above description is only one embodiment for carrying out the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, it will be said that the technical spirit of the present invention exists to the extent that anyone with ordinary skill in the art to which the present invention pertains can make various modifications without departing from the gist of the present invention.

Claims

1. Unwinder for supplying the wound polar plate foil; A plurality of slitters for cutting the polar plate foil supplied from the above unwinder at predetermined intervals; A plurality of rewinders that wind a plurality of polar plate foils discharged from the slitter in one direction; and A secondary battery manufacturing device comprising a first winding device and a second winding device that wind the polar plate foil and separator wound in the above rewinder and discharge the wound electrode assembly.

2. In paragraph 1, A secondary battery manufacturing device in which the reels of wound polar plate foil discharged from the above rewinder have the directions of the non-conductive portions facing different directions.

3. In paragraph 2, A secondary battery manufacturing device, wherein the reel of the wound polar plate foil discharged from the above rewinder has the same surface facing the outer side of the winding.

4. In paragraph 3, A secondary battery manufacturing device, wherein the above unwinder is provided in two units to supply negative electrode foil and positive electrode foil, respectively.

5. In paragraph 4, The above first winding device is a secondary battery manufacturing device that winds an electrode assembly with an A reel in which the negative electrode non-coated portion and the positive electrode non-coated portion each face a preset direction.

6. In paragraph 5, The above second winding device is a secondary battery manufacturing device that winds the electrode assembly with a B reel in which the negative electrode non-coated portion and the positive electrode non-coated portion each face in a direction opposite to a preset direction.

7. In paragraph 6, A secondary battery manufacturing device, wherein the electrode assembly wound with the above A reel and the electrode assembly wound with the above B reel are wound in opposite winding directions.

8. In paragraph 4, A secondary battery manufacturing device, wherein the negative electrode foil and the positive electrode foil are coated with an active material in a stripe pattern along the length direction.

9. In paragraph 8, A secondary battery manufacturing device, wherein either the negative electrode plate foil or the positive electrode plate foil, or the negative electrode plate foil or the positive electrode plate foil, has the active material unbalancedly coated on one or both sides.

10. A battery module comprising a plurality of secondary batteries manufactured by a secondary battery manufacturing device according to any one of claims 1 to 9.

11. In paragraph 10, A battery module comprising a plurality of first secondary batteries and second secondary batteries in which the winding directions of the electrode assemblies are opposite to each other.

12. In paragraph 11, A battery module, wherein the electrode assembly includes a negative electrode plate and a positive electrode plate.

13. In paragraph 12, A battery module in which the negative electrode plate and the positive electrode plate are coated with an active material in a stripe pattern along the length direction.

14. In paragraph 13, A battery module, wherein either one of the negative electrode plate and the positive electrode plate, or the negative electrode plate and the positive electrode plate, has the active material unbalancedly coated on one or both sides.

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