Secondary battery

Abstract

A secondary battery according to an embodiment of the present invention may comprise: a cylindrical can that is open at one end and closed at the other end; an electrode assembly accommodated in the can; a terminal coupled to the closed end of the can and electrically connected to the electrode assembly; and a cap plate coupled to the open end of the can and having a partial region made of a material that adheres to magnets. According to an embodiment of the present invention, the secondary battery can be easily transferred by magnetic force since a material that can be attached to magnetic objects is provided in the cap plate. Accordingly, work efficiency can be maximized when configuring a battery module and / or a pack. In addition, since the material of the cap plate is changed, rust generation may be reduced and rigidity may be increased.

Description

secondary battery

[0001] An embodiment of the present invention relates to a secondary battery.

[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.

[0004] An embodiment of the present invention is intended to provide a secondary battery capable of transport using magnetism.

[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.

[0006] A secondary battery according to an embodiment of the present invention may include: a cylindrical can having one end open and the other end closed; an electrode assembly accommodated in the can; a terminal coupled to the closed end of the can and electrically connected to the electrode assembly; and a cap plate coupled to the open end of the can, with a portion of the cap plate made of a material that adheres to a magnet.

[0007] The above cap plate is in the shape of a disc, and the area made of the material that adheres to the magnet may be a partial area including the center.

[0008] The above cap plate may include a first region made of a material that adheres to the magnet, a second region connected to the outside of the first region, and a third region connected to the outside of the second region.

[0009] The material of the first region above may include any one of SUS (Stainless Steel), carbon steel, stainless steel, nickel, and cobalt.

[0010] The material of the second region above may be a different material from the first region above.

[0011] The above can may include a circular upper portion which is a closed end to which the terminal is connected, and a side portion extending from the upper portion and having an open end.

[0012] The above can may further include a beading portion formed inwardly concavely adjacent to the end of the side portion and a crimping portion formed by bending the end of the side portion inward.

[0013] The above cap plate can be inserted between the beading portion and the crimping portion.

[0014] It may further include a gasket of insulating material that surrounds the third region of the cap plate.

[0015] It may further include a reinforcing member disposed between the gasket and the third region of the cap plate.

[0016] The above reinforcing member may be in the shape of a circular ring having a predetermined width.

[0017] The reinforcing member above can be made of the same material as the first region.

[0018] The first region and the second region can be welded together.

[0019] The cross-sections of the first region and the second region may have interlocking shapes.

[0020] The cross-sections of the first region and the second region may be triangular or have an uneven shape.

[0021] The first region and the second region can be combined with each other by a pressing method.

[0022] The first region may include a first portion located on the outer side of the cap plate, a second portion inserted into the inner diameter portion of the second region, and a third portion located on the inner side of the cap plate.

[0023] The outer diameter of the first part and the second part may be larger than the inner diameter of the second region.

[0024] The outer diameter of the second part may be the same as or smaller than the inner diameter of the second region.

[0025] According to an embodiment of the present invention, since a material capable of being attached to a magnetic object is provided on the cap plate, the secondary battery can be easily transported by magnetic force. Accordingly, work efficiency can be maximized when configuring battery modules and / or packs.

[0026] In addition, changing the material of the cap plate can reduce rust formation and increase rigidity.

[0027] 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.

[0028] 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.

[0029] FIG. 1 is a perspective view of an exemplary secondary battery.

[0030] Figure 2 is a cross-sectional view of a secondary battery according to Figure 1.

[0031] FIG. 3 is a schematic diagram illustrating a cross-section of a secondary battery according to one embodiment of the present invention.

[0032] FIGS. 4 and FIGS. 5 are schematic diagrams illustrating cross-sections of a secondary battery according to other embodiments of the present invention.

[0033] FIG. 6 is a schematic diagram illustrating a secondary battery according to FIG. 3 to FIG. 5 in a top view.

[0034] FIG. 7 is a schematic diagram illustrating a plan view of a secondary battery according to another embodiment of the present invention.

[0035] FIG. 8 is a schematic diagram illustrating a secondary battery according to embodiments of the present invention in a state in which it is housed in a tray.

[0036] FIG. 9 is a schematic diagram illustrating a transfer device for transferring a secondary battery according to embodiments of the present invention.

[0037] Figures 10 and 11 are schematic diagrams showing the combined state of the transfer head and the secondary battery during the transfer of the secondary battery.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0048] First, the structure of an exemplary secondary battery is described with reference to the attached drawings.

[0049] FIG. 1 is a perspective view of an exemplary secondary battery. FIG. 2 is a cross-sectional view of a secondary battery according to FIG. 1.

[0050] Referring to FIGS. 1 and 2, an exemplary secondary battery (10) may include a can (100), an electrode assembly (200), a first current collector (300), a second current collector (350), a terminal (400), an insulating member (500), and a cap plate (600).

[0051] 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).

[0052] A terminal (400) and an insulating member (500) may be coupled to the upper surface (110). To this end, a terminal hole (not shown) may be formed through the center of the upper surface (110). Additionally, at least one notch (112) serving as a vent may be provided on the upper surface (110).

[0053] The side portion (120) has an open bottom, and a cap plate (600), which will be described later, can be attached to the bottom. To this end, a beading portion (122) and a crimping portion (124) may be provided at the bottom of the side portion (120). In some manufacturing steps, the top portion (110) may be positioned downward to insert the electrode assembly (200) together with the electrolyte, and then the beading portion (122) may be formed. The beading portion (122) may be provided by processing the bottom of the side portion (120) concavely toward the inside of the can (100). After forming the beading portion (122), the cap plate (600) and the gasket (800) may be assembled. Afterward, the crimping portion (124) may be formed to prevent the cap plate (600) from coming off. The crimping portion (124) can be formed by bending the end of the side portion (120) toward the inside of the can (100). A secondary battery (10) with this structure does not require a separate injection hole.

[0054] 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 with a metal such as steel, nickel-plated steel, steel alloy, aluminum, aluminum alloy, or a cooling sheet for deep drawing (SPCE), or a laminate film or plastic material that constitutes a pouch. An electrode assembly (200) may be accommodated inside the can (100) together with an electrolyte.

[0055] 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, a second electrode plate, and a separator. The electrode assembly (200) may have a separator interposed between the first electrode plate and the second electrode plate, and may be wound in a cylindrical shape. In some examples, the electrode assembly (120) may have a roughly central region empty. The empty central region may also be referred to as a core (240). A cylindrical center pin (optional) may be inserted into the core (240) for support. The core (240) may serve as a passage for the pressure to be discharged when the internal pressure of the secondary battery (10) exceeds a reference pressure. In some examples, when internal pressure is applied to the upper surface (110) through the core (240), the notch (112, 622) is broken and the internal pressure of the secondary battery (10) can be reduced.

[0056] The first electrode plate may be either a negative electrode plate or a positive electrode plate. The first electrode plate 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-substrate portion in which the first active material is not provided. The first non-substrate portion may be referred to as the first substrate. The first non-substrate portion may be notched in a certain shape to function as a first substrate tab (210). Alternatively, the first non-substrate portion itself may function as a first substrate tab (210) without notching. In the embodiments of FIGS. 1 and 2, the first substrate tab (210) may protrude upward from the separator (230). The first substrate tab (210) may be electrically connected to the first current collector plate (300), which will be described later, without separate notching. Alternatively, the first substrate tab (210) may be notched in a specific shape to be electrically connected to the first current collector plate (300). For example, the connection method may be laser welding, etc.

[0057] For example, the first electrode plate 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.

[0058] 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.

[0059] 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.

[0060] As an example, compounds 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).

[0061] 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.

[0062] 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.

[0063] 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.

[0064] Aluminum may be used as the current collector mentioned above, but is not limited thereto.

[0065] The second electrode plate may be the other of the negative electrode plate and the positive electrode plate. The second electrode plate 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-substrate where the second active material layer is not provided. The second non-substrate may be referred to as the second substrate. The second non-substrate may be notched in a certain shape to function as a second substrate tab (220). Alternatively, the second non-substrate itself may function as a second substrate tab (220) without notching. The second substrate tab (220) may protrude downward from the separator (230). The second substrate tab (220) may be electrically connected to the second current collector plate (350), which will be described later, without separate notching. Alternatively, the second substrate tab (220) may be notched in a specific shape to be electrically connected to the second current collector plate (350). For example, the connection method may be laser welding, etc.

[0066] For example, the second electrode plate can function as a negative electrode. 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, tin alloy composite, transition metal oxide, lithium metal nitrite, or metal oxide, etc.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] The separator (230) is interposed between the first electrode plate and the second electrode plate and serves to prevent a short circuit between the first electrode plate and the second electrode plate. 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.

[0077] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic-based polymer.

[0078] 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.

[0079] 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.

[0080] The electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0081] 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.

[0082] In addition, when using carbonate-based solvents, cyclic carbonates and chain carbonates can be mixed and used.

[0083] The first current collector plate (300) may be placed between the insulating member (500), which will be described later, and the first substrate tab (210). More specifically, the first current collector plate (300) may be welded in contact with the first substrate tab (210). The first current collector plate (300) may be approximately circular in shape. The first current collector plate (300) may be electrically connected to the terminal (400) in the central portion. A hollow may be provided in the center of the first current collector plate (300). Since the first current collector plate (300) must be insulated from the can (100), an insulating tape (540) may be attached to the area other than the area connected to the terminal (400).

[0084] The second current collector plate (350) can be placed between the second base plate (210) and the cap plate (600). More specifically, the second current collector plate (350) can be welded to the second base plate (220). Additionally, the second current collector plate (350) can be electrically connected to the can (100) by contacting the beading portion (122). Accordingly, the can (100) takes on a negative polarity. However, the second current collector plate (350) does not come into contact with the cap plate (600).

[0085] The terminal (400) may include a main body (410) inserted into the can (100) and a head (420) positioned outside the can (100). For example, the terminal (400) may be a rivet terminal that is fixed by a rivet method from the outside of the can (100) while the main body (410) is inserted into the inside of the can (100). To this end, a groove (412) may be provided in the center of the head (420) and the main body (410). An insulating member (500) may be provided between the terminal (400) and the upper surface (110). Since the terminal (400) is electrically connected to the first current collector plate (300), it may function as a positive terminal.

[0086] The insulating member (500) is an insulating material and may include first to fourth insulating members (510 to 540). The first insulating member (510) may insulate between the upper surface (110) and the head (420) of the terminal (400). The second insulating member (520) may insulate between the upper surface (110) and the terminal hole. The third insulating member (530) may insulate between the upper surface (110) and the first current collector plate (300). The fourth insulating member (540) may be provided on the upper surface of the first current collector plate (300). For example, the aforementioned insulating tape (540) may replace the fourth insulating member (540) (thus, in FIG. 2, the insulating tape and the fourth insulating member are indicated by the same reference numeral). The first to third insulating members (510 to 530) may each be provided separately or may be provided as a single unit. Each of the first to third insulating members (510 to 530) may be provided with a hollow so that the terminal (400) passes through it. The fourth insulating member (540) may also be provided with a hollow. In some embodiments, if the fourth insulating member (540) is provided as an insulating tape, its thickness may be smaller than that of the third insulating member (530). The terminal (400) may be insulated from the can (100) and the first current collector plate (300) by the insulating member (500). A cap plate (600) may be attached to the opposite side facing the terminal (400).

[0087] The cap plate (600) can seal the open end of the can (100) (the end of the side (120)). The cap plate (600) is approximately circular in shape when viewed from above and can be provided with the same or similar material as the can (100). The cap plate (600) can be attached to the side (120) via a gasket (800). Since the gasket (800) is placed between the cap plate (600) and the side (120), the cap plate (600) can be insulated from the can (100). Thus, the cap plate (600) becomes neutral, not having negative or positive polarity. Additionally, the cap plate (600) may be divided into a first region (610) which is a part of the center, a second region (620) connected to the outside of the first region (610), and a third region (630) which is connected to the outside of the second region (620) and is the edge of the disc.

[0088] For example, the first region (610) and the third region (630) may be arranged on the same line as in FIG. 2 when viewed from the side. The second region (620) may protrude outward compared to the first region (610) and the third region (630). That is, the first region (610) and the third region (630) may be closer to the electrode assembly (200) than the second region (620). The second region (620) may serve as a buffer space where gas generated during the charging and discharging of the secondary battery (10) is collected. Additionally, since the first region (610) and the third region (630) are also spaced apart from the electrode assembly (200), the entire space between them and the electrode assembly (200) may serve as a buffer space where gas is collected. A notch (622) that functions as a vent may be provided on the second region (620). The third region (630) is a region covered by a gasket (800) and can be inserted between the beading portion (122) and the crimping portion (124).

[0089] In an exemplary secondary battery (10) having the structure described above, the cap plate (600) is made of a material similar to or identical to that of the can (100). That is, the cap plate (600) is made of steel, aluminum, etc. If the cap plate (600) is made of a metal such as aluminum, it does not stick to a magnet. If the cap plate (600) is made of steel, it sticks to a magnet but has the disadvantage of being prone to rust. To solve these problems, the following describes a secondary battery (10) capable of being transported by magnetic force by changing the material and structure of the cap plate (600).

[0090] A secondary battery according to embodiments of the present invention will be described in detail with reference to the attached drawings (detailed description of features identical to those of the previously described embodiments is omitted).

[0091] FIG. 3 is a schematic diagram illustrating a cross-section of a secondary battery according to one embodiment of the present invention. FIG. 4 and FIG. 5 are schematic diagrams illustrating cross-sections of secondary batteries according to other embodiments of the present invention. FIG. 6 is a schematic diagram illustrating a top view of the secondary battery according to FIG. 3 to FIG. 5. FIG. 7 is a schematic diagram illustrating a plan view of a secondary battery according to another embodiment of the present invention.

[0092] Referring to FIG. 3, the secondary battery (10a) according to one embodiment of the present invention may differ only in the structure of the cap plate (600) from the secondary battery (10) according to FIG. 1 and FIG. 2. More specifically, the cap plate (600a) may include a first region (610a) and a second region (620a) made of different materials. The cap plate (600a) according to FIG. 3 may also include a third region (630) in the same way as the cap plate (600) of FIG. 2. Since the third region has the same structure as the cap plate (600) of FIG. 2, a detailed description is omitted (Fig. 3 also omits this and illustrates it briefly).

[0093] The first region (610a) may be made of a metal material that has magnetic properties. For example, the material of the first region (610a) may include SUS (Stainless Steel). Additionally, the material of the first region (610a) may include carbon steel, stainless steel, nickel, cobalt, etc. These materials have strong corrosion resistance and durability and have magnetic properties. The first region (610a) may be approximately disc-shaped. Also, since the first region (610a) must be transported by the transport device (2000) described later, it may be a flat shape without curvature. The first region (610a) may be connected to the second region (620a) by welding or pressing methods.

[0094] The second region (620a) may be identical or similar to the second region (620) of the cap plate (600) according to FIG. 2. A notch (622) may be provided on the second region (620a). The second region (620a) may be connected to the outer diameter portion of the first region (610a). The second region (620a) may be made of the same material as the can (100).

[0095] When the first region (610a) and the second region (620a) are connected by welding, the welding is performed between dissimilar metals. Therefore, to improve weldability, the outer diameter portion of the first region (610a) and the inner diameter portion of the second region (620a) may have cross-sectional shapes that interlock with each other. Referring to FIG. 7, the outer diameter portion of the first region (610a) may have a triangular cross-section (see FIG. 7 A). Correspondingly, the inner diameter portion of the second region (620a) may also have a triangular cross-section that interlocks with the cross-section of the first region (610a). Alternatively, the outer diameter portion of the first region (610a) may have an uneven cross-section (see FIG. 7 B). Correspondingly, the inner diameter portion of the second region (620a) may also have an uneven cross-section that interlocks with the cross-section of the first region (610a).

[0096] Alternatively, to further improve weldability, a filler metal may be used to weld between the interlocking sections of the first region (610a) and the second region (620a). Generally, welding with a filler metal close to the melting temperatures of the two different metals allows the metal with the lower melting point to absorb heat and provide additional heat to the metal with the higher melting point, thereby effectively bonding the two metals. Alternatively, welding between dissimilar metals can be efficiently performed using laser welding. Or, a shielding gas welding method, such as TIG (Tungsten Inert Gas) welding or MIG (Metal Inert Gas) welding, may be used to protect the weld area of ​​the second region (620a), which has a relatively lower melting point. The shielding gas blocks external elements such as oxygen, thereby preventing oxidation of the molten metal and improving the quality of the weld area.

[0097] When the first region (610c) and the second region (620c) are connected by a pressing method, the first region (610c) and the second region (620c) may have an overlapping area. An embodiment of the connection by the pressing method will be described later.

[0098] FIG. 4 illustrates an embodiment in which a reinforcing member (630b) is additionally provided on the cap plate (600b) according to FIG. 3. Referring to FIG. 4, the cap plate (600b) may include a first region (610b) and a second region (620b) made of different materials, and a reinforcing member (630b).

[0099] The first region (610b) and the second region (620b) may be identical to the cap plate (600a) according to FIG. 3.

[0100] The reinforcing member (630b) may be provided in a portion corresponding to the third region of the cap plate (600) according to FIG. 2. When viewed from above, the reinforcing member (630b) may be in the shape of a circular ring having a predetermined width. The reinforcing member (630b) may be made of the same metal material as the first region (610b). The reinforcing member (630b) may be welded to and joined to the cap plate (600b) by the welding method described above. The reinforcing member (630b) is a component intended to increase the rigidity of the cap plate (600b) and may be omitted.

[0101] FIG. 5 illustrates an embodiment in which a first region (610c) and a second region (620c) are connected by a pressing method. Referring to FIG. 5, the cap plate (600c) may include a first region (610c), a second region (620c), and a reinforcing member (630c). The second region (620c) may be identical to the second region (620a) according to FIG. 3. The reinforcing member (630c) may be identical to the reinforcing member (630b) according to FIG. 4.

[0102] The first region (610c) may include a first part (6102), a second part (6104), and a third part (6106). The first region (610c) may be joined to the second region (620c) by a pressing method.

[0103] The first part (6102) is a portion located on the outer side of the cap plate (600c). The outer diameter of the first part (6102) may be larger than the inner diameter of the second region (620c). Therefore, a portion of the first part (6102) may overlap with the second region (620c).

[0104] The second part (6104) is a part that is inserted into the inner diameter portion of the second region (620c). Therefore, the outer diameter of the second part (6104) may be the same as or slightly smaller than the inner diameter of the second region (620c).

[0105] The third part (6106) is a portion located on the inner side (direction toward the electrode assembly) of the cap plate (600c). The outer diameter of the third part (6106) may also be larger than the inner diameter of the second region (620c). Therefore, a portion of the third part (6106) may overlap with the second region (620c).

[0106] Since parts of the first part (6102) and the third part (6106) are pressed in an overlapping state with the second region (620c) and adhere to the second region (620c), welding between the first part (6102) and the third part (6106) and the second region (620c) is unnecessary. Since the first part (6102) and the third part (6106) and the second region (620c) can be closely joined without welding, the manufacturing process can be shortened.

[0107] The secondary batteries (10a to 10c) according to the above-described embodiments have a structure in which a magnetically adhesive material is placed in the central region as shown in FIG. 6 when viewed from above. That is, since the first region (610a to 610c) is a magnetically adhesive material, it can be utilized for transporting the secondary batteries (10a to 10c).

[0108] In the following, a transfer device and a transfer method for transferring a secondary battery having the aforementioned structure are described in detail.

[0109] FIG. 8 is a schematic diagram illustrating a state in which a secondary battery is stored in a tray according to embodiments of the present invention. FIG. 9 is a schematic diagram illustrating a transfer device for transferring a secondary battery according to embodiments of the present invention. FIG. 10 and FIG. 11 are schematic diagrams showing the combined state of a transfer head and a secondary battery during the transfer of a secondary battery.

[0110] Referring to FIG. 8, when a plurality of secondary batteries (10a to 10c) are stored in a tray (1000), the first region (610) of the cap plate may be positioned so as to face upward. Depending on the manufacturing process, the secondary batteries (10a to 10c) may be transported by transporting the tray (1000) itself, or the secondary batteries (10a to 10c) may be transported by separating them from the tray (1000). The secondary batteries (10a to 10c) may be transported by a magnetic transport device (2000).

[0111] An exemplary transfer device (2000) may include a transfer member (2100), a lifting member (2200), and a support member (2300). The transfer member (2100) may include a plurality of transfer heads (2110). The transfer heads (2110) may be made of magnets or may include magnets. The lifting member (2200) may be coupled to the upper part of the transfer member (2100). The lifting member (2200) may function to raise or lower the transfer member (2100) in the Y-axis direction. The support member (2300) may be coupled to the upper part of the lifting member (2200). The support member (2300) may move the lifting member (2200) in the X-axis direction. If necessary, the support member (2300) may be configured to move the lifting member (2200) in the Z-axis direction not shown in the drawing. Since the lifting member (2200) is moved in the X-axis direction (or including the Z-axis direction) by the support member (2300), the transfer member (2100) can also move in the X-axis direction. When the transfer member (2100) descends toward the tray (1000) and approaches the secondary batteries (10a~10c), the secondary batteries (10a~10c) can be attached to the transfer head (2110) by magnetic force.

[0112] Referring to FIGS. 10 and 11, the transfer head (2110) can be magnetically attached to the first region (610b, 610c) of the cap plate (600). In the secondary battery (10a~10c) according to an embodiment of the present invention, the size of the first region (610b, 610c) may be larger than that of the transfer head (2110). Therefore, the transfer head (2110) can be easily attached to the first region (610b, 610c). In addition, even if the position of the transfer head (2110) is slightly misaligned, the attachment state with the transfer head (2110) can be maintained because the first region (610b, 610c) is larger. In this way, since the cap plate (600b~600c) of the secondary battery (10a~10c) has a region made of a material that adheres to a magnet, it can be easily and safely transferred by magnetic force.

[0113] For convenience, FIGS. 10 and 11 show the attachment state of the transfer head (2110) based on the secondary battery of FIGS. 4 and 5. However, since the secondary battery of FIG. 3 also has the same first region (610a) on the cap plate (600a), it can be attached to the transfer head (2110) and transferred in the same way.

[0114] Magnetic transport offers the advantage of transporting secondary batteries easily and quickly compared to the clamping method, which involves clamping and transporting them one by one. Additionally, magnetic transport has the advantage of preventing scratches or damage to the exterior of the secondary batteries.

[0115] As mentioned above, since secondary batteries can be transported easily and quickly by magnetic force, work efficiency can be maximized when assembling battery modules and / or packs.

[0116] In addition, changing the material of the cap plate can reduce rust formation and increase rigidity.

[0117] 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.

Claims

1. A cylindrical can with one end open and the other end closed; Electrode assembly accommodated in the above can; A terminal coupled to the closed end of the can and electrically connected to the electrode assembly; and A secondary battery comprising a cap plate that is coupled to the open end of the above-mentioned can and has a portion made of a material that is magnetic.

2. In Paragraph 1, A secondary battery, wherein the above-mentioned cap plate is in the shape of a disc, and the area made of the material that adheres to the magnet is a partial area including the center.

3. In Paragraph 2, The above-mentioned cap plate comprises a first region made of a material that adheres to the magnet, a second region connected to the outside of the first region, and a third region connected to the outside of the second region, in a secondary battery.

4. In Paragraph 3, The material of the first region above is a secondary battery comprising any one of SUS (Stainless Steel), carbon steel, stainless steel, nickel, and cobalt.

5. In Paragraph 4, The material of the second region above is a secondary battery that is a different material from the first region above.

6. In Paragraph 5, The above can is a secondary battery comprising a circular upper surface portion having a closed end to which the terminal is connected, and a side portion extending from the upper surface portion and having an open end.

7. In Paragraph 6, The above-mentioned can further comprises a beading portion formed inwardly concavely adjacent to the end of the side portion and a crimping portion formed by bending the end of the side portion inward, a secondary battery.

8. In Paragraph 7, The above cap plate is a secondary battery inserted between the beading portion and the crimping portion.

9. In Paragraph 8, A secondary battery further comprising a gasket of insulating material covering the third region of the cap plate.

10. In Paragraph 9, A secondary battery further comprising a reinforcing member disposed between the gasket and the third region of the cap plate.

11. In Paragraph 10, The above reinforcing member is a secondary battery having a circular ring shape with a predetermined width.

12. In Paragraph 11, The above reinforcing member is a secondary battery made of the same material as the above first region.

13. In Paragraph 5, A secondary battery in which the first region and the second region are welded together.

14. In Paragraph 13, A secondary battery having cross-sections of the first region and the second region that interlock with each other.

15. In Paragraph 14, A secondary battery in which the cross-sections of the first region and the second region are triangular or irregular in shape.

16. In Paragraph 5, A secondary battery in which the first region and the second region are combined by a pressing method.

17. In Paragraph 16, A secondary battery, wherein the first region comprises a first portion located on the outer side of the cap plate, a second portion inserted into the inner diameter portion of the second region, and a third portion located on the inner side of the cap plate.

18. In Paragraph 17, A secondary battery in which the outer diameter of the first part and the second part is larger than the inner diameter of the second region.

19. In Paragraph 18, A secondary battery in which the outer diameter of the second part is equal to or smaller than the inner diameter of the second region.

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