Apparatus for manufacturing secondary battery and electrode plate cutting unit

Abstract

The present disclosure provides an apparatus for manufacturing a secondary battery and an electrode plate cutting unit capable of preventing the occurrence of cracks or impurities in a mixture portion and preventing the transfer of an active material to a separator by reducing a load applied to a load concentration region of an electrode plate when cutting the electrode plate. The apparatus for manufacturing a secondary battery includes: a transfer unit configured to transfer an electrode plate; a winding unit configured to wind the electrode plate; and a cutting unit having an upper cutter, a lower cutter, and a stripper mounted on a side portion of the lower cutter, the stripper configured to support the electrode plate when the upper cutter moves downward to transmit a reaction force corresponding to a downward force of the upper cutter to the electrode plate, and provides a stress relief space for preventing a reaction force from being transmitted to a portion of the electrode plate to which a shearing force is applied by the upper cutter and the lower cutter.

Description

Technical Field

[0001] This disclosure relates to the manufacture of secondary batteries, and more specifically, to an apparatus for manufacturing secondary batteries and an electrode plate cutting unit. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are rechargeable and dischargeable. A secondary battery typically includes an electrode assembly comprising a positive electrode plate, a separator, and a negative electrode plate; a housing (or canister) for containing the electrode assembly; substrate tabs formed by extending uncoated portions of each electrode plate of the electrode assembly; and external terminals connected to the substrate tabs.

[0003] Electrode assemblies housed within a housing include stacked and wound-core types. Wound-core type electrode assemblies are manufactured by winding continuously supplied electrode plates using a winding device. The winding device includes an electrode plate cutter. The electrode plate cutter is a device for cutting electrode plates at designed length intervals and includes an upper cutter and a lower cutter.

[0004] The information disclosed in this background section is intended to enhance understanding of the background of this disclosure and may therefore contain information that does not constitute related (or prior art). Summary of the Invention

[0005] This disclosure aims to provide an apparatus for manufacturing secondary batteries and an electrode plate cutting unit that can prevent cracks or impurities in the mixture by reducing the load applied to the load concentration area of ​​the electrode plate when cutting the electrode plate.

[0006] According to one aspect of this disclosure, an apparatus for manufacturing a secondary battery is provided, comprising: a conveying unit configured to convey an electrode plate to be cut along a conveying path; a winding unit configured to receive and wind the electrode plate conveyed by the conveying unit; and a cutting unit having an upper cutter mounted above the conveying path of the electrode plate, a lower cutter mounted below the conveying path, and a peeler mounted on a side portion of the lower cutter, the peeler being configured to support the electrode plate as the upper cutter moves downward to transmit a reaction force corresponding to the downward force of the upper cutter to the electrode plate, and providing a stress relief space for preventing the reaction force from being transmitted to portions of the electrode plate subjected to shearing forces due to the upper and lower cutters.

[0007] According to another aspect of the present invention, an electrode plate cutting unit is provided, comprising: an upper cutter mounted above a conveying path of an electrode plate being conveyed along a conveying path; a lower cutter mounted below the conveying path; and a peeler mounted on a side portion of the lower cutter, the peeler being configured to support the electrode plate as the upper cutter moves downward to transmit a reaction force corresponding to the downward force of the upper cutter to the electrode plate, and providing a stress relief space for preventing the reaction force from being transmitted to portions of the electrode plate subjected to shearing forces due to the upper and lower cutters.

[0008] The aspects and features of this disclosure are not limited to those described herein, and those skilled in the art will clearly understand from the description of this disclosure herein other aspects and features not specifically mentioned herein. Attached Figure Description

[0009] Other objects, features, and advantages of this disclosure will become more apparent to those skilled in the art from the detailed description of exemplary embodiments thereof with reference to the accompanying drawings, in which:

[0010] Figure 1 A schematic diagram of an electrode assembly of a secondary battery, which may be manufactured by an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure, is shown.

[0011] Figure 2 Example application Figure 1 An internal view of the electrode assembly of a pouch-type secondary battery;

[0012] Figure 3 A cross-sectional view of a cylindrical secondary battery that can be manufactured by an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure is shown.

[0013] Figure 4 An external perspective view of a prismatic secondary battery that may be manufactured by an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure is shown.

[0014] Figure 5 For along Figure 4 Cross-sectional view of line AA in the diagram;

[0015] Figure 6 A schematic diagram illustrating the configuration of an apparatus for manufacturing secondary batteries according to an embodiment of the present disclosure is provided.

[0016] Figure 7 for Figure 6 A magnified view of part K in the image;

[0017] Figures 8 to 10 A view illustrating a modified example of an apparatus for manufacturing secondary batteries according to an embodiment of the present disclosure;

[0018] Figures 11A to 11C , Figures 12A to 12C , Figures 13A to 13C , Figures 14A to 14C and Figure 15A and Figure 15B A view illustrating the configuration of the stripper of the electrode plate cutting unit according to an embodiment of the present disclosure; and

[0019] Figure 16 For application Figure 15A and Figure 15B The diagram illustrates the configuration of a device for manufacturing secondary batteries, specifically a stripper. Detailed Implementation

[0020] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be narrowly interpreted according to their general or dictionary meaning, and based on the principle that the inventor can be his / her own lexicographer to appropriately define terms and concepts for the best manner in which his / her disclosure is described, they should be interpreted as having meanings and concepts consistent with the technical spirit of the present disclosure.

[0021] The embodiments described in this specification and the configurations illustrated in the accompanying drawings are merely some embodiments of this disclosure and do not represent all aspects, features, and embodiments of this disclosure. Accordingly, it should be understood that various equivalents and modifications may exist at the time of filing this application, and one or more embodiments or features described herein may be replaced or modified.

[0022] It will be understood that when an element or layer is described as being "on" another element or layer, "connected to," or "linked to" another element or layer, it may be directly on, connected to, or linked to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is described as being "directly on" another element or layer, "directly connected to," or "directly linked to" another element or layer, no intermediary element or layer is present. For example, if a first element is described as being "linked" or "connected" to a second element, the first element may be directly linked to or connected to the second element, or the first element may be indirectly linked to or connected to the second element via one or more intermediary elements.

[0023] In the accompanying drawings, the dimensions of various elements, layers, etc., may be enlarged for clarity. The same reference numerals denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated enumerated items. Furthermore, the use of "may" when describing embodiments of this disclosure refers to "one or more embodiments of this disclosure." Expressions such as "at least one of" and "any one of" modify the entire list of elements without modifying individual elements within the list when placed before / after the list of elements. When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group of A, B, and C," or "at least one selected from A, B, and C" are used to denote a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the terms “use,” “using,” and “used” are to be regarded as synonyms with the terms “utilize,” “utilizing,” and “utilized,” respectively. As used herein, the terms “substantially,” “about,” and similar terms serve as approximations rather than terms of degree and are intended to describe the inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0024] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, areas, layers, and / or segments, these elements, components, areas, layers, or segments should not be limited by these terms. These terms are used to distinguish one element, component, area, layer, or segment from another. Therefore, the first element, component, area, layer, or segment discussed herein may be referred to as the second element, component, area, layer, or segment without departing from the teachings of the exemplary embodiments.

[0025] For ease of description, spatial relative terms, such as “below,” “under,” “down,” “above,” and “above,” are used herein to describe the relationship of one element or feature to another element or feature illustrated in the figures. It will be understood that, in addition to the orientation depicted in the figures, spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “above” those other elements or features. Thus, the term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0026] The terminology used herein is for describing embodiments of the present disclosure and is not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are intended to also include the plural forms. It will be further understood that the terms “includes,” “including,” “comprises,” and / or “comprising,” when used in this specification, indicate the presence of said features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0027] Furthermore, any numerical range disclosed and / or set forth herein is intended to include all subranges with the same numerical precision contained within the set forth range. For example, the range “1.0 to 10.0” is intended to include all subranges between the set forth minimum value of 1.0 and the set forth maximum value of 10.0, i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit set forth herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to expressly set forth any subranges contained within the range expressly set forth herein. All such ranges are intended to be described inherently in this specification such that any modification to expressly set forth any of these subranges will comply with the requirements of the patent rules.

[0028] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include situations in the art where the deviation is considered low, for example, a deviation of 5% or less. Additionally, if a parameter is described as uniform in a given region, this can mean that it is uniform in terms of average value.

[0029] Throughout the instruction manual, unless otherwise stated, each element may be singular or plural.

[0030] Placing any element "above (or below)" or "on (below)" another element means that the element can contact the upper (or lower) surface of the element, and that the other element can be inserted between the element and any element located above (or below) the element.

[0031] Additionally, it will be understood that if a component is referred to as a “connection,” “link,” or “attachment” to another component, these components may be directly “connected,” “linked,” or “attached” to each other, or another component may be “inserted” between the components.

[0032] Throughout the instruction manual, unless otherwise stated, when “A and / or B” is mentioned, it means A, B, or A and B. That is, “and / or” includes any or all combinations of the listed items. Unless otherwise indicated, when “C to D” is mentioned, it means C or equal to C and D or less than D.

[0033] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure.

[0034] Conventional electrode plate cutting devices suffer from a problem: due to the concentrated load transmitted to the electrode plate during cutting, cracks can appear in the composite layer of the electrode plate. Specifically, during cutting, the upper cutter, lower cutter, and peeler simultaneously press on a localized area of ​​the electrode plate, initiating cracks. In severe cases, the cracked portion may separate, resulting in impurities. A technique is needed to prevent cracking by dispersing the load applied to the concentrated load area.

[0035] Figure 1 The diagram illustrates an electrode assembly of a secondary battery that can be manufactured by an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0036] The electrode assembly 10 can be formed by winding or stacking a first electrode plate 10a, a diaphragm 10c, and a second electrode plate 10e, each of which is formed as a thin plate or a membrane.

[0037] In other embodiments, the electrode assembly 10 may be stacked rather than wound, and the shape of the electrode assembly 10 is not limited in this disclosure. Additionally, the electrode assembly 10 may be a Z-shaped stacked electrode assembly, wherein the positive electrode plate and the negative electrode plate are inserted into both sides (e.g., opposite sides) of the diaphragm and then bent (or folded) into a Z-shaped stack.

[0038] Additionally, one or more electrode assemblies may be stacked (e.g., arranged) such that the long sides of the electrode assemblies are adjacent to each other and housed in a housing, and the number of electrode assemblies in the housing is not limited in this disclosure. The first electrode plate 10a of the electrode assembly 10 may serve as a negative electrode, and the second electrode plate 10e may serve as a positive electrode. Of course, the reverse is also possible.

[0039] The first electrode plate 10a can be formed by applying (e.g., coating or depositing) a first electrode active material (such as graphite or carbon) onto a first electrode substrate formed of a metal foil (such as copper, copper alloy, nickel, or nickel alloy). The first electrode plate 10a may include a first electrode tab 10g (e.g., a first uncoated portion), which is an area where the first electrode active material is not applied. The first electrode tab 10g may be connected to an external first terminal. In some embodiments, when manufacturing the first electrode plate 10a, the first electrode tab 10g may be formed by pre-cutting to protrude to one side of the electrode assembly 10 (or protruding from one side of the electrode assembly 10), or the first electrode tab 10g may protrude further than the diaphragm 10c to one side of the electrode assembly 10 without separate cutting (e.g., protruding further than or beyond the diaphragm 10c).

[0040] The second electrode plate 10e can be formed by applying (e.g., coating or depositing) a second electrode active material (such as a transition metal oxide) onto a second electrode substrate formed of a metal foil (such as aluminum or an aluminum alloy). The second electrode plate 10e may include a second electrode tab 10h (e.g., a second uncoated portion), which is an area where the second electrode active material is not applied. The second electrode tab 10h can be connected to an external second terminal. In some embodiments, the second electrode tab 10h can be formed by pre-cutting it during the manufacture of the second electrode plate 10e to protrude to one side or the other side (e.g., opposite sides) of the electrode assembly 10, or the second electrode plate 10e can protrude further than the diaphragm 10c to one side or the other side of the electrode assembly 10 without separate cutting (e.g., protruding further than or beyond the diaphragm 10c).

[0041] The diaphragm 10c prevents short circuits between the first electrode plate 10a and the second electrode plate 10e while allowing lithium ions to move between them. The diaphragm 10c can be made of, for example, a polyethylene membrane, a polypropylene membrane, or a polyethylene-polypropylene membrane.

[0042] In some embodiments, the electrode assembly 10 may be housed together with the electrolyte in a housing. In a pouch-type secondary battery, the electrode assembly 10 may be housed in a pouch made of a flexible material (e.g., see...). Figure 2 In cylindrical or prismatic secondary batteries, the electrode assembly 10 may be housed in a cylindrical or prismatic metal casing (e.g., see...). Figure 3 and Figure 5 ).

[0043] A description of the materials of the electrode plates that can be used in the electrode assembly described herein is given.

[0044] As the positive electrode active material, compounds capable of reversibly inserting / deintercalating lithium (e.g., lithiation intercalation compounds) can be used. For example, at least one of lithium and a composite oxide of a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0045] The composite oxide may be a lithium transition metal composite oxide, and examples may include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, or combinations thereof.

[0046] For example, a compound represented by any of the following chemical formulas can be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li aMn2G b O4(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a Mn 1-g G g PO4(0.90 ≤ a ≤ 1.8, 0 ≤ g ≤ 0.5); Li (3-f) Fe2(PO4)3(0 ≤ f ≤ 2); Li a FePO4(0.90 ≤ a ≤ 1.8).

[0047] In the chemical formulas in this article: 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 L 1 is Mn, Al, or a combination thereof.

[0048] The positive electrode of a lithium secondary battery may include a substrate and a positive electrode active material layer formed on the substrate. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0049] Based on 100 wt% of the positive electrode active material layer, the content of the positive electrode active material is in the range of about 90 wt% to about 99 wt%, and based on 100 wt% of the positive electrode active material layer, the contents of the binder and the conductive material are each in the range of about 0.5 wt% to about 5 wt%.

[0050] The substrate may be aluminum (Al), but is not limited thereto.

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

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

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

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

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

[0056] The negative electrode of a lithium secondary battery may include a substrate and a negative electrode active material layer disposed on the substrate. The negative electrode active material layer may include a negative electrode active material and may further include a binder and / or a conductive material.

[0057] For example, the negative electrode active material layer may include about 90 wt% to about 99.5 wt% of negative electrode active material, about 0.5 wt% to about 5 wt% of binder, and about 0 wt% to about 5 wt% of conductive material.

[0058] Non-aqueous binders, aqueous binders, dry binders, or combinations thereof may serve as binders. When an aqueous binder is used as a negative electrode binder, it may further include cellulose compounds capable of imparting viscosity.

[0059] As the negative electrode substrate, one can be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, conductive metal coated polymer substrate, and combinations thereof.

[0060] Electrolytes used in lithium secondary batteries may include non-aqueous organic solvents and lithium salts.

[0061] Non-aqueous organic solvents act as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0062] Non-aqueous organic solvents can be carbonates, esters, ethers, ketones, alcohols, or aprotic solvents, and can be used alone or in combination of two or more.

[0063] In addition, when using carbonate solvents, a mixture of cyclic carbonates and chain carbonates can be used.

[0064] Depending on the type of lithium-ion secondary battery, a separator may be present between the first electrode plate (e.g., the negative electrode) and the second electrode plate (e.g., the positive electrode). Polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films comprising two or more layers thereof can be used as the separator.

[0065] The diaphragm may include a porous substrate and a coating on one or both surfaces of the porous substrate, the coating comprising an organic material, an inorganic material, or a combination thereof.

[0066] Organic materials may include polyvinylidene fluoride polymers or (meth)acrylic acid polymers.

[0067] Inorganic materials may include, but are not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0068] Organic and inorganic materials can be mixed in a coating, or can be in the form of a coating that includes (or contains) organic materials and a coating that includes (or contains) inorganic materials stacked on top of each other.

[0069] Figure 2 Example application Figure 1 An internal view of the electrode assembly of a pouch-type secondary battery.

[0070] The pouch-type secondary battery includes an electrode assembly 10 and a pouch 11a that houses the electrode assembly 10.

[0071] Electrode assembly 10 and Figure 1 The same as illustrated in the example. The first electrode terminal 11g and the second electrode terminal 11h of the electrode assembly 10 can be electrically connected by soldering to the corresponding external first terminal lead 11b and second terminal lead 11c. Each of the first terminal lead 11b and the second terminal lead 11c can be attached to the terminal film 11d for insulation from the bag 11a.

[0072] The bag 11a containing the electrode assembly 10 can be sealed by bringing the sealing portions 11e at its edges into contact with each other. In this case, the seal can be achieved by inserting a thin connecting piece film 11d between the sealing portions 11e. The sealing portions 11e of the bag 11a can each be made of a hot-melt material that generally has weak adhesion to metals. Therefore, by inserting a thin connecting piece film 11d between the sealing portions 11e, it can be fused to the bag 11a.

[0073] Figure 3 The following is a cross-sectional view of a cylindrical secondary battery manufactured by an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0074] The cylindrical secondary battery 13 includes an electrode assembly 13a, a housing 13p containing the electrode assembly 13a and an electrolyte, a cover assembly 13v connected to an opening in the housing 13p to seal the housing 13p, and an insulating plate 13n located inside the housing 13p between the electrode assembly 13a and the cover assembly 13v.

[0075] The electrode assembly 13a may include a diaphragm 13d and a first electrode 13c and a second electrode 13e positioned therebetween and interposed in the diaphragm 13d, and may be wound into a core shape.

[0076] The first electrode 13c includes a first substrate and a first active material layer on the first substrate. A first lead tab 13j can extend outward from a first uncoated portion of the first substrate where there is no first active material layer, and the first lead tab 13j can be electrically connected to the cover assembly 13v.

[0077] The second electrode 13e includes a second substrate and a second active material layer on the second substrate. A second lead tab 13k extends outward from a second uncoated portion of the second substrate where the second active material layer is absent, and the second lead tab 13k is electrically connected to the housing 13p. The first lead tab 13j and the second lead tab 13k extend in opposite directions.

[0078] The first electrode 13c can serve as a positive electrode. In this embodiment, for example, the first substrate can be made of aluminum foil, and the first active material layer can include, for example, a transition metal oxide. The second electrode 13e can serve as a negative electrode. In this embodiment, for example, the second substrate can be made of copper foil or nickel foil, and the second active material layer can include, for example, graphite.

[0079] The diaphragm 13d prevents a short circuit between the first electrode 13c and the second electrode 13e, while allowing lithium ions to move between them. For example, the diaphragm 13d can be made of polyethylene film, polypropylene film, or polyethylene-polypropylene film, etc.

[0080] The housing 13p houses the electrode assembly 13a and, together with the cover assembly 13v, forms the appearance of a secondary battery. The housing 13p may have a generally cylindrical body portion 13r and a bottom portion 13q connected to one side (e.g., one end) of the body portion 13r. An inwardly deformed crimped portion 13f (e.g., rolled edge) may be formed in the body portion 13r, and an inwardly bent crimped portion 13g (e.g., curled) may be formed at the open end of the body portion 13r.

[0081] The crimping portion 13f reduces or prevents movement of the electrode assembly 13a within the housing 13p and facilitates placement of the gasket 13h and the cover assembly 13v. The crimping portion 13g securely holds the cover assembly 13v in place by pressing the edge of the cover assembly 13v against the gasket 13h. For example, the housing 13p may be formed of nickel-plated steel.

[0082] The cover assembly 13v can be secured to the interior of the crimp portion 13g via the gasket 13h to seal the housing 13p. The cover assembly 13v may include, but is not limited to, an upper cover 13w, a safety vent 13s, a lower cover 13t, an insulating member, and a sub-plate 13u, and may be modified in various ways.

[0083] The top cover 13w may be located at the top of the cover assembly 13v. The top cover 13w may include terminal components that project upward and connect to external circuitry, and outlets for venting gas may be arranged around the terminal components.

[0084] The safety vent 13s may be located below the top cover 13w. The safety vent 13s may include a downwardly projecting protrusion that connects to the sub-plate 13u, and at least one cutout may be formed in the safety vent 13s around the protrusion.

[0085] When gas is generated due to overcharging or abnormal operation of the secondary battery, the protrusion deforms upward under pressure and separates from the sub-plate 13u, while the safety vent 13s is cut along the cut (e.g., bursts or tears). The cut safety vent 13s prevents the secondary battery from exploding by allowing gas to escape to the outside.

[0086] The lower cover 13t may be located below the safety vent 13s. The lower cover 13t may have a first opening for exposing the protrusion of the safety vent 13s and a second opening for gas venting. An insulating member may be located between the safety vent 13s and the lower cover 13t to insulate the safety vent 13s and the lower cover 13t.

[0087] Subplate 13u is located below lower cover 13t. Subplate 13u can be fixed to the lower surface of lower cover 13t to block the first opening of lower cover 13d, and the protrusion of safety vent 13s can be fixed to subplate 13u. First lead connector 13j pulled out from electrode assembly 13a can be fixed to subplate 13u. Accordingly, upper cover 13w, safety vent 13s, lower cover 13t, and subplate 13u can be electrically connected to the first electrode 13c of electrode assembly 13a.

[0088] The insulating plate 13n can be positioned below the coiled portion 13 to contact the electrode assembly 13a. The insulating plate 13n may have a tab opening through which the first lead tab 13j is pulled out. The cover assembly 13v, electrically connected to the first electrode 13c via the first lead tab 13j, can face the electrode assembly 13a, with the insulating plate 13n inserted therebetween, and the insulating plate 13n can maintain an insulated (e.g., electrically insulated) state from the electrode assembly 13a. Additionally, another insulating plate 13m may be included for insulation between the electrode assembly 13a and the bottom portion 13q of the housing 13p.

[0089] Figure 4 An external perspective view of a prismatic secondary battery manufactured by an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure is shown as an example.

[0090] The housing 15a forms the overall appearance of the prismatic secondary battery and can be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. Additionally, the housing 15a provides space for housing the electrode assembly therein.

[0091] The cover assembly 15b may include a cover plate 15c that covers the opening of the housing 15a. In some examples, the housing 15a and the cover plate 15c may be made of a conductive material. Here, the first terminal 15d and the second terminal 15e may be electrically connected to corresponding positive and negative electrodes (or negative and positive electrodes) inside the housing and may be mounted to protrude outward through the cover plate 15c.

[0092] An electrolyte inlet 15f may be formed in a cover plate 15c, a gas vent 15g may be opened, and a venting device (i.e., a gas venting device 15h) may be connected to the gas vent 15g. The gas venting device 15h is opened by gas generated inside the battery and performs a degassing function.

[0093] Figure 5 For along Figure 4 Cross-sectional view of centerline AA.

[0094] The electrode assembly 15r can be formed by winding or stacking the first electrode plate, the diaphragm, and the second electrode plate. When the electrode assembly 15r is wound, the winding axis can be parallel to the longitudinal direction of the housing 15a. In some other embodiments, the electrode assembly 15r is stacked instead of wound. The shape of the electrode assembly 15r is not limited in this disclosure.

[0095] Alternatively, the electrode assembly 15r can be a Z-shaped stacked electrode assembly, wherein the positive electrode plate and the negative electrode plate are inserted into both sides of the diaphragm and then bent into a Z-shaped stack. Furthermore, one or more electrode assemblies 15r can be stacked such that the long sides of the electrode assemblies 15r are adjacent to each other and housed within the housing 13a, and the number of electrode assemblies 15r in the housing 13a is not limited in this disclosure. The first electrode plate of the electrode assembly 15r can serve as a negative electrode, and the second electrode plate can serve as a positive electrode. Of course, the reverse is also possible.

[0096] The first electrode plate can be formed by applying a first electrode active material, such as graphite or carbon, to a first electrode current collector formed of a metal foil such as copper, copper alloy, nickel, or nickel alloy. The first electrode plate may include a first electrode tab 15p (e.g., a first uncoated portion), which is an area where the first electrode active material is not coated. The first electrode tab 15p can serve as a current path between the first electrode plate and the first current collector 15m. In some embodiments, when manufacturing the first electrode plate, the first electrode tab 15p is formed by pre-cutting to protrude to one side of the electrode assembly 15r, or the first electrode tab protrudes to one side of the electrode assembly 15r beyond the diaphragm (e.g., protruding further than or beyond the diaphragm) without separate cutting.

[0097] The second electrode plate can be formed by applying a second electrode active material, such as a transition metal oxide, to a second electrode current collector formed of a metal foil such as aluminum or an aluminum alloy. The second electrode plate may include a second electrode tab 15q (e.g., a second uncoated portion), which is a region where the second electrode active material is not applied. The second electrode tab 15q can serve as a current path between the second electrode plate and the second current collector 15n. In some embodiments, the second electrode tab 15q can be formed by pre-cutting it during the manufacture of the second electrode plate to protrude to the other side (e.g., the opposite side) of the electrode assembly 15r, or the second electrode plate can protrude to the other side of the electrode assembly 15r beyond the diaphragm (e.g., protruding further than or beyond the diaphragm) without separate cutting.

[0098] exist Figure 5 In this embodiment, the first electrode contact 15p and the second electrode contact 15q are illustrated as being located on the right and left sides of the electrode assembly 15r, respectively. However, in some other embodiments, the first electrode contact 15p and the second electrode contact 15q may both be positioned together on the right or left side of the electrode assembly 15r.

[0099] Here, the left and right sides of the electrode assembly 15r are based on ease of explanation. Figure 5 The battery is illustrated in the diagram. The left side refers to the side of the electrode assembly 15r connected to the second current collector 15n on its vertical surface, and the right side refers to the opposite side connected to the first current collector 15m. Therefore, the terms "left side" and "right side" for the electrode assembly 15r used herein may change when the battery is rotated left and right or up and down.

[0100] The separator prevents or substantially reduces short circuits between the first and second electrodes while allowing lithium ions to move between them. The separator can be made of, for example, polyethylene film, polypropylene film, or polyethylene-polypropylene film.

[0101] In some embodiments, the electrode assembly 15r is housed together with the electrolyte in a housing 15a.

[0102] In the electrode assembly 15r, the first current collector 15m and the second current collector 15n can be welded and connected to the first electrode terminal 15p extending from the first electrode plate and the second electrode terminal 15q extending from the second electrode plate, respectively.

[0103] like Figure 5 As illustrated, the first current collector 15m and the second current collector 15n are respectively connected to the first terminal 15d and the second terminal 15e via connecting members 15k. In some embodiments, the connecting members 15k may each have a threaded outer peripheral surface and may be fastened to the first terminal 15d and the second terminal 15e by screws. However, this disclosure is not limited thereto. For example, the connecting members 15k may also be riveted or welded to the first terminal 15d and the second terminal 15e.

[0104] Figure 6 A schematic diagram illustrating the configuration of an apparatus for manufacturing secondary batteries according to an embodiment of the present disclosure is provided. Figure 7 for Figure 6 A magnified view of part K in the image.

[0105] As illustrated, the apparatus 20 for manufacturing secondary batteries according to this embodiment may include a conveying unit, a winding unit 23, and an electrode plate cutting unit 30.

[0106] The conveying unit can move the electrode plate 17 to be cut along a predetermined conveying path. The conveying unit may include multiple conveying rollers 21. Some of the conveying rollers are driven rollers, and the remaining rollers are not driven and can be used only to tensionally support the electrode plate 17 conveyed by the conveying rollers 21.

[0107] The electrode plate 17 is a stack with a predetermined width and is formed from a substrate 17a and a mixture 17b. The electrode plate 17 can be a negative electrode plate or a positive electrode plate. The electrode plate 17 can be continuously conveyed along a conveying path provided by the conveying unit and wound on the winding unit 23 in a state of being cut by the electrode plate cutting unit 30.

[0108] The winding unit 23 can be rotated by power received from the winding unit driver 25 to wind the electrode plate 17. The electrode plate 17 wound around the winding unit 23 can be pulled out by an operator and moved to a subsequent process. The winding unit 23 may include a winding turret for winding the electrode plate 17.

[0109] The winding unit driver 25 can be controlled by the control unit 27. The winding unit driver 25 can be operated by the control signal of the control unit 27 to make the winding unit 23 rotate or not rotate.

[0110] The control unit 27 can control the on / off state and rotation speed of the winding unit driver 25. In addition, the control unit 27 can send control signals to the upper cutter drive unit 32, so that the upper cutter drive unit 32 moves the upper cutter 31 downward to cut the electrode plate 17 through the cross motion of the upper cutter 31 and the lower cutter 33.

[0111] Simultaneously, the electrode plate cutting unit 30 can cut the conveyed electrode plate 17 into units of predetermined length. Since the core-type electrode assembly is formed by winding the electrode plate 17, the cutting length of the electrode plate 17 can vary according to the diameter of the manufactured core. The electrode plate 17 cut by the electrode plate cutting unit 30 can be wound around the winding unit 23 and then led out to the outside.

[0112] The electrode plate cutting unit 30 may include an upper cutter 31, a lower cutter 33, and a peeler 35.

[0113] The upper cutter 31 may have a cutting edge 31a on one side of its lower end portion and may be mounted to move upward and downward along the conveying path of the electrode plate 17. The upward and downward movement of the upper cutter 31 may be achieved by the upper cutter drive unit 32. Additionally, the lower cutter 33 may be disposed below the conveying path of the electrode plate 17 and may have a cutting edge 33a on its upper end portion. The lower cutter 33 may cut the electrode plate 17 by intersecting with the upper cutter 31.

[0114] The peeler 35 is mounted on the side portion of the lower cutter 33 and supports the electrode plate 17 when the upper cutter 31 moves downward, transmitting the reaction force corresponding to the downward force of the upper cutter to the electrode plate 17. Specifically, the peeler 35 provides a stress relief space 30a. The stress relief space 30a may be a space formed between the electrode plate 17, the lower cutter 33, and the peeler 35. The stress relief space 30a prevents the reaction force from being transmitted to the portion of the electrode plate 17 subjected to shearing forces due to the upper cutter 31 and the lower cutter 33.

[0115] When electrode plate 17 is cut, shear stress and compressive stress can occur in electrode plate 17. Shear stress occurs when the upper cutter 31 and the lower cutter 33 intersect. Shear stress is concentrated in... Figure 7 The stress concentration region 100 is illustrated in the example. In addition, compressive stress occurs when the electrode plate 17 is compressed between the upper cutter 31 and the peeler 35 due to the downward movement of the upper cutter 31.

[0116] However, when the stress relief space 30a is absent, the shear force generated by the cross motion of the lower cutter 33 and the upper cutter 31, and the compressive force as a reaction force, can be simultaneously applied to the stress concentration region 100. When shear force and compressive force are applied simultaneously, cracks may appear in the mixture, or the mixture may separate from the substrate 17a.

[0117] However, when a stress relief space 30a is provided, compressive force is prevented from being applied to the stress concentration region 100. The load on the stress concentration region can be greatly reduced. With the reduction of the load, the mixture 17b can remain undamaged or separated. The stress relief space 30a can be formed by processing the stripper 35.

[0118] The peeler 35 may include an upper surface 35h and a side surface 35j. The upper surface 35h is the surface that contacts the lower surface of the electrode plate 17, and the side surface 35j is the surface that faces the lower cutter 33. The side surface 35j may contact the surface of the lower cutter 33. When the side surface 35j of the peeler 35 contacts the surface of the lower cutter 33, vibration can be prevented when the peeler 35 moves upward or downward.

[0119] The stress relief space 30a can be the space between the removal surface formed by removing the corner where the upper surface 35h and the side surface 35j intersect, the lower cutter 33, and the electrode plate 17. The compressive force generated by the reaction of the peeler 35 does not act on the portion of the electrode plate 17 open to the stress relief space 30a. The shape of the removal surface can be achieved in any of a variety of ways.

[0120] Figure 7 The removal surface illustrated is an inclined surface (e.g., a flat inclined surface) 35a. Figures 11A to 11C A peeler 35 having an inclined surface 35a as a removal surface is shown separately.

[0121] exist Figure 11A In the case of the peeler 35 illustrated, the angle (θ) between the inclined surface 35a and the upper surface 35h can be 45 degrees. Furthermore, Figure 11B The inclined surface 35a of the peeler 35 illustrated in the figure has an inclination angle of approximately 30 degrees, which is more than... Figure 11A The tilt angle is gentle, and Figure 11C The tilt angle of the tilted surface 35a of the peeler 35 illustrated is greater than... Figure 11A The tilt angle of the tilted surface 35a of the peeler 35 illustrated in the figure.

[0122] As the tilt angle decreases, the length of the upper surface 35h can be reduced and the area of ​​the stress relief space 30a can be increased. Various sizes of peelers 35 are available, and the peeler 35 can be selected and used according to the size of the electrode plate 17 to be cut.

[0123] Figure 8 Here is a view illustrating a modified example of an apparatus for manufacturing secondary batteries according to an embodiment of this disclosure.

[0124] In the following text, the same reference numerals as those in the accompanying drawings indicate the same components having the same function.

[0125] As an example, Figure 8 The peeler 35 illustrated may have a curved surface 35c formed as a removal surface. The curved surface 35c is a curved surface with a constant curvature and a convex shape. Due to the curved surface 35c, a stress relief space 30a can be formed between the curved surface 35c, the electrode plate 17, and the lower cutter 33. The peeler 35 with the curved surface 35c formed in... Figures 12A to 12C A separate example is provided.

[0126] like Figures 12A to 12C As illustrated, the curved surface 35c may have a curvature with a specific radius. The dimensions of the curved surface 35c may be varied. Figure 12A The curved surface has the curvature of a circle with radius r1. Additionally, Figure 12B The curved surface has a curvature of a circle with radius r2, and Figure 12C The curved surface 35c has a curvature of a circle with a radius of r3. The difference in radius dimensions is r2>r1>r3.

[0127] Figure 9 A view illustrating another modified example of an apparatus for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0128] like Figure 9 As illustrated, a right-angled groove 35e may be formed in the peeler 35 of the electrode plate cutting unit 30. The right-angled groove 35e is a groove with a right-angled bottom surface and provides a stress relief space 30a. That is, the removal surface may be the bottom surface (e.g., a right-angled bottom surface) of the groove recessed in the peeler 35. The size and shape of the right-angled groove 35e may be implemented differently in various embodiments.

[0129] Figure 10 This is a view illustrating yet another modified example of an apparatus for manufacturing secondary batteries according to an embodiment of the present disclosure.

[0130] like Figure 10 As illustrated, the groove 35g can be applied to the peeler 35 of the electrode plate cutting unit 30. The groove 35g is a groove with a concave bottom surface and provides a stress relief space 30a. That is, the removal surface can be the bottom surface (e.g., a concave bottom surface) of the groove recessed in the peeler 35.

[0131] Figures 13A to 13CThis is a view for describing another configuration example of the peeler 35 suitable for the electrode plate cutting unit 30 according to an embodiment of the present disclosure.

[0132] As illustrated, the stripper 35 may include a stripper body 35m and a fixed tip 35p. The stress relief space 30a may be the space between the removal surface formed by removing a portion of the fixed tip 35p, the lower cutter 33, and the electrode plate 17.

[0133] The stripper body 35m may have a structure in which the upper surface 35h contacts the lower surface of the electrode plate 17 and the side surface 35j faces the lower cutter 33, and a mounting groove 35n is formed in the portion where the upper surface 35h and the side surface 35j intersect. The dimensions of the mounting groove 35n may be implemented in different ways.

[0134] The fixing tip 35p is a component detachably connected to the mounting groove 35n. The fixing tip 35p may be made of the same material as the peeler body 35m or a different material. The peeler body 35m may be made of metal, and the fixing tip 35p may be made of synthetic resin.

[0135] Additionally, an inclined surface (e.g., a flat inclined surface) 35a may be formed on the fixed tip 35p, and the removal surface formed by removing a portion of the fixed tip 35p may be an inclined surface 35a. The inclination angle of the inclined surface 35a relative to the horizontal plane can be varied. The gentler the inclination angle, the wider the stress relief space 30a.

[0136] Figures 14A to 14C Each of the peelers 35 illustrated also includes a peeler body 35m and a fixed tip 35p. A mounting groove 35n may be formed in the peeler body 35m. Additionally, the fixed tip 35p may be fixedly inserted into the mounting groove 35n. Furthermore, a curved surface 35c may be formed on the fixed tip 35p, and the removal surface formed by removing a portion of the fixed tip 35p may be a curved surface 35c with a predetermined curvature. The curved surface 35c may have a convex shape. A stress relief space 30a may be formed between the curved surface 35c, the electrode plate 17, and the lower cutter.

[0137] At the same time, such as Figure 15A and Figure 15B As illustrated, the peeler 35 of the electrode plate cutting unit 30 in this embodiment may include a peeler body 35m and a plurality of inclined plates 35t.

[0138] The peeler body 35m may include an upper surface 35h that contacts the lower surface of the electrode plate 17 and a fixed inclined surface 35s. The fixed inclined surface 35s may be an inclined surface facing the blade 33a formed at the upper end of the lower cutter 33. The fixed inclined surface 35s may have an angle of 40 to 60 degrees relative to the horizontal plane.

[0139] Additionally, the inclined plate 35t can be mounted on the fixed inclined surface 35s and can provide a stress relief space 30a between the lower cutter 33 and the electrode plate 17. The inclined plate 35t is a plate-shaped member with a predetermined thickness, and multiple inclined plates 35t can be fixedly stacked on the fixed inclined surface 35s. As the number of stacked inclined plates 35t increases, the size of the stress relief space 30a can be reduced. Figure 15A An example is shown where three inclined plates of 35t are used, and Figure 15B An example is shown where two inclined plates of 35t are used.

[0140] The fixing of the inclined plate 35t to the stripper body 35m and the fixing of the inclined plates 35t to each other can be done by adhesive bonding or welding.

[0141] Figure 16 For application Figure 15A and Figure 15B The diagram illustrates the configuration of device 20 for manufacturing secondary batteries, which uses a stripper as an example.

[0142] As illustrated, the peeler 35 can be mounted on the side portion of the lower cutter 33. The peeler 35 is formed by the peeler body 35m and two inclined plates 35t, and it can be seen that the stress relief space 30a is formed between the inclined plates 35t, the electrode plate 17 and the lower cutter 33.

[0143] According to the apparatus and electrode plate cutting unit for manufacturing secondary batteries as described herein, by reducing the load applied to the load concentration area of ​​the electrode plate during cutting, cracks or impurities in the mixture portion and the transfer of active material to the separator can be prevented.

[0144] Although this disclosure has been described herein with respect to embodiments thereof, it is not limited thereto. Various modifications and variations may be made by those skilled in the art within the spirit of this disclosure as defined by the appended claims and their equivalents.

Claims

1. An apparatus for manufacturing secondary batteries, comprising: A conveying unit is configured to convey the electrode plate to be cut along a conveying path; A winding unit is configured to receive and wind the electrode plate conveyed by the conveying unit; as well as The cutting unit has: The upper cutter is installed above the conveying path. The lower cutter is installed below the conveying path, and A peeler, mounted on the side portion of the lower cutter, is configured to support the electrode plate as the upper cutter moves downward to transmit a reaction force corresponding to the downward force of the upper cutter to the electrode plate, and to provide stress relief space for the portion of the electrode plate subjected to shear force due to the upper and lower cutters to prevent the reaction force from being transmitted to the electrode plate.

2. The device according to claim 1, wherein the peeler has an upper surface in contact with the lower surface of the electrode plate and a side surface facing the lower cutter, and The stress relief space is the space between the removal surface formed by removing the corner where the upper surface and the side surface intersect, the lower cutter, and the electrode plate.

3. The device according to claim 2, wherein the removal surface is the bottom surface of a groove recessed in the peeler.

4. The device according to claim 1, wherein the stripper comprises: The stripper body has an upper surface that contacts the lower surface of the electrode plate and a side surface that faces the lower cutter, and has a mounting groove in the portion where the upper surface and the side surface intersect. as well as The fixed tip is installed in the mounting slot, and The stress relief space is the space between the removal surface formed by removing a portion of the fixed tip, the lower cutter, and the electrode plate.

5. The device according to claim 2 or 4, wherein the removal surface is a flat inclined surface.

6. The device according to claim 2 or 4, wherein the removal surface is a curved surface having a preset curvature.

7. The apparatus of claim 1, wherein the stripper comprises: The peeler body has a fixed inclined surface facing the blade formed at the upper end of the lower cutter; as well as An inclined plate is mounted on the fixed inclined surface and provides the stress relief space between the lower cutter and the electrode plate.

8. The device of claim 7, wherein the inclined plate is provided as a plurality of inclined plates mounted by stacking on the fixed inclined surface, each of the plurality of inclined plates being a plate-like member.

9. An electrode plate cutting unit, comprising: An upper cutter is installed above the conveying path of the electrode plate, which is conveyed along the conveying path. The lower cutter is installed below the conveying path; as well as A peeler, mounted on the side portion of the lower cutter, is configured to support the electrode plate as the upper cutter moves downward to transmit a reaction force corresponding to the downward force of the upper cutter to the electrode plate, and to provide stress relief space for the portion of the electrode plate subjected to shear force due to the upper and lower cutters to prevent the reaction force from being transmitted to the electrode plate.

10. The electrode plate cutting unit according to claim 9, wherein the peeler has an upper surface in contact with the lower surface of the electrode plate and a side surface facing the lower cutter, and The stress relief space is the space between the removal surface formed by removing the corner where the upper surface and the side surface intersect, the lower cutter, and the electrode plate.

11. The electrode plate cutting unit according to claim 10, wherein the removal surface is the bottom surface of a groove recessed in the stripper.

12. The electrode plate cutting unit according to claim 9, wherein the peeler comprises: The stripper body has an upper surface that contacts the lower surface of the electrode plate and a side surface that faces the lower cutter, and has a mounting groove in the portion where the upper surface and the side surface intersect. and The fixed tip is installed in the mounting slot, and The stress relief space is the space between the removal surface formed by removing a portion of the fixed tip, the lower cutter, and the electrode plate.

13. The electrode plate cutting unit according to claim 10 or 12, wherein the removal surface is a flat inclined surface.

14. The electrode plate cutting unit according to claim 10 or 12, wherein the removal surface is a curved surface with a preset curvature.

15. The electrode plate cutting unit according to claim 9, wherein the peeler comprises: The peeler body has a fixed inclined surface facing the blade formed at the upper end of the lower cutter; as well as An inclined plate is mounted on the fixed inclined surface and provides the stress relief space between the lower cutter and the electrode plate.

16. The electrode plate cutting unit of claim 15, wherein the inclined plate is provided as a plurality of inclined plates mounted by stacking on the fixed inclined surface, each of the plurality of inclined plates being a plate-like member.

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