Apparatus, method, and slit mold for coating electrode substrate of secondary battery

Abstract

The present disclosure relates to an apparatus and a method for manufacturing an electrode plate of a secondary battery. In an embodiment, a slit mold is provided that discharges a mixture slurry and an insulating slurry simultaneously. The slit mold includes an insulating slurry discharge portion protruding more toward the substrate than the mixture slurry discharge portion, which enables fine adjustment of the thickness of an insulating material coating portion on the substrate.

Description

Technical Field

[0001] This disclosure relates to apparatus and methods for manufacturing electrode plates for secondary batteries. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries can be charged and discharged. Generally, a secondary battery consists of an electrode assembly, which includes a positive electrode plate, a negative electrode plate, and a separator.

[0003] The positive and negative electrode plates can be manufactured using a coating process that coats one or both surfaces of an electrode substrate with a mixture of electrode active materials, a rolling process that presses and stretches the electrode plate coated with the mixture (i.e., the coated substrate) to make the electrode plate thin and flat, a slitting process that cuts the electrode plate longitudinally into multiple rows to separate it into individual electrode plates, and a cutting process that cuts each separated electrode plate transversely, removes unwanted parts, and forms a connecting piece.

[0004] In the coating process, a slurry-like mixture is used to coat a substrate using a slotted die. The coated substrate consists of a coated portion and an uncoated portion. Recently, a method has been used to prevent short circuits between the positive and negative electrode plates by coating the edges of the coated portion with an insulating material to prevent direct contact between the positive and negative electrodes.

[0005] Because the physical properties of the mixture coating portion and the insulating coating portion formed at the edge of the mixture coating portion are different, there may be a problem of ripples forming in the electrode plate during the coating process and also during subsequent processes, depending on the thickness of the insulating coating portion.

[0006] The information disclosed in this section is intended to enhance understanding of the background of this disclosure and may contain information that does not constitute related (or prior art). Summary of the Invention

[0007] This disclosure relates to a coating apparatus and method for finely adjusting the thickness of an insulating coating portion formed at the edge of a mixture coating portion, and a slit mold for providing the coating.

[0008] This disclosure provides an integrated slit mold for simultaneously discharging a mixed slurry and an insulating slurry. Furthermore, the insulating slurry discharging portion protrudes further toward the coating roller or substrate than the mixed slurry discharging portion, allowing for precise adjustment of the thickness of the insulating coating portion formed on the substrate.

[0009] According to one aspect of this disclosure, an apparatus for coating an electrode substrate of a secondary battery is provided, comprising a coating unit configured to simultaneously provide a mixture coating and an insulating coating to the electrode substrate, the coating unit including a slit mold having a mixture slurry discharge portion and an insulating slurry discharge portion, wherein the apparatus is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is less than the distance between the mixture slurry discharge portion and the electrode substrate.

[0010] According to another aspect of this disclosure, a method for coating an electrode substrate of a secondary battery is provided, comprising simultaneously providing a mixture coating and an insulating coating to the electrode substrate using an integrated slit mold having a mixture slurry discharge portion and an insulating slurry discharge portion, wherein the distance from the insulating slurry discharge portion to the electrode substrate is less than the distance from the mixture slurry discharge portion to the electrode substrate.

[0011] According to another aspect of this disclosure, a slit mold for coating an electrode substrate of a secondary battery is provided, comprising an upper plate, a lower plate, and a separator. The upper plate includes a mixed slurry supply portion and an insulating slurry supply portion, and the lower plate includes a cavity configured to collect the mixed slurry supplied to the mixed slurry supply portion. The separator is located between the upper plate and the lower plate to form a mixed slurry discharge portion and an insulating slurry discharge portion. The slit mold is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is less than the distance between the mixed slurry discharge portion and the electrode substrate.

[0012] The aspects and features of this disclosure are not limited to those described above, and other aspects and features not specifically mentioned herein will be clearly understood by those skilled in the art from the following description. Attached Figure Description

[0013] The above and other objects, features and advantages of the present invention will become more apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0014] Figure 1 The electrode assembly of a secondary battery is schematically shown;

[0015] Figure 2 A pouch-type secondary battery is schematically shown;

[0016] Figure 3 This is a cross-sectional view of a cylindrical secondary battery;

[0017] Figure 4 This is a diagram of the internal configuration of a prismatic secondary battery;

[0018] Figure 5 Manufacturing process is shown Figure 1 The manufacturing process of the electrode plate of the electrode assembly shown;

[0019] Figure 6 An electrode plate coated with a mixture layer and an insulating layer by a coating unit is shown;

[0020] Figure 7 This is a schematic diagram of an integrated slot mold according to an embodiment of the present disclosure;

[0021] Figure 8 This is an exploded view of an integrated slit mold according to an embodiment of the present disclosure;

[0022] Figure 9 This is a top view of an integrated slot die;

[0023] Figure 10 It is along Figure 9 A sectional view of line A-A' in the middle;

[0024] Figure 11 This is a configuration diagram of the spacers according to embodiments of the present disclosure;

[0025] Figure 12 This is an exemplary view of a secondary battery module having secondary battery cells that can be manufactured according to this disclosure;

[0026] Figure 13 It includes Figure 12 An exemplary view of the secondary battery module; and

[0027] Figure 14 It includes Figure 13 A concept image of a vehicle with a secondary battery pack. Detailed Implementation

[0028] 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 will not be interpreted narrowly according to their common or dictionary meaning, but should be interpreted, based on the principle that the inventor can be his / her own lexicographer, to have meanings and concepts consistent with the technical ideas of the present disclosure in order to properly define the concepts of the terms and thus best describe his / her invention.

[0029] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some embodiments of this disclosure and do not represent all aspects, features, and embodiments of this disclosure. Therefore, it should be understood that various equivalents and modifications may exist to replace or modify one or more embodiments or features described herein at the time of filing this application.

[0030] It will be understood that if an element or layer is described as being "on" another element or layer, "connected" to another element or layer, or "bonded" to another element or layer, then it can be directly on, directly connected to, or directly bonded to the other element or layer, or there may be one or more intermediary elements or layers. When an element or layer is described as being "directly on" another element or layer, "directly connected" to another element or layer, or "directly bonded" to another element or layer, there are no intermediary elements or layers. For example, if a first element is described as being "bonded" or "connected" to a second element, then the first element can be directly bonded or connected to the second element, or the first element can be indirectly bonded or connected to the second element via one or more intermediary elements.

[0031] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity of illustration. 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 listed items. Furthermore, the use of "may" refers to "one or more embodiments of this disclosure" when describing embodiments of the present disclosure. Expressions such as "at least one of" and "any one" modify the entire list of elements, not individual elements of the list, if following a 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 specify 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 "being used" may be considered synonymous with the terms "utilize," "using," and "being exploited," respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as approximate terms rather than as terms of degree, and are intended to explain the inherent variations in the measured or calculated values ​​that will be recognized by one of ordinary skill in the art.

[0032] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0033] For ease of description, spatial relation terms such as “below,” “under,” “down,” “above,” and “above” are used herein to describe the relationship of an element or feature to other elements or features as shown in the figures. It will be understood that, in addition to the orientation depicted in the figures, spatial relation terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “above” said other elements or features. Therefore, the term “below” can cover both above and below orientations. Devices may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relation descriptions used herein should be interpreted accordingly.

[0034] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to be limiting. As used herein, the singular form “a” is also intended to include the plural form unless the context clearly indicates otherwise. It will also be understood that, if used in this specification, the terms “comprising,” “including,” “including,” and / or “containing” indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0035] The numerical ranges disclosed and / or described herein include all subranges with the same numerical precision falling within the listed ranges. For example, the range “1.0 to 10.0” includes all subranges between the described minimum value of 1.0 and the described maximum value of 10.0 (and includes both the described minimum value of 1.0 and the described maximum value of 10.0), i.e., all subranges having 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 described herein includes all lower numerical limits falling within it, and any minimum numerical limit described in this specification includes all higher numerical limits falling within it. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly describe any subrange falling within the range expressly described herein. All such ranges are intended to be inherently described in this specification such that amendments to expressly describe any such subrange will comply with the requirements of the patent rules.

[0036] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with deviations considered low in the art (e.g., 5% or less). Furthermore, if a parameter is said to be uniform in a given region, it can mean that it is uniform in terms of average value.

[0037] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0038] Arranging an element "above (or below)" or "on (below)" another element can mean that the element can contact the upper (or lower) surface of the other element, or that another element can be inserted between the other element and the element located above (or below) the other element.

[0039] Furthermore, it will be understood that if a component is referred to as “linked,” “joined,” or “connected” to another component, then these components can be directly “joined,” “linked,” or “connected” to each other, or another component can be “inserted” between these components.

[0040] Throughout this specification, the statement "A and / or B" means A, B, or A and B, unless otherwise stated. That is, "and / or" includes any or all of the listed items. When "C to D" is stated, it means C or more and D or fewer, unless otherwise stated.

[0041] Figure 1 The electrode assembly of a secondary battery is shown schematically.

[0042] Reference Figure 1 The electrode assembly 10 can be formed by winding or stacking a first electrode plate 11, a separator 12, and a second electrode plate 13, each of which is formed as a plate or film. When the electrode assembly 10 is a wound stack, the winding axis can be parallel to the longitudinal direction of the secondary battery casing. Furthermore, the electrode assembly 10 can be a Z-stacked electrode assembly, in which a positive electrode plate and a negative electrode plate are provided to both sides (e.g., opposite sides) of a separator that is bent (or folded) into a Z-shape. Additionally, one or more electrode assemblies can be stacked (e.g., arranged) such that the long sides of the electrode assemblies are adjacent to each other and housed within a casing. The number of electrode assemblies in the casing is not limited in this disclosure. The first electrode plate 11 of the electrode assembly can serve as a negative electrode, and the second electrode plate 13 can serve as a positive electrode. Of course, the reverse is also possible.

[0043] The first electrode plate 11 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 11 may include a first electrode tab 14 (e.g., a first uncoated portion), the first electrode tab 14 being an area in which the first electrode active material is not provided. The first electrode tab 14 may be connected to an external first terminal. In some embodiments, when fabricating the first electrode plate 11, the first electrode tab 14 may be cut to protrude from one side of the electrode assembly 10. In other embodiments, the first electrode tab 14 may protrude from one side of the electrode assembly 10 further than the diaphragm 12 (e.g., protrude further than or beyond the diaphragm 12) without being individually cut.

[0044] The second electrode plate 13 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 13 may include a second electrode tab 15 (e.g., a second uncoated portion), the second electrode tab 15 being an area in which no second electrode active material is provided. The second electrode tab 15 may be connected to an external second terminal. In some embodiments, when fabricating the second electrode plate 13, the second electrode tab 15 may be cut to protrude from the other side (e.g., the opposite side) of the electrode assembly 10. In other embodiments, the second electrode tab 15 may protrude further than the diaphragm 12 from the other side of the electrode assembly (e.g., protrude further than or beyond the diaphragm 12) without being individually cut.

[0045] The diaphragm 12 prevents short circuits between the first electrode plate 11 and the second electrode plate 13 while allowing lithium ions to move between them. The diaphragm 12 can be made of, for example, a polyethylene membrane, a polypropylene membrane, or a polyethylene-polypropylene membrane.

[0046] In some embodiments, the electrode assembly 10 may be housed together with the electrolyte within a casing. In pouch-type secondary batteries, the electrode assembly 10 may be housed within a pouch made of a flexible material (see...). Figure 2 In cylindrical or prismatic secondary batteries, the electrode assembly 10 can be housed in a cylindrical or prismatic metal casing (see...). Figure 3 and Figure 4 ).

[0047] Suitable materials that can be used in secondary batteries according to embodiments of this disclosure will be described below.

[0048] As the positive electrode active material, compounds capable of reversibly inserting / deintercalating lithium (e.g., lithiated intercalation compounds) can be used. For example, a composite oxide of lithium with at least one of metals selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0049] The composite oxide can be a lithium transition metal composite oxide, examples of which may include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, or combinations thereof. As an example, compounds represented by any of the following chemical formulas may 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 a Mn2G bO4 (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). In these chemical formulas: 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; L 1 is Mn, Al or a combination thereof.

[0050] The positive electrode for 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.

[0051] Based on 100 wt% of the positive electrode active material layer, the amount of the positive electrode active material may be in the range of about 90 wt% to about 99.5 wt%. Based on 100 wt% of the positive electrode active material layer, the amounts of the binder and the conductive material may be in the range of about 0.5 wt% to about 5 wt% respectively.

[0052] The substrate may be aluminum (Al), but the present disclosure is not limited thereto.

[0053] The negative electrode active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of being lithium-doped and non-lithium-doped, or a transition metal oxide.

[0054] 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 include graphite, such as natural graphite or artificial graphite, and examples of amorphous carbon include soft carbon, hard carbon, pitch carbide, mesophase pitch carbide, sintered coke, etc.

[0055] A Si-based negative electrode active material or a Sn-based negative electrode active material may be used as a material capable of being lithium-doped and non-lithium-doped. 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.

[0056] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to an embodiment, the silicon-carbon composite may be in the form of silicon particles, with amorphous carbon coated on the surface of the silicon particles.

[0057] 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 on the surface of the core.

[0058] The negative electrode for 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.

[0059] The negative electrode active material layer may include about 90 wt% to about 99 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.

[0060] Non-aqueous adhesives, aqueous adhesives, dry adhesives, or combinations thereof can be used as adhesives. When using an aqueous adhesive as the negative electrode adhesive, it may further include a cellulose compound capable of imparting viscosity.

[0061] As the negative electrode substrate, one of the following can be used: copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof.

[0062] Electrolytes used in lithium-ion secondary batteries may include non-aqueous organic solvents and lithium salts. The non-aqueous organic solvents act as the medium through which ions involved in the electrochemical reactions of the battery can move. Non-aqueous organic solvents can be carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, and aprotic solvents, and can be used alone or in combination of two or more. Furthermore, when using carbonate solvents, mixtures of cyclic carbonates and chain carbonates can be used.

[0063] Depending on the type of lithium secondary battery, a separator may be provided between the first electrode plate (e.g., the negative electrode) and the second electrode plate (e.g., the positive electrode). The separator may be formed of polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer membrane comprising two or more of these layers may be used.

[0064] The diaphragm may include a porous substrate and a coating layer on one or both surfaces of the porous substrate, the coating layer comprising an organic material, an inorganic material, or a combination thereof. The organic material may include a polyvinylidene fluoride polymer or a (meth)acrylic acid polymer. The inorganic material may include 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. However, this disclosure is not limited to these examples. The organic and inorganic materials may be mixed in a single coating layer, or may be in the form of a coating layer comprising an organic material and a coating layer comprising an inorganic material stacked on top of each other.

[0065] Figure 2 A pouch-type secondary battery is schematically shown. The pouch-type secondary battery includes an electrode assembly 10 and a pouch 20 for housing the electrode assembly 10.

[0066] Figure 2 The electrode assembly 10 shown is Figure 1 The electrode assembly 10 shown is identical. The first electrode tab 14 and the second electrode tab 15 of the electrode assembly 10 can be electrically connected to corresponding external first terminal lead 16 and second terminal lead 17 by soldering. Each of the first terminal lead 16 and the second terminal lead 17 can be attached to a tab film 18 for insulation from the bag 20.

[0067] The bag 20 can be sealed by bringing the sealing portions 21 at the edges of the bag 20 into contact with each other when the electrode assembly 10 is inside the bag 20. The seal can be achieved using a connecting film 18 inserted between the sealing portions 21 and the electrode connecting pieces 14 and 15. The sealing portions 21 of the bag 20 can each be made of a heat-fused material with weak adhesion to metals. Therefore, the bag 20 can be fused together by inserting a thin connecting film 18 between the sealing portions 21 and the electrode connecting pieces 14 and 15.

[0068] Figure 3 This is a cross-sectional view of a cylindrical secondary battery. (Example) Figure 3 As shown, the secondary battery may include an electrode assembly 10 and a housing 31 that houses the electrode assembly 10 and an electrolyte therein. A cover assembly 32 may be coupled to an opening in the housing 31 to seal the housing 31. An insulating plate 33 may be located inside the housing 31 between the electrode assembly 10 and the cover assembly 32.

[0069] The housing 31 houses the electrode assembly 10 and the electrolyte, and together with the cover assembly 32 forms the appearance of a secondary battery. The housing 31 may have a substantially cylindrical body portion and a bottom attached to one side of the body portion. An inwardly deformed beading part 34 (e.g., a bead) may be formed in the body portion. An inwardly bent crimped part 35 (e.g., a crimp) may be formed at the open end of the body portion.

[0070] The grooved portion 34 can reduce or prevent movement of the electrode assembly 10 within the housing 31 and facilitates the placement of the gasket and cover assembly 31. The rolled edge portion 35 can securely fix the cover assembly 32 by pressing the edge of the housing 31 against the gasket 36. The housing 31 can be formed of, for example, nickel-plated iron.

[0071] The cover assembly 32 can be secured to the inside of the rolled edge 35 via the gasket 36 to seal the housing 31. A first lead connector 37 extending from the electrode assembly 10 can be connected to the cover assembly 32. A second lead connector 38 extending from the electrode assembly 10 can be electrically connected to the bottom of the housing 31.

[0072] Figure 4 This is a diagram of a prismatic secondary battery. As shown, the prismatic secondary battery may include an electrode assembly 40, a first current collector 41, a first terminal 62, a second current collector 42, a second terminal 63, a housing 51, and a cover assembly 60.

[0073] Electrode assembly 40 can be formed by winding or stacking a first electrode plate, a diaphragm, and a second electrode plate, each of which is formed as a plate or a film. When electrode assembly 40 is a wound stack, the winding axis can be parallel to the longitudinal direction (e.g., the y-direction) of housing 51. In other embodiments, electrode assembly 40 is a stack type rather than a wound type. The shape of electrode assembly 40 is not limited in this disclosure. Furthermore, electrode assembly 40 can be a Z-stack electrode assembly, in which a positive electrode plate and a negative electrode plate are provided on both sides of a diaphragm bent into a Z-shape. In addition, one or more electrode assemblies can be stacked such that the long sides of the electrode assemblies are adjacent to each other and can be housed in a housing. The number of electrode assemblies in the housing is not limited in this disclosure. The first electrode plate of the electrode assembly can act as a negative electrode, and the second electrode plate can act as a positive electrode. Of course, the reverse is also possible.

[0074] The first electrode plate can be formed by applying a first electrode active material (such as graphite, carbon, etc.) to a first electrode current collector formed of a metal foil (such as copper, copper alloy, nickel, nickel alloy, etc.). The first electrode plate may include a first electrode tab 43 (e.g., a first uncoated portion), which is a region where the first electrode active material is not provided. The first electrode tab 43 can serve as a current flow path between the first electrode plate and the first current collector 41. In some embodiments, when the first electrode plate is fabricated, the first electrode tab 43 is formed by cutting to protrude from one side of the electrode assembly 40. In other embodiments, the first electrode tab 43 protrudes from one side of the electrode assembly 40 further than the diaphragm (e.g., protrudes further than or beyond the diaphragm) without being cut separately.

[0075] The second electrode plate can be formed by applying a second electrode active material (such as a transition metal oxide) onto 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 44 (e.g., a second uncoated portion), the second electrode tab 44 being a region in which no second electrode active material is provided. The second electrode tab 44 can serve as a current flow path between the second electrode plate and the second current collector 42. In some embodiments, when fabricating the second electrode plate, the second electrode tab 44 can be cut to protrude from the other side (e.g., the opposite side) of the electrode assembly. In other embodiments, the second electrode tab may protrude further than the diaphragm from the other side of the electrode assembly (e.g., protrude further than or beyond the diaphragm) without being cut separately.

[0076] The separator essentially prevents or reduces instances of short circuits between the first and second electrode plates while allowing the movement of lithium ions between them. The separator can be made of, for example, polyethylene membranes, polypropylene membranes, polyethylene-polypropylene membranes, etc.

[0077] In some embodiments, the electrode assembly 40 is housed together with the electrolyte in a housing 51.

[0078] In the electrode assembly 40, the first current collector 41 and the second current collector 42 can be welded and connected to the first electrode terminal 43 extending from the first electrode plate and the second electrode terminal 44 extending from the second electrode plate, respectively. In an embodiment where the first electrode terminal 43 and the second electrode terminal 44 are located on top of the electrode assembly 40, the first current collector and the second current collector are located on top of the electrode assembly 40.

[0079] like Figure 4As shown, the first current collector 41 and the second current collector 42 are respectively connected to the first terminal 62 and the second terminal 63 via connecting members 67. In an embodiment, the connecting members 67 may each have a threaded outer peripheral surface and can be tightened to the first terminal 62 and the second terminal 63 by screwing. However, this disclosure is not limited thereto. For example, the connecting members 67 may also be riveted or welded to the first terminal 62 and the second terminal 63.

[0080] Figure 5 It is used for manufacturing Figure 1 A schematic diagram of the manufacturing process of the electrode plate (i.e., the first electrode plate 11 or the second electrode plate 13) of the electrode assembly 10 shown.

[0081] A supply roller 110 is provided on which a substrate (also referred to as an electrode substrate) P1 for an electrode plate is wound. When a positive electrode plate is manufactured using the apparatus for manufacturing an electrode plate according to the present disclosure, the substrate P1 may be, for example, an aluminum (Al) metal foil. Alternatively, when the apparatus is used to manufacture a negative electrode plate, the substrate P1 may be, for example, a copper (Cu) or nickel (Ni) metal foil.

[0082] The conveyor roller 150 is provided as an idle roller to guide the substrate P1 unwound from the supply roller 110 or as a drive roller to apply tension to unwound the substrate P1 from the supply roller 110. Figure 5 A total of four conveyor rollers 150 are shown as an example, but the number and position of the conveyor rollers may differ from the configuration shown.

[0083] The coating unit 120 forms a coating layer by coating the substrate P1 with a coating mixture. Here, the coating mixture includes an electrode active material. For example, when using the electrode plate manufacturing apparatus to manufacture a positive electrode plate, the coating mixture may include an active material, a binder, and a volatile solvent, wherein the active material includes a lithium transition metal oxide. When manufacturing a negative electrode plate, the coating mixture may also be prepared using an active material, a binder, and a solvent. Both the upper and lower surfaces of the substrate P1 can be coated simultaneously by adding a second coating unit 120'. The second coating unit 120' may have a similar structure to... Figure 5 The coating unit 120 shown has the same configuration and is configured to apply the coating mixture to the lower surface of the substrate P1.

[0084] The pressurizing unit 130 (i.e., the rolling unit) uses rollers to compress the electrode plate P2, which is coated with a mixture (a mixture of electrode active materials) applied by the coating unit 120. This process enables the production of high-capacity and high-density secondary batteries.

[0085] The winding roller 140 winds and holds the electrode plate P3 coated and rolled by the coating unit 120 and the pressurizing unit 130.

[0086] Figure 5 The coating unit 120 and the pressurizing unit 130 used in one process are shown. However, this is just an example, and the coating process and the rolling process can be performed separately.

[0087] Figure 6 Through Figure 5 A top view of an example of an electrode plate P2 coated with a mixture by a coating unit 120. The electrode plate P2 has a mixture-coated portion where the substrate is coated with the mixture and an uncoated portion 74 where the substrate is not coated.

[0088] For reference, in the following text, the width direction of the electrode plate or substrate is referred to as the transverse direction TD, and the longitudinal direction of the electrode plate or substrate as the direction of movement is referred to as the processing direction MD.

[0089] Figure 6 A multi-row coated electrode plate P2' is shown, having multiple rows of hybrid coating portions formed extending in the processing direction MD of the substrate. The hybrid coating portions are formed using a multi-row slit mold, which simultaneously provides coating material to hybrid coating areas arranged in the lateral direction TD of the substrate. Figure 6 An example is shown where a first row of mixed coating portions 72a, a second row of mixed coating portions 72b, and a third row of mixed coating portions 72c are provided, and an uncoated portion 74 is formed at a boundary arranged in the lateral direction TD. The uncoated portion 74 includes the outermost portion of the multi-row coated electrode plates P2'.

[0090] A method has been used to prevent short circuits by coating the edges of the mixture-coated portion with insulating material to prevent the positive electrode from contacting the negative electrode. Figure 6 An insulating coating portion 76 is shown, which is formed at the edges of the first row of mixture coating portions 72a, the second row of mixture coating portions 72b, and the third row of mixture coating portions 72c and extends in the longitudinal direction.

[0091] Figure 6 The image shows a three-row mixture coating section. However, this is just an example, and mixture coating sections with different numbers of rows can be formed.

[0092] In order to manufacture Figure 6 The electrode plate can use a mixture coating slit mold for discharging the mixture slurry to form the mixture coating portion and an insulation coating slit mold for discharging the insulating slurry to form the insulation coating portion.

[0093] Figure 7 This is a schematic diagram of an integrated slot mold for simultaneously discharging a mixed slurry and an insulating slurry, according to an embodiment of the present disclosure. Figure 7 It shows the method for forming Figure 6The integrated slot mold 200 for the three rows (three lines) of mixture coating section shown in the example.

[0094] While the substrate is conveyed along the processing direction MD by the roller 121, three rows of mixed coating portions 72a, 72b and 72c are formed by the mixed slurry and insulating slurry discharged from the integrated slit mold 200, as well as an insulating coating portion 76 formed at each edge of the mixed coating portion.

[0095] The thickness of the insulating coating portion 76 can be important. In some cases, due to the different physical properties of the mixture and the insulating material, ripples may form in the electrode plate depending on the thickness of the insulating coating portion 76, appearing during the coating process and also during subsequent processes. Ripples are undesirable, and to prevent such ripples, it is necessary to control the amount of insulating slurry and the amount of mixed slurry discharged in the integrated slot die 200.

[0096] Figure 8 This is an exploded view of an integrated slit mold 200 according to an embodiment of the present disclosure.

[0097] The integrated slit mold 200 may include an upper plate 210, a lower plate 220, and a separator 230. The upper plate 210 includes a mixed slurry supply section (not shown) and an insulating slurry supply section (not shown). The lower plate 220 includes a cavity 221 in which the mixed slurry supplied to the mixed slurry supply section is collected. The separator 230 is located between the upper plate 210 and the lower plate 220. The integrated slit mold 200 may also include a mixed slurry discharge section 222 for discharging the mixed slurry and an insulating slurry discharge section 233 for discharging the insulating slurry. The mixed slurry discharge sections 222 may discharge the same mixture. For example, each mixed slurry discharge section 222 may discharge a mixture of positive electrode active materials or a mixture of negative electrode active materials. Optionally, the mixed slurry discharge sections 222 may discharge different mixtures. For example, one mixed slurry discharge section 222 may discharge a mixture of positive electrode active materials, and another mixed slurry discharge section 222 may discharge a mixture of negative electrode active materials.

[0098] exist Figure 8 In the middle, the edge of the end of the protrusion 231 forms an insulating grout discharge portion 233. Figure 11 A more detailed configuration is shown. Therefore, the insulating coating portion can be formed at both edges of the mixture-coated portion.

[0099] The insulating slurry discharge portion 233, whose protrusion 231 protrudes further than the mixed slurry discharge portion 222, is configured such that the thickness of the insulating coating portion 76 is controlled by making the distance between the insulating slurry discharge portion 233 and the substrate smaller than the distance between the mixed slurry discharge portion 222 and the substrate. That is, because the insulating slurry discharge portion 233 of the separator 230 protrudes closer to the substrate, thereby reducing the distance to the substrate, the thickness of the insulating coating portion 76 can be controlled.

[0100] Figure 9 This is a top view of the integrated slot die 200, and schematically shows the flow of insulating slurry I and mixed slurry M.

[0101] In a top view of the upper plate 210, the protrusions 231 of the separator 230 may be located between the mixture slurry discharge portions 222, and the insulating slurry I may be discharged from the two edges of the protrusions 231.

[0102] Figure 10 It is along Figure 9 The cross-sectional view along line A-A'. As described above, the distance d2 between the insulating slurry discharge portion 233 and the electrode substrate P1 can be smaller than the distance d1 between the mixed slurry discharge portion 222 and the electrode substrate P1 of the integrated slit mold 200. For this purpose, it can be done as follows: Figure 8 and Figure 9 As shown, protrusion 231 is formed.

[0103] Typically, when the spacer is secured to the upper and lower plates of the slot die, the spacer is designed to be secured to the die lips of the upper and lower plates. In this disclosure, the insulating slurry discharge portion 233, which is part of the spacer 230, protrudes further than the mixed slurry discharge portion 222. Therefore, the thickness of the insulating coating portion 76 can be finely adjusted.

[0104] Because the insulating paste discharge portion 233 protrudes to form the insulating coating portion 76, the gap between the mixed paste discharge portion 222 and the substrate P1 can be as follows: Figure 10 As shown, this would reduce the flatness of the mixture slurry during coating and cause ripples in the electrode plate. However, using the integrated slot die 200 for coating a mixture-insulator according to the present disclosure, the mixture slurry and the insulating slurry can be dispensed together, which has the effect of compensating for the flatness of the mixture slurry. For example, the insulating slurry can overlap with the mixture slurry during coating. In this way, because the integrated slot die for coating an insulating-mixture layer according to the present disclosure can compensate for the flatness of the mixture slurry with the insulating slurry, the spacer 230 can be designed to protrude further compared to coating only the mixture.

[0105] The following shows experimental results relating the thickness and coating condition of the insulating coating portion 76 to the protrusion amount of the protrusion 231 (i.e., the length of the protrusion from the mixture slurry discharge portion 222).

[0106]

[0107] In the experiment, the negative protrusion amount indicates that the insulating slurry discharge portion 233 is positioned further away from the electrode substrate than the mixed slurry discharge portion 222. As shown in the table, when the protrusion amount of protrusion 231 is zero or less, the mixed slurry and insulating slurry mix, leading to contamination of the mixed slurry. Therefore, protrusion 231 can protrude such that the insulating slurry discharge portion is positioned closer to the substrate than the mixed slurry discharge portion, resulting in appropriate mixed coating portions and insulating coating portions.

[0108] More specifically, when the protrusion 231 is greater than 0 and less than 30 μm, ripples appear in the electrode plate, but they are still within the specifications that the coating process can perform. Good coating results are obtained when the protrusion 231 protrudes between 30 μm and 80 μm. Therefore, it was found that in order to simultaneously form the mixture coating portion and the insulating coating portion, the protrusion amount of the protrusion 231 can be greater than 0 and less than or equal to 80 μm. When the protrusion 231 protrudes greater than 80 μm, the gap between the mixture slurry discharge portion 222 and the substrate P1 (see...) Figure 10 The mixture is too large. Therefore, the slurry is coated in a less straight line, making the process difficult.

[0109] As can be seen in the table above, the thickness of the formed insulating coating depends on the amount of protrusion of the protrusion 231 corresponding to the distance between the insulating slurry discharge portion 233 and the electrode substrate P1. Specifically, the amount of protrusion is inversely proportional to the thickness of the insulating coating. The distance between the insulating slurry discharge portion 233 and the electrode substrate P1 can be adjusted based on the desired thickness of the insulating coating to be formed on the electrode substrate P1. The thickness of the insulating coating portion 76 can be varied taking into account factors affecting process progress (such as ripples appearing in the electrode plate) and the stability of the battery.

[0110] Figure 11 This is a configuration diagram of the spacer 230 according to an embodiment of this disclosure. Figure 8 As shown, protrusions 231 can be provided between the mixed slurry discharge portions 222, and insulating slurry discharge portions 233 can be provided at the two edges of the protrusions 231. In order to discharge the insulating slurry according to this method, an insulating slurry flow path (not shown) can be formed at the edge of the insulating slurry discharge portion 233, through which the supplied insulating slurry is discharged.

[0111] The protrusion amount of the protrusion 231 can be adjusted by changing the distance between the mixture slurry discharge portion 222 and the insulating slurry discharge portion 233 (i.e., changing the protrusion length 234). In one embodiment, multiple spacers 230 with different protrusion amounts (i.e., protrusion lengths 234) of the protrusion 231 are manufactured. Therefore, an appropriate spacer 230 can be selected and used depending on the type of substrate to be coated, the desired thickness of the insulating coating portion, and any other coating factors. In another embodiment, a protrusion amount changing portion can be added to the spacer 230 to change the protrusion length 234, making the distance between the insulating slurry discharge portion 233 and the substrate variable. For example, when individually manufactured protrusions 231 are attached to spacers 230 using screws, the protrusion amount changing portion can be implemented as a mechanism for changing the position of the protrusion 231.

[0112] Figure 12 This is an exemplary view of a secondary battery module including secondary battery cells manufactured according to the manufacturing apparatus and method of this disclosure. Utilizing the high capacity of secondary battery cells used to drive electric vehicles, etc., the secondary battery module is manufactured by arranging and connecting multiple secondary battery cells in the lateral and / or longitudinal directions. Multiple secondary battery cells can be arranged in a space defined by a pair of facing end plates 68a and 68b and a pair of facing side plates 69a and 69b. The arrangement of the secondary battery cells can be designed to have an arrangement direction and number that achieves desired voltage and current specifications.

[0113] Figure 13 This is an exemplary view of a secondary battery pack 70, which is formed to hold... Figure 12 The secondary battery module shown is used in an actual product (e.g., a vehicle). Secondary battery packs can be manufactured by embedding multiple secondary battery modules within a housing designed for mounting on an actual product. The housing may include fastening components and electrical connectors necessary for mounting on the product. Figure 13 Components including busbars, cooling units, and external terminals for electrical connection to the battery are not shown.

[0114] The secondary battery pack can be installed on (or inside) the vehicle. The vehicle can be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle can be a four-wheeled vehicle or a two-wheeled vehicle, but this disclosure is not limited thereto. Figure 14 It is shown that it includes on its lower body Figure 13 The vehicle with battery pack 70 shown.

[0115] The vehicle can be operated by receiving power from the battery pack 70 (e.g., it can be propelled by receiving power from the battery pack 70).

[0116] According to this disclosure, by reducing the gap between the substrate and the separator protruding from the integrated slit mold that simultaneously discharges the mixed slurry and the insulating slurry, the thickness of the insulating coating portion can be adjusted, thereby preventing or reducing problems such as ripples depending on the thickness of the insulating coating portion.

[0117] Although embodiments of this disclosure have been described above, this disclosure is not limited thereto. Various modifications and variations can be made to it within the spirit of this disclosure by those skilled in the art.

Claims

1. An apparatus for coating an electrode substrate for a secondary battery, the apparatus comprising: A coating unit configured to simultaneously provide a mixture coating and an insulating coating to the electrode substrate, the coating unit comprising a slit mold having a mixture slurry discharge section and an insulating slurry discharge section. The device is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is less than the distance between the mixed slurry discharge portion and the electrode substrate.

2. The apparatus according to claim 1, wherein, The device is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is variable.

3. The apparatus according to claim 2, wherein, The device is configured to adjust the distance between the insulating slurry discharge portion and the electrode substrate based on the desired thickness of the insulating coating portion to be formed on the electrode substrate.

4. The apparatus according to claim 2, wherein, The device is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is proportional to the thickness of the insulating coating portion formed on the electrode substrate.

5. The apparatus according to claim 1, wherein, The slit mold includes: The upper plate includes a mixture slurry supply section and an insulating slurry supply section; The lower plate includes a cavity configured to collect the mixed slurry supplied to the mixed slurry supply section; and An isolator is located between the upper plate and the lower plate to form the mixture slurry discharge section and the insulating slurry discharge section.

6. The apparatus according to claim 5, wherein, The separator includes protrusions that form the portion of the insulating slurry discharge.

7. The apparatus according to claim 6, wherein, The protrusion extends up to 80 μm from the discharge portion of the mixture slurry.

8. The apparatus according to claim 6, wherein, The separator includes a protrusion adjustment portion configured to adjust the distance by which the protrusion protrudes from the mixture slurry discharge portion.

9. A method for coating an electrode substrate of a secondary battery, the method comprising: A slit mold with a mixture slurry discharge section and an insulating slurry discharge section is used to simultaneously apply a mixture coating and an insulating coating to the electrode substrate. The distance from the insulating slurry discharge portion to the electrode substrate is less than the distance from the mixed slurry discharge portion to the electrode substrate.

10. The method according to claim 9, wherein, The distance between the insulating slurry discharge portion and the electrode substrate is adjusted based on the desired thickness of the insulating coating portion to be formed on the electrode substrate.

11. The method according to claim 9, wherein, The distance between the insulating slurry discharge portion and the electrode substrate is proportional to the thickness of the insulating coating portion on the electrode substrate.

12. The method according to claim 9, wherein, The mixture coating includes coating at least one of the positive electrode active material and the negative electrode active material.

13. A slit mold for coating an electrode substrate of a secondary battery, the slit mold comprising: The upper plate includes a mixture slurry supply section and an insulating slurry supply section; The lower plate includes a cavity configured to collect the mixed slurry supplied to the mixed slurry supply section; as well as A separator is located between the upper plate and the lower plate to form a mixture slurry discharge section and an insulating slurry discharge section. The slit mold is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is less than the distance between the mixed slurry discharge portion and the electrode substrate.

14. The slit mold according to claim 13, wherein, The slit mold is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is variable.

15. The slit mold according to claim 13, wherein, The slit mold is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is adjusted based on the desired thickness of the insulating coating portion to be formed on the electrode substrate.

16. The slit mold according to claim 15, wherein, The slit mold is configured such that the distance between the insulating slurry discharge portion and the electrode substrate is proportional to the thickness of the insulating coating portion formed on the electrode substrate.

17. The slit mold according to claim 13, wherein, The separator includes protrusions that form the portion of the insulating slurry discharge.

18. The slit mold according to claim 17, wherein, The protrusion extends up to 80 μm from the discharge portion of the mixture slurry.

19. The slit mold according to claim 17, wherein, The separator includes a protrusion adjustment portion configured to adjust the distance by which the protrusion protrudes from the mixture slurry discharge portion.

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