Coating System

Abstract

A system for applying material is provided. The system includes a die and a flow guide. The die includes an opening and a cavity in communication with the opening. The die is configured to extrude material in a primary application direction through the opening. The flow guide is disposed within the cavity and configured to shape a flow of material extruded by the die. The flow guide includes a flow narrowing portion and a flow shaping portion. The flow narrowing portion extends in a width direction perpendicular to the primary application direction to block material flow in the primary application direction. The flow shaping portion extends downstream from the flow narrowing portion in the primary application direction. The width of the flow shaping portion is less than or decreases from the width of the flow narrowing portion.

Description

[Technical Field]

[0001] The present invention relates to a system for applying a material to a substrate, for example. Such a system may be embodied in a system for manufacturing batteries, particularly secondary batteries. Such a system may be used to implement a method for manufacturing batteries, particularly secondary batteries. [Background technology]

[0002] In some manufacturing processes, a solid-liquid mixture material, such as a slurry containing a battery active material, may be applied to a substrate, such as an electrode substrate for battery manufacturing. Depending on the material to be applied and the requirements for the manufacturing method and system, applying the material to obtain a specific thickness profile on the substrate may be a technical challenge. Conventional systems may not be able to provide a clear thickness profile, especially at a sharp transition between two clear thickness levels. Furthermore, applying the material in an efficient and precise manner according to the specific thickness profile on the substrate may be a technical challenge. Summary of the Invention [Problem to be solved by the invention]

[0003] The technical problem known from the prior art is solved by the subject matter of the independent claims. Specific embodiments are provided by the features of the dependent claims. [Means for solving the problem]

[0004] A system for applying a material is provided. The system includes a die and a flow guide. The die includes an opening and a cavity. The cavity is in communication with the opening. The die is configured to extrude the material in a primary application direction through the opening. The flow guide is disposed within the cavity. The flow guide is configured to shape the flow of material extruded by the die. The flow guide comprises a flow narrowing portion and a flow shaping portion. The flow narrowing portion extends in a width direction perpendicular to the primary application direction and blocks the material from flowing in the primary application direction. The flow shaping portion extends downstream from the flow narrowing portion in the primary application direction. The width of the flow shaping portion is smaller than or decreases from the width of the flow narrowing portion.

[0005] Here, width is determined by the width direction. Length as used herein is determined by the main coating direction. As described above, the width direction and the main coating direction are perpendicular to each other. Furthermore, height as used herein is determined by the height direction, which is perpendicular to the width direction and perpendicular to the main coating direction. As will be explained below, the main coating direction is defined by the direction of material flow from the cavity toward the opening, and therefore the main coating direction is directional. In other words, a position or flow along the main coating direction is referred to herein as "downstream" relative to the main coating direction (or forward main coating direction). In contrast, a position or flow opposite or counter to the main coating direction is referred to herein as "upstream" relative to the main coating direction (or rearward main coating direction). The width direction and height direction are used herein in a bidirectional manner, i.e., without reference to the positive or negative direction.

[0006] The main application direction can refer to the direction in which the material is extruded from / through the die. In other words, the main application direction can refer to the direction in which the material is extruded from the die opening. Since the material may be a flowable material as defined herein, the material can spread after being discharged from the die. Here, the main application direction can refer to the average direction of all directions in which the material is extruded from the die opening. Alternatively or additionally, the main application direction can correspond to the flow direction of the material contained in the cavity and discharged through the die opening. In this way, the main application direction can be determined by the positional relationship between the die opening and the cavity.

[0007] The system may be implemented in a single facility or a single device, or may be implemented as a distributed system consisting of several devices or devices. As described below, the system may further include a unit such as a coating roll for transporting a substrate onto which a material is applied. The system may include any one of the functions described below.

[0008] Unless otherwise specified or technically inappropriate, a battery generally includes a primary battery, a secondary battery, or more generally, an electrochemical cell for energy storage, but may be any one of them. In particular, the term "battery" as used herein may refer to a secondary battery, i.e., a rechargeable battery. For example, a battery may include one or more electrode layers and one or more separator layers stacked in a specific manner. A battery may be a coin-type, cylindrical, prismatic, or pouch-type battery. In particular, a battery may be configured to power an electric vehicle. Hereinafter, the term "battery" will be used to avoid limiting the subject matter to the manufacture of a specific battery. Alternatively or additionally, a battery may refer to a primary battery or a non-rechargeable battery.

[0009] The material may be a flowable and / or viscous material. The material may also be referred to as a slurry. The material may be 100% viscous at atmospheric pressure (1013.25 hPa) and 25°C. 2More specifically, the material may have a viscosity of 10 mPa·s or greater at atmospheric pressure and 25°C. 3 mPa·s or more, 10 4 mPa·s or more, 10 6 mPa·s or more, 10 10 mPa·s or more, or 10 12 The upper viscosity limit can be determined by the transition to the solid state, and is 10 mPa·s or more at atmospheric pressure and 25°C. 24 The viscosity may be greater than or equal to mPa·s. Unless otherwise specified, the viscosity may be measured using a viscometer according to standard EN ISO 3219. Alternatively or additionally, the viscosity may be measured using, for example, a Stabinger SVM kinematic viscometer according to ASTM 7042 at atmospheric pressure and 25°C. The material may include one of the characteristics described below.

[0010] The material may be or include a mixture of liquid and solid materials and / or a material that is partially liquid and partially solid. Specifically, the material may refer to a mixture including a binder mixed with a solid active material, which may be provided as, for example, a granular and / or powdered material. The active material may be or include lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium manganese oxide (LMO), lithium nickel manganese spinel (LNMO), lithium iron phosphate (LFP), etc. The active material may additionally include graphite, pure lithium, and / or silicon.

[0011] The material may include an active material used to form an electrode of a battery, particularly a secondary battery. The material may include an active material used to form a positive electrode or a negative electrode. The slurry may additionally include solid conductive particles, such as carbon black and / or carbon nanotubes. The slurry may additionally include a dispersant. For simplicity of explanation, the terms active material and slurry may be used interchangeably hereinafter unless otherwise specified or technically inappropriate.

[0012] The binder may be a polymeric binder. The binder may be or include polyvinylidene fluoride (PVDF), polymethyl acrylate (PMMA), carboxymethyl cellulose (CMC), polyacrylate, xanthan gum, polyethylene glycol, or styrene butadiene. The slurry may further include one or more liquid components. The liquid components may be or include water and / or an organic solvent such as tetrahydrofuran (THF) or N-methyl-2-pyrrolidone (NMP).

[0013] The material can be extruded through a die. The extrusion process is also called coating, and in this process, the material can be coated onto a substrate, which can be called an electrode substrate, to form a battery electrode. The electrode substrate can be a metal foil made of one or more metallic materials, such as copper, nickel, or aluminum.

[0014] The die may be a device configured to extrude a material through an opening in the die. The die may also be referred to as an ejector, an injector, an application device, or an extrusion device. The die may be configured to extrude a material through a cavity and an opening in the die. The die may further include any one of the corresponding features as described below.

[0015] A cavity can refer to a hollow space formed in a die. While a cavity can refer to a hollow space within a die, a cavity can also be considered a structural feature of a system and / or die, where appropriate. Thus, a system and / or die can include a cavity. In particular, a cavity can be formed between separated portions of a die with a flow guide inserted therebetween. A cavity can be additionally configured as described below.

[0016] The cavity may be shaped and dimensioned to accommodate the material. The cavity may be fluidly coupled to a material supply system. A feed port may be provided in the die cavity to supply the material into the die cavity. The feed port may be configured to allow the material to be supplied to the die cavity. A manifold may be formed in communication with the cavity so that the material supplied to the cavity first spreads in the manifold and then fills the cavity. If applicable, the feed port may be formed in the manifold. The manifold may have an elongated concave shape along its width. The manifold may have any one of the characteristics, as described below.

[0017] The cavity may be fluidly connected to an opening in the die. The cavity may be configured (e.g., sized and shaped) so that a material contained therein expands toward the opening or can be expelled from the die through the opening. In particular, the cavity may be filled with material when the material is supplied to the cavity such that the material is expelled from the cavity through the opening. This process may be referred to as extruding the material from the die and / or applying the material onto the substrate.

[0018] The die may be configured to respond to flow rate and / or pressure applied by a material supply system to extrude material through an opening in the die. Upon actuation, the cavity may contain, i.e., be filled (partially or completely) with, material. Once the cavity is filled with material, the material may be expelled from the cavity through the opening.

[0019] Here, an opening can be a two-dimensional empty area, particularly located between two individual parts of the die at the front surface of the die. As mentioned above, a die can include two or more individual parts, including, for example, an upper die and a lower die, a first die half and a second die half, or a die cover and a die base. A cavity can be formed as a gap between two or more individual parts of the die. Alternatively, a cavity can be formed as a void inside the integral body of the die, and an opening can be formed in the outer surface of the die so that the cavity is exposed to the exterior of the die.

[0020] When viewed from the direction opposite to the main coating direction, the opening may have the shape of an elongated slit along its width. The front face of the die may extend in a plane perpendicular to the main coating direction. In particular, the opening and the cavity may have the same uniform height, particularly since they are formed between two individual parts of the die. Here, uniform height can mean that the height is locally invariant, i.e., maintained constant at any position.

[0021] A flow guide may be disposed within the cavity. The flow guide may be configured to shape the flow of material extruded by the die. The flow guide may be an integral part of the die, partially or entirely. The flow guide may be shaped and dimensioned to shape the flow of material. The flow guide, also referred to as a spacer, interposer, or shim, may be provided as an integral member inserted into the die cavity or between individual parts of the die. Alternatively, the flow guide may be provided at least partially as an integral part of the die within the cavity. The flow guide may include the features described below, unless otherwise specified or technically inappropriate.

[0022] The flow narrowing portion may extend in the width direction to block the material from flowing in the primary application direction. In particular, the flow narrowing portion or flow guide may have the same height as the cavity so that the material does not flow above or below the flow narrowing portion. In particular, the flow narrowing portion may be shaped and dimensioned so that the material in the cavity flows around the flow narrowing portion instead of passing through the flow narrowing portion along the primary application direction. Thus, the flow narrowing portion can narrow the flow of material extruded by the die. The general shape and geometric and topological features of the flow narrowing portion are not limited to specific examples. Some specific examples are described below with reference to the drawings.

[0023] For example, the flow narrowing portion may include a rear wall disposed perpendicular to (and facing away from) the main application direction to block material in the cavity from flowing in the main application direction. Additionally or alternatively, the flow narrowing portion may include a rear wall having a sloped, inclined, bent, and / or curved surface relative to the main application direction to block or redirect the flow of material in the cavity toward the opening. Here, the rear wall of the flow narrowing portion generally refers to the outer wall of the flow narrowing portion facing away from the main application direction. The flow narrowing portion may include any one of the corresponding features described below, unless otherwise specified or technically inappropriate.

[0024] The flow shaping portion extends downstream from the flow narrowing portion in the primary application direction. The width of the flow shaping portion is smaller than the width of the flow narrowing portion. Alternatively, the width of the flow shaping portion decreases to the width of the flow narrowing portion. In particular, the flow shaping portion may have sidewalls extending along the primary application direction, or may have at least a component extending along the primary application direction. The sidewalls of the flow shaping portion may extend along the primary application direction, or may be offset from the sidewalls of the flow narrowing portion that extend along the primary application direction, or have at least a component extending along the primary application direction in the width direction. In this way, after the material flows around the flow narrowing portion, the material can flow along the sidewalls of the flow shaping portion within the cavity. Alternatively or additionally, the flow of material from the opening may be restricted by the sidewalls of the flow shaping portion. The general shape and geometric and topological features of the flow shaping portion are not limited to specific examples. Some specific examples are described below with reference to the drawings.

[0025] The configuration of the flow narrowing section and flow shaping section disclosed in the present invention allows for precise control of the thickness profile of the material extruded by the die. In particular, the material is redirected to flow around the flow narrowing section, and then the flow of material is aligned downstream by the flow shaping section. Therefore, a more defined thickness profile of the material applied to the substrate can be obtained. In particular, the thickness profile of the applied material can exhibit a more abrupt transition between two distinct thickness levels.

[0026] In particular, the material may be or may include an active material for the manufacture of a secondary battery, particularly an active material for a positive electrode. It is preferable that the thickness of the applied material be reduced at one or more specific locations. In a specific example, the electrode assembly may include a positive electrode and a negative electrode arranged on opposite sides of a separator sheet. In such an example, the thickness of the positive electrode material is preferably less than the thickness of the negative electrode material on the rear surface of the separator sheet. To ensure that this requirement is met even at locations where the thickness of the negative electrode material is locally reduced, it may be advantageous to also reduce the thickness of the positive electrode material at the exact corresponding location. This can prevent undesirable crystallization of material components, particularly lithium, due to an excess of positive electrode material compared to the negative electrode material at the same location on the rear surface.

[0027] Specifically, it may be advantageous for the loading ratio of the positive electrode active material to the negative electrode active material to be greater than 1.0, particularly greater than 1.03, greater than 1.05, greater than 1.08, greater than 1.10, and maximum at 1.2, 1.3, or 1.5. The loading of the positive electrode active material on one side of the separator sheet may be smaller than the loading of the negative electrode active material on the opposite side, preferably by a factor of 0.85 to 0.99, a factor of 0.90 to 0.98, a factor of 0.92 to 0.97, or a factor of 0.92 to 0.95. Here, loading refers to the mass applied per unit area (e.g., g / m). 2 ) can be represented as

[0028] Generally, different materials are used as the active materials for the negative and positive electrodes. Therefore, the material properties, particularly the viscosity and the contact angle with the substrate material, are different. This can cause the boundary of the positive electrode active material to have a different thickness profile than the boundary of the negative electrode active material. In particular, the boundaries on both sides of the positive and negative electrodes can be formed along the flow (which may be called "sliding") of the respective materials on the respective substrates. From this perspective, the subject matter disclosed herein can enable the application of more clearly defined and distinct boundaries for the applied materials. This can lead to accurate configuration of secondary batteries. Furthermore, the subject matter disclosed herein can enable more efficient material use.

[0029] In particular, the width offset between the flow narrowing section and the sidewalls of the flow shaping section (i.e., walls extending parallel or partially parallel to the main coating direction, or aligned perpendicular to the width direction) can be set according to the spreading width of the material after coating. The spreading width can represent the distance the material spreads in the width direction after exiting the die. The spreading width can be determined not only by the composition and properties of the material, but also by the interface characteristics with the substrate to which the material is coated. The spreading width can also vary depending on the distance between the die opening and the substrate and the coating speed (i.e., the flow rate of the material through the die). The spreading width can also be referred to as the sliding length. Depending on the material and substrate, the spreading width can be between 0.1 mm and 100 mm, 0.5 mm and 50 mm, or 1 mm and 10 mm.

[0030] The presently disclosed subject matter therefore allows for more precise control of the thickness profile of the applied material than conventional systems and methods. Application of material with a specific thickness profile on a substrate may be facilitated and improved. The combination of flow narrowing portions and flow shaping portions may be specifically configured to meet individual needs and requirements. The presently disclosed subject matter therefore also increases the versatility of systems for applying material on a substrate. To this end, the flow narrowing portions and flow shaping portions may be specifically shaped and specifically dimensioned not only individually but also relative to one another. Herein, the combination of flow narrowing portions and flow shaping portions may also be referred to as a flow edge portion.

[0031] In some cases, the flow narrowing portion has sidewalls perpendicular to the width direction. The flow shaping portion has sidewalls perpendicular to the width direction. The sidewalls of the flow shaping portion are offset from the sidewalls of the flow narrowing portion in the width direction.

[0032] Thus, material flowing in the primary application direction can first flow around the flow constriction along its rear wall, then flow along the sidewall of the flow constriction. Downstream of the flow constriction, the material can spread toward the sidewall of the flow shaping section (resulting in flow in both the primary application direction and the width direction). Depending on the viscosity and interfacial properties of the material, the material may flow along the sidewall of the flow shaping section or reach the sidewall of the flow shaping section at a downstream location close to the opening. In this way, the flow of material can be restricted and shaped by the sidewall of the flow shaping section. As a result, a well-defined thickness profile can be achieved.

[0033] In some examples, the flow guide further includes a flow guide portion extending along the main application direction to block the material from flowing in the width direction. The flow guide portion may extend from the flow narrowing portion in a direction opposite to the main application direction. The flow guide portion may extend from an upstream side of the flow narrowing portion in a direction opposite to the main application direction.

[0034] The flow guide may have a uniform width that is smaller than the width of the flow narrowing. Alternatively or additionally, the flow guide may have side walls that extend along the main application direction, or at least components of the side walls that extend along the main application direction that are offset in the width direction from the side walls of the flow narrowing.

[0035] Thus, the flow guide may be configured to guide the material along the flow guide portion to the flow narrowing portion. The flow guide may also be configured to enclose the material within the cavity, particularly within a volume defined by the flow guide. In particular, the flow guide may provide a lateral barrier to maintain the material within the cavity, particularly within a volume defined by the flow guide.

[0036] In some examples, the flow guide may include other flow narrowing portions, other flow shaping portions, and other flow directing portions extending from the other flow narrowing portions. In a specific example, the flow narrowing portions, flow shaping portions, and flow directing portions may be located on one side edge of the die cavity, and the other flow narrowing portions, other flow shaping portions, and other flow directing portions may be located on the opposite side edge of the die cavity to provide a barrier to block material from flowing in the width direction. Here, the side edge may refer to the side of the die cavity in the width direction.

[0037] In some examples, the flow guide further includes a widthwise extending base portion, the flow guide portion extending from the base portion in the primary application direction to the flow narrowing portion, and the flow guide portion having a uniform width that is smaller than the width of the flow narrowing portion.

[0038] In some examples, the die includes an upper die having a lower end surface. The die may also include a (corresponding or complementary) lower die having an upper end surface. The lower end surface of the upper die and the upper end surface of the lower die may be configured (e.g., sized and shaped) to rest against each other. As described above, the die may be comprised of two separate parts, where a cavity is formed between the two separate parts of the die.

[0039] The terms upper and lower may vary depending on the arrangement of the dies relative to gravity. Because flowable or viscous materials may be used, it may be advantageous to provide an end surface through which the material can flow and spread. The upper end surface of the lower die may support the material and provide a surface through which the material can flow and spread. The opposite end surface, i.e., the lower end surface of the upper die, may provide an upper cover to upwardly limit the volume of the cavity. The lower end surface of the upper die and the upper end surface of the lower die may be impermeable to the material (except for the feed port through which the material may be fed into the cavity, as described above).

[0040] The cavity can be formed by a flow guide interposed between the end faces of the upper die and the lower die. The lower end face of the upper die and the upper end face of the lower die can have a generally flat shape and corresponding size (in the main coating direction and width direction), so that the cavity formed therebetween has a uniform height. This allows the die opening to be formed as a slit-like two-dimensional gap in the front face of the die.

[0041] Such a configuration may make it easier to control the flow of the material extruded by the die, and may enable a variety of configurations for the manufacturing method and system for the secondary battery.

[0042] In some examples, the system further includes a manifold formed in the die and in communication with the cavity. The flow guide can surround at least a rear surface of the manifold opposite the opening of the die and a side surface of the manifold relative to the width of the manifold.

[0043] The term "surrounding" here is not limited to physical contact with the manifold, but instead, a flow guide may be provided to block the material supplied to the cavity through the manifold from flowing in a direction opposite to the width direction and the main coating direction.

[0044] For example, the flow guide may include a base portion as described above. In particular, the base portion may be located between the rear edge of the cavity (the side opposite the front where the cavity opening is formed) and the manifold and may block material from flowing to the rear side of the cavity. The flow guide may additionally or alternatively include two or more flow guide portions as described above. The flow guide portions are configured to block material from flowing to the side of the cavity. Thus, the flow guide may be configured to enclose material in the cavity within a volume defined by the flow guide, particularly surrounded by the base portion and the flow guide portions.

[0045] In some cases, at least a portion of the flow narrowing portion is disposed between the die opening and the manifold. Specifically, the flow narrowing portion may be disposed such that the rear wall of the flow narrowing portion faces the manifold. In particular, the flow narrowing portion may extend from the flow guide portion in the width direction toward the centerline of the cavity parallel to the main application direction, and the flow narrowing portion may also be disposed such that it surrounds the manifold by being located between the manifold and the die opening.

[0046] In some examples, the flow guide further includes a flow separator extending along the primary application direction to block the material from flowing in the width direction, the flow separator being spaced apart from the flow narrowing portion.

[0047] The flow guide section extends from the flow narrowing section in a direction opposite to the main application direction, and the flow separation section is spaced apart from the flow narrowing section. In particular, the flow separation section is spaced apart from the flow narrowing section in the width direction. The separation section can have a length and width depending on the material properties and the specific application requirements.

[0048] In some cases, the flow separator can extend from the base in the primary application direction. As shown in connection with the figures below, the flow guide and flow separator can both extend from the base in the primary application direction, but can also extend from different locations on the base that are spaced apart from one another in the width direction.

[0049] In some cases, the distance between the flow shaping portion and the die opening is less than the distance between the flow separation portion and the die opening. In other words, the flow shaping portion may be positioned closer to the opening than the flow separation portion. The flow separation portion may have a length such that it terminates at one point, while the flow shaping portion may extend further toward or be positioned closer to the die opening.

[0050] In some examples, the flow guide can include multiple flow separation sections, each configured as described above. By having one or more flow separation sections, the flow of material can be controlled to provide a specific thickness profile on the substrate. For example, each flow separation section can reduce the loading of material at a location corresponding to the location of the flow separation section. By using one or more flow separation sections with reduced height (i.e., further away from the opening than the flow shaping section), the degree of reduction in the loading of material applied to the substrate can be precisely controlled.

[0051] In some examples, the flow narrowing portion and the flow shaping portion are perpendicular to the main application direction and, when viewed from a plane perpendicular to the width direction, have the shape of a capital T or a capital L. That is, the plane means a view according to the height direction. Here, the capital T can be reversed, i.e., the vertical bar of the capital T is located near the opening of the die and the horizontal bar of the capital T is located near the rear surface of the die.

[0052] More specifically, the flow narrowing portion may form the horizontal bar of a capital T and the flow shaping portion may form the vertical bar of the capital T, or the flow narrowing portion may form the horizontal bar of a capital L and the flow shaping portion may form the vertical bar of the capital L, and the position, length and width of the flow narrowing portion and flow shaping portion may be adjusted depending on the requirements of the material and product being applied.

[0053] In some examples, the flow guide further includes an additional flow narrowing portion and an additional flow shaping portion. The additional flow narrowing portion extends in the width direction to block material flow in the main application direction. The additional flow shaping portion extends downstream from the additional flow narrowing portion in the main application direction. The width of the additional flow shaping portion is smaller or decreases than the width of the additional flow narrowing portion. The additional flow narrowing portion is spaced apart from the flow narrowing portion, particularly in the width direction.

[0054] Thus, the flow guide of the system disclosed herein may include a first flow narrowing portion, which is the flow narrowing portion described above, and a second flow narrowing portion, which is an additional flow narrowing portion. The flow guide may further include a first flow shaping portion, which is the flow shaping portion described above, and a second flow shaping portion, which is an additional flow shaping portion. The flow guide may further include an additional flow guiding portion provided as described above with respect to the flow guiding portion. Thus, the system may be comprised of two sets of flow narrowing portions, flow shaping portions, and flow guiding portions. The two sets may be positioned on opposite edges of the die cavity in the manner described above. Together with the base portion described above, the two sets may partially surround the manifold described above, thereby containing material within the cavity, particularly within the volume defined by the flow guide.

[0055] In some examples, the flow guide may further include a set of a third flow narrowing portion, a third flow shaping portion, and a third flow directing portion configured in the manner described above with respect to the (first) flow narrowing portion, the (first) flow shaping portion, and the (first) flow directing portion, respectively. The flow guide, or system, may further include more sets of additional flow narrowing portions, flow shaping portions, and flow directing portions configured in the manner described above.

[0056] Several sets of flow narrowing, flow shaping and flow directing elements may be used to tailor the thickness profile of the applied material in a more granular manner, allowing for even greater thematic versatility.

[0057] In some cases, the flow narrowing portion and the additional flow narrowing portion are positioned at the outermost positions in the width direction within the cavity of the die. Thus, the flow narrowing portion and the additional flow narrowing portion may provide lateral boundary walls at opposite edges of the cavity. Thus, the flow narrowing portion and the additional flow narrowing portion may contribute to containing the material within the cavity, particularly within the volume defined by the flow guide.

[0058] In some instances, the width of the additional flow constriction is different from the width of the flow constriction. Alternatively or additionally, the length of the additional flow constriction is different from the length of the flow constriction. This can result in an asymmetric thickness profile of the material deposited on the substrate, thereby enhancing the versatility of the presently disclosed subject matter.

[0059] In another example, the width of the flow narrowing and the width of the additional flow narrowing are the same, and the length of the flow narrowing and the length of the additional flow narrowing are the same, which allows for a symmetrical thickness profile of the material deposited on the substrate.

[0060] According to another aspect, there is provided a secondary battery manufacturing system including the system as described above, or any embodiment thereof, wherein the material can be an active material, particularly a positive electrode active material, for manufacturing the secondary battery.

[0061] Thus, the system for applying materials as described above can be used explicitly for manufacturing batteries, in particular secondary batteries, said materials may include active materials for manufacturing battery electrodes, as described above.

[0062] According to another aspect, a method for manufacturing a secondary battery is provided. This method may use (i.e., may be performed by) the system described above or any one of its exemplary embodiments. According to this method, active material, particularly positive electrode active material, is supplied to a die such that the active material is contained in a cavity of the die and expelled through an opening in the die. This may be referred to as coating (onto a substrate, as described above) or extrusion (i.e., applying pressure or volumetric flow to force the material through the die), and may be performed as detailed above.

[0063] All the features described above with respect to the system may also be applied to the manufacturing method of a secondary battery without being explicitly formulated as procedural features, unless technically inappropriate.

[0064] In some examples of the above methods, the material released through the die opening can be applied to the first side of the electrode substrate, which may also be referred to as coating the first side of the electrode substrate with the material released through the die opening.

[0065] In some examples of the above methods, the material applied to the first side of the electrode substrate may be dried, which may also be referred to as drying the material applied to the first side of the electrode substrate.

[0066] In some examples of the above methods, the electrode substrate can optionally be rotated after the material applied to the first side of the electrode substrate has dried, which may also be referred to as rotating the electrode substrate so that the material applied to the first side is reversed and / or so that a second side opposite the first side faces up.

[0067] In some examples of the above methods, the material or other material may be applied through a die on the second side of the electrode substrate. This may also be referred to as applying the material or other material through a die on the second side of the electrode substrate. Optionally, the material or other material applied to the second side of the electrode substrate may then be dried.

[0068] The secondary battery manufacturing system and method each achieve the technical effects and advantages discussed above with respect to the material application system.

[0069] According to another aspect, a system for applying a material may be provided. The system includes a die and a flow guide. The die includes an opening and a cavity. The cavity communicates with the opening. The die is configured to extrude the material through the opening in a primary application direction. The flow guide is disposed within the cavity of the die. The flow guide is configured to shape a flow of the material extruded by the die.

[0070] In the system, the flow guide includes a flow guide portion and a flow edge portion. The flow guide portion extends in a primary application direction. The flow edge portion extends in a width direction from the flow guide portion. The width of the flow edge portion is different from, and in particular larger than, the width of the flow guide portion.

[0071] Also in the system, the flow edge portion is recessed on the distal edge of the flow guide portion, downstream with respect to the main application direction. For example, the flow edge portion has a recessed width and a recessed height, i.e., a rectangular recessed edge. In another example, the flow edge portion is recessed on the edge in the shape of a circular sector having a recessed diameter. In another example, the flow edge portion is recessed on the edge in the shape of a triangle.

[0072] According to another aspect, batteries, particularly secondary batteries, are disclosed that are produced using the systems and / or by the methods disclosed herein.

[0073] In some examples, the battery may include an active material that is applied such that the profile of the applied active material exhibits a sigmoidal curve in the boundary regions, and the profile of the applied active material may be approximately constant in the central region.

[0074] In some examples, the border region can be the outermost region of the widthwise applied active material, where the widthwise extent of the border region is 1 mm to 15 mm, 2 mm to 10 mm, or 3 mm to 8 mm from the outermost position of the applied active material.

[0075] In some examples, the central region may be a region of the applied active material in which the profile of the applied active material is substantially constant, and in particular, the variation of the profile of the applied active material is 0.1% to 5%, 0.1% to 4%, or 0.1% to 3% relative to the maximum value of the profile. The central region may be contiguous with the border regions and may be located further in width from the outermost position of the applied active material than the border regions. The central region may be a region of the applied active material in which the variation of the profile of the applied active material is 0.1% to 5%, 0.1% to 4%, or 0.1% to 3% relative to the maximum value of the profile. Such variation may be considered substantially constant.

[0076] In some cases, the battery includes a coated active material, the profile of the coated active material having a depression with a local maximum centrally located between two minima.

[0077] In some cases, the difference in the amount of applied material between the local maximum and at least one of the two minimum values ​​may be between 0.1% and 10%, or between 0.5% and 8%, or between 1% and 5% of the maximum value.

[0078] In some examples, the profile of the applied active material can have at least one shoulder formed by a depression and respective maxima laterally adjacent to the depression, and the profile of the applied active material can be generally constant outward from the at least one shoulder.

[0079] In some examples, the difference in the amount of applied material between each maximum value and the outer region of the constant profile may be 0.1% to 10%, or 0.5% to 8%, or 1% to 5% of the value of each maximum value.

[0080] The batteries disclosed herein may provide a distinctive coating profile for the active material, which may be for the positive and / or negative electrodes. Such coating profiles may result in distinctive boundary regions of the coated active material where the loading or coating thickness of the active material is significantly reduced compared to conventional batteries. They may also result in distinctive central regions of the coated active material where the loading or coating thickness of the active material is more uniform than conventional batteries. This may increase the energy density of the battery.

[0081] The accompanying drawings illustrate several specific embodiments and are intended to aid in understanding the present invention. In the present specification and drawings, the same reference numerals or series of reference numerals may be used in other embodiments to indicate identical, similar, or analogous elements. Generally, repeated descriptions will be omitted below. Unless otherwise expressly stated or technically inappropriate, the embodiments described below with reference to the drawings may include the features described above. Furthermore, for the sake of conciseness and efficiency of description, the embodiments described below with reference to the drawings may include any of the features described with reference to each previous embodiment, unless otherwise expressly stated or technically inappropriate. It should be noted that the drawings have not been scaled. Certain features and aspects may be enlarged or reduced for clarity. [Brief explanation of the drawings]

[0082] [Figure 1A] 1A and 1B schematically illustrate perspective views of a die according to an embodiment. [Figure 1B] 1A and 1B schematically illustrate cross-sectional side views of a die according to an embodiment. [Figure 2A] 10A and 10B are schematic plan views of other examples of flow guides; [Figure 2B] 10A and 10B are schematic plan views of other examples of flow guides; [Figure 3A] 1A and 1B schematically illustrate cross-sectional plan views of systems according to embodiments. [Figure 3B] 1 shows a schematic perspective view of a system according to an embodiment; [Figure 4A] 1A and 1B schematically illustrate cross-sectional plan views of systems according to embodiments. [Figure 4B] 1A and 1B schematically illustrate cross-sectional plan views of systems according to embodiments. [Figure 5A] 1A and 1B schematically illustrate cross-sectional plan views of systems according to embodiments. [Figure 5B] 1 shows a schematic perspective view of a system according to an embodiment; [Figure 6A] 1A and 1B schematically illustrate cross-sectional plan views of systems according to embodiments. [Figure 6B] 1A and 1B schematically illustrate cross-sectional plan views of systems according to embodiments. [Figure 7] 1 shows profiles of applied materials according to examples and comparative examples. [Figure 8] 1 shows a profile of the applied material according to an example. DETAILED DESCRIPTION OF THE INVENTION

[0083] 1. A system for applying a material, the system comprising: a die including an opening and a cavity in communication with the opening, the die configured to extrude material in a primary application direction through the opening; and a flow guide within the cavity configured to shape a flow of material extruded by the die; wherein the flow guide includes a flow narrowing portion extending in a width direction perpendicular to the main coating direction to block the material from flowing in the main coating direction, and a flow shaping portion extending downstream from the flow narrowing portion in the main coating direction; Here, the width of the flow shaping portion is smaller than or reduced from the width of the flow narrowing portion, said width being determined in the width direction.

[0084] The secondary battery manufacturing system is a system that corresponds to any of the systems described above, and the material here is an active material for manufacturing a secondary battery, in particular, a positive electrode active material.

[0085] A method for manufacturing a secondary battery using the above system may include the following.

[0086] Supplying the active material, particularly the positive electrode active material, to the die so that the active material is contained within the cavity of the die and is released through the opening in the die.

[0087] Batteries, particularly secondary batteries, can be produced using the systems and / or methods.

[0088] FIG. 1A schematically illustrates an exemplary perspective view of a die 10. FIG. 1B schematically illustrates a cross-sectional side view of the die 10 taken along line BB in FIG. 1A. In this and subsequent drawings, a main coating direction D, a width direction W, and a height direction H are illustrated for reference. The directions D, W, and H are as described above. As described above, the main coating direction D is directional, whereas the width direction W and the height direction H are bidirectional. Thus, as described above, the term "downstream" as used herein can refer to a direction along with the main coating direction D, and the term "upstream" can refer to a direction opposite to the main coating direction D.

[0089] The die 10 shown in FIGS. 1A and 1B can be part of a system and / or can be used to perform the methods disclosed herein. The die 10 includes an upper die 12 and a lower die 14. The upper die 12 and the lower die 14 are provided as separate components of the die 10. The upper die 12 has a lower end surface 12E, hereinafter referred to as end surface 12E for simplicity. The lower die 14 has an upper end surface 14E, hereinafter referred to as end surface 14E for simplicity. The end surfaces 12E and 14E have dimensions (e.g., the same size) and shapes (e.g., flat along a plane perpendicular to the height direction H) that compensate for each other. In other embodiments not explicitly shown, the die can be provided as an integrated device having a cavity therein and an opening communicating with the cavity.

[0090] Optionally, as shown in Figure 1A, the upper die 12 and the lower die 14 are mechanically coupled via a hinge 16. Thus, the upper die 12 and the lower die 14 are coupled in a manner that allows them to rotate relative to each other and about a central axis that passes through the hinge 16. The central axis may be parallel to the width direction W.

[0091] Further optionally, as shown in FIG. 1A , the die 10 may include an arrest member 18 on the rear surface of the die 10. Here, the rear surface may be perpendicular to the main coating direction D and point toward the upstream side. In the example of FIG. 1A , the arrest member 18 is provided on the rear surface of the lower die 14. The arrest member 18 is perpendicular to the main coating direction D and provides a surface facing downstream on which a flow guide may be disposed. Thus, the arrest member 18 may be useful for positioning and aligning the flow guide within the cavity of the die 10.

[0092] The die 10 further includes a manifold 20 and a feed port 22 disposed within the manifold 20. The manifold 20 is provided as an elongated recessed portion along a width direction W and a depth along a height direction. The manifold 20 may be recessed within the die 10, particularly within the end face 14E of the lower die 14. As best shown in the example of FIG. 1A and in the cross section of FIG. 1B taken along BB in FIG. 1A, the manifold 20 has a curved lower surface recessed within the lower die 14. In other embodiments not explicitly shown, the manifold may have other suitable shapes, such as a polygonal shape, or a cylindrical, ellipsoidal, or spherical portion, or a combination thereof.

[0093] 1B, the die 10 includes a cavity 24 formed therein. While the term "cavity" as used herein can refer to an empty space formed in the die 10, for simplicity, the cavity 24 will be considered to be part of the die 10 hereinafter. In the embodiment shown in the drawings, the cavity 24 is formed as a gap between the upper die 12 and the lower die 14. In particular, the cavity 24 may be formed between the end faces 12E and 14E of the upper die 12 and the lower die 14, and as described above, the cavity 24 may be formed with dimensions (e.g., to have the same size) and shapes (e.g., to be flat along a plane perpendicular to the height direction H) that compensate for each other.

[0094] 1A and 1B, die 10 is configured to extrude material (not shown in the drawings) through opening 26. For example, material may be supplied to cavity 24 via feed port 22. To this end, optionally, die 10 may further include duct 28 fluidly connecting feed port 22 with a feed system (not shown in the drawings) that supplies material to die 10. The material may be as described above, and in particular may be an active electrode material of a secondary battery.

[0095] Cavity 24 is configured to contain material. Material is fed into cavity 24, causing cavity 24 to fill with material to the extent that the material exits die 10 through opening 26 in primary application direction D. This process may be referred to as extruding and / or applying material through die 10. The flow of material within cavity 24 may be driven by the pressure at which the material is supplied to cavity 24 by a feed system.

[0096] 1B, the die 10 further includes an opening 26 formed in a front side (not numbered) of the die 10. In the example shown in the drawing, the opening 26 is formed in the front side of the die 10 as a gap between the upper die 12 and the lower die 14. More generally, the opening may be formed in the front side of the die 10. The front side may refer to the side of the die 10 that is perpendicular to the main coating direction D and faces downstream.

[0097] 2A and 2B show schematic plan views of other example flow guides 30a-30f. Any of the flow guides 30a-30f shown herein can be part of a system and / or can be used to perform the methods disclosed herein. It should be noted that flow guides 30a-30f are embodiments selected to illustrate what a flow guide may look like in connection with the subject matter disclosed herein. Flow guides including flow narrowing and flow shaping portions configured in accordance with the claimed subject matter are not limited to the specific embodiments illustrated in the drawings.

[0098] Each flow guide 30a-30f is disposed within the cavity 24 of the die 10. The flow guides 30a-30f are configured to shape the flow of material extruded by the die 10. Each flow guide 30a-30f includes a flow narrowing portion 32 and a flow shaping portion 34. The height of each flow guide 30a-30f in the height direction H may be the same as the height of the cavity 24. In particular, the height of the flow guide 30 and the height of the cavity 24 may be uniform, i.e., constant at any position. In some examples, as described above, the cavity 24 may be formed by inserting the flow guides 30a-30f between individual components of the die 10, such as the upper die 12 and the lower die 14. The flow narrowing portion 32 and the flow shaping portion 34 may also have respective heights identical to the height of the cavity 24. Therefore, material may not flow above or below the flow guide 30, particularly above or below the flow narrowing portion 32 and the flow shaping portion 34.

[0099] Referring to the example of the upper left corner of flow guide 30a in Figure 2A, flow narrowing portion 32 of flow guide 30a extends in width direction W and blocks material from flowing in main application direction D. In particular, flow narrowing portion 32 includes an upstream-facing rear wall 32B that is perpendicular to main application direction D (i.e., rear wall 32B extends parallel to width direction W and height direction H). The flow narrowing portion, and in particular rear wall 32B, may block material from flowing in main application direction D.

[0100] Additionally, the flow narrowing 32 of the flow guide 30a includes a sidewall 32S extending along the primary application direction D and the height direction H. Thus, material exiting the manifold 20 within the cavity 24 can flow toward the rear wall 32B of the flow narrowing 32. The material cannot flow through the flow narrowing 32 or above or below the flow narrowing 32, and is therefore blocked from flowing in the primary application direction. Thus, the material flows widthwise around the flow narrowing 32 along the rear wall 32B and in the primary application direction D along the sidewall 32S.

[0101] The flow shaping portion 34 extends downstream of the flow narrowing portion 32 in the primary application direction. The width W34 of the flow shaping portion 34 is smaller than the width W32 of the flow narrowing portion 32. The sidewall 34S is offset from the sidewall 32S of the flow narrowing portion 32 in the width direction W. Therefore, material flowing along the sidewall 32S in the primary application direction D flows toward the sidewall 34S of the flow shaping portion 34. As described above, the material may be viscous and fluid, and therefore, after passing through the flow narrowing portion 32, it may flow toward the sidewall 34S of the flow shaping portion 34. The flow of the material in the width direction W (spreading or sliding as described above) may be restricted by the sidewall 34S of the flow shaping portion 34. Therefore, the combination of the flow narrowing portion 32 and the flow shaping portion 34 may shape the boundary of the applied material at the position corresponding to the sidewall 34S of the flow shaping portion 34 into a sharper, more clearly defined boundary. This allows for precise configuration of the thickness profile of the material applied onto the substrate.The technical effects and advantages may be as described above.

[0102] The same or similar principles may be applied to any one of the other examples of flow guides 30b-30f. In Figures 2A and 2B, rear wall 32B, side wall 32S, and side wall 34S are shown only once in flow guide 30a for clarity. Also, width W32 and width W34 are shown only once in flow guide 30a for clarity. For the same reason, lengths L32 and L34 (described below) are shown only once in flow guide 30c.

[0103] The flow guides may be positioned anywhere within the cavity. In particular, the flow guides may be positioned at the side edges of the cavity 24 of the die 10. Referring to the example shown in FIGS. 2A and 2B, the example flow guides 30a, 30c, 30d, and 30f are positioned at the outermost positions within the cavity 24 relative to the width direction W, while the example flow guides 30b and 30e are positioned at the central positions within the cavity 24 relative to the width direction W. In some examples, the disclosed system may include two flow guides, such as flow guides 30a, 30c, 30d, and 30f, positioned at the outermost positions within the cavity 24 of the die 10. Such outermost positions may be referred to as the side edges of the cavity 24 or die 10. Alternatively or additionally, the system may include one or more flow guides, such as flow guides 30b and 30e, positioned between the side edges of the cavity 24 of the die 10.

[0104] Additionally, the width W32 of the flow narrowing portion 32 and the width W34 of the flow shaping portion 34 can be adjusted depending on the material, application process, and individual requirements. Referring to the example of Figure 2A, the ratio of the width W34 of the flow shaping portion 34 to the width W32 of the flow narrowing portion 32 can be variable. In particular, the offset between the sidewall 32S of the flow narrowing portion 32 and the sidewall 34S of the flow shaping portion 34 can be adjusted to accommodate the diffusion width, as discussed above.

[0105] Similarly, the length L32 of the flow narrowing portion 32 and the length L34 of the flow shaping portion 34 can vary depending on the material, application process, and particular requirements, as generally illustrated in the examples of flow guides 30a-30f.

[0106] Referring to FIG. 2B, the flow shaping portion 34 may have a shape other than a rectangular block, as shown in FIG. 2A. Although not explicitly shown in the drawing, the flow narrowing portion 32 is not limited to a rectangular block shape and may have any other shape suitable for blocking material from flowing in the main application direction D. Any of the examples of flow guides 30d-30f shown in FIG. 2B may also achieve the above-described technical effect. Furthermore, different shapes and sizes, as exemplarily shown in FIGS. 2A and 2B, may result in different boundary shapes of the material applied to the substrate. Therefore, the subject matter disclosed herein may enable finer configurations of the thickness profile of the material applied to the substrate, particularly in the boundary region.

[0107] In other nomenclature, the flow guide may be considered to include blocks corresponding to the combination of the flow narrowing portion 32 and the flow shaping portion 34, which may be collectively referred to as a flow edge portion. The flow edge portion may be considered to be recessed by a groove width and a groove length. The offset between the side walls 32S, 34S of the flow narrowing portion 32 and the flow shaping portion 34 in the width direction W may be considered to be the groove width. The offset between the front wall (not labeled) of the flow narrowing portion 32 and the flow shaping portion 34 may be considered to be the groove length. Similarly, with respect to the embodiment shown in FIG. 2B , the flow edge portion may be considered to be recessed by a polygonal shape, a circular shape, an ellipsoidal shape, or a combination thereof, by their respective characteristic lengths. The technical effect may be as described above.

[0108] Figure 3A shows a schematic cross-sectional plan view of the system. Figure 3B shows a schematic perspective view of the system. The system includes a die 10 including a cavity 24 and an opening 26 in the manner described above. The die 10 has a front face 10F and a rear face 10B that are opposite each other in the primary application direction. The die 10 further includes a manifold 20, as described above.

[0109] Figure 3B shows a die including an upper die 12 and a lower die 14 having respective end faces 12E, 14E in the manner described above. Thus, the view shown in Figure 3A may be a top view with the upper die 12 opened or removed.

[0110] The system includes a flow guide 30, which may be configured as described above. In particular, the flow guide 30 of FIGS. 3A and 3B includes a first flow narrowing portion 32L, a first flow shaping portion 34L, and a first flow directing portion 36L, configured and arranged in the manner described above. The first flow narrowing portion 32L, the first flow shaping portion 34L, and the first flow directing portion 36L form a first prong 30L, which may be referred to as the left prong 30L. Similarly, the flow guide 30 includes a second flow narrowing portion 32R, a second flow shaping portion 34R, and a second flow directing portion 36R, configured and arranged in the manner described above. The second flow narrowing portion 32R, the second flow shaping portion 34R, and the second flow directing portion 36R form a second prong 30R, which may be referred to as the right prong 30R. Here, the terms left and right simply refer to a direction relative to the primary application direction, as shown in FIGS. 3A and 3B.

[0111] 3A and 3B further includes a base portion 38 extending in the width direction W and disposed between the rear face 10B of the die 10 and the manifold 20. In this manner, the base portion 38 may be configured to prevent material from flowing in a direction opposite the primary application direction, particularly to block leakage to the rear face 10B of the die 10.

[0112] The first and second flow guide portions 36L and 36R, and thus the left and right prongs 30L and 30R, respectively, extend from the base portion 38 in the primary application direction to the respective flow narrowing portions 34L and 34R. The first and second guide portions 36L and 36R have sidewalls 36S that are offset in the width direction W from the sidewalls 32S of the first and second narrowing portions 32L and 32R, respectively. In particular, the first and second flow guide portions 36L and 36R have widths that are smaller than the respective flow narrowing portions 32L and 32R. Thus, material flowing from the manifold 20 and spreading into the cavity 24 flows along the sidewalls 36S of the flow guide portions 36L and 36R before flowing into the flow narrowing portions 32L and 32R and can be shaped in the manner described above.

[0113] The prongs (30L and 30R) can block material flow in the width direction W. Because the prongs (30L and 30R) are connected to the base portion 38, the manifold 20 is surrounded by the flow guide 30 at least on its rear surface toward the rear surface 10B of the die and on its side surfaces relative to the width direction W. The flow narrowing portions (32L and 32R) also extend between a portion of the manifold 20 and the opening 26. Therefore, the manifold 20 is also partially surrounded by the flow guide 30 on its front surface toward the opening 26.

[0114] In Figures 3A and 3B, the left prong 30L and the right prong 30R are shown as having different sizes and shapes. This is merely exemplary. In other examples, the left prong 30L and the right prong 30R may have the same shape and size and may be arranged in a mirrored manner relative to a die centerline parallel to the primary coating direction. In other examples, the first flow narrowing portion 32L and the first flow shaping portion 34L may be configured as described above, particularly as illustrated in Figures 2A and 2B. Similarly, the second flow narrowing portion 32R and the second flow shaping portion 34R may be configured as described above, particularly as illustrated in Figures 2A and 2B.

[0115] The flow guide 30 of FIGS. 3A and 3B optionally further includes a flow separation portion 40 protruding from the base portion 38. The flow separation portion 40 is positioned at a widthwise distance from the flow narrowing portions 32L and 32R. The flow separation portion 40 is spaced apart from the prongs 30L and 30R. The flow separation portion 40 may have an elongated shape along the primary coating direction. The flow separation portion 40 may be configured to separate the flow of material extruded by the die 10. For example, the flow separation portion 40 may result in a reduction in the loading (i.e., coating weight per area or coating thickness) of the material applied to the substrate. The width and / or length of the flow separation portion 40 may be tailored to suit material properties, product requirements, and process specifications. In particular, the length of the flow separation portion 40 may be tailored with respect to the size and arrangement of the first flow narrowing portion 32L (and / or second flow narrowing portion 32R) and the first flow shaping portion 34L (and / or second flow shaping portion 34R).

[0116] The systems shown in Figures 3A and 3B may function in the manner described above, and may further include any of the features described above, unless otherwise specified or technically inappropriate.

[0117] 4A and 4B each schematically illustrate a cross-sectional plan view of a system according to an embodiment. The example shown in FIG. 4A may include all of the features of the example of FIGS. 3A and 3B, except that an additional flow edge portion 30C is provided between the left prong 30L and the right prong 30R. The additional flow edge portion 30C includes an additional (central) flow narrowing portion 32C and an additional (central) flow shaping portion 34C, each of which may be configured and function as described above.

[0118] The example shown in FIG. 4B may include all of the features of the examples of FIGS. 3A and 3B, but excludes the flow separation portion 40 of FIG. 4B. In FIG. 4B, the length of the flow separation portion 40 is adjusted relative to the size and arrangement of the first flow narrowing portion 32L (and / or second flow narrowing portion 32R) and the first flow shaping portion 34L (and / or second flow shaping portion 34R), so that the distance DC between the flow separation portion 40 and the opening 26 is greater than the distance DL (and / or DR) between the first flow shaping portion 34L (and / or second flow shaping portion 34R) and the opening 26. Additionally or alternatively, the example flow separation portion 40 of FIG. 4B may have a reduced width that is less than the width of the flow directing portions 36L and 36R. In this manner, the reduction in material loading may be finely adjusted.

[0119] In the example of Figure 4B, the first flow shaping portion 34L and the second flow shaping portion 34R have different lengths, resulting in different distances DL and DR. This is merely an example. In other embodiments not explicitly shown, different distances DL and DR may result from different shapes and / or sizes of the first flow narrowing portion 32L, the second flow narrowing portion 32R, the first flow directing portion 36L, and / or the second flow directing portion 36R.

[0120] 4B, the first prong 30L and the second prong 30R have different shapes and sizes. This may change the thickness profile of the material applied to the border area across the width. In the following embodiments, the left prong 30L and the right prong 30R are not limited to this and may have the same size and shape.

[0121] 5A and 5B schematically illustrate cross-sectional plan and perspective views of a system according to one embodiment. The example shown in FIGS. 5A and 5B may include all of the features of the example in FIGS. 3A and 3B, except that the flow guide 30 in the example in FIGS. 5A and 5B additionally includes two flow reducers 42. As shown in FIGS. 5A and 5B, the flow reducers 42 each extend from the base portion 38 in the primary application direction.

[0122] Each flow reduction portion 42 has a length L42 that is less than the length L40 of the flow separation portion 40. Thus, the flow reduction portion 42 may be suitable for slightly reducing the thickness of the material applied to the substrate at a location corresponding to the location of the flow reduction portion 42. In particular, the flow reduction portion 42 may be configured to reduce the thickness of the material applied to the substrate at that location to a smaller extent than the flow separation portion 40 does. For example, the flow separation portion 40 may be used to form a gap in the width direction between regions of material applied to the substrate, and the flow reduction portion 42 may be used to reduce the thickness of the applied material to a small extent.

[0123] Such variable thickness reduction can be utilized to provide a finely tuned thickness profile depending on the material, which can be particularly useful for coating a cathode active material in a secondary battery in conjunction with coating an anode active material on the opposite side of the separator.

[0124] Figures 6A and 6B show schematic cross-sectional plan views of another example system. The example shown in Figure 6A includes the features described with reference to Figures 5A and 5B of the previous drawings, except that one of the flow reduction sections 42a and 42b has the same length as the length of the flow separation section 40. In this manner, the system according to this embodiment can produce an asymmetric thickness profile of the material applied to the substrate.

[0125] The example shown in Figure 6A includes features as described with reference to Figures 5A and 5B of the previous drawings, except that flow separator 40 has been omitted. This indicates that the flow separator is optional. As a result, the material applied to the substrate may have a relatively smooth thickness profile.

[0126] 2A, for example and without limitation to this particular example, the width W32 of the flow narrowing portion 32 can be 1 mm to 100 mm, 2 mm to 80 mm, or 5 mm to 60 mm. Alternatively or additionally, the ratio W32 / L32 of the width W32 of the flow narrowing portion 32 to its length L32 can be 0.1 to 10, 0.2 to 8, or 0.5 to 5.

[0127] Here, the width offset ΔW refers to the offset W in the width direction between the sidewall 32S of the flow narrowing portion 32 and the sidewall 34S of the adjacent flow shaping portion 34, as shown in FIG. 2A and is not limited to this particular example. In some examples, the ratio of the width offset (ΔW) to the width W32 of the (corresponding) flow narrowing portion 32 can be 0.01 to 0.9, 0.05 to 0.8, or 0.1 to 0.6. In particular, the width offset ΔW can be 0.1 mm to 30 mm, 0.2 mm to 20 mm, or 0.5 mm to 10 mm.

[0128] In some examples, the flow narrowing portion 32 and (respectively adjacent) flow shaping portion 34 may be coplanar in one width direction (i.e., their side walls (32S, 34S) are aligned and continuous), and the side walls (32S and 34S) may be widthwise offset from one another in the opposite width direction by the width offset ΔW. In these examples, the width offset ΔW may correspond to the width difference, i.e., W34-W32.

[0129] In some examples, the ratio L34 / L32 of the length L34 of the flow shaping portion 34 to the length 32L of the adjacent flow narrowing portion 32 is not limited to this particular example and can be, for example, 0.01 to 1, 0.02 to 0.5, or 0.05 to 0.1, as shown in Figure 2A. In particular, the length L34 of the flow shaping portion 34 can be 0.1 to 5 mm, 0.1 to 4 mm, or 0.2 mm to 2 mm.

[0130] In some examples, the region between the manifold 20 and the opening 26 of the die 10 may be referred to as a land portion (not limited to this particular example, but implied by its length L21 in FIG. 1B). In other words, the land portion may refer to a portion of the cavity 24 between the manifold 20 and the opening 26. The length L21 of the land portion in the primary application direction D may be 1 to 100 mm, 10 to 80 mm, or 20 to 60 mm. In specific examples, the ratio of the length L32 of the flow narrowing portion 32 to the length of the land portion may be 0.5 to 0.999, 0.8 to 0.995, or 0.9 to 0.99.

[0131] The percentages, values, and ranges mentioned herein may apply to any shape of the flow narrowing portion 32 and the flow shaping portion 34. It is understood that the percentages, values, and ranges will vary primarily depending on process specifications and product requirements, i.e., the secondary battery manufactured using the system and / or method disclosed herein. In addition, in examples where the sidewall 32S of the flow narrowing portion 32 and / or the sidewall 34S of the flow shaping portion 34 are not parallel to the main application direction D, the respective widths (W32, W34) and respective lengths (L32, L34) may refer to the width and length at the most downstream position on the side of the flow narrowing portion 32 and the flow shaping portion 34 in the main application direction D, respectively.

[0132] In some examples, the distance between flow molding portion 34 and opening 26 may be, for example and without being limited to these specific examples, 0.1 mm to 2 mm, 0.2 mm to 1 mm, or 0.3 mm to 0.8 mm, as shown as distance DL and distance DR in FIG. 4B. Alternatively or additionally, the ratio of the distance to land portion length L21 (DL / L21 and / or DR / L21) may be 0.001 to 0.5, 0.005 to 0.3, or 0.001 to 0.1.

[0133] As disclosed herein, the use of flow narrowing portion 32 and flow shaping portion 34 allows material to be applied in a manner such that the profile (thickness profile and / or loading profile) of the applied material has a uniform central region and distinct boundary regions. The boundary regions can be distinctive in that the amount of applied material is significantly reduced compared to the central region. The shape and location of the boundary regions can be influenced by the shape and dimensions of flow shaping portion 34, particularly in combination with flow narrowing portion 32.

[0134] FIG. 7 shows examples of coated material profiles, each expressed in arbitrary units of millimeters (mm) from the outermost location of the coated material in the width direction. In FIG. 7, examples E1 and E2 show profiles that can be obtained using the flow narrowing section 32 and flow shaping section 34 as disclosed herein. The profiles for Examples E1 and E2 each exhibit a sigmoidal curve in the boundary region, which extends over a width of approximately 6.5 mm for Example E1 and approximately 4 mm for Example E2. Also observed are central regions extending inward from the boundary region. In the central regions for Examples E1 and E2, the profiles are nearly constant. That is, the profile variation of the coated active material in the central regions is 0.1% to 5%, 0.1% to 4%, or 0.1% to 3% relative to the maximum value of the profile.

[0135] In contrast, Comparative Example C1 shows a profile obtained by applying a thickness-reducing tape to a coating roll, a conventional technique for reducing the thickness of material applied to an electrode sheet. As shown in FIG. 7 , Comparative Example C1 exhibits a sharp increase in the outermost region (i.e., near 0 mm) and thus no clear boundary region. Moving more inward, the profile of Comparative Example C1 exhibits a somewhat broadened saturation curve, steadily increasing from the outermost position to approximately 15 mm. Thus, the profile obtained in Comparative Example C1 may be less beneficial to the efficiency of the battery manufacturing process and battery products because the applied material profile is relatively non-uniform and the boundary region is relatively thick (or unclear). This further demonstrates that the use of flow narrowing and flow shaping devices as disclosed herein can contribute to improving the efficiency of the battery manufacturing process and battery products.

[0136] In accordance with the above, the present application discloses a battery, particularly a secondary battery, manufactured using a material application system or a secondary battery manufacturing system or by the secondary battery manufacturing method disclosed herein. In particular, the battery may include an active material applied such that the applied active material profile exhibits a sigmoid curve (S-shaped curve) in the boundary regions and is substantially constant in the central region. Here, the profile may refer to a widthwise thickness profile or a loading profile (i.e., a profile of the applied weight). The applied active material may be for the positive or negative electrode of a (secondary) battery.

[0137] The boundary region may be the outermost region of the applied active material in the width direction, and the width direction range of the boundary region may be 1 mm to 15 mm, 2 mm to 10 mm, or 3 mm to 8 mm from the outermost position of the applied active material.

[0138] The central region can be contiguous with the border regions and can be located further in width from the outermost position of the coated active material than the border regions. The central region can be a region of the coated active material in which the profile of the coated active material varies by 0.1% to 5%, 0.1% to 4%, or 0.1% to 3% relative to the maximum value of the profile. Such variation can be considered to be approximately constant.

[0139] 4B, the distance (spacing) DC between the flow separator 40 and the opening 26 may be 0.1 to 2 mm, 0.2 to 1 mm, or 0.3 to 0.8 mm. Alternatively or additionally, the ratio of the distance DC to the length L21 of the land (DC / L21) may be 0.001 to 0.5, 0.005 to 0.3, or 0.001 to 0.1.

[0140] In some examples, the ratio of the distance (spacing) between the flow reduction portion 42 (for example, as shown in Figures 5A to 6B, but not limited to these specific examples) and the opening 26 and the above-mentioned length L21 of the land portion may be 0.001 to 0.5, 0.005 to 0.3, or 0.001 to 0.1.

[0141] Figure 8 shows profiles of applied material according to another example. Figure 8(A) shows a schematic diagram of an example of a flow guide including two flow narrowing portions 32 and two flow shaping portions 34 arranged at the outermost positions on the side (i.e., from the side in the width direction). The flow guide further includes a flow separation portion 40 arranged at the center of the flow guide and two flow reduction portions 42 arranged offset from the flow separation portion 40 on the side.

[0142] The right diagram (B) of Figure 8 shows an example of an applied material profile that can be obtained using the flow reduction sections 42 as disclosed herein. Figure 8 (B) shows the amount of applied material in arbitrary units relative to a widthwise position near one of the flow reduction sections 42, as shown in Figure 8 (A). As shown, when using the flow reduction sections 42 as disclosed herein, the profile characteristically exhibits curvature in the region corresponding to the location of the flow reduction sections 42. That is, the applied material profile exhibits a local maximum at the center (from the sides in the widthwise direction) of the flow reduction section 42, decreases outward from there to respective local minima, and then sharply increases outward in both widthwise directions (i.e., positive and negative directions) (relative to the center of the flow reduction section 42). The profile then exhibits a maximum value on each side outward from the depression formed by the flow reduction section 42. Moving further outward from each maximum, the profile smoothly decreases to a relatively constant level, forming shoulders on each side of the depression.

[0143] 8B, profile drop T10 represents the difference in material application between the local maximum (in terms of the width direction W) at the center of flow reduction section 42 and each minima (one on each side) outward therefrom. In some examples, profile drop T10 is 0.1% to 10%, or 0.5% to 8%, or 1% to 5% of the local maximum at the center of flow reduction section 42.

[0144] 8B, profile drops T21 and T22 respectively represent the difference in material application between the respective local maximums (positive and negative, respectively) adjacent to and outward from the depression formed by flow reduction portion 42 and the constant levels further outward in the width direction. In some examples, profile drop T21 and / or profile drop T22 are 0.1% to 10%, or 0.5% to 8%, or 1% to 5% of the respective maximums forming shoulders outward on the sides from the depression formed by flow reduction portion 42.

[0145] The present application discloses batteries, particularly secondary batteries, manufactured using the material application system or secondary battery manufacturing system described above or by the secondary battery manufacturing method disclosed herein. In particular, the battery may include an active material applied such that the profile of the applied active material has a recessed portion with a central local maximum interposed between two minima. In examples, the difference in the amount of applied material between the local maximum and at least one of the two minima may be 0.1% to 10%, or 0.5% to 8%, or 1% to 5% of the maximum.

[0146] Alternatively or additionally, the battery may include an applied active material, wherein the profile of the applied active material includes at least one shoulder formed by a depression and respective maxima adjacent to sides of the depression. The profile of the applied active material outward from the at least one shoulder may be substantially constant. The difference in the amount of applied material between each maximum and the outer region of the constant profile may be 0.1% to 10%, or 0.5% to 8%, or 1% to 5% of the respective maximum.

[0147] The foregoing are separate examples illustrating how the claimed subject matter may be embodied. There may be additional possibilities for embodying the claimed subject matter that are not explicitly shown in the drawings. For example, a flow guide may include a greater number of flow separation portions (e.g., two, three, four, etc.). A flow guide may include a greater number of flow reduction portions (e.g., three, four, five, etc.). Also, a flow guide may include a greater number of flow edge portions (e.g., four, five, six, seven, etc.), each of which may couple a respective flow narrowing portion with a respective flow shaping portion in the manner described above.

Claims

1. A material application system for applying a material, comprising: a die including an opening and a cavity in communication with the opening, the die configured to extrude material through the opening in a primary application direction; a flow guide within the cavity configured to shape the flow of material extruded by the die; the flow guide includes a flow narrowing portion extending in a width direction perpendicular to the main coating direction so as to block the material from flowing in the main coating direction, and a flow shaping portion extending downstream from the flow narrowing portion in the main coating direction; the width of the flow shaping portion is less than the width of the flow narrowing portion or decreases in the width direction from the width of the flow narrowing portion; the flow guide further includes a flow separator extending along a primary application direction to block the material from flowing in a width direction; the flow separation portion is spaced from the flow narrowing portion; the flow narrowing portion has a sidewall perpendicular to a width direction, the flow shaping portion has a sidewall perpendicular to a width direction, the sidewall of the flow shaping portion being offset in a width direction from the sidewall of the flow narrowing portion; the flow guide further includes a flow reducer extending along the primary application direction to reduce the thickness of the material being applied; The material application system, wherein the flow reduction portion has a length that is less than a length of the flow separation portion.

2. the flow guide further includes a flow guide portion extending along the main application direction to block the material from flowing in a width direction; The material application system of claim 1 , wherein the flow guide extends from the flow narrowing in a direction opposite the primary application direction.

3. The flow guide further includes a base portion extending in the width direction, The material application system of claim 2 , wherein the flow guide extends from the base in the main application direction to the flow narrowing.

4. the die includes an upper die and a lower die, the upper die includes a lower end surface, the lower die includes an upper end surface, and the lower end surface of the upper die and the upper end surface of the lower die are configured to seat on each other; The material application system according to claim 1 or 2, wherein the cavity is formed by a flow guide interposed between an end surface of the upper die and an end surface of the lower die.

5. a manifold formed in the die and in communication with the cavity; The material application system according to claim 1 or 2, wherein the flow guide surrounds the manifold at least on a rear surface of the manifold opposite the opening of the die and on a side surface of the manifold in a width direction.

6. The material application system of claim 5 , wherein at least a portion of the flow narrowing is located between the die opening and the manifold.

7. The material application system of claim 1 or 2, wherein the distance between the flow shaping portion and the die opening is less than the distance between the flow separating portion and the die opening.

8. 3. The material application system according to claim 1, wherein the flow narrowing portion and the flow shaping portion both have the shape of a capital letter T or a capital letter L when viewed from a plane perpendicular to the main application direction and the width direction.

9. The flow guide is an additional flow narrowing portion extending in said width direction to block material from flowing in the main application direction; an additional flow shaping portion extending downstream from the additional flow narrowing portion in the primary application direction, the width of said additional flow shaping portion is less than or reduced from the width of said additional flow narrowing portion; The material application system of claim 1 , wherein the additional flow narrowing is spaced apart from the flow narrowing.

10. The material application system of claim 9 , wherein the flow narrowing portion and the additional flow narrowing portion are disposed at outermost positions in a width direction within the cavity of the die.

11. the width of the additional flow constriction is different from the width of the flow constriction; and / or 11. The material application system of claim 9 or 10, wherein the length of the additional flow narrowing portion is different from the length of the flow narrowing portion, and the length of the additional flow narrowing portion and the length of the flow narrowing portion are determined in the main application direction.

12. A secondary battery manufacturing system including the material application system according to claim 1 or 2, The material is an active material for manufacturing a secondary battery.

13. A secondary battery manufacturing method using the material coating system according to claim 1 or 2, A method for manufacturing a secondary battery, comprising the step of supplying an active material to a die such that the active material is contained within a cavity of the die and is released through an opening in the die.

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