Electrode manufacturing apparatus and method for manufacturing electrodes

Abstract

A dry electrode manufacturing apparatus according to an embodiment of the present invention comprises: a feeder unit that includes an open discharge port on the bottom and includes a feeder roller provided in the discharge port; a conveying unit for providing an electrode powder, supplied from the discharge port, onto a traveling current collector; and a squeezer for flattening the electrode powder provided on the current collector. The density of the flattened electrode powder in the traveling direction of the current collector can be adjusted according to the amount of the electrode powder supplied from the conveying unit onto the current collector.

Description

Electrode manufacturing device and method for manufacturing electrodes

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0176585 filed on December 2, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to an apparatus for manufacturing an electrode and a method for manufacturing an electrode, and more specifically, to an apparatus for manufacturing an electrode and a method for manufacturing an electrode such that the density of the retaining portion of the electrode is controlled during the electrode process.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), has become commonplace, the development of technologies in related fields is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0006] The manufacturing process of such lithium secondary batteries is broadly divided into three stages: electrode process, assembly process, and formation process. The electrode process is further divided into active material mixing process, electrode coating process, rolling process, slitting process, and winding process. Among these, the electrode coating process is divided into a wet process that provides an active material slurry to the electrode current collector and a dry process that provides the active material to the current collector in a solid state.

[0007] A more effective method is needed to manufacture electrodes so that the density of the electrode's retaining portion is controlled during the electrode manufacturing process.

[0008] The present invention aims to form an electrode pattern and manufacture an electrode accordingly so that the density of the electrode powder layer is controlled in the electrode process.

[0009] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0010] A dry electrode manufacturing apparatus according to one embodiment of the present invention comprises: a feeder unit including a discharge port open at the bottom and a supply roller provided at the discharge port; a chute unit for providing electrode powder provided from the discharge port onto a current collector traveling thereon; and a squeegee for flattening the electrode powder provided on the current collector, wherein the density of the flattened electrode powder in the direction of travel of the current collector is controlled according to the amount of electrode powder supplied from the chute unit onto the current collector.

[0011] The density of the electrode powder flattened by the squeezer can be controlled according to the height of the electrode powder supplied onto the current collector in the feeder section.

[0012] When the angular velocity of the supply roller increases, the amount of electrode powder discharged between the discharge port and the supply roller increases, and when the angular velocity of the supply roller decreases, the amount of electrode powder discharged between the discharge port and the supply roller decreases, and when the angular velocity of the supply roller is 0, the supply of the electrode powder may be stopped.

[0013] The feeder unit controls the rotational angular velocity of the supply roller to regulate the supply amount of electrode powder provided to the chute unit, and the supply roller can be controlled by the angular velocity w(t) of the following mathematical formula 1.

[0014] [Mathematical Formula 1]

[0015]

[0016] Here, is the first predetermined time interval, and is a second predetermined time interval, and is the maximum angular velocity, and n can be a positive integer.

[0017] The feeder section may further include a leakage prevention structure having inclined surfaces formed on both sides facing the discharge port and capable of moving up and down along the inclined surfaces according to the angular velocity of the supply roller.

[0018] The above-mentioned chute may include a trapezoidal chute having a cross-sectional area formed in the downward direction and two sides parallel to each other and having different lengths, and may supply more electrode powder to one side portion having a shorter length compared to the other side portion.

[0019] The supply direction of the electrode powder in the above-mentioned mobilization section can be arranged to have at least a component in the TD direction.

[0020] The above-mentioned movable member may be movable in the TD direction and configured to supply the electrode powder in the TD direction on the current collector.

[0021] The above feeder may supply electrode powder to the chording section for a first predetermined time interval to form a retaining section of the electrode, and stop supplying the electrode powder to the chording section for a second predetermined time interval to form a non-retaining section of the electrode.

[0022] If the electrode powder remains in the unused portion of the electrode, an air blow for removing the electrode powder in the unused portion may be further included.

[0023] A method for manufacturing a dry electrode according to another embodiment of the present invention comprises: (A) a step of supplying electrode powder from a feeder section to a chute section; (B) a step of providing the electrode powder supplied from the feeder section through the chute section onto a current collector traveling thereon; and (C) a step of flattening the electrode powder provided onto the current collector; wherein the density of the flattened electrode powder in the traveling direction of the current collector can be controlled according to the amount of electrode powder provided in step (B).

[0024] Depending on the height of the electrode powder supplied on the current collector in step (B), the density of the flattened electrode powder in step (C) can be controlled.

[0025] The above step (A) includes (A-1) a step of supplying electrode powder from a feeder section to a chording section during a first predetermined time interval; and (A-2) a step of stopping the supply of electrode powder from the feeder section to the chording section during a second predetermined time interval, wherein a retaining section of the electrode is formed by step (A-1) and a non-retaining section of the electrode is formed by step (A-2).

[0026] By alternately repeating the above steps (A-1) and (A-2), the patterns of the retaining portion and the non-retaining portion can be formed alternately.

[0027] In step (A) above, the amount of electrode powder supplied to the chute is controlled according to the angular velocity of the feeder roller provided at the discharge port of the feeder supplying the electrode powder, and if the angular velocity of the feeder roller is 0, the supply of the electrode powder may be stopped.

[0028] If the angular velocity of the supply roller increases, the amount of electrode powder discharged between the discharge port and the supply roller increases, and if the angular velocity of the supply roller decreases, the amount of electrode powder discharged between the discharge port and the supply roller may decrease.

[0029] In step (A) above, the angular velocity of the supply roller and the amount of electrode powder supplied from the discharge port of the feeder may have a linear relationship.

[0030] In the above step (B), (B-1) a step of moving the mobilizing part in the TD direction while the electrode powder is provided on the current collector; and (B-2) a step of stopping the mobilizing part from moving in the TD direction while the electrode powder is not provided on the current collector; wherein the electrode retaining part is formed by the above step (B-1) and the electrode unsupported part is formed by the above step (B-2).

[0031] By alternately repeating the above steps (B-1) and (B-2), the patterns of the retaining portion and the non-retaining portion can be formed alternately.

[0032] In step (A), the height of the electrode powder supplied to the chute is adjusted according to the angular velocity of the supply roller, and in step (B), the electrode powder supplied from the feeder is provided on a current collector traveling through the chute at the adjusted height, and in step (C), the electrode powder is flattened so that the density can be adjusted accordingly.

[0033] In step (A) above, the feeder unit controls the rotational angular velocity (w(t)) of the supply roller to regulate the supply amount of electrode powder provided to the chute unit, and the angular velocity of the supply roller can be controlled according to the following [Equation 1].

[0034] [Mathematical Formula 1]

[0035]

[0036]

[0037] Here, is the first predetermined time interval, and is a second predetermined time interval, and is the maximum angular velocity, and n can be a positive integer.

[0038] After the above step (C), (D) if the electrode powder remains in the uncoated portion of the electrode, the electrode powder in the uncoated portion may be removed; and (E) the electrode powder may be rolled.

[0039] FIG. 1 schematically illustrates an apparatus for manufacturing an electrode and a process for manufacturing an electrode according to one embodiment of the present invention.

[0040] Figure 2 is an enlarged view of the feeder section of Figure 1.

[0041] Figure 3 shows the angular velocity of the feeder section of Figure 2 as a graph.

[0042] FIG. 4 shows a plan view of a movable section of an apparatus for manufacturing an electrode according to one embodiment of the present invention.

[0043] FIGS. 5 and FIGS. 6 respectively illustrate, in enlarged view, the start time and the time immediately before the end of the step of supplying electrode powder from the feeder section during a first predetermined time interval.

[0044] FIG. 7 illustrates, in enlarged view, the step of stopping the supply of electrode powder from the feeder during a second predetermined time interval.

[0045] Figure 8 illustrates an enlarged view of the step of flattening the electrode powder with a squeegee.

[0046] Figures 9 and 10 are reference drawings of Figure 8.

[0047] Figure 11 illustrates an enlarged step of removing electrode powder remaining in the unused portion.

[0048] FIG. 12 illustrates an enlarged view of an electrode on which an electrode manufacturing process according to an embodiment of the present invention has been performed.

[0049] FIGS. 13 and 14 illustrate the starting point and ending point of the movement of the movable part during the electrode manufacturing process according to an embodiment of the present invention.

[0050] FIG. 15 is a flowchart of an electrode manufacturing method according to one embodiment of the present invention.

[0051] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0052] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0053] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0054] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0055] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0056] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0057] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0058]

[0059] FIG. 1 schematically illustrates an apparatus for manufacturing an electrode and a process for manufacturing an electrode according to one embodiment of the present invention.

[0060] First, the apparatus (10) for manufacturing the electrode of FIG. 1 includes a feeder section comprising a discharge port open at the bottom and a feeder roller provided at the discharge port, a chute section (30) for providing electrode powder provided from the discharge port onto a current collector that travels, and a squeegee (40) for flattening the electrode powder provided onto the current collector, and may optionally further include an air blow (50) for removing electrode powder from the uncoated section.

[0061] Electrode powder can be supplied from the discharge port of the feeder section to the chul-go section (30), and the electrode powder supplied from the discharge port can be supplied onto the current collector (3) that travels. Depending on the amount of electrode powder (1) supplied from the feeder section (20) and supplied through the chul-go section (30), the density of the electrode powder (1) flattened by the squeezer (40) in the travel direction of the current collector (3) can be controlled. Additionally, depending on the amount of electrode powder (1) supplied from the feeder section (20), the height of the electrode powder (1) supplied onto the current collector (3) can be controlled, and subsequently, the density of the electrode powder (1) flattened by the squeezer (40) can be controlled.

[0062] To elaborate, in the area where a relatively large amount of electrode powder (1) is discharged from the feeder section (20), a larger amount of electrode powder (1) exists within the same thickness, so the density of the electrode powder (1) after flattening can be relatively higher. Conversely, in the area where a relatively small amount of electrode powder (1) is discharged, a smaller amount of electrode powder (1) exists within the same thickness, so the density of the electrode powder (1) after flattening can be relatively lower. Accordingly, there is a change in density in the electrode powder (1) layer (see FIG. 12). In addition, the flattened area where the electrode powder (1) is supplied from the feeder section (20) to the chul-go section (30) corresponds to the electrode retention area, and the area where the supply of electrode powder (1) from the feeder section (20) to the chul-go section (30) is stopped corresponds to the electrode non-retaining area. In summary, a pattern is formed in which the electrode retaining portion and the electrode unretaining portion are arranged depending on whether the electrode powder (1) is supplied from the feeder portion (20), and the density of the electrode retaining portion can be controlled according to the amount of electrode powder (1) supplied from the feeder portion (20) through the chulsong portion (30).

[0063] The method of controlling the supply of electrode powder (1) in the feeder section (20) will be described in detail later with reference to the examples in FIG. 2 and FIG. 3.

[0064] At this time, the current collector (3) can travel (move) in the form of a sheet along the direction indicated by the arrow in FIG. 1. The electrode powder (1) can be provided on the current collector (3) traveling through the chul-go unit (30). The meaning of being provided “on” the current collector (3) includes not only the case where the electrode powder (1) is provided directly on the current collector (3), but also the case where, as shown in FIG. 1, the electrode powder (1) is provided on the current collector (3) after another electrode powder (2) has been provided on the current collector (3). That is, it includes the case where the electrode powder (1) supplied from the feeder unit (20) through the chul-go unit (30) comes into contact with the current collector (3), and it may also include the case where another electrode powder (2) is interposed between the electrode powder (1) supplied from the feeder unit (20) through the chul-go unit (30) and the current collector (3).

[0065] For reference, the layer of electrode powder (2) shown in FIG. 1 may be supplied from a feeder unit through a chording unit (30) onto a current collector (3), flattened by a squeezer, and then further subjected to a drying process, etc. There are no limitations on the types of feeder unit and squeezer for manufacturing the electrode powder (2) shown in FIG. 1. The feeder unit for manufacturing the layer of electrode powder (2) may be, for example, the feeder unit (20) according to the present invention described later in FIG. 2, or any other commonly used feeder. Likewise, the squeezer for manufacturing the layer of electrode powder (2) may be, for example, the roller-type squeezer (40) of FIG. 1, or a doctor blade.

[0066] In some cases, multiple layers of different electrode powders (2) may be interposed between the electrode powder (1) and the current collector (3). To elaborate, as a multilayer electrode structure, multiple active material layers including the electrode powder (1) and the electrode powder (2) may be provided on the current collector (3), and in such cases, the porosity of the electrode powder (1) and the electrode powder (2) may be set differently, for example. Accordingly, the charging speed can be improved and the stability of the battery can be secured. The porosity of the electrode powder (1) and the electrode powder (2) may be modified or changed in various ways depending on the environment in which the present invention is implemented, the type of electrode, etc.

[0067] The electrode powder (1, 2) may be provided in a dry electrode manufacturing process, for example, as a mixture of an electrode active material and a binder polymer, etc., that is, provided in powder form. That is, it may be provided in the form of solid particles of fine size. The electrode active material will be described in detail later with examples in the latter part of the specification.

[0068] Meanwhile, a primer (4) may be additionally applied to the current collector (3). Accordingly, the electrode powder (2) applied to the current collector (3) can be fixed. In some cases, a primer (4) may also be additionally applied to the electrode powder (2) so that the electrode powder (1) applied thereon can be fixed.

[0069] The electrode powder (1) provided on the current collector (3) can be flattened with a squeezer (40).

[0070] The squeezer (40) may be a roller (e.g., a cylindrical roller) as shown in FIG. 1, but the present invention is not limited to what is shown and may be a doctor blade, and various modifications and changes are possible depending on the environment in which the present invention is applied.

[0071] Optionally, if electrode powder (1) remains in the unused portion, the electrode powder (1) can be removed with an air blower (50). For example, in a dry electrode manufacturing process, air can be blown with an air blower (40) to remove the electrode powder (1) remaining in the unused portion. Additionally, even if the provided electrode powder (2) remains in the unused portion at any stage of the electrode manufacturing process, the electrode powder (2) can be removed with an air blower (40).

[0072] In addition, the electrode (1) in which the electrode powder (1) has been flattened can be rolled into a rolling member (not shown).

[0073] FIG. 2 is an enlarged view of the feeder section (20) of FIG. 1, which is a feeder section (20) that can be used as an example of the electrode manufacturing method of the present invention. FIG. 3 is a graph showing the angular velocity of the feeder roller rotating in the feeder section (20) of FIG. 2.

[0074] Referring to FIG. 2, the feeder unit (20) may include a storage unit (21) for storing electrode powder (1), a discharge port (22) for discharging electrode powder (1), and a feeder roller (23) positioned below the discharge port (22). Additionally, a guide unit (24) may be additionally included at the bottom of the discharge port (22) to guide the movement of the electrode powder (1) discharged from the discharge port (22).

[0075] An opening may be provided at the bottom of the storage section (21) to provide a discharge port (22). A feeder roller (23) may be positioned below the discharge port (22) to partially block the discharge port (22). That is, a gap may exist between the discharge port (22) and the feeder roller (23). The electrode powder (1) stored in the storage section (21) may be discharged out of the feeder (20) through the gap between the discharge port (22) and the feeder roller (23). The movement of the electrode powder (1) discharged out of the feeder (20) may be guided along the guide section (24).

[0076] The feeder part (20) has a first predetermined time interval ( (See FIG. 3) supply electrode powder (1) from the feeder section (20) during a second predetermined time interval ( (See Fig. 3) During this time, the supply of electrode powder (1) from the feeder (20) can be stopped.

[0077] At this time, the feeder roller (23) may rotate during a first predetermined time interval. At this time, the angular velocity of the feeder roller (23) may be controlled. Control of the angular velocity of the feeder roller (23) may include increasing the angular velocity of the feeder roller (23) and / or decreasing the angular velocity of the feeder roller (23). Additionally, the feeder roller (23) may stop rotating during a second predetermined time interval.

[0078] angular velocity of the feeder roller (23) ) can follow, for example, [Mathematical Formula 1] below.

[0079] [Mathematical Formula 1]

[0080]

[0081]

[0082] Here, is the above-mentioned first predetermined time interval, and is the above-mentioned second predetermined time interval, and is the maximum angular velocity, and n is a natural number.

[0083] That is, the feeder roller (23) has an angular velocity (as described in [Equation 1]) during a first predetermined time interval. It can rotate. In addition, it can stop rotating for a second predetermined time interval.

[0084] Referring again to FIG. 2, the gap between the discharge port (22) and the feeder roller (23) is formed narrowly, and the electrode powder (1) present in the gap between the discharge port (22) and the feeder roller (23) can be discharged by moving downward along the surface of the feeder roller (23) (by friction with the feeder roller (23)) by the rotation of the feeder roller (23).

[0085] If the angular velocity of the feeder roller (23) increases, the amount of electrode powder (1) discharged between the discharge port (22) and the feeder roller (23) may increase. If the angular velocity of the feeder roller (23) decreases, the amount of electrode powder (1) discharged between the discharge port (22) and the feeder roller (23) may decrease. Additionally, if the angular velocity of the feeder roller (23) is 0, the supply of electrode powder (1) may be stopped.

[0086] In other words, the electrode powder (1) is discharged and provided onto the chute (30) only while the feeder roller (23) is rotating (i.e., only during the first predetermined time interval). Also, while the feeder roller (23) is not rotating (i.e., during the second predetermined time interval), the gap between the discharge port (22) and the feeder roller (23) is formed narrowly, so the electrode powder (1) may not be discharged.

[0087] Also, while the feeder roller (23) is rotating, the angular velocity ( If the ) is changed, the amount of electrode powder (1) discharged also changes accordingly. The angular velocity of the feeder roller (23) ( The relationship between the electrode powder (1) and the amount discharged may generally be linear. When the feeder roller (23) rotates at a faster angular velocity, the amount of electrode powder (1) moving along the surface of the feeder roller (23) increases, so a larger amount of electrode powder (1) can be discharged. Conversely, when the feeder roller (23) rotates at a slower angular velocity, the amount of electrode powder (1) moving along the surface of the feeder roller (23) decreases, so a smaller amount of electrode powder (1) can be discharged.

[0088] As illustrated in the graph of FIG. 3(a), according to one example of the present invention, the feeder roller (23) has an angular velocity of [Equation 1] ( When rotating at ), it can rotate at a fast angular velocity at the beginning of the first predetermined time interval and then gradually rotate at a slowing angular velocity. Accordingly, the electrode powder (1) can be discharged in a large amount and then gradually discharged in a smaller amount. FIG. 3(b) shows the feeder roller (23) rotating at an angular velocity ( When rotating in the manner shown in Fig. 6, the amount of electrode powder (1) discharged from the feeder section (20) is illustrated in a graph. Accordingly, as shown in Fig. 6, the height of the electrode powder (1) provided onto the current collector (3) through the chute section (30) can be high at the front end relative to the direction of travel of the current collector (3) and gradually decrease towards the rear end.

[0089] Meanwhile, the concept of “linear relationship” in the specification of the present invention also includes an error range that may occur during the process, and for example, in the example of FIG. 3, at the time when the feeder roller (23) starts rotating, the angular velocity of the feeder roller (23) due to the frictional force between the feeder roller (23) and the discharge port (22) Even if ) is at its highest, the discharge volume is angular velocity ( It may not be completely proportional to ). Also, as shown in FIG. 6, when electrode powder (1) is provided on the current collector (3), a portion of the dry electrode powder that is stacked relatively high may move to the surroundings by gravity. As an example, FIG. 6 illustrates that the height of the electrode powder (1) stacked on the current collector (3) by being provided through the chute (30) at the start of rotation of the feeder roller (23) has a smooth shape.

[0090] Meanwhile, regarding the method of controlling the discharge amount in the feeder section (20) of the present invention, the method of controlling the angular velocity of the feeder roller (23) positioned below the discharge port (22) in FIG. 2 is illustrated as an example. Accordingly, the present invention is not limited to what is shown in FIG. 2, and various types of supply units can be applied depending on the environment in which the present invention is implemented, as long as there is a method of controlling the discharge amount in the feeder section (20).

[0091] In addition, the angular velocity of the feeder roller (23) of the present invention ( ) is not limited to what is shown in FIG. 3, and can be modified or changed depending on the characteristics of the electrode to be manufactured and the environment in which the present invention is implemented. That is, the angular velocity of the feeder roller (23) of the present invention ( ) is not limited to the [Mathematical Formula 1] described above and can be implemented by applying various functions.

[0092] Meanwhile, even if the feeder unit (20) is designed to precisely control the angular velocity of the feeder roller (23) to the level of μs, as described above, a problem may arise in which the discharge amount is not completely proportional to the angular velocity due to the resistance of the electrode powder between the feeder roller (23) and the discharge port. To compensate for this, an embodiment of the present invention may be provided with a chute unit (30) configuration including a leak-prevention structure and / or a trapezoidal chute.

[0093] First, referring to FIG. 2, the feeder section (20) may further include a leak prevention structure that can move up and down the inclined surface according to the angular velocity of the feeder roller (23), wherein inclined surfaces are formed on both sides of the storage section toward the discharge port. Specifically, the leak prevention structure located on the side where the electrode powder accumulates more thickly according to the operation of the feeder roller (23) among the two inclined surfaces of the storage section may be movable, and the inclined surface may be determined according to the rotational direction of the feeder roller (23). Alternatively, the leak prevention structure may be installed on both inclined surfaces of the storage section.

[0094] For example, when the angular velocity of the feeder roller (23) is zero (i.e., a second predetermined time), the leakage prevention structure may move downward on the inclined surface to prevent the electrode powder from leaking out finely. Additionally, when the feeder roller (23) resumes rotation (i.e., a first predetermined time), the leakage prevention structure may move upward on the inclined surface to prevent interference with the discharge of the electrode powder, as the leakage prevention structure being located at the bottom of the inclined surface may interfere with the discharge of the electrode powder.

[0095] In addition, to compensate for the problem that the discharge amount is not completely proportional to the angular velocity of the feeder roller (23), the embodiment of the present invention may include a chute-shaped feeder (30) configuration. Specifically, to provide electrode powder provided from the discharge port uniformly onto a current collector traveling thereon, the chute-shaped feeder (30) may be included.

[0096] For example, the above-mentioned chute (30) may include a trapezoidal chute having a cross-sectional area formed in the downward direction and two sides parallel to each other and having different lengths.

[0097] Of the two side parts of this trapezoidal shape, more electrode powder can be supplied to the side part having a shorter length compared to the other side part having a longer length. The chute is a conveying device that moves electrode powder onto a current collector by sliding it through the trapezoidal chute body, and the electrode powder can be conveyed as follows.

[0098] Referring to FIG. 4, the upper surface of the chute included in the chute section (30) is shown and has a trapezoidal shape. Electrode powder can fall from the discharge port of the feeder section (20) to corner CD of the chute, and the fallen electrode powder can slide downward through the trapezoidal chute body to corner AB and fall onto the current collector. At this time, since BC < AD when comparing the lengths of the corners, the powder falls from part B before part A, and thus more electrode powder falls from part B in the same amount of time. As a result, thicker electrode powder accumulates in the direction of travel of the current collector, thereby forming a density gradient.

[0099] Meanwhile, the supply direction of the electrode powder in the above-mentioned chul-go-bu (30) can be arranged to have at least a component in the TD direction. Through this, the electrode powder supplied through the above-mentioned chul-go-bu (30) can be stacked more thickly in the direction of travel of the current collector to form a density gradient.

[0100] Referring to FIGS. 13 and 14, the chugging unit (30) may be movable in the TD direction and may have a structure capable of supplying electrode powder (1) in the TD direction on the current collector (3). Specifically, when electrode powder (1) is dropped and supplied from the feeder unit to the upper part of the chugging unit (30), the electrode powder (1) is supplied onto the current collector (3) through the chugging unit (30). When the electrode powder (1) begins to fall onto the current collector (3), the chugging unit (30) can move in the TD direction. This allows the electrode powder (1) to be evenly spread out in the TD direction on the current collector (3).

[0101] Then, when all of the electrode powder (1) falls onto the current collector (3) and no more electrode powder (1) is supplied onto the current collector (3), the bolster (30) may stop moving in the TD direction. That is, while the bolster (30) moves in the TD direction, a retaining portion of the electrode is formed, and while the bolster (30) stops moving in the TD direction, a non-retaining portion of the electrode may be formed.

[0102] FIGS. 5 to 12 illustrate the electrode manufacturing process of FIG. 1 in detail, in enlarged steps. FIG. 15 is a flowchart of an electrode manufacturing method according to an embodiment of the present invention.

[0103] A method for manufacturing an electrode according to one embodiment of the present invention may largely include a step (S110) of supplying electrode powder from a feeder section to a chul-go section (30), a step (S120) of providing the electrode powder supplied from the feeder section through the chul-go section (30) onto a current collector traveling thereon, and a step (S130) of flattening the electrode powder (1) supplied onto the current collector. Additionally, it may include a step (S140) of removing the electrode powder (1) remaining in the uncoated section. Furthermore, it may additionally include a step (S150) of rolling the flattened electrode powder (1) with a rolling member.

[0104] The step (S110) of supplying electrode powder from the feeder section to the chulsing section (30) is more specifically, a first predetermined time interval ( A step (S111) of supplying electrode powder (1) from the feeder section (20) to the chute section (30) during (see FIG. 3) and a second predetermined time interval ( (See Fig. 3) It may include a step (S112) of stopping the supply of electrode powder (1) from the feeder section (20) to the chute section (30).

[0105] FIGS. 5 and FIGS. 6 illustrate, in enlarged view, the step (S111) of supplying electrode powder (1) from the feeder (20) during a first predetermined time interval. FIG. 5 illustrates the start point of the first predetermined time interval, and FIG. 6 illustrates the point immediately before the end of the first predetermined time interval.

[0106] Referring to FIG. 5, the feeder roller (23) begins to rotate, and the electrode powder (1) begins to be supplied onto the current collector (3) through the chute (30). Referring to FIG. 6, when the rotating feeder roller (23) stops rotating, the supply of the electrode powder (1) onto the current collector (3) through the chute (30) can be stopped. The area where the electrode powder (1) is supplied onto the current collector (3) and is flattened in step S130 may correspond to the electrode holding area.

[0107] At this time, as indicated by the dotted lines in FIGS. 5 and 6, in some cases, the electrode powder (1) may be provided only up to a point spaced a predetermined distance from the front and / or rear end of the region where the electrode retaining portion is finally formed. That is, the electrode powder (1) may not be provided up to the shortest part of the front and / or rear end. This is because when flattening is performed in step S130, the electrode powder (1) provided near the front and / or rear end may be pushed by the squeezer (40) so that the electrode powder (1) may ultimately be located up to the front and / or rear end of the region where the electrode retaining portion is formed. However, according to the present invention, whether the region where the electrode powder (1) is provided is spaced from the shortest part of the front and / or rear end, and the degree of spacing, may vary depending on the viscosity according to the composition of the electrode powder (1).

[0108] In addition, in this case, depending on the situation, even if the section where the largest amount is discharged is located at the edge as indicated by the dotted line in Fig. 6, the height of the edge may change slightly due to gravity before the flattening of the electrode is performed, but this is not always the case, and the degree of this may vary depending on the viscosity according to the composition of the electrode powder (1).

[0109] Meanwhile, as described above, the meaning of providing an electrode powder (1) through a chute (30) on the current collector (3) also includes the meaning of providing another electrode powder (2), etc., interposed between the current collector (3) and the electrode powder (1), as shown in FIGS. 5 and 6.

[0110] FIG. 7 illustrates, in enlarged view, the step (S112) of stopping the supply of electrode powder (1) from the feeder (20) during a second predetermined time interval. At this time, the feeder roller (23) may stop rotating during the second predetermined time interval. Since the electrode powder (1) cannot be discharged through the narrow gap between the opening (22) of the feeder part (20) and the feeder roller (23), the supply of electrode powder (1) is stopped. Since the current collector (3) continues to run even during the second predetermined time interval, the area where the current collector (3) is exposed because the electrode powder (1) is not supplied can become an electrode-free area.

[0111] Steps S111 and S112 can be performed alternately. In step S111, electrode powder (1) is provided on the current collector (3) for a first predetermined time interval, and the flattened portion in step S140 described later can become the electrode retention portion. In step S112, the supply of electrode powder (1) from the feeder portion (20) is stopped for a second predetermined time interval (i.e., electrode powder (1, 2) is not applied on the current collector (3) through the chute portion (30), and the exposed area of ​​the current collector (3) can become the electrode non-retaining portion. An electrode pattern can be formed by the arrangement of such non-retaining portions and retention portions.

[0112] Next, the electrode powder supplied from the feeder unit can be provided onto the current collector traveling through the chute (30) (S120). As previously described, to compensate for the problem that the angular velocity of the feeder roller rotating in the feeder unit and the amount of electrode powder discharged are not perfectly proportional, the electrode powder can be applied onto the current collector through the chute (30) which includes a trapezoidal chute. Through the step S120, the electrode powder supplied through the chute (30) can be piled up more thickly in the direction of travel of the current collector to form a density gradient.

[0113] At this time, (B-1) while the electrode powder (1) is provided on the current collector (3), the mobilizing part (30) may move in the TD direction, and (B-2) while the electrode powder (1) is not provided on the current collector (3), the mobilizing part (30) may stop moving in the TD direction. Through this, the electrode retaining part may be formed in step (B-1), and the electrode non-retaining part may be formed in step (B-2). In particular, in a continuous process, the steps (B-1) and (B-2) are performed alternately, so that the patterns of the retaining part and the non-retaining part may be formed alternately.

[0114] A step (S130) of flattening the supplied electrode powder (1) with a squeezer (40) is performed. FIG. 8 illustrates the step (S130) of flattening the electrode powder (1) with a squeezer (40) in enlargement. FIG. 9 and FIG. 10 are reference drawings of FIG. 8. First, as described above, the squeezer (40) may be, for example, a roller, or a doctor blade, or various other types of squeezers.

[0115] After performing flattening in step S130 as illustrated in FIG. 8, the electrode powder (1) can have a uniform thickness over the entire retaining portion area as illustrated in FIG. 12. At this time, as described above, in the area where a relatively large amount of electrode powder (1) is discharged, a larger amount of electrode powder (1) exists within the same thickness, so the density can be relatively higher. Conversely, in the area where a relatively small amount of electrode powder (1) is discharged, a smaller amount of electrode powder (1) exists within the same thickness, so the density can be relatively lower. Accordingly, there may be a change in density in the electrode powder (1) layer (see FIG. 12).

[0116] In addition, regardless of whether the height of the electrode powder (1) provided to the current collector (3) in step S110 is high or low, the height of the electrode powder (1) must be uniformly flattened by the squeezer (40) in step S130, so in some cases, the pressure applied by the squeezer (40) to the electrode powder (1) may be adjusted. The area where the height of the provided electrode powder (1) is relatively high (i.e., the area where a relatively large amount of electrode powder (1) is provided) may be pressed with a higher pressure, and the area where the height of the provided electrode powder (1) is relatively low (i.e., the area where a relatively small amount of electrode powder (1) is provided) may be pressed with a lower pressure.

[0117] At this time, since the height of the provided electrode powder (1) is adjusted according to the angular velocity of the feeder roller (23), the control unit (not shown) can adjust the pressure of the squeezer (40) linked thereto according to the angular velocity of the feeder roller (23). Alternatively, various modifications and changes are possible, such as measuring the height of the provided electrode powder (1) with a sensor (not shown), transmitting the measured height to the control unit (not shown), and adjusting the pressure of the squeezer (40) linked thereto according to the measured height of the electrode powder (1).

[0118] Meanwhile, as shown in FIG. 9, in the case of FIG. 9, the feeder part (20) and the squeezer (40) are arranged adjacently so that the electrode powder (1) is supplied to the feeder part (20) based on one holding part area and then flattened by the squeezer (40) to form one electrode holding part. Alternatively, as shown in FIG. 10, the area where the feeder part (20) is placed and the area where the squeezer (40) is placed are separated (i.e., the feeder part (20) and the squeezer (40) are placed far apart from each other than one holding part area), and in the area where the feeder part (20) is placed, the process of supplying electrode powder (1) to the feeder part (20) (S110) and stopping the supply of electrode powder (1) (S112) is repeated, while the current collector (3) to which the electrode powder (1) is supplied enters the area where the squeezer (40) is placed and the electrode powder (1) can be flattened (S130) with the squeezer (40).

[0119] Optionally, a step (S140) of removing electrode powder (1) remaining in the untreated portion can be performed. FIG. 11 illustrates an enlarged view of the step (S140) of removing electrode powder (1) remaining in the untreated portion. If electrode powder (1) remains, it affects the quality of the manufactured electrode, and to prevent this, step S140 can be additionally performed. As described above, as a dry electrode manufacturing process, electrode powder (1) can be removed by blowing air with an air blower (40).

[0120] Additionally, a step (S150) of rolling the flattened electrode powder (1) with a rolling member (not shown) can be performed optionally. The rolling member may be, for example, a rolling roller used in a conventional electrode manufacturing process, and there are no special restrictions on the rolling member.

[0121]

[0122] FIG. 12 illustrates an enlarged view of the electrode after steps S110 to S140 have been performed.

[0123] First, referring again to Fig. 3, the angular velocity of Fig. 3 ( In the example of [Mathematical Formula 1] regarding ), during the operation of the current collector (3), in one cycle (first predetermined time interval) in which the retaining part is formed, the feeder roller (23) rotates at a high angular velocity in the beginning, and the angular velocity of the feeder roller (23) can decrease as it moves toward the latter part. Accordingly, with respect to the direction of operation of the current collector (3), the electrode powder (1) is supplied in a relatively large amount through the chul-go (30) at the front end of the retaining part, and the amount of electrode powder (1) supplied through the chul-go (30) can decrease as it moves toward the rear end of the retaining part. Accordingly, the density of the electrode powder (1) can gradually decrease along the length direction of the electrode (length direction of the current collector (3), length direction of the retaining part). FIG. 12 illustrates the case where the density of the electrode powder (1) gradually decreases.

[0124] In summary, when the current collector (3) travels in a sheet form and the electrode powder (1) is supplied thereon (S110), the amount of electrode powder (1) supplied can also change according to the angular velocity of the feeder roller (23). The thickness of the electrode powder supplied through the chute (30) including a trapezoidal chute can be changed as it accumulates in the direction of travel of the current collector (S130), and after flattening of the electrode powder (1) is performed with the squeezer (40) (S130), the density of the electrode powder (1) in the electrode holding part can be different along the length direction of the electrode (i.e., the length direction of the current collector (3) and the length direction of the holding part).

[0125]

[0126] The electrode according to the present invention may be an anode or a cathode. That is, the manufacturing process of the electrode according to the present invention is not particularly limited to an anode or a cathode and can be easily applied to the manufacture of any electrode, and different electrodes can be manufactured depending on the material used in the manufacture of each electrode (e.g., an anode active material or a cathode active material). Accordingly, the term "electrode" used in the electrode, electrode powder (1), electrode current collector (3), etc. in this specification may mean both an anode and a cathode unless specifically defined otherwise.

[0127] In the manufacturing process of the dry electrode of the present invention, an electrode active material and a binder polymer, etc. are dry-mixed to obtain a dry powder as a mixture.

[0128] Any material containing lithium capable of absorbing and releasing lithium ions can be used as the cathode active material. For example, the cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; chemical formula Li 1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2, etc.; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7, etc.; chemical formula LiNi 1-x M x Ni-site type lithium nickel oxide represented by O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 ~ 0.3); chemical formula LiMn 2-x M x Lithium manganese composite oxide represented by O2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); LiNi x Mn2-x Lithium manganese composite oxide with a spinel structure represented by O4; LiMn2O4 in which a portion of the Li in the chemical formula is substituted with alkaline earth metal ions; disulfide compounds; Fe2(MoO4)3, etc. may be included, but are not limited to these. Additionally, the anode may have an anode composite layer comprising lithium metal, a carbon material, a metal compound, and a mixture thereof. The metal compound may be a compound containing one or more metal elements selected from the group consisting of Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ag, Mg, Sr, and Ba, or a mixture thereof.

[0129] The cathode can be manufactured by providing a cathode active material on a cathode current collector and rolling it, or by manufacturing it dry, as in the manufacturing process of the anode described above, and optionally additionally may include a conductive material, an organic binder polymer, an additive, etc., as in the anode.

[0130] In addition, the cathode active material may include, for example, a carbon material and a silicon material. The carbon material refers to a carbon material having carbon atoms as its main component. Such carbon materials may include graphite, which has a completely layered crystal structure like natural graphite; soft carbon, which has a low-crystallinity layered crystal structure (graphene structure; a structure in which hexagonal honeycomb-shaped planes of carbon are arranged in layers); hard carbon, in which such structures are mixed with amorphous portions; artificial graphite; expanded graphite; carbon fiber; non-graphitized carbon; carbon black; acetylene black; ketjen black; carbon nanotubes; fullerene; activated carbon; graphene; carbon nanotubes; and, preferably, one or more selected from the group consisting of natural graphite, artificial graphite, and carbon nanotubes. More preferably, the carbon material may include natural graphite and / or artificial graphite, and together with natural graphite and / or artificial graphite, one or more of carbon black and carbon nanotubes. In this case, the carbon material may comprise 0.1 to 10 parts by weight of carbon black and / or carbon nanotubes per 100 parts by weight of the total carbon material, and more specifically, 0.1 to 5 parts by weight; or 0.1 to 2 parts by weight of carbon black and / or carbon nanotubes per 100 parts by weight of the total carbon material.

[0131] In addition, silicon material is a particle containing silicon (Si) as the main component as a metallic component, comprising silicon (Si) particles and silicon oxide (SiO₂). X It may include one or more of the particles (1≤X≤2). As one example, the silicon material may include silicon (Si) particles, silicon monoxide (SiO) particles, silicon dioxide (SiO2) particles, or a mixture of these particles.

[0132] In addition, in the present invention, the current collector may be a metal plate or the like that exhibits electrical conductivity, and may be appropriate depending on the polarity of the current collector electrode known in the field of secondary batteries.

[0133] In addition, the conductive material in the present invention is not particularly limited as long as it has conductivity without causing chemical changes in the battery.

[0134] In addition, in the present invention, the binder resin is not particularly limited as long as it is a component that assists in the bonding of the active material and the conductive material, and the bonding to the current collector.

[0135]

[0136] The electrode manufactured by applying the electrode manufacturing apparatus and electrode manufacturing method according to the embodiment described above may be included in a secondary battery, and such secondary batteries may be assembled in plurality to form a battery module. The battery module may be mounted together with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack.

[0137] Secondary batteries, battery modules, or battery packs can be applied to various devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but are not limited to these; they can be applied to various devices capable of using secondary batteries.

[0138] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0139] [Explanation of the symbol]

[0140] 1, 2: Electrode powder

[0141] 3: The whole house

[0142] 4: Primer

[0143] 10: Electrode manufacturing device

[0144] 20: Feeder

[0145] 21: Storage section

[0146] 22: Discharge port

[0147] 23: Feeder Roller

[0148] 24: Guide Department

[0149] 30: Sling

[0150] 40: Squeezer

[0151] 50: Air blow

Claims

1. In a dry electrode manufacturing apparatus, A feeder section comprising a discharge port open at the bottom and a feeder roller provided below the discharge port; A chute providing electrode powder provided from the discharge port onto a current collector traveling thereon; and It includes a squeegee for flattening the electrode powder provided on the above current collector, A dry electrode manufacturing apparatus in which the density of the flattened electrode powder in the direction of travel of the current collector is controlled according to the amount of electrode powder supplied from the above-mentioned chulsing unit onto the above-mentioned current collector.

2. In Paragraph 1, A dry electrode manufacturing apparatus in which the density of the electrode powder flattened by the squeezer is controlled according to the height of the electrode powder supplied on the current collector in the feeder section.

3. In Paragraph 1, When the angular velocity of the feeder roller increases, the amount of electrode powder discharged between the discharge port and the feeder roller increases, and When the angular velocity of the feeder roller decreases, the amount of electrode powder discharged between the discharge port and the feeder roller decreases, and A dry electrode manufacturing apparatus in which the supply of the electrode powder is stopped when the angular velocity of the feeder roller is 0.

4. In Paragraph 1, The feeder unit controls the rotational angular velocity of the feeder roller to regulate the supply amount of electrode powder provided to the chute unit, and The above feeder roller is a dry electrode manufacturing device controlled by an angular velocity w(t) of the following mathematical formula 1: [Mathematical Formula 1] Here, is the first predetermined time interval, and is a second predetermined time interval, and is the maximum angular velocity, and n is a positive integer.

5. In Paragraph 1, A dry electrode manufacturing apparatus further comprising: a feeder section having inclined surfaces formed on both sides toward the discharge port, and a leakage prevention structure capable of moving up and down the inclined surfaces according to the angular velocity of the feeder roller.

6. In Paragraph 1, The above-mentioned chute includes a trapezoidal shape with a cross-sectional area formed in the downward direction, and two sides parallel to each other and having different lengths; A dry electrode manufacturing device in which more electrode powder is supplied from one side portion having a shorter length compared to the other side portion.

7. In Paragraph 1, A dry electrode manufacturing apparatus in which the supply direction of the electrode powder in the above-mentioned chulsing section is arranged to have at least a component in the TD direction.

8. In Paragraph 1, A dry electrode manufacturing apparatus configured such that the above-mentioned movable member is movable in the TD direction to supply the electrode powder in the TD direction on the current collector.

9. In Paragraph 1, A dry electrode manufacturing apparatus, wherein the feeder part supplies electrode powder to a chording part for a first predetermined time interval to form a retaining part of the electrode, and stops supplying the electrode powder to the chording part for a second predetermined time interval to form a non-retaining part of the electrode.

10. In Paragraph 1, A dry electrode manufacturing apparatus further comprising: an air blow for removing electrode powder from the unused portion of the electrode when the electrode powder remains in the unused portion of the electrode.

11. (A) A step of supplying electrode powder from the feeder section to the chute section; (B) A step of providing electrode powder supplied from the feeder unit through the above-mentioned chulsing unit onto a current collector traveling thereon; (C) a step of flattening the electrode powder provided on the current collector; comprising, A dry electrode manufacturing method in which the density of the flattened electrode powder in the direction of travel of the current collector is controlled according to the amount of electrode powder provided in step (B).

12. In Paragraph 11, A dry electrode manufacturing method in which the density of the electrode powder flattened in step (C) is controlled according to the height of the electrode powder supplied on the current collector in step (B).

13. In Paragraph 11, The above step (A) is: (A-1) A step of supplying electrode powder from a feeder section to a chute section during a first predetermined time interval; and (A-2) Includes the step of stopping the supply of the electrode powder from the feeder section to the chute section during a second predetermined time interval, and A dry electrode manufacturing method in which a retaining portion of the electrode is formed in step (A-1) and a non-retaining portion of the electrode is formed in step (A-2).

14. In Paragraph 13, A dry electrode manufacturing method in which the above steps (A-1) and (A-2) are performed alternately so that the patterns of the retaining portion and the non-retaining portion are alternately formed.

15. In Paragraph 11, In the above step (A): The amount of electrode powder supplied to the chute is controlled according to the angular velocity of the feeder roller provided at the discharge port of the feeder that supplies the electrode powder, and A dry electrode manufacturing method in which the supply of the electrode powder is stopped when the angular velocity of the feeder roller is 0.

16. In Paragraph 15, When the angular velocity of the feeder roller increases, the amount of electrode powder discharged between the discharge port and the feeder roller increases, and A dry electrode manufacturing method in which the amount of electrode powder discharged between the discharge port and the feeder roller decreases when the angular velocity of the feeder roller decreases.

17. In Paragraph 15, A dry electrode manufacturing method in which, in step (A) above, the angular velocity of the feeder roller and the amount of electrode powder supplied from the discharge port of the feeder part have a linear relationship.

18. In Paragraph 11, In the above step (B): (B-1) While the electrode powder is provided on the current collector, the activating member moves in the TD direction; and (B-2) A step in which the mobilizing member stops moving in the TD direction while the electrode powder is not provided on the current collector; A dry electrode manufacturing method in which a retaining portion of the electrode is formed in step (B-1) and a non-retaining portion of the electrode is formed in step (B-2).

19. In Paragraph 18, A dry electrode manufacturing method in which the above steps (B-1) and (B-2) are performed alternately so that the patterns of the retaining portion and the non-retaining portion are alternately formed.

20. In Paragraph 15, In step (A) above, the height of the electrode powder supplied to the chute is adjusted according to the angular velocity of the feeder roller, and In the above step (B), the electrode powder supplied from the feeder section is provided on the current collector traveling through the chute section at an adjusted height, and A dry electrode manufacturing method in which, in step (C) above, the electrode powder is flattened so that the density is controlled accordingly.

21. In Paragraph 15, In the above step (A), the feeder unit controls the rotational angular velocity (w(t)) of the feeder roller to regulate the supply amount of electrode powder provided to the chute unit, and A dry electrode manufacturing method in which the angular velocity of the above feeder roller is controlled according to the following [Equation 1]: [Mathematical Formula 1] Here, is the first predetermined time interval, and is a second predetermined time interval, and is the maximum angular velocity, and n is a positive integer.

22. In Paragraph 11, After the above step (C), (D) a step of removing the electrode powder from the unused portion of the electrode when the electrode powder remains therein; and (E) A step of rolling the electrode powder; further comprising a dry electrode manufacturing method.

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