Film forming apparatus and method for powder, and method for manufacturing film using same

Abstract

The invention discloses a film forming improvement device for powder, and particularly relates to a film forming improvement device for a dry electrode mixture. An apparatus for manufacturing a film includes a roller press configured to apply pressure to a supplied powder to form a film, and a film formation improvement apparatus configured to flow the powder fed into a feeding region of the roller press in a predetermined direction.

Description

Technical Field

[0001] The present disclosure relates to an improved film-forming device for powders, and more particularly, to an improved film-forming device for dry electrode mixtures of batteries. Background Art

[0002] In recent years, the application of rechargeable secondary batteries has expanded to various fields from small electronic devices to large energy storage systems. In particular, due to the rapid growth of the electric vehicle market, research and development of secondary batteries is being actively carried out.

[0003] Electrodes for secondary batteries are generally manufactured by a wet process. In the wet process, a slurry is manufactured by dissolving an electrode active material, a binder, and a conductive material contained in the electrode in a solvent. However, in order to increase the energy density of the battery compared to the wet process, a dry process that does not use a solvent required in the wet process has recently been introduced.

[0004] In the drying process of the electrode, a mixture is prepared by mixing the electrode active material, the conductive material and the binder. A series of film-forming processes are then performed by pressing or calendering to form a dry electrode film. Subsequently, the electrode is manufactured by bonding the formed dry electrode film to the current collector.

[0005] Compared with the wet electrode manufacturing process, the dry electrode manufacturing process does not require solvents, so it can reduce manufacturing time and reduce costs. In addition, since the thickness of the film can be controlled, a dry electrode film with high energy density can be obtained.

[0006] However, due to the characteristics of the powdered dry electrode mixture, it is difficult to form a film at a high speed to achieve large-scale production of dry electrodes.

[0007] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0008] The present disclosure is made in an effort to solve the above-mentioned problems associated with the prior art, and an object of the present disclosure is to provide an improved film-forming device for powders, which can form a film at a high speed while ensuring the quality of the obtained film product.

[0009] In one aspect, the present disclosure provides an apparatus for manufacturing a film, the apparatus comprising a roller press, the roller press being configured to apply pressure to supplied powder to form a film. The present disclosure further provides a film-forming improvement device, the device being configured to guide the flow of the powder fed into a feed zone of the roller press.

[0010] In another aspect, the present disclosure provides a method for manufacturing a film, which includes: feeding powder to be formed into a film into a feeding zone of a roller press; and rotating the roller press and a blade located in the feeding zone while providing a pressing force to the roller press.

[0011] Other aspects and embodiments of the disclosure are discussed further below.

[0012] The above features and other features of the present disclosure are discussed further below. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above-mentioned and other features of the present disclosure will now be described in detail with reference to certain exemplary embodiments of the present disclosure as shown in the accompanying drawings, which are given hereinafter by way of illustration only and thus do not limit the present disclosure, and in which:

[0014] Figure 1 is a view showing an exemplary process of manufacturing a dry electrode film in one embodiment of the present disclosure;

[0015] Figure 2 is a view showing a feed zone of an upstream roller press in one embodiment of the present disclosure;

[0016] Figure 3A It is intercepted along the z-axis direction Figure 2 A cross-sectional view of the feed zone;

[0017] Figure 3B It is shown Figure 3A A cross-sectional view of the angle of repose of the dry electrode mixture shown in ;

[0018] Figure 3C and 3D is through Figure 3B The angle of repose shown is a cross-sectional view illustrating the behavior of the dry electrode mixture;

[0019] Figure 4 is a view showing a film formation improving device provided around a roller press according to one embodiment of the present disclosure;

[0020] Figure 5 It is intercepted along the z-axis direction Figure 4 Simplified cross-sectional view of

[0021] Figure 6 It is conceptually shown Figure 4 A view showing the operation of the blade in the feed zone;

[0022] Figure 7 is a view showing a film formation improving device according to an embodiment of the present disclosure;

[0023] Fig. 8A , 8B8C is a view showing the position of a blade in a film formation improvement device according to some embodiments of the present disclosure;

[0024] Fig. 9 is a plan view of a film formation improvement device including a guide according to an embodiment of the present disclosure;

[0025] Fig.10 is a view showing the relationship between a guide and a roller press in one embodiment of the present disclosure;

[0026] Fig.11 is a view showing the setting of the height of the blade of the film formation improving device according to one embodiment of the present disclosure;

[0027] Fig.12 is a view showing the size or diameter of a blade of a film formation improving device according to one embodiment of the present disclosure; and

[0028] Fig.13 is a cross-sectional view of a film formation improvement device taken along the z-axis direction according to an embodiment of the present disclosure.

[0029] It should be understood that the accompanying drawings are not necessarily drawn to scale, and that they present a slightly simplified display of various features used to illustrate the basic principles of the present disclosure. The specific design features of the present disclosure disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, should be determined in part by specific intended applications and use environments.

[0030] In the drawings, reference numbers refer to the same or equivalent parts of the present disclosure throughout the several figures of the drawing. DETAILED DESCRIPTION

[0031] The specific structure or function description in the embodiment of the present disclosure set forth in the following description is given exemplarily to describe the embodiment of the present disclosure, and the present disclosure can be presented in many alternative forms. In addition, it should be understood that the present disclosure should not be interpreted as being limited to the embodiment set forth herein, and the embodiment of the present disclosure is provided to cover modifications, equivalents or alternatives within the scope of the present disclosure and the technical scope.

[0032] In the following description of the embodiments, terms such as "first" and "second" are used only to describe various elements, and these elements should not be interpreted as being limited by these terms. These terms are used only to distinguish one element from other elements. For example, without departing from the scope of the present disclosure, the first element described below may be referred to as the second element, and similarly, the second element described below may be referred to as the first element.

[0033] When an element or layer is referred to as being "connected to" or "coupled to" another element or layer, it may be directly connected or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element or layer is referred to as being "directly connected to" or "directly coupled to" another element or layer, it should be understood that there are no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner, for example, "between" versus "directly between," "adjacent" versus "directly adjacent," etc.

[0034] Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. The terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting. As used herein, the singular form may also be intended to include the plural form, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are intended to indicate the presence of the features, numbers, operations, elements, components, and / or combinations thereof mentioned, but do not exclude the presence or addition of one or more other features, numbers, operations, elements, components, and / or combinations thereof.

[0035] When a component, device, element, etc. of the present disclosure is described as having a purpose or performing an operation, function, etc., the component, device or element should be considered herein as "configured to" satisfy the purpose or perform the operation or function.

[0036] Hereinafter, reference is made in detail to various embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings and described below.

[0037] The dry electrode can be made of a solvent-free dry electrode mixture M and a current collector. The dry electrode mixture M is a mixture comprising an electrode active material, a conductive material, and a binder. The dry electrode can be a cathode or an anode. In some embodiments, when the cathode is manufactured, the electrode active material includes a cathode active material. As a non-limiting example, the cathode active material may include lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), lithium cobalt oxide (LCO) or sulfur. In some embodiments, when the anode is manufactured, the electrode active material includes an anode active material. For example, the cathode active material may be: such as lithium cobalt oxide (LiCoO 2 ) or lithium nickel oxide (LiNiO 2 ) or a layered compound in which a part of the layered compound is substituted by one or more transition metals; a layered compound having the chemical formula Li 1+x Mn 2-x O 4 (x=1 to 0.33) represented by a lithium manganese compound, such as LiMnO 3 、LiMn2 O 3 or LiMnO 2 ; Lithium copper oxide, such as Li 2 CuO 2 ; Vanadium oxides, such as LiV 3 O 8 、LiFe 3 O 4 、V 2 O 5 or Cu 2 V 2 O 7 ; By chemical formula LiNi 1-x M x O 2 (wherein, M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3) represented by Ni-type lithium nickel oxide; represented by the chemical formula LiMn 2-x M x O 2 (wherein M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1) or the chemical formula Li 2 Mn 3 MO 8 (wherein M = Fe, Co, Ni, Cu or Zn) represented by a lithium manganese composite oxide; LiMn wherein a portion of Li in the chemical formula is replaced by an alkaline earth metal ion 2 O 4 ; Chemical formula LiMPO 4 (wherein M=Fe, Co, Ni or Mn) represented by lithium metal phosphate; disulfide; Fe 2 (MoO 4 ) 3 , but not limited to this.

[0038] As a non-limiting example, the anode active material may include graphite or silicon. For example, the anode active material may be: carbon, such as hard carbon or graphite carbon; a metal composite oxide, such as Li x Fe 2 O 3 (0≤x≤1), Li x WO 2 (0≤x≤1) or Sn x Me 1-x Me' y O z(wherein Me = Mn, Fe, Pb or Ge; Me′ = Al, B, P, Si, an element of Group I, II or III in the periodic table, or a halogen element; 0 < x ≤ 1, 1 ≤ y ≤ 3, 1 ≤ z ≤ 8); lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; silicon-based oxide, such as SiO, SiO / C or SiO 2 ; Metal oxides, such as SnO, SnO 2 、PbO、PbO 2 , Pb 2 O 3 , Pb 3 O 4 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 、GeO、GeO 2 、Bi 2 O 3 、Bi 2 O 4 Or Bi 2 O 5 ; Conductive polymers such as polyacetylene; Li-Co-Ni based materials.

[0039] The conductive material may include a carbonaceous material. For example, the conductive material may include one of various carbonaceous materials, such as super P, Ketjen black, single-walled carbon nanotubes (SWCNT, single-walled carbon nanotube) or multi-walled carbon nanotubes (MWCNT, multi-walled carbon nanotube) etc. In addition, in the case of manufacturing a dry electrode for an all-solid-state battery, the prepared dry electrode mixture may further include a polyethylene oxide (PEO)-based polymer, an oxide-based solid electrolyte and / or a sulfide-based solid electrolyte.

[0040] The binder may include a material having a CF bond, that is, including carbon and fluorine elements, such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF). The binder may also include styrene-butadiene rubber (SBR) / carboxymethyl cellulose (CMC) or polyacrylonitrile (PAN).

[0041] like Figure 1As shown, the dry electrode mixture M is manufactured into a dry electrode film F by a series of film-forming processes applying heat and pressure. First, the dry electrode mixture M containing electrode active materials, conductive materials and adhesives is mixed at a predetermined speed for a predetermined time by a mixer 10. As a non-limiting example, the dry electrode mixture can be manufactured by utilizing a rotating high shear mixer or a pneumatic mixer utilizing air. The predetermined time and speed can be adjusted by changing the rotation speed and operation time of the mixer 10. As another non-limiting example, a compactor, a granulator or a combination thereof can be used to manufacture the dry electrode mixture.

[0042] The mixed dry electrode mixture M can be mainly pressed by the upstream roller press 20 to form a dry electrode film F. The upstream roller press 20 rotates while providing a pressing force, thereby forming a dry electrode film F from the dry electrode mixture M. The dry electrode film F obtained by pressing the dry electrode mixture M once can be pressed by the additional downstream roller press 30. The thickness of the dry electrode film F can be adjusted by this additional pressing. The dry electrode film F is wound by a winder 40. Afterwards, a dry electrode can be manufactured by bonding the dry electrode film F to a collector or laminating it on a collector. The formation of the dry electrode film F and the lamination of the dry electrode film F on the collector can be performed in a single device, or can be performed separately in each device.

[0043] like Figure 2 As shown, the dry electrode mixture M stays in the feed zone FZ of the upstream roller press 20, into which the dry electrode mixture M is fed. The shape of the dry electrode mixture M staying in the feed zone FZ has a specific pattern over time due to the repose angle of the dry electrode mixture M. As the rollers 20a and 20b of the upstream roller press 20 rotate, the dry electrode mixture M accumulated in the feed zone FZ is consumed while being formed into a dry electrode film F. The dry electrode mixture M is moved to the empty space formed due to the consumption of the dry electrode mixture M. This flow forms a specific pattern caused by the repose angle while collapsing the dry electrode mixture M flatly accumulated in the feed zone FZ. Figure 2 In the figure, the x-axis direction refers to the horizontal direction, and the z-axis direction refers to the vertical direction.

[0044] Figure 3A , Figure 3B , Figure 3C and Figure 3Dis a cross-sectional view of the dry electrode mixture M in the feed zone FZ taken in the z-axis direction. Region R1 refers to the end region of the feed zone FZ, the angle of which is greater than the repose angle A1 of the dry electrode mixture M. The funnel flow region R2 is a region where the dry electrode mixture M partially flows, and indicates that the dry electrode mixture M in contact with the region R1 does not flow and only the dry electrode mixture M located in the center flows. The mass flow region R3 indicates a region in which the entirety of the dry electrode mixture M flows.

[0045] Figure 3A The dry electrode mixture M is shown piled up to a specified height in the feed zone FZ. The dry electrode mixture M in powder form has a repose angle A1 (refer to Figure 3B ). The angle of repose A1 is a unique property of a powder and refers to the steepest angle at which a powder can be deposited on an inclined plane without collapsing.

[0046] Here, if Figure 3C As shown, the dry electrode mixture M in the region R1 located at a position where its angle is greater than the repose angle A1 is in an unstable state. In order to get rid of the unstable state of the dry electrode mixture M in the region R1, the dry electrode mixture M in the funnel flow region R2 located below the region R1 flows rapidly. In other words, the dry electrode mixture S accumulated between the rollers 20a and 20b of the upstream roller press 20 exhibits the characteristics of the repose angle A1, and the flow of the dry electrode mixture M is concentrated on a specific portion thereof.

[0047] In order to recover from the unstable state of the dry electrode mixture M in the region R1 caused by the characteristics of the repose angle A1, the dry electrode mixture M should flow quickly. Figure 3D As shown, plane S1 (i.e., a vertical plane facing the repose angle A1) acts as a wall that blocks the flow of powder (i.e., dry electrode mixture M). Plane S1, which is an interface between the mass flow region R3 and the funnel flow region R2, acts as a wall that blocks the flow of the powdered dry electrode mixture M.

[0048] The dry electrode mixture M is smoothly fed into the upstream roller press 20 without any blockage in the mass flow region R3 in which the dry electrode mixture M flows as a whole. However, in the funnel flow region R2 in which the powder such as the dry electrode mixture M is encircled and flows with the plane S1 as a reference, the aggregation of the powder occurs at a specific position. Such aggregation causes a larger amount of the dry electrode mixture M to be fed between the rollers 20a and 20b of the upstream roller press 20 in this portion than in other portions, and therefore, a larger amount of the powder such as the dry electrode mixture M is consumed in this portion.

[0049] A relatively large amount of powder in this part is fed into the upstream roller press 20 and formed into a dry electrode film F, which causes the manufactured dry electrode film F to have an uneven thickness. When the film forming process is performed at a high speed, the dry electrode film F having an uneven thickness may be torn. Since both sides of the dry electrode film F are used in the subsequent lamination process, such a thickness deviation may cause a serious impact.

[0050] Therefore, the object of the present disclosure is to provide a film formation improvement device 100 for powder, which can form a film at a high speed while ensuring the quality of the manufactured dry electrode mixture. The film formation improvement device 100 can prevent the powder (i.e., the dry electrode mixture M) from aggregating on a specific portion of the funnel flow area R2 by guiding the flow of the dry electrode mixture M fed into the funnel flow area R2.

[0051] refer to Figures 4 to 7 According to the present disclosure, the film formation improving device 100 is disposed around the upstream roller press 20. The film formation improving device 100 may be supported by a frame 110 surrounding the upstream roller press 20. The frame 110 includes an extension rod 120 extending in the longitudinal direction (i.e., the y-axis direction of the rollers 20a and 20b).

[0052] The blade 130 is suspended from the extension rod 120. For example, the blade 130 may be suspended from the extension rod 120 by a vertical rod 140. The blade 130 may be detachably attached to the vertical rod 140.

[0053] The blade 130 is configured to be rotatable. When the rotatable vertical rod 140 rotates, the blade 130 connected to the vertical rod 140 may also rotate. The vertical rod 140 may be rotated by a rotating gear 150 rotatably disposed in the extension rod 120. As non-limiting examples, the blade 130 may be a propeller type, a blade type, an anchor type, a gate type, a belt type, a screw type, a turbine type, a disc type, or a Brumagin type.

[0054] The motor 160 is provided in the extension rod 120. The rotation gear 150 is mounted on the rotation shaft 170 of the motor 160. The rotation of the rotation gear 150 may be transmitted to the vertical rod 140. As a non-limiting example, the motion may be transmitted between the vertical rod 140 and the extension rod 120 by meshing such as in bevel gears.

[0055] Furthermore, the film formation improving device 100 may include a power supply 182 configured to provide driving force to the motor 160, and a controller 180 configured to adjust the rotation speed of the motor 160. As a non-limiting example, the power supply 182 and the controller 180 may be disposed in the frame 110.

[0056] The controller 180 can control the motor 160 so that the blade 130 is driven by the drive value of the upstream roller press 20. For example, the rollers 20a and 20b and the blade 130 can be configured to rotate at the same speed. On the other hand, the blade 130 can be configured to rotate at a higher speed than the rollers 20a and 20b. When the dry electrode mixture M includes a portion of solid electrolyte or the powdered dry electrode mixture M is severely agglomerated, the agglomeration can be reduced or prevented by rotating the blade 130 at a higher speed than the rollers 20a and 20b. As an example, the rotation speed of the blade 130 can be tens of RPM to thousands of RPM.

[0057] like Figure 5 and Figure 6 As shown, the blade 130 is configured to be rotatable in the feed zone FZ. The position of the blade 130 in the feed zone FZ can be adjusted and set.

[0058] In some embodiments, the position of the blade 130 in the longitudinal direction (i.e., in the y-axis direction) of the rollers 20a and 20b of the upstream roller press 20 can be set. The position of the blade 130 in the longitudinal direction of the rollers 20a and 20b depends on the width of the dry electrode film F manufactured by the upstream roller press 20 and the height of the feed zone FZ, which varies according to the feed amount of the dry electrode mixture M.

[0059] In one embodiment, the dry electrode mixture M accumulated in the feed zone FZ may be formed by six planes (for example, may have a pyramid shape). However, the dry electrode mixture M accumulated in the feed zone FZ may be represented by four planes Q1, Q2, Q3, and Q4 in a cross-sectional view taken along the longitudinal direction of the feed zone FZ, as shown in FIG. Fig. 8A shown.

[0060] Plane Q1 represents the bottom surface of the dry electrode mixture M stacked in the feed zone FZ, and plane Q2 represents the upper surface of the dry electrode mixture M stacked in the feed zone FZ. Planes Q3 and Q4 represent the end surfaces of the dry electrode mixture M stacked in the feed zone FZ in the longitudinal direction (i.e., the y-axis direction).

[0061] Point P1 is a point where plane Q1 and plane Q3 meet each other, and an inclined plane L1 having an angle of repose A1 is drawn from this point P1, and the inclined plane L1 is extended to plane Q2. Let the point where the inclined plane L1 and plane Q2 meet each other be P2, then a vertical plane L2 that vertically connects point P2 to plane Q1 can be obtained. The vertical plane L2 faces the angle of repose A1. According to the present disclosure, the blade 130 can be set in a space defined by the vertical plane L2, the inclined plane L1, and the plane Q1.

[0062] In some embodiments, Figure 8BAs shown, one or more blades 130 may be provided according to the diameter or size of the blade 130. In another embodiment, when the height of the dry electrode mixture M is high, one or more blades 130 may be provided on one vertical rod 140. In some examples, when a plurality of blades 130 are provided, the sizes of the respective blades 130 may be the same or different.

[0063] refer to Fig. 9 and Fig.10 According to one embodiment of the present disclosure, a guide 210 may be disposed around the film forming improvement device 100. The guide 210 may be disposed in parallel with the rollers 20a and 20b. A roller 214 configured to be movable along the guide rail 212 of the guide 210 is disposed on the guide rail 212. A horizontal rod 216 configured to extend toward the feed zone FZ is disposed on the roller 214. A guide member 218 configured to adjust the width of the dry electrode mixture M fed between the rollers 20a and 20b is disposed on the horizontal rod 216. Therefore, the position of the guide member 218 in the longitudinal direction of the guide rail 212 can be changed by the movement of the roller 214 along the guide rail 212, and thereby the width of the dry electrode mixture M to be formed into the dry electrode film F can be adjusted.

[0064] The height of the blade 130 in the feed zone FZ and the diameter or size of the blade 130 can be set.

[0065] In one embodiment, the height or position of the blade 130 in the vertical direction (i.e., in the z-axis direction) can be determined based on the gap between the rollers 20a and 20b and whether there is a guide 210. Regardless of whether there is a guide 210, the blade 130 can be set at a position between the rollers 20a and 20b that does not interfere with the rollers 20a, 20b. However, when the guide 210 is present, the height of the dry electrode mixture M in the feed zone FZ increases compared to the use case where the guide member 218 is not provided, and therefore, the height of the blade 130 can be determined as a position that does not interfere with the guide member 218 in the vertical direction. Referring again to Fig.10 In theory, when the guide 210 is not present, the feed zone FZ can be formed by stacking the dry electrode mixture M to the horizontal line HL1 between the rollers 20a and 20b; when the guide 210 is present, the feed zone FZ can be formed by stacking the dry electrode mixture M to the horizontal line HL2. Therefore, in the former case, the blade 130 having a diameter that does not interfere with the rollers 20a and 20b can be set at any position in the vertical direction. In the latter case, the blade 130 can be set at a position that does not interfere with the rollers 20a and 20b and the guide 210 in the vertical direction.

[0066] In summary, the blade 130 is disposed above the point at which the dry electrode mixture M starts to be formed into a film by the rollers 20a and 20b, and may be disposed below the uppermost end of the dry electrode mixture M accumulated in the feed zone FZ. As described herein, the point at which the dry electrode mixture M starts to be formed into a film may be indicated as an area where the gap between the rollers 20a and 20b is the smallest.

[0067] refer to Fig.11 , the minimum height of the blade 130 can be determined based on the distance from the center O1 of the dry electrode mixture M in the feed zone FZ to the center O2 of one of the rollers 20a and 20b, the angle θ between the line R+d connecting the center O1 of the dry electrode mixture M to the center O2 of one of the rollers 20a and 20b and the horizontal line L passing through the center O2 of one of the rollers 20a, 20b, and the radius of the dry electrode mixture M. Here, when viewed from the vertical direction (i.e., from the z-axis direction), the area where the horizontal line L meets the gap between the rollers 20a and 20b can be referred to as the point where the film starts to be formed by the dry electrode mixture M through the rollers 20a and 20b. In addition, the radius d of the dry electrode mixture M refers to the radius of a cluster formed by agglomerating particles of the dry electrode mixture M due to fibrillation of the binder.

[0068] In one embodiment, the minimum height of the blade 130 can be set to a value greater than (R+d)sinθ+d. Here, R is the radius of the rollers 20a and 20b. The minimum height of the blade 130 in the feed zone FZ is calculated based on the condition that the blade 130 almost contacts the rollers 20a and 20b. In other words, the minimum height of the blade 130 can be the minimum height of the blade from the upstream roller press 20, or the minimum height of the blade from the position in the vertical direction of the point where the film is started to be formed.

[0069] The diameter or size of the blade 130 may be determined in consideration of the gap between the rollers 20a and 20b and the size of the particles of the dry electrode mixture M. This is because, when the blade 130 is disposed between the rollers 20a and 20b, a space is required for the dry electrode mixture M to flow between the blade 130 and the rollers 20a and 20b. Fig.12 , the maximum diameter or size of the blade 130 can be determined based on the radius R of the rollers 20a and 20b, the gap G between the rollers 20a and 20b, and the angle θ between the line connecting the center O1 of the dry electrode mixture M to the center O2 of one of the rollers 20a and 20b and the horizontal line L passing through the center O2 of one of the rollers 20a and 20b. In one embodiment, the diameter of the blade 130 can be selected to be less than a value of 2R+G-2Rcosθ. The maximum diameter of the blade 130 can be the maximum diameter of the blade 130 when the blade is set at a position where film formation starts in the upstream roller press 20 or in a vertical position relative to the roller press 20.

[0070] The angle θ, the so-called bite angle, is defined based on one particle. However, in the case of the dry electrode mixture M, the mixture of the electrode active material, the conductive material and the binder exists in the form of clusters. Therefore, for the dry electrode mixture M, the bite angle θ is defined based on one cluster, not on one particle. Therefore, the minimum value of the height of the blade 130 and the maximum value of the size of the blade 130 can be theoretically calculated.

[0071] According to some embodiments, the film forming improvement device 100 may include a gas supply line 190. A gas nozzle 192 may be mounted on the extension rod 120. The gas supplied through the gas supply line 190 may be sprayed through the gas nozzle 192. The gas may be supplied to the gas supply line 190 through a gas supply source 194 (e.g., a gas tank) provided in the frame 110 or outside the film forming improvement device 100. The sprayed gas may prevent the dry electrode mixture M from accumulating on the frame 110 of the film forming improvement device 100, which is caused by the film forming improvement device 100 being partially disturbed by the dry electrode mixture M in the direction of feeding the dry electrode mixture M between the rollers 20a and 20b of the upstream roller press 20. Therefore, the sprayed gas may be sprayed in a direction opposite to the flow of the dry electrode mixture M.

[0072] The operation of the gas nozzle 192 can be controlled by the controller 180. For example, the gas nozzle 192 can spray gas at intervals of 1 minute or less by instructions from the controller 80, and can spray gas for 30 seconds or less at one time. However, these values ​​are not fixed and can be changed according to the characteristics of the dry electrode mixture M or powder in the feed zone FZ. As a non-limiting example, the pressure of the sprayed gas can be 0.1 bar to 50 bar.

[0073] In one embodiment, the gas supplied by the gas supply line 190 may be compressed air. In other embodiments, the gas supplied by the gas supply line 190 may be an inactive gas or an inert gas, such as argon. For example, when the electrode active material of the dry electrode mixture M includes a solid electrolyte or a highly reactive additive, an inactive gas or an inert gas may be used.

[0074] like Fig.13As shown, the gas supply line 190 and the blade drive unit 200 are physically spaced apart from each other in the frame 110. The upper end of the film forming improvement device 100 facing the line LL can be designed to have an angle β, which is a value obtained by adding about 5 degrees or more to the repose angle A1 of the dry electrode mixture M used in the film forming process, so that the dry electrode mixture M can slide better. For example, the angle β can be at least 40 degrees. This is to allow the dry electrode mixture M supplied from the upper end of the film forming improvement device 100 to slide toward the upstream roller press 20 without accumulating in the film forming improvement device 100.

[0075] The operation and effects of the film formation improving device 100 according to the present disclosure are as follows.

[0076] The dry electrode mixture M is fed into the upstream roller press 20 and is accumulated in the feed zone FZ of the upstream roller press 20 .

[0077] When the film formation improving device 100 disposed in the feed zone FZ is operated, the upstream roller press 20 is operated. In one embodiment, the blade 130 is operated at a predetermined speed. Therefore, the film formation improving device 100 can prevent the dry electrode mixture M from gathering at a specific position in the feed zone FZ by guiding the flow of the dry electrode mixture M.

[0078] Since the dry electrode mixture M is supplied from above the film formation improving device 100 in the flow direction I, the film formation improving device 100 may partially disturb the flow of the supplied dry electrode mixture M. Therefore, the film formation improving device 100 may intermittently or continuously spray gas through the gas nozzle 192 of the gas supply line 190 .

[0079] The film formation improving device 100 can improve the aggregation of the dry electrode mixture M at a specific location, thereby being able to supply a uniformly distributed amount of the dry electrode mixture M to all areas between the rollers 20a and 20b, thereby being able to complete the formation of a dry electrode film F having uniform quality.

[0080] Although the above description shows the use of the film formation improving apparatus 100 in a film formation process of a dry electrode mixture for a battery, the film formation improving apparatus 100 according to the present disclosure may be applied to film formation processes of other powders as well as film formation processes of dry electrode mixtures.

[0081] As is apparent from the above description, the present disclosure provides an improved film-forming apparatus for powders that can form a film at a high speed while ensuring the quality of the obtained film product.

[0082] The present disclosure has been described in detail with reference to some embodiments of the present disclosure. However, it should be understood by those skilled in the art that changes may be made in these embodiments without departing from the principles and technical ideas of the present disclosure. The scope of protection of the present disclosure is defined by the appended claims and their equivalents.

Claims

1. A device for producing a film, in, include: a roller press configured to apply pressure to the supplied powder and form the powder into the film; as well as A film-forming device is configured to induce flow of the powder fed into a feed zone of the roller press in a preset direction.

2. The device according to claim 1, wherein: The film forming device comprises: Framework; and A rotatable blade is connected to the frame and disposed in the feed zone.

3. The device according to claim 2, wherein: The film forming device further includes a motor configured to provide a rotational force to the rotatable blade.

4. The device according to claim 3, wherein: A controller is further included, the controller being configured to control a rotation speed of the motor.

5. The device according to claim 2, wherein: The film forming device further comprises: a gas supply pipeline disposed in the frame; and A gas nozzle is provided on the gas supply line and is configured to spray air to remove the powder accumulated on the frame.

6. The device according to claim 2, wherein: Further included is a guide disposed in the feeding area and configured to be movable along the roller press to adjust a width of the fed powder.

7. The device according to claim 6, wherein: The guide comprises: a roller configured to be movable along a guide rail of the guide; a horizontal rod connected to the roller; and A guide member is connected to the horizontal rod and is configured to be movable relative to the feed zone.

8. The device according to claim 2, wherein: The rotatable blade is disposed in a predetermined area of ​​the feed zone, the predetermined area being formed in a longitudinal end portion of the feed zone.

9. The device according to claim 8, wherein: The predetermined area is defined by: a bottom surface of the powder fed into the feed zone; an inclined plane connecting a first point where the bottom surface and the longitudinal end surface of the powder meet each other to an upper surface of the powder at an angle of repose of the powder; as well as A vertical plane is configured to vertically connect a second point connecting the inclined plane to the upper surface of the powder to the bottom surface of the powder.

10. The device according to claim 2, wherein: The height of the rotatable blade from the roller press in the feed zone is determined based on the gap between the rollers in the roller press.

11. The device according to claim 2, wherein: The diameter of the rotatable blade in the feed zone is determined based on the gap between the rollers of the roller press and the size of the particles of the powder.

12. The device according to claim 2, wherein: The minimum height of the rotatable blade in the feed zone is determined based on the distance from the center of the powder in the feed zone to the center of one roller of the roller press, the angle θ between a line connecting the center of the powder to the center of the one roller and a horizontal line passing through the center of the one roller, and the radius of the powder, and, The minimum height of the rotatable blade is further determined by the position where the gap between the rollers of the roller press is minimum.

13. The device according to claim 12, wherein: The minimum height of the rotatable blade is set to a value greater than (R+d)sinθ+d, where R is the radius of the roller and d is the radius of the powder.

14. The device according to claim 2, wherein: The maximum diameter of the rotatable blade in the feed zone is determined based on the radius of the rollers of the roller press, the gap G between the rollers of the roller press, and the angle θ between the line connecting the center of the powder to the center of the one roller and the horizontal line passing through the center of the one roller, and, The maximum diameter of the rotatable blade is the permissible radius at a position where the gap between the rollers is smallest.

15. The device according to claim 14, wherein: The maximum diameter of the rotatable blade is set to a value less than 2R+G-2Rcosθ, where R is the radius of the roller.

16. The device according to claim 6, wherein: The height of the rotatable blade from the roller press in the feed zone is determined based on the gap between rollers of the roller press and the height of the guide from the roller press.

17. The device according to claim 1, wherein: The powder is a dry electrode mixture, The dry electrode mixture is a mixture in powder form including an electrode active material, a conductive material, and a binder.

18. A method of manufacturing a film, in, include: feeding the powder to become the film into the feed zone of the roller press; and While providing a pressing force to the roller press, the roller press and the blade located in the feed zone are rotated.

19. The method according to claim 18, wherein: The roller press and the blade rotate at the same speed, or the blade rotates at a higher speed than the rollers of the roller press.

20. The method according to claim 18, wherein: When the roller press and the blade are rotated, gas is sprayed in a direction opposite to the flow direction of the powder through a gas supply pipeline arranged around the feed zone.

21. The method according to claim 18, wherein: The powder is a dry electrode mixture, The dry electrode mixture is a mixture in powder form including an electrode active material, a conductive material, and a binder.

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