Electrode, method for manufacturing same, and groove-shaped mold for coating active material

Abstract

The present disclosure relates to a groove-type mold for coating an active material layer on a foil, an electrode manufacturing method for manufacturing an electrode using the groove-type mold, and an electrode manufactured using the groove-type mold. According to the present disclosure, a groove mold is configured to move in a width direction with respect to a foil.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0100538, filed on July 29, 2024, and the entire contents disclosed in the documents of that patent application are incorporated in this specification.

[0002] This disclosure relates to a groove mold for coating an active material layer on a foil, an electrode manufacturing method for manufacturing an electrode using the groove mold, and an electrode manufactured using the groove mold. Background Technology

[0003] Secondary batteries with high application capabilities and electrical characteristics (such as high energy density) are typically used not only in portable devices, but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power sources.

[0004] These secondary batteries are gaining attention as a new energy source for enhancing eco-friendliness and energy efficiency, not only because of their major advantage of significantly reducing the use of fossil fuels, but also because they do not produce byproducts during energy use.

[0005] Currently widely used examples of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. These individual rechargeable battery cells, i.e., single-cell batteries, operate at voltages ranging from approximately 2.5 V to 4.5 V. Therefore, when a higher output voltage is required, multiple cells can be connected in series to form a battery pack. Furthermore, battery packs can be configured by connecting multiple cells in parallel based on the required charge and discharge capacity. Thus, the number of battery cells included in a battery pack and their electrical connections can be configured differently based on the required output voltage and / or charge and discharge capacity.

[0006] On the other hand, known types of secondary battery cells include cylindrical cells, prismatic cells, and pouch cells. Among these cells, pouch cells typically comprise a stacked electrode assembly consisting of multiple electrodes cut to a constant width and stacked with a separator between them. Each electrode includes a foil made of metal and layers of active material coated on both surfaces of the foil.

[0007] Figure 1 The diagram shows the state of a grooved mold coating an active material layer onto a foil, and... Figure 2 It shows the cutting Figure 1The electrode is formed by coating an active material layer 11 onto both surfaces of a foil 10 that is unrolled from a foil roll 100 and continuously supplied, with an active material slurry discharged from a trough mold 2. The coated foil is then cut at predetermined intervals along its length to form the electrode 1.

[0008] At this point, the active material layer 11 is not coated on the entire surface of the foil 10, and an uncoated area 12 is formed at one end along the width direction of the foil, on which the active material paste is not coated. The uncoated area 12 then undergoes a grooving process to form a terminal piece for electrically connecting each electrode 1 to a terminal.

[0009] Figure 3 It is shown in Figure 2 An enlarged cross-sectional view of the end next to the uncoated area of ​​the active material layer in the electrode. Meanwhile, return to reference. Figure 1 Due to the flow of the active material slurry, sliding portions 110 may form in the regions corresponding to the two ends of the active material layer 11 along the length direction of the groove mold 2. This sliding phenomenon is caused by the active material layer 11 gradually thinning towards its ends, resulting in uneven coating surface area and thickness. This unevenness negatively impacts the overall charging and discharging efficiency and stability of the battery.

[0010] Furthermore, the active material layer 11 coated on the foil 10 as described above is typically planarized by a rolling step, but the sliding portion 110, which is formed to have a thickness smaller than that of the rest of the portion, cannot be properly pressurized during the rolling process and cannot be planarized together with the rest of the portion.

[0011] Furthermore, when the surface area and thickness of the active material layer 11 are uneven, the adhesion between the separator and the electrode 1, generated by the binder contained in the active material slurry and the binder coated on the separator surface, may weaken. As a result, the fixing force between the electrode 1 and the separator may weaken, and the structural stability of the electrode assembly may be significantly reduced. In particular, when the fixing force between the electrode 1 and the separator is weak around the uncoated area where the connecting piece is formed, the active material layer 11 is likely to be easily exposed to the outside and come into contact with the connecting piece, leading to a short circuit. When a short circuit occurs in the electrode assembly, this can lead to an explosion or fire; therefore, it can be said that this is a very serious risk to battery safety. Summary of the Invention

[0012] Technical issues

[0013] This disclosure was conceived in the context of the related technologies described above, and provides an electrode structure and a method for manufacturing the same, wherein the thickness and coating surface area of ​​the active material layer are uniform, thereby achieving stable charging and discharging performance.

[0014] This disclosure also provides a method for manufacturing electrodes to prevent uneven rolling caused by slippage.

[0015] Another technical objective of this disclosure is to provide an electrode structure and a method for manufacturing the same, which improves the adhesion between the diaphragm and the electrode and prevents short circuits.

[0016] The technical problem to be solved by this disclosure is not limited to the above-described objectives, and other objectives and advantages of this disclosure not described herein may be understood through the following description and will become clearer through examples of this disclosure. Furthermore, it will be apparent that the objectives and advantages of this disclosure can be embodied by the apparatus and combinations thereof as stated in the claims.

[0017] Technical solution

[0018] To address the aforementioned problems, this disclosure provides an electrode manufacturing method, which includes a coating step of coating an active material layer by applying an active material slurry to both surfaces of a foil having a predetermined first width as it unfolds from and travels from a foil roll. Each active material layer is coated on an area of ​​the foil other than an uncoated area having a predetermined second width extending from one end along the width direction of the foil.

[0019] According to this disclosure, in the coating step, the coating of the active material layer is performed by discharging the active material slurry through a trough-shaped mold that moves relative to the foil along the width direction.

[0020] According to this disclosure, no slippage occurs at the end adjacent to the uncoated area of ​​the active material layer, thereby enhancing the adhesion between the electrode and the separator, stabilizing charging and discharging performance, and reducing the risk of short circuits.

[0021] According to an embodiment, when the trough mold moves relative to the foil in the first width direction, the active material slurry is discharged, and when the trough mold moves relative to the foil in the second width direction, the active material slurry is not discharged. That is, the trough mold can reciprocate and move relative to the foil in both width directions; however, the discharge of the active material slurry can only be performed in one direction.

[0022] According to a modified embodiment, the active material slurry can be discharged when the trough mold moves in both the first and second width directions. That is, the trough mold can reciprocate and move relative to the foil in both width directions, and the trough mold can also discharge the active material slurry in both directions.

[0023] The electrode manufacturing method according to this disclosure may further include a cutting step, in which the foil is cut along cutting lines extending in the width direction at first length intervals after the coating step to form an electrode. In this case, preferably, the discharge groove of the slot mold extends to a second length equal to or greater than the first length. If the second length is shorter than the first length, there may be sliding between a pair of adjacent cutting lines; therefore, this can be prevented by making the second length greater than the first length.

[0024] Specifically, preferably, the second length is equal to or greater than twice the first length. In this case, two or more electrodes without sliding portions can be obtained from the area that has already been coated once by the groove mold.

[0025] According to one embodiment, in the cutting step, preferably, the cutting line is located in a region where an active material layer is continuously coated on both sides along its length. In this case, the two ends of the electrode along its length can be formed flatly without slippage, thus improving adhesion to the diaphragm, achieving more stable charging and discharging performance, and preventing short circuits.

[0026] The electrode manufacturing method according to this disclosure may further include a rolling step, wherein the foil is rolled and planarized in the thickness direction after the coating step.

[0027] According to one embodiment, in the coating step, an overlap of two or more layers of active material can be formed in at least a portion of the area extending along the width direction on both surfaces of the foil.

[0028] Specifically, an overlapping portion can be formed by overlapping a first coating portion formed by a groove mold and a second coating portion immediately following it by a predetermined length.

[0029] According to one embodiment, the overlapping portion can be formed to be thicker than the rest of the active material layer, and thus can be planarized during the rolling step. Therefore, the active material layer can be formed to be continuously flat along its length without rolling unevenness caused by slippage.

[0030] According to another embodiment, in the coating step, an active material layer may be formed as a raised portion thicker than the rest in at least a portion of the two surfaces of the foil extending along the width direction.

[0031] The raised portion can be formed in the region corresponding to the end of the discharge groove in the longitudinal direction of the trough die. Because of this, even if slippage occurs in the portion of the active material layer corresponding to the end of the discharge groove in the longitudinal direction, its thickness can be formed to be greater than the thickness of the rest of the active material layer. Therefore, the thicker raised portion can be flattened during the rolling process. Thus, the active material layer can be formed to be continuously flat along the length direction without rolling unevenness caused by slippage.

[0032] In the coating step according to one embodiment, a raised portion of the active material layer is formed along the length direction at at least one of the two ends in the width direction of the active material layer, where the active material layer is coated to be thicker than the rest. The raised portion can be formed by additionally and temporarily discharging the active material slurry in a stationary state before and / or after the relative movement with respect to the foil begins in the width direction using a trough mold.

[0033] For example, when coating begins on the uncoated area side of the trough mold, the trough mold can discharge the active material slurry for a predetermined time in a stationary state to form a raised portion, and then begin relative movement to perform coating on the remaining area. Alternatively, after the trough mold begins relative movement from one end in the width direction of the foil to coat the active material layer, and reaches the boundary next to the uncoated area of ​​the active material layer, it can temporarily discharge the active material slurry in a stationary state to form a raised portion.

[0034] Preferably, a raised portion is formed along the end of the active material layer on the uncoated area side. Therefore, even if slippage occurs at the end next to the uncoated area of ​​the active material layer, it can be formed to have a thickness greater than the rest of the active material layer. This thicker raised portion can be planarized during the rolling process, thus improving the adhesion between the electrode and the separator, the stability of charging and discharging performance, and the safety against short circuits.

[0035] In addition, this disclosure provides a trough mold that coats an active material layer by applying an active material slurry to both surfaces of a foil having a predetermined width that is unrolled from and travels from a foil roll. The trough mold includes a discharge trough from which the active material slurry is discharged, and the discharge trough extends in the length direction.

[0036] The trough mold can be configured to discharge an active material slurry while moving relative to the foil along its width. An electrode manufacturing method according to one embodiment can be performed using a trough mold configured as described above.

[0037] At both ends of the discharge channel along its length, extensions with a width greater than the rest are formed. The electrode manufacturing method according to the other embodiment described above can be performed using a channel-shaped mold with the extensions as described above. Specifically, the extensions have a greater width and form a larger discharge cross-sectional area per unit length, allowing the active material slurry to be discharged at a greater flow rate even at the same pressure as the rest. Consequently, the thickness of the active material layer in the region corresponding to the extensions becomes relatively greater, and a bulge with a thickness greater than the rest can be formed in the portion of the active material layer corresponding to the ends along the length of the discharge channel.

[0038] Additionally, this disclosure provides an electrode structure as a result of performing an electrode manufacturing method, the electrode comprising: a foil; an active material layer coated on both surfaces of the foil; an uncoated region extending along one end of the foil in the length direction and having no active material layer coated thereon; and an insulating layer comprising a covering portion covering the active material layer and an attachment portion attached to the uncoated region.

[0039] According to this disclosure, the cover portion may include an arched portion having an arched shape that protrudes toward the uncoated area. The arched portion can be formed by rolling an electrode in a state where a protrusion has been formed at the end adjacent to the uncoated area of ​​the active material layer and the cover portion covers the protrusion. More specifically, with the inner end of the attachment portion firmly attached to the foil, the cover portion also forms an arched portion protruding toward the uncoated area as the protrusion is rolled to protrude in the horizontal direction.

[0040] According to this disclosure, an electrode structure can be provided that can prevent instability in charging and discharging performance caused by non-uniformity of the active material layer and the risk of short circuit or insufficient adhesion between the electrode and the diaphragm caused by slippage at the ends of the flatly formed active material layer.

[0041] Beneficial effects

[0042] According to this disclosure, by not forming a sliding portion, or by forming an overlapping portion and / or a raised portion, or by cutting the middle portion of the coated portion, an electrode structure and its manufacturing method can be provided that achieves stable charging and discharging performance by having a uniform thickness and coating surface area of ​​the active material layer.

[0043] This disclosure also provides an electrode manufacturing method that prevents uneven rolling caused by slippage by making the portion that may slip thicker and then rolling that portion.

[0044] Another advantage of the groove mold, electrode manufacturing method and / or electrodes manufactured using the present disclosure is that the adhesion between the diaphragm and the electrode is improved and short circuits are prevented due to the uniform thickness of the active material layer.

[0045] Furthermore, this disclosure may have various other effects, some of which will be described in various embodiments, while effects that can be readily inferred by those skilled in the art may be omitted from the description. Attached Figure Description

[0046] Figure 1 The diagram shows the state of an active material layer being coated onto a foil using a grooved mold.

[0047] Figure 2 It shows the cutting Figure 1 Electrodes formed from foil.

[0048] Figure 3 It is shown in Figure 2 An enlarged cross-sectional view of the end next to the uncoated area of ​​the active material layer in the electrode.

[0049] Figure 4 An electrode manufacturing method according to one embodiment is shown.

[0050] Figure 5 The coating steps according to one embodiment are shown.

[0051] Figure 6 The coating steps according to a modified embodiment are shown.

[0052] Figure 7 A cross-section of the overlapping portion according to one embodiment is shown.

[0053] Figure 8 and Figure 9 The diagram illustrates the state in which the overlapping portion is flattened during the rolling step according to one embodiment.

[0054] Figure 10 A coating step according to another embodiment is shown.

[0055] Figure 11 A cross-sectional view of the raised portion according to another embodiment is shown.

[0056] Figure 12 and Figure 13 This illustrates the state in which the raised portion is flattened during the rolling step according to another embodiment.

[0057] Figure 14 The cutting steps according to one embodiment are shown.

[0058] Figure 15An electrode without an insulating layer is shown according to one embodiment.

[0059] Figure 16 and Figure 17 The following are examples of the methods used to demonstrate ... Figure 15 The state of the electrode before and after the rolling step.

[0060] Figure 18 An electrode coated with an insulating layer according to one embodiment is shown.

[0061] Figure 19 and Figure 20 The following are examples of the methods used to demonstrate ... Figure 18 The state of the electrode before and after the rolling step.

[0062] [Explanation of reference numerals in the attached figures]

[0063] 1: Electrode 10: Foil 100: Foil roll 11: Active material layer 110: Sliding part 111: Overlapping part 112: Raised part 113: Raised part 11a: First coating part 11b: Second coating part 3 12: Uncoated area 13: Insulating layer 130: Attachment part 131: Covering part 132: Arched part 2: Groove mold 20: Discharge groove 200: Extension part 3: Rolling roll 4: Cutting line W1~2: First width~Second width L1~2: First length~Second length RD: Direction of travel Detailed Implementation

[0064] The above-described objects, features, and advantages will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily practice the technical concepts of this disclosure. In describing this disclosure, detailed descriptions of known technologies related to this disclosure will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the main points of this disclosure. Preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same or similar components.

[0065] Although the terms "first," "second," etc., are used to describe various components, it is obvious that these components are not limited by these terms. These terms are only used to distinguish one component from another, and it is obvious that, unless otherwise specifically stated otherwise, the first component can also be the second component.

[0066] Throughout this instruction manual, unless otherwise specified, each element may be in the singular or plural.

[0067] In the following text, the phrase “any configuration disposed on the upper or lower side of the component” or “above or below the component” can mean not only any configuration disposed in contact with the upper or lower surface of the aforementioned component, but also another configuration may be between the aforementioned component and any configuration disposed above or below the aforementioned component.

[0068] Additionally, if a component is described as being “connected,” “joined,” or “in contact” with another component, then the two components may be directly connected or in contact with each other. However, it should be understood that another element may be “between” the two components, or the two components may be “connected,” “joined,” or “in contact” with each other through another element.

[0069] Unless the context clearly specifies otherwise, the singular expression used herein includes the plural expression. In this document, the terms “comprise” or “comprising” should not be construed as including all the various components or steps described in the specification, but should be construed as meaning that some components or steps may be excluded, or that additional components or steps may be included.

[0070] Throughout this disclosure, unless otherwise stated, the phrase “A and / or B” means A, B, or A and B, and unless otherwise stated, the phrase “C to D” means equal to or greater than C and equal to or less than D.

[0071] In the following description, preferred embodiments of the present disclosure will be illustrated with reference to the accompanying drawings.

[0072] Figure 4 An electrode manufacturing method according to one embodiment is illustrated. Referring to this figure, the electrode manufacturing method according to one embodiment of the present disclosure includes a coating step S1 of coating an active material layer onto a foil, a rolling step S2 of rolling the foil coated with the active material layer onto a rolling roll, and a cutting step S3 of cutting the rolled foil at predetermined length intervals. The processes performed in each step, the equipment used therein, and the structure of the electrode as the resulting product will be described in detail below.

[0073] Figure 5 A coating step according to one embodiment is shown. Referring to this figure, the coating step S1 is performed by discharging an active material slurry onto a foil 10 that is unrolled from a foil roll 100 and continuously supplied and travels along its length direction through a groove mold 2. The groove mold 2 includes a discharge groove 20 through which the active material slurry is discharged and coated onto the surface of the foil 10.

[0074] The foil 10 may have a first width W1. In this case, an uncoated region 12 extending with a second width W2 and not coated with the active material layer 11 is formed on the foil 10. The uncoated region 12 may then undergo a notching process to form a terminal block for connecting the electrode assembly to the outside.

[0075] The trough mold 2 has a shape that extends along the length direction or the travel direction of the foil 10, and the discharge trough 20 also has such a shape. The trough mold 2 is configured to reciprocate and move relative to the foil 10 in the width direction. In this case, the trough mold 2 moves relative to the surface of the foil 10 in the width direction, and the active material layer 11 is coated on the foil 10 by discharging the active material slurry via the discharge trough 20.

[0076] According to one embodiment, the trough mold 2 is configured to reciprocate relative to the foil 10 in a first width direction and an opposite second width direction. In this case, the trough mold 2 is configured to discharge active material slurry when moving in the first width direction and not discharge active material slurry when moving in the second width direction, so that the coating of the active material layer 11 can be performed in only one direction, thereby achieving high coating consistency.

[0077] Figure 6 The coating steps according to a modified embodiment are shown. Referring to this figure, the trough mold 2 according to the modified embodiment can discharge the active material slurry when moving in both the first and second width directions. That is, the trough mold 2 can reciprocate and move relative to the foil 10 in both width directions, and the discharge of the active material slurry can be performed in both directions. This is more ideal in terms of process speed and efficiency because it can improve the moving efficiency of the trough mold 2, thereby increasing the traveling speed of the foil 10.

[0078] According to this disclosure, since the groove mold 2 coats the active material layer 11 along the width direction of the foil 10, the sliding phenomenon of the active material layer 11 mainly occurs at its end in the length direction of the coated portion. However, the sliding phenomenon occurs less at its end on the side of the uncoated area.

[0079] Return to reference Figure 5 In the rolling step S2, the foil 10 coated with the active material layer 11 through the groove mold 2 is passed through the rolling roll 3 so that it is rolled and flattened in the thickness direction.

[0080] According to this embodiment, the rolling roll 3 can be a pair of rolls spaced apart in the thickness direction to contact the two surfaces of the foil 10, and the rolling roll 3 is configured to press the foil 10 and the active material layer 11 in the thickness direction. However, as long as rolling and planarization operations can be performed, it is acceptable even if it has another form such as a vertically moving press, regardless of its name.

[0081] Figure 7 A cross-section of the overlapping portion according to one embodiment is shown. (Return to reference) Figure 5 as well as Figure 7 In the coating step S1 according to one embodiment, an overlap 111 may be formed in at least a portion of the two surfaces of the foil 10 extending in the width direction, where two or more layers of active material 11 are coated.

[0082] Specifically, the overlapping portion 111 can be formed by overlapping the first coating portion 11a formed by the groove mold 2 and the immediately following second coating portion 11b with each other by a predetermined length.

[0083] Figure 8 and Figure 9 The diagram illustrates the state in which the overlap is planarized during the rolling step according to one embodiment. According to these figures, the overlap 111 is formed to be thicker than the remainder of the active material layer 11, and therefore can be planarized in the rolling step S2. Thus, the active material layer 11 can be formed to be continuously flat along its length without rolling unevenness caused by slippage.

[0084] Figure 10 The coating steps according to another embodiment are shown. Referring to this figure, extensions 200 may be formed at both ends of the discharge groove 20 in the length direction according to another embodiment, each extension 200 having a width larger than the rest.

[0085] The electrode manufacturing method according to the other embodiment described above can be performed using a groove-shaped mold 2 having the extension portion 200 as described above. Specifically, the extension portion 200 has a larger width and forms a larger discharge cross-sectional area per unit length, so that the active material slurry can be discharged at a larger flow rate even at the same pressure as the rest of the portion. As a result, the thickness of the active material layer 11 in the region corresponding to the extension portion 200 becomes relatively larger, and a bulge 112 with a thickness greater than that of the rest of the portion can be formed in the portion of the active material layer 11 corresponding to the end in the length direction of the discharge groove 20.

[0086] Figure 11 A cross-sectional view of the raised portion according to another embodiment is shown, and Figure 12 and 13The diagram illustrates the state in which the raised portion is flattened during the rolling step according to another embodiment. Referring to these figures, the raised portion 112 can be formed in the portion corresponding to the end of the discharge groove 20 of the slot die 2 in the longitudinal direction. Therefore, even if slippage occurs in the portion of the active material layer 11 corresponding to the end of the discharge groove 20 in the longitudinal direction, its thickness can be formed to be greater than the thickness of the rest of the active material layer 11. Thus, the thicker raised portion 112 can be flattened in the rolling step S2. Therefore, the active material layer 11 can be formed to be continuously flat along the length direction without rolling unevenness caused by slippage.

[0087] Specifically, the raised portions 112 can be formed at one end of the first coating portion 11a in the longitudinal direction and at the other end of the second coating portion 11b, which is coated immediately after the first coating portion 11a, adjacent to the aforementioned end in the longitudinal direction. In this case, during the rolling step S2, the pair of raised portions 112 formed at one end and the other end in the longitudinal direction can be joined together to fill the gap between the first coating portion 11a and the second coating portion 11b in a flat manner.

[0088] Figure 14 A cutting step according to one embodiment is shown. Referring to this figure, the foil 10, which has undergone rolling step S2, undergoes a cutting step S3 in which it is cut at predetermined length intervals along the width direction. When the cutting step S3 is performed, the foil 10 is divided into multiple electrodes.

[0089] According to one embodiment, in the cutting step S3, the foil 10 can be cut along the cutting line 4 extending in the width direction at intervals of a first length L1.

[0090] In this case, preferably, the discharge groove 20 of the groove mold 2 extends to a second length L2 that is equal to or greater than the first length L1. If the second length L2 is shorter than the first length L1, there may be a sliding portion between a pair of adjacent cutting lines 4. Therefore, this can be prevented by making the second length L2 greater than the first length L1.

[0091] Specifically, preferably, the second length L2 is equal to or greater than twice the first length L1. In this case, two or more electrodes 1 without sliding portions can be obtained from the area that has already been coated once by the groove mold 2.

[0092] According to one embodiment, in the cutting step S3, preferably, the cutting line 4 is located in the region where the active material layer 11 is continuously coated in two directions along its length. In this case, the two ends of the electrode 1 along its length can be formed flat without slippage, thus improving adhesion to the diaphragm, achieving more stable charging and discharging performance, and preventing short circuits.

[0093] Electrodes can be either positive or negative electrodes. When electrodes are stacked to form an electrode assembly, positive and negative electrodes can be stacked alternately and repeatedly, with a diaphragm between the positive and negative electrodes. The electrodes without an insulating layer and the electrodes with an insulating layer, as described below, can correspond to one of the positive and negative electrodes that is relatively less susceptible to short circuits, and the other electrode that is relatively more susceptible to short circuits, respectively.

[0094] Figure 15 An electrode without an insulating layer is shown according to one embodiment. Referring to this figure, an insulating layer may not be coated on the electrode 1. In this case, the electrode 1 includes an active material layer 11 and an uncoated region 12 thereon where the active material layer 11 is not coated.

[0095] Figure 16 and Figure 17 They are shown respectively Figure 15 The electrode is shown in its foil state before and after the rolling step. Referring to these figures, in the coating step S1 according to one embodiment, a raised portion 113, thicker than the rest, can be formed along the length direction at at least one of the two ends of the active material layer 11 in the width direction. The raised portion 113 can be formed by additionally and temporarily discharging the active material slurry in a stationary state before and / or after the relative movement with respect to the foil 10 begins.

[0096] For example, when the trough mold 2 begins coating from the uncoated area side, the trough mold 2 can discharge the active material slurry for a predetermined time in a stationary state to form the raised portion 113, and then begin relative movement to perform coating on the remaining area. Alternatively, after the trough mold 2 begins relative movement from one end of the foil 10 in the width direction to coat the active material layer 11, and reaches the boundary next to the uncoated area of ​​the active material layer 11, it can temporarily discharge the active material slurry in a stationary state to form the raised portion 113.

[0097] Preferably, the raised portion 113 is formed along the end adjacent to the uncoated region 12 of the active material layer 11. Thus, even if slippage occurs at the end adjacent to the uncoated region of the active material layer 11, it can be formed to have a thickness greater than the rest of the active material layer 11. The thicker raised portion 113 formed in this way can be planarized in the rolling step S2, thereby improving the adhesion between the electrode and the separator, the stability of charging and discharging performance, and the safety against short circuits.

[0098] Figure 18 An electrode coated with an insulating layer according to one embodiment is shown. Referring to this figure, electrode 1 may include an insulating layer 13 coated along the boundary between the active material layer 11 and the uncoated region 12.

[0099] The insulating layer 13 may include a covering portion 131 covering the active material layer 11 and an attachment portion 130 attached to the uncoated area 12.

[0100] Because of the insulating layer 13, the active material layer 11 can be prevented from being exposed through the space between the pair of diaphragms between the electrodes 1, and the risk of short circuit can be reduced. Therefore, the insulating layer 13 can be provided on the one of the positive electrode and the negative electrode that is more susceptible to short circuit. However, it is of course possible to provide the insulating layer 13 on both the positive electrode and the negative electrode.

[0101] Figure 19 and Figure 20 They are shown respectively Figure 18 The electrode in foil state before and after the rolling step. Refer to these figures.

[0102] According to one embodiment, the cover portion 131 may include an arched portion 132 having an arched shape that protrudes toward the uncoated area. The arched portion 132 can be formed by rolling an electrode 1 in a state where a protrusion 113 has been formed at the end adjacent to the uncoated area of ​​the active material layer 11 and the cover portion 131 covers the protrusion 113. More specifically, with the inner end of the attachment portion 130 firmly attached to the foil 10, the cover portion 131 also forms an arched portion 132 protruding toward the uncoated area as the protrusion 113 is rolled to protrude in the horizontal direction.

[0103] According to one embodiment, an electrode structure can be provided that can prevent instability in charging and discharging performance caused by non-uniformity of the active material layer and the risk of short circuits or insufficient adhesion between the electrode and the separator caused by slippage at the ends of the flatly formed active material layer.

[0104] The foregoing embodiments should be interpreted as illustrative rather than restrictive in all respects, and the scope of this disclosure will be indicated by the claims described below rather than by the foregoing detailed embodiments. The meaning and scope of the claims described below, as well as all modifications and variations derived from equivalent concepts, should be interpreted as being included within the scope of this disclosure.

[0105] Although this disclosure has been described with reference to exemplary accompanying drawings, it will be understood that this disclosure is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications are possible without departing from the scope and spirit of this disclosure. Furthermore, although the operational effects of a configuration according to this disclosure are not explicitly described in the description of one embodiment, it should be understood that predictable effects will also be recognized through the configuration.

Claims

1. A method for manufacturing an electrode, comprising: The coating step involves coating an active material layer by applying an active material slurry to both surfaces of a foil having a predetermined first width, which is unrolled from and travels from the foil roll. Each active material layer coats an area of ​​the foil, excluding an uncoated area having a predetermined second width extending from one end along the width direction of the foil. In the coating step, the coating of the active material layer is performed by discharging the active material slurry through a trough-shaped mold that moves relative to the foil along the width direction.

2. The electrode manufacturing method according to claim 1, wherein, When the trough mold moves relative to each other in the first width direction, the active material slurry is discharged; when the trough mold moves relative to each other in the second width direction, the active material slurry is not discharged.

3. The electrode manufacturing method according to claim 1, wherein, When the trough mold moves in the first width direction and the second width direction, the active material slurry is discharged.

4. The electrode manufacturing method according to claim 1, further comprising: The cutting step, following the coating step, involves cutting the foil along cutting lines extending in the width direction at first length intervals to form electrodes. Wherein, the discharge groove of the groove mold extends to a second length equal to or greater than the first length.

5. The electrode manufacturing method according to claim 4, wherein, The second length is equal to or greater than twice the first length.

6. The electrode manufacturing method according to claim 4, wherein, In the cutting step, the cutting line is located in a region on both sides of which the active material layer is continuously coated.

7. The electrode manufacturing method according to claim 1, further comprising: The rolling step, following the coating step, involves rolling and planarizing the foil in the thickness direction.

8. The electrode manufacturing method according to claim 7, wherein, In the coating step, at least a portion of the active material layer is formed on at least a portion of the two surfaces of the foil extending along the width direction, forming an overlap of two or more layers coated with the active material.

9. The electrode manufacturing method according to claim 8, wherein, The overlapping portion is formed by overlapping the first coating portion formed by the groove mold and the immediately following second coating portion with each other by a predetermined length.

10. The electrode manufacturing method according to claim 7, wherein, In the coating step, in at least a portion of the two surfaces of the foil extending along the width direction, an active material layer is coated as a raised portion that is thicker than the rest.

11. The electrode manufacturing method according to claim 10, wherein, The raised portion is formed in the region corresponding to the end of the discharge channel of the groove mold along its length.

12. The electrode manufacturing method according to claim 7, wherein, In the coating step, at least one of the two ends of the active material layer in the width direction is coated along the length direction as a raised portion of the active material layer that is thicker than the rest.

13. The electrode manufacturing method according to claim 12, wherein, The raised portion is formed along the end of the active material layer on the uncoated area side.

14. A grooved mold, the grooved mold coating an active material layer by applying an active material slurry to both surfaces of a foil having a predetermined width that is unrolled from and travels from a foil roll, the grooved mold comprising: A discharge channel from which the active material slurry is discharged, and the discharge channel extends in the length direction. The groove mold is configured to discharge the active material slurry while moving relative to the foil along the width direction.

15. The groove mold according to claim 14, wherein, At both ends of the discharge trough along its length, extensions with a width greater than the rest are formed.

16. An electrode comprising: foil; An active material layer is coated on both surfaces of the foil; An uncoated area extends along one end of the foil in the length direction and is not coated with an active material layer; as well as An insulating layer, the insulating layer comprising a cover portion covering the active material layer and an attachment portion attached to the uncoated area, The covering portion includes an arched portion having an arched shape that bulges toward the uncoated area.

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