CN112750971A

CN112750971A - Method of manufacturing electrode plate and electrode plate manufactured thereby

Info

Publication number: CN112750971A
Application number: CN202011189767.5A
Authority: CN
Inventors: 崔诚铉; 金正勋; 金哲焕; 朴俊亨; 李在旭
Original assignee: Samsung SDI Co Ltd
Current assignee: Samsung SDI Co Ltd
Priority date: 2019-10-31
Filing date: 2020-10-30
Publication date: 2021-05-04
Also published as: KR20210052050A; KR102446291B1

Abstract

Provided are a method for manufacturing an electrode plate, in which a coating layer is formed on a film, cut by slitting, and laminated on a substrate to manufacture the electrode plate, thereby preventing the coating layer and the substrate from being damaged and improving the efficiency per unit area of the electrode plate, and an electrode plate manufactured by the method. The method for manufacturing an electrode plate includes: a slurry preparation process of preparing a slurry containing an active material; a coating process of applying the slurry on one surface of the film conveyed in one direction to form a coating layer; a primary pressing process of hot pressing the coating on the film; a slitting process of cutting the film on which the coating layer is formed in the conveying direction; a substrate laminating process of peeling off the coating from the film that has been slit to laminate the coating on the substrate to be the current collector; a secondary pressing process of hot-pressing the coating on the substrate; and a dicing/cutting process of cutting the substrate to which the coating is attached in the conveying direction.

Description

Method of manufacturing electrode plate and electrode plate manufactured thereby

Technical Field

Embodiments relate to a method for manufacturing an electrode plate and an electrode plate manufactured by the method.

Background

In general, a secondary battery is manufactured by accommodating an electrode assembly, which is composed of a positive electrode plate, a negative electrode plate, and a separator interposed between the two electrode plates, in a case together with an electrolyte. Unlike a primary battery that is not rechargeable, a secondary battery is a rechargeable and dischargeable battery. As the technology of mobile devices such as mobile phones and laptop computers has been developed and the output of the mobile devices has increased, the demand for secondary batteries as energy sources has rapidly increased. In recent years, secondary batteries have been actively researched and developed as alternative energy sources for replacing fossil fuels even for the purpose of electric vehicles or hybrid electric vehicles.

Secondary batteries currently commercialized include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, the lithium secondary battery is spotlighted because the lithium secondary battery shows almost no memory effect, has a very low self-discharge rate, and has a high energy density, and thus can be freely charged and discharged, compared to the nickel-based secondary battery.

One of the particularly important problems of secondary batteries that must be studied is the significant increase in capacity per unit volume, which is caused, for example, by the advent of high-power/high-capacity consumption fields such as electric automobiles. For this reason, there is a need for even improving the process of manufacturing positive and negative electrode plates, that is, electrode plates constituting a secondary battery.

The above information disclosed in this background is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute prior art.

Disclosure of Invention

An aspect of the present disclosure provides a method for manufacturing an electrode plate and an electrode plate manufactured by the method, in which a coating layer is formed on a film, cut by slitting, and laminated on a substrate to manufacture an electrode plate, thereby preventing the coating layer and the substrate from being damaged and improving efficiency per unit area of the electrode plate.

According to at least one embodiment, a method for manufacturing an electrode plate includes: a slurry preparation process of preparing a slurry containing an active material; a coating process of forming a coating layer by coating the slurry on one surface of the film conveyed in one direction; a primary pressing process of hot pressing the coating on the film; a slitting process of cutting the film on which the coating layer is formed in the conveying direction; a substrate laminating process of peeling the coating layer from the film that has been slit and laminating the coating layer on a substrate to be a current collector; a secondary pressing process of hot-pressing the coating on the substrate; and a dicing/cutting process of cutting the substrate to which the coating is attached in the conveying direction.

In the substrate laminating process, a plurality of coating layers are attached to the substrate so as to be parallel to each other in the conveying direction, and the plurality of coating layers may be spaced apart from each other in a width direction of the substrate perpendicular to the conveying direction so as to be attached to the substrate.

In the substrate lamination process, the substrate may include an uncoated portion to which the coating is not attached.

The slitting/cutting process may include: the substrate is cut with reference to a center line parallel to the conveying direction of the uncoated portion and with reference to a center line parallel to the conveying direction of each of the plurality of coating layers, thereby forming an electrode plate having a bar shape.

The slitting/cutting process may include: the strip-shaped electrode plates are cut along cutting lines so as to be parallel to the width direction of the substrate to form unit electrode plates having a rectangular shape.

The temperature at which the coating is hot pressed onto the film in the primary pressing process may be greater than the temperature at which the coating is hot pressed onto the substrate in the secondary pressing process.

In the coating process, the film may include an exposed area without the coating layer on a partial area of each of both ends of the film in a width direction perpendicular to the conveying direction of the film.

In the slitting process, the film on which the coating layer is formed may be slit into a strip shape in the conveying direction so that the coating layer has the same width.

The coating layer may have a rectangular shape having a predetermined height with respect to the substrate.

The radius of curvature R of each corner of the coating spaced apart from the substrate may be in a range of about 0.01 μm to about 10 μm.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. In the figure:

FIG. 1 is a flow diagram illustrating a method for manufacturing an electrode according to an embodiment;

FIG. 2 is a view showing a coating layer forming apparatus for performing the method of FIG. 1;

fig. 3 is an enlarged plan view showing a coating portion and a first pressing portion of the coating layer forming apparatus of fig. 2;

FIG. 4 is an enlarged plan view showing a slitting section of the coating layer forming apparatus in FIG. 2;

fig. 5 is a diagram showing an example of a laminating apparatus for performing the method of fig. 1;

fig. 6 is an enlarged plan view showing a second pressing part in the laminating device of fig. 5;

FIG. 7 is a cross-sectional view taken along line a-a of FIG. 6;

fig. 8 is a partial plan view illustrating a process of dicing the substrate to which the coating is attached by the dicing/cutting part in fig. 5;

fig. 9 is a partial plan view illustrating a process of cutting the diced substrate in fig. 8;

fig. 10 is a plan view showing an example of a unit electrode plate which is completely cut and incised; and

fig. 11A is a partially enlarged photograph of an electrode plate manufactured by the manufacturing method of fig. 1, and fig. 11B is a partially enlarged photograph of an electrode plate according to a comparative example.

Detailed Description

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

The exemplary embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art. The following exemplary embodiments may be modified into various types, and the scope of the present disclosure is not limited to the following embodiments. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

In the drawings, the thickness and size of each layer are exaggerated for convenience of explanation and clarity, and the same reference numerals refer to the same elements throughout. As used in this specification, the term "and/or" includes any and all combinations of one or more of the associated listed items. Also, in the present specification, it will be understood that when element a is referred to as being "connected to" element B, element a may be directly connected to element B, or intermediate element C may be present between element a and element B, such that element a may be indirectly connected to element B.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms also are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, it will be further understood that the terms "comprises or includes" and/or "comprises or including … … or … …," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, elements, and/or groups thereof.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, a first component, a first region, a first layer, and/or a first portion discussed below could be termed a second element, a second component, a second region, a second layer, and/or a second portion without departing from the teachings of the present disclosure.

For ease of description, spatial relationship terms, such as "below … …," "below … …," "below," "above … …," "upper," etc., may be used herein to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "on" the other elements or features. Thus, the exemplary term "below … …" can encompass both an orientation of "above … …" and "below … …".

Referring to fig. 1, a flow chart of a method for manufacturing an electrode plate according to an embodiment is shown. As shown in fig. 1, the method for manufacturing the electrode plate may include a paste preparation process (S1), a coating process (S2), a primary pressing process (S3), a slitting process (S4), a substrate laminating process (S5), a secondary pressing process (S6), and a slitting/cutting process (S7).

First, in the slurry preparation process (S1), a slurry is prepared. Here, the slurry may be applied on a collecting plate for forming an electrode plate, and may include an active material. As an example, the slurry may include an active material including a transition metal oxide, a binder, and a volatile solvent.

The coating process (S2), the primary pressing process (S3), and the slitting process (S4) will be described with reference to the coating layer forming apparatus 100 of fig. 2.

The coating layer forming apparatus 100 may include: a supply roller 110 around which the film 1 is wound; a coating portion 120 configured to form a coating layer 12; a first pressing portion 130 configured to press the coating layer 12 formed on the film 1 onto the film 1; a slitting section 140 configured to slit the film 1 having the coating layer 12 formed thereon; and a winding roller 150 configured to wind the film on which the coating has been completed again to accommodate the film. In addition, the coating layer forming apparatus 100 may further include a transfer roller 160, the transfer roller 160 being configured to move the film 1 released from the supply roller 110 until the film 1 is wound on the winding roller 150. Hereinafter, the coating process (S2), the primary pressing process (S3), and the slitting process (S4) will be sequentially described with reference to the coat forming apparatus 100.

In the coating process (S2), the coating section 120 applies a previously prepared slurry on the film 1 to form the coating layer 12. The coating section 120 uniformly applies a coating layer on the top surface of the film 1 to form the coating layer 12 on the film 1. Here, the film 1 may be provided with the exposed regions 1a having no coating layer 12 on partial regions of both ends of the film 1 in the width direction Y of the film 1 perpendicular to the conveying direction X. Here, the outer exposed region 1a may be provided to prevent the slurry from flowing down to the outside of the film 1 when the coating layer 12 is formed on the film 1.

The film 1 may be supplied from a supply roll 110. The film 1 may be made of a material having heat resistance capable of preventing the film 1 from being damaged when the first pressing part 130 of the coating layer forming apparatus 100 presses the film 1 or when the slurry contained in the coating layer 12 is dried, and chemical resistance capable of preventing the film 1 from being modified when the coating layer 12 is applied on the film 1. The film 1 may be made of PP, PET and their equivalents. In addition, the film 1 may be configured such that the coating 12 is easily peeled off from the film 1 in the substrate laminating process S5 by performing an equivalent treatment (corona treatment) such as corona treatment on the surface of the film 1.

Also, the film 1 discharged from the supply roller 110 may be guided to the coating section 120 by the conveying roller 160. Here, the transfer roller 160 may be an idle roller or a driving roller that applies tension to release the film 1. In particular, in the latter case, the conveying roller 160 may include a conveying portion that releases and conveys the film 1. Fig. 2 shows a total of four conveying rollers 160, but this is merely an example, and thus the conveying rollers 160 may be changed in position and number as needed.

In the primary pressing process (S3), the first pressing part 130 may press the coating layer 12 of the slurry applied on the film 1 to densify the coating layer 12 or to make the thickness of the coating layer 12 uniform. Also, although the first pressing part 130 is provided as a pair of rollers provided on the upper and lower sides of the film 1 with the coating layer 12 formed on the film 1, any member may be employed as long as the member can press the coating layer 12. For example, a platen press or a conveyor belt may be provided that operates intermittently, and the form of a press is also possible. When the first pressing part 130 includes a roller, a rotation center axis of the roller may be disposed in a direction crossing the conveying direction X, that is, in a direction parallel to the width direction Y of the film 1.

A drying part may be added at the rear end of the coating part 120 to dry or cure the slurry coated on the film 1. The drying part may include a heat source, and may be provided to be physically separated from the first pressing part 130, but may be functionally integrated with the first pressing part 130. In this embodiment, a case in which the drying part is integrated with the first pressing part 130 will be described. When the first pressing part 130 is provided in the form of a roller, a heat source is provided in the roller so that the roller contacts the coating layer 12 to press the coating layer 12 toward the film 1 and simultaneously raise the temperature of the slurry forming the coating layer 12. As a result, the first pressing part 130 can also function as a drying part. This will be effective even when the first pressing part 130 has a different form from the roller. Then, the temperature of the first pressing part 130 for drying or curing the paste of the coating layer 12 may be at least one temperature of about 140 ℃ to about 170 ℃.

In the slitting process (S4), the slitting section 140 may cut the film 1 that has been pressed in the longitudinal direction (i.e., the conveying direction) of the film 1. The slitting section 140 cuts the film 1 in the conveying direction X, and can be realized by a conventional technique using a cutter or a rotary blade. The slitting part 140 may be provided at the rear end of the pressing part 130. In addition, the slitting section 140 may slit the film 1 in a direction parallel to the conveying direction X. Here, the film 1 may be cut such that the coating layer 12 has a predetermined width. That is, the film 1 is cut into a strip shape by the slitting section 140, and can be divided into a plurality of films 2 including the coatings 12 having the same width. Further, the slit film 2 may be wound around a winding roll 150. Alternatively, the slitting section 140 may be provided in a separate line to feed the film 1 with the coating layer 12 formed thereon to the slitting device, in addition to in the coating layer forming device 100. Here, the winding roller 150 may function as a supply roller with respect to the slitting device.

The film 2 on which the coating, pressing and slitting are completed may be wound around a winding roll 150 and contained. Here, the winding roller 150 may be driven by a power source to facilitate the release of the film 1 from the supply roller 110, and may be used as a part of a conveyance roller.

The laminating apparatus 200 may include: a coating supply roller 210 around which the slit film 2 is wound; a substrate supply roller 220 configured to supply a substrate 11 to be a current collector; a second pressing part 240 configured to press the coating layer 12 onto the substrate 11; a dicing/cutting section 250 configured to dice and cut the substrate 11 to which the coating layer 12 is attached; and a winding roller 260 configured to wind the slit and cut-completed substrate 11 again and to accommodate the substrate 11. In addition, the laminating apparatus 200 may further include a collecting roller 270, and the collecting roller 270 is configured to collect the film 2 released from the coating supply roller 210. In addition, the laminating apparatus 200 may further include a transfer roller 230, the transfer roller 230 being configured to transfer the coating layer 12 released from the coating layer supply roller 210 and the substrate 11 released from the substrate supply roller 220 to the winding roller 260.

Here, the coating supply roller 210 of the laminating apparatus 200 may be the winding roller 150 of the coating layer forming apparatus 100. Hereinafter, the substrate laminating process (S5), the secondary pressing process (S6), and the slitting/cutting process (S7) will be sequentially described with reference to the laminating apparatus 200.

In the substrate laminating process (S5), the coating layer 12 supplied from the paint supply roller 210 is attached on the substrate 11. Here, a plurality of slit films 2 may be wound around the coating supply roller 210, and the coating 12 may be peeled off from the slit films 2 and supplied to contact one surface of the substrate 11. Here, the collecting roller 270 may collect the film 2 separated from the coating layer 12. Also, the collecting roller 270 may be an idle roller or a driving roller that applies tension to release the film 2 from the coating supply roller 210. In particular, in the latter case, the collecting roller 270 may release the film 2 from the coating supply roller 210 and separate the film 2 from the coating 12 to wind the film 2. Here, the collecting roller 270 may collect a plurality of slit films 2 separated from the coating layer 12 at a time.

The plurality of coatings 12 peeled off from the film 2 supplied by the coating supply roller 210 may contact the top surface of the substrate 11 so as to be parallel to each other in the conveyance direction X by the conveyance roller 230.

Here, the substrate 11 may be a metal foil including aluminum (Al), which is to be a positive electrode current collector for manufacturing a positive electrode plate. Alternatively, the substrate 11 is to become a negative electrode current collector for manufacturing a negative electrode plate, and may be a metal foil including copper (Cu) or nickel (Ni). However, the material of the substrate 11 may be replaced by various materials for forming the electrode plate 10, and the present disclosure is not limited thereto.

The substrate 11 may be supplied from a substrate feed roller 220, and may be supplied in the transfer direction X by a transfer roller 230.

Here, the transfer roller 230 may guide the coating layer 12 separated from the film 2 released from the coating layer supply roller 210 and then slit, and the substrate 11 released from the substrate supply roller 220 to the second pressing part 240. The transfer roller 230 may be an idle roller or a driving roller that applies tension to release the substrate 11 and the coating 12. Fig. 5 shows a total of two conveying rollers 230, but this is merely an example, and thus the conveying rollers 230 may be changed in position and number as needed.

In the secondary pressing process (S6), the second pressing part 240 may thermally press the coating 12 onto the top surface of the substrate 11 to attach the coating 12 to the substrate 11. Here, as shown in fig. 6, the coatings 12 may be supplied in the conveying direction X so as to be spaced apart from each other in the width direction Y of the substrate 11. That is, the substrate 11 may include uncoated portions 11a having no coating layer 11 between the coating layers 12 parallel to the conveying direction X. Further, the substrate 11 may also include the uncoated portion 11a in a partial region of each of both ends of the substrate 11 in the width direction Y of the substrate 11.

After the coatings are provided on the substrate 11 in a strip shape so as to be spaced apart from each other in the width direction Y of the substrate 11, the coatings 12 may be thermally pressed onto the substrate 11 by the second pressing part 240. The temperature for hot-pressing the coating layer 12 onto the substrate 11 through the second pressing part 240 may be lower than the temperature of the first pressing part 130 for drying and curing the paste. The hot pressing temperature of the second pressing part 240 may be at least one temperature of about 100 ℃ to about 130 ℃. Although three coating layers 12 are shown in fig. 6 as being separated from each other, the present disclosure may be variously modified and thus is not limited thereto.

Alternatively, the same composition as the coating feed roller 210 may be provided on the bottom surface of the substrate 11, and the coating layer 12 may be added to be supplied to the bottom surface of the substrate 11, so that the coating layer 12 is formed on both the top surface and the bottom surface of the substrate 11. Here, as shown in fig. 7, the coating layer 12 may be attached to the respective positions of the top and bottom surfaces of the substrate 11. The coating layer 12 may have a rectangular shape having a predetermined height with respect to the substrate 11. That is, since the coat layer 12 may be attached to the substrate 11 after being formed in the film 1 and then cut by slitting, both ends of the coat layer 12 may be formed at right angles in the width direction Y of the coat layer 12. The radius of curvature R of each corner of the coating 12 spaced from the substrate 11 may be any value from about 0.01 μm to about 10 μm. In addition, since the coating layer 12 is attached to the substrate 11 after being applied to the film 1, dried, and cured, the substrate 11 can be prevented from being deformed due to the high temperature of the slurry for drying and curing the coating layer 12.

In the dicing/cutting process (S7), as shown in fig. 8, the dicing section 250 may cut the substrate 11 along the cutting line 13 parallel to the conveyance direction X of the substrate 11. A slitting/cutting portion 250 may be provided at the rear end of the second pressing portion 240. The slitting/cutting section 250 can cut the substrate 11 with reference to the center line of the uncoated portion 11a of the substrate in the conveying direction X and the center line of the coating layer 12 along the conveying direction X. That is, the substrate 11 may be an electrode plate 10 cut into a strip shape in which the uncoated portion 11a is provided on at least one side in the width direction Y of the substrate 11 with respect to the substrate 11.

In addition, when the slitting/cutting part 250 additionally cuts the strip along the cutting line 14 parallel to the width direction of the substrate in fig. 9, the unit electrode plate 10 having a rectangular shape can be obtained. Also, as shown in fig. 10, a portion of the uncoated portion 11a of the rectangular unit electrode plate 10 is cut to form an electrode tab 11 b.

That is, in the slitting/cutting process (S7), the electrode plates may be cut into a strip shape or may be cut into substantially rectangular unit electrode plates. The electrode plates in a bar shape may be wound together with the separators and the electrode plates having different polarities to form a jelly-roll type electrode assembly, and the unit electrode plates in a rectangular shape may be sequentially stacked together with the separators and the electrode plates having different polarities to form a stacking type electrode assembly.

When the slitting/cutting part 250 cuts the electrode plates into the unit electrode plates, the winding roller 260 provided at the rear end of the slitting/cutting part 250 may be omitted. Alternatively, the slitting/cutting section 250 may be provided in a separate line. In this case, after attaching the coating layer 12 to the substrate 11 and winding the substrate 11 around the winding roller 260, the substrate 11 on which the coating layer 12 is formed may be fed from the winding roller 260 to the slitting/cutting section 250 provided in a separate line. Here, the winding roller 260 may be used as a supply roller of the slitting/cutting portion 250.

Fig. 11A is an enlarged photograph showing a portion of an electrode plate 10 formed by laminating a coating layer 12 on a substrate 11 by means of the manufacturing method of fig. 1 according to an embodiment, and fig. 11B is an enlarged photograph showing a portion of an electrode plate 20 formed by directly applying a coating layer 22 on a substrate 21 according to a comparative example.

As shown in fig. 11A, it can be seen that, in the electrode plate 10 manufactured according to an embodiment, since the coating 12 is attached to the substrate 11 after the coating 12 is formed in the film 1 and then cut by slitting, the coating 12 having substantially vertical end portions is obtained.

Further, as shown in fig. 11B, it can be seen that, in the electrode plate 20 according to the comparative example, when the coating layer 22 is directly formed on the substrate 21, the end portion of the coating layer 21 is collapsed or deformed due to the difference in stress and elongation of the coating layer 22 and the substrate 21 at a high temperature of the slurry for drying and curing the coating layer 22.

That is, in the electrode plate 10 manufactured according to an embodiment, since the film 1 is cut and attached to the substrate 11 by slitting after the coating 12 is formed on the film 1, the substrate 11 may be prevented from being damaged, and the end portions of the coating 12 may be prevented from collapsing or deforming, thereby improving the efficiency per unit area of the electrode plate 10.

According to the method for manufacturing an electrode plate and the electrode plate manufactured by the method according to the embodiments, since the film may be cut and laminated on the substrate by slitting after the coating layer is formed on the film, the substrate may be prevented from being damaged when the slurry contained in the coating layer is dried or cured, and the end portions of the coating layer may be prevented from collapsing or deforming, thereby improving the efficiency per unit area of the electrode plate.

The above-described embodiment is only one embodiment for performing the method of manufacturing the electrode plate and the electrode plate manufactured by the method, and the present disclosure is not limited to the embodiment, and the technical spirit of the present disclosure includes all technical scopes that can be variously modified by a person of ordinary skill in the art to which the present disclosure pertains, without departing from the spirit of the present disclosure as claimed in the following claims.

Claims

1. A method for manufacturing an electrode plate, the method comprising:

a slurry preparation process of preparing a slurry containing an active material;

a coating process of applying the slurry on one surface of a film conveyed in one direction to form a coating layer;

a primary pressing process of hot pressing the coating on the film;

a slitting process of cutting the film on which the coating layer is formed in a conveying direction;

a substrate laminating process of peeling the coating layer from the film that has been slit to laminate the coating layer on a substrate to be a current collector;

a secondary press process of hot pressing the coating on the substrate; and

a dicing/cutting process of cutting the substrate to which the coating is attached in the conveying direction.

2. The method of claim 1, wherein in the substrate laminating process, a plurality of coating layers are attached to the substrate so as to be parallel to each other in the conveyance direction, and the plurality of coating layers are spaced apart from each other in a width direction of the substrate, which is perpendicular to the conveyance direction, so as to be attached to the substrate.

3. The method of claim 2, wherein in the substrate lamination process, the substrate includes an uncoated portion to which the coating is not attached.

4. The method of claim 3, wherein the slitting/cutting process comprises:

cutting the substrate with reference to a center line of the uncoated portion parallel to the conveying direction and with reference to a center line of each of the plurality of coating layers parallel to the conveying direction, thereby forming an electrode having a bar shape.

5. The method of claim 4, wherein the slitting/cutting process comprises:

the electrode plates in a bar shape are cut along cutting lines so as to be parallel to the width direction of the substrate to form unit electrode plates having a rectangular shape.

6. The method of claim 1, wherein a temperature at which the coating is hot-pressed onto the film in the primary pressing process is greater than a temperature at which the coating is hot-pressed onto the substrate in the secondary pressing process.

7. The method according to claim 1, wherein in the coating process, the film includes an exposed area without the coating layer on a partial area of each of both ends of the film in a width direction perpendicular to the conveying direction of the film.

8. The method according to claim 1, wherein, in the slitting process, the film on which the coatings are formed is cut into a strip-like shape in the conveying direction so that the coatings have the same width.

9. An electrode plate manufactured by the method of any one of claims 1 to 8, wherein the coating layer has a rectangular shape having a predetermined height with respect to the substrate.

10. The electrode plate of claim 9, wherein a radius of curvature R of each corner of the coating spaced from the substrate is in a range of 0.01 μm to 10 μm.