Method for manufacturing electrode sheets and apparatus for manufacturing electrode sheets

Abstract

To provide a manufacturing method of an electrode sheet, by which the reduction in the peeling strength between an electrode layer and a collector sheet can be suppressed.SOLUTION: A method for manufacturing an electrode sheet comprises the steps of: preparing a coating sheet on which coating parts 2a, 2b and an un-coating part 3a are alternately arranged on a collector sheet 1; and irradiating the coating sheet with laser light from a plurality of laser heads L1, L2 to dry the coating parts while conveying the coating sheet. In the drying step, while sensing a position or positions of the coating parts or the un-coating part of the coating sheet, laser light radiated from the respective laser heads is controlled by turning OFF from ON when the requirement (i) is satisfied, and turning ON from OFF when the requirement (ii) is satisfied. The requirement (i) is a rate of a width of the un-coating part which enters a laser light irradiation region to a width of the laser light irradiation region is 20% or more and 80% or less. The requirement (ii) is a rate of a width of the coating part which enters a laser light irradiation scheduling region to a width of the laser light irradiation scheduling region is 20% or more and 80% or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing an electrode sheet and an apparatus for manufacturing an electrode sheet. [Background technology]

[0002] Regarding the technology for manufacturing electrode sheets used in the production of batteries such as lithium-ion secondary batteries, a method is known in which an electrode material is applied to a transported current collector sheet to form a coated area, and the coated area is dried to obtain an electrode layer.

[0003] For example, Patent Document 1 discloses a method for manufacturing an electrode, comprising: a coating step of applying an active material mixture to a long metal foil being transported to form a coated area of ​​the active material mixture; a first irradiation step performed before the coating step, in which a laser is irradiated onto an irradiation position on the long metal foil located upstream in the transport direction of the long metal foil from both ends of the mixture application area along the short direction of the long metal foil; a second irradiation step performed after the first irradiation step, in which a laser is irradiated onto both edges in the short direction of the coated area formed by the coating step; and a drying step performed after the second irradiation step to dry the coated area. Patent Document 1 also describes forming the coated area on the long metal foil by intermittent coating. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-029256 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] When electrode material coatings are formed on a transported current collector sheet using intermittent coating, a coated sheet is obtained in which coated areas and uncoated areas are alternately formed along the transport direction. The coating film at the edges of the electrode material coatings may differ from that at the center of the coating. For example, the thickness at the edges of the coating tends to be thinner than that at the center. When electrode material coatings are formed using intermittent coating, the effect of this difference in thickness between the edges and the center of the coating becomes more pronounced.

[0006] One method for drying electrode materials is to use a lamp as a heat source. Because the lamp is a diffusing heat source, it irradiates the surface of the coated sheet uniformly. Therefore, with lamp irradiation, the edges of the coated area tend to dry excessively, causing the current collector sheet near the edges of the coated area to become hot, and the peel strength between the electrode layer and the current collector sheet tends to decrease. In addition, since the lamp takes several seconds to tens of seconds to start up, it is difficult to control the ON / OFF of the lamp depending on the intermittently arranged location of the coated area.

[0007] This disclosure has been made in view of the above circumstances, and its main purpose is to provide a method for manufacturing an electrode sheet that can suppress a decrease in peel strength between the electrode layer and the current collector sheet. [Means for solving the problem]

[0008] [1] A preparation step of preparing a coated sheet in which coated portions coated with electrode material and uncoated portions not coated with the electrode material are alternately arranged along the first direction on the first surface of a current collector sheet having a longitudinal direction in the first direction, The process includes a drying step in which the coated sheet is dried by irradiating it with laser light from multiple laser heads while the coated sheet is being transported in the first direction, In the drying process, while detecting the position of the coated part or the uncoated part of the coated sheet, the laser light irradiated from each laser head is controlled by switching from ON to OFF when the following (i) occurs, and switching from OFF to ON when the following (ii) occurs. A method for manufacturing an electrode sheet. (i) When the ratio of the width of the uncoated part within the laser light irradiation area to the width of the laser light irradiation area in the first direction satisfies 20% or more and 80% or less (ii) When the ratio of the width of the coated part within the planned laser light irradiation area to the width of the planned laser light irradiation area in the first direction satisfies 20% or more and 80% or less

[0009] [2] In the drying process, the position of the coated part or the uncoated part of the coated sheet is detected by a laser displacement meter or an image inspection device. The method for manufacturing an electrode sheet according to [1].

[0010] [3] The laser light is irradiated so that the width of the laser light irradiation area and the width of the planned laser light irradiation area are 10 cm or more and 40 cm or less. The method for manufacturing an electrode sheet according to [1] or [2].

[0011] [4] An electrode sheet manufacturing apparatus for manufacturing an electrode sheet by drying a coated sheet in which a coated part coated with an electrode material and an uncoated part not coated with the electrode material are alternately arranged along the first direction on a first surface of a current collecting sheet having a longitudinal direction in the first direction, A conveyor for conveying the coated sheet in the first direction, A laser light irradiation machine including a plurality of laser heads for irradiating the coated sheet with laser light, A position detector for detecting the position of the coated part or the uncoated part of the coated sheet, Based on the position information obtained by the above position detector, the laser light irradiation machine is controlled so that the laser light emitted from each of the above laser heads is switched from ON to OFF when the following (i) occurs, and is switched from OFF to ON when the following (ii) occurs. The manufacturing apparatus for an electrode sheet includes such a control device. (i) When the ratio of the width of the uncoated portion that has entered the laser light irradiation area to the width of the laser light irradiation area in the above first direction satisfies 20% or more and 80% or less (ii) When the ratio of the width of the coated portion that has entered the planned laser light irradiation area to the width of the planned laser light irradiation area in the above first direction satisfies 20% or more and 80% or less

[0012] [5] The manufacturing apparatus for an electrode sheet according to [4], wherein the position detector is a laser displacement meter or an image inspection device.

Advantages of the Invention

[0013] According to the method for manufacturing an electrode sheet in the present disclosure, it is possible to manufacture an electrode sheet in which a decrease in the peel strength between the electrode layer and the current collector sheet is suppressed.

Brief Description of the Drawings

[0014] [Figure 1] It is a schematic plan view and a schematic cross-sectional view illustrating a coated sheet in the present disclosure. [Figure 2] It is a schematic cross-sectional view for explaining a drying process in the present disclosure. [Figure 3] It is a schematic cross-sectional view illustrating an electrode sheet in the present disclosure.

Embodiments for Carrying Out the Invention

[0015] The method for manufacturing an electrode sheet and the apparatus for manufacturing an electrode sheet as described herein will be explained in detail below with reference to the drawings. The following figures are schematic representations, and the size and shape of each part are exaggerated as appropriate for ease of understanding. In addition, in this specification, when describing a manner in which one member is placed relative to another member, the terms "above" or "below" include, unless otherwise specified, both cases in which one member is placed directly above or directly below another member so as to be in contact with that member, and cases in which one member is placed above or below another member via another member.

[0016] A. Method for manufacturing electrode sheets Figure 1(a) is a schematic plan view illustrating a coated sheet prepared in the preparation step of this disclosure, and Figure 1(b) is a cross-sectional view AA of Figure 1(a). As shown in Figures 1(a) and (b), the coated sheet 10 has coated portions 2 coated with electrode material and uncoated portions 3 not coated with electrode material arranged alternately along the first direction D1 on the first surface S1 of a current collector sheet 1 having a longitudinal direction in the first direction D1.

[0017] Figure 2 is a schematic cross-sectional view illustrating the drying process in this disclosure. As shown in Figure 2, in the drying process, the coated sheet 10 is transported in a first direction D1 while laser light is irradiated onto the coated sheet 10 from a plurality of laser heads L1 and L2 as a heat source. This dries the coated portion 2 and obtains an electrode layer. In the drying process, while the position of the coated portion 2 or uncoated portion 3 of the coated sheet 10 is detected by a position detector Z, the laser light irradiated from each laser head is directed as follows: (i) the width W0 of the uncoated portion 3 that has entered the laser light irradiation area relative to the width W0 of the laser light irradiation area in the first direction D1 α The system switches from ON to OFF when the ratio is between 20% and 80% (Figures 2(a) and 2(b)). Furthermore, the laser light emitted from each laser head is directed towards (ii) the width W of the coated area 2 that has entered the laser light irradiation area relative to the width W0 of the laser light irradiation area in the first direction D1. β The laser light is switched from OFF to ON when the ratio is between 20% and 80% (Figures 2(c) and 2(d)).

[0018] According to this disclosure, in the drying process of a coated sheet, by detecting the position of the coated or uncoated area and switching the laser light emitted from each laser head from ON to OFF at timings that satisfy a predetermined range, and switching from OFF to ON at timings that satisfy a predetermined range, it is possible to suppress insufficient drying of the coated area while suppressing over-drying of the edges of the coated area. Therefore, it is possible to suppress the current collector sheet near the edges of the coated area from becoming too hot, and to manufacture an electrode sheet in which the reduction in peel strength between the electrode layer and the current collector sheet is suppressed. In addition, oxidation caused by the current collector sheet becoming too hot can be suppressed.

[0019] 1. Preparation process The preparation step in this disclosure is a step of preparing a coated sheet, as shown in Figure 1, in which coated portions 2 coated with electrode material and uncoated portions 3 not coated with electrode material are alternately arranged along the first direction D1 on the first surface S1 of the current collector sheet having a longitudinal direction in the first direction D1.

[0020] The current collector sheet has a longitudinal direction in the first direction. The current collector sheet has a first surface S1 which is one surface in the thickness direction and a second surface S2 which is the back surface of the first surface S1. The current collector sheet is preferably used as a current collector such as a negative electrode current collector, a positive electrode current collector, or a bipolar current collector. As the current collector sheet, metal foil such as aluminum, copper, SUS, or nickel can be used. The thickness of the current collector sheet is, for example, 0.1 μm or more, and may be 1 μm or more. On the other hand, the thickness of the current collector sheet is, for example, 1 mm or less, and may be 100 μm or less.

[0021] The electrode material may be the negative electrode material (material for the negative electrode active material layer). The negative electrode material includes, for example, a negative electrode active material, a conductive material, a binder, and a solvent. Alternatively, the electrode material may be the positive electrode material (material for the positive electrode active material layer). The positive electrode material includes, for example, a positive electrode active material, a conductive material, a binder, and a solvent. These materials are not particularly limited, and known materials can be used.

[0022] The method for preparing the coated sheet is not particularly limited, but for example, it can be manufactured by intermittently coating the first surface of the current collector sheet with electrode material using a coating machine while conveying the current collector sheet in a first direction using a conveyor. Furthermore, it is preferable that the coating machine be positioned upstream of the position detector and laser beam irradiator described later in the conveying direction (first direction), and that this process and the drying process described later be performed continuously.

[0023] 2.Drying process The drying process in this disclosure is a process of drying the coated portion by irradiating the coated sheet with laser light from a plurality of laser heads while conveying the coated sheet in a first direction.

[0024] In the drying process, the coated sheet is transported in a first direction, that is, along the longitudinal direction of the coated sheet. For example, in Figures 2(a) to (d), it is transported from the left side of the drawing to the right side. The transport speed of the coated sheet is, for example, constant. By transporting the coated sheet 10 and passing it under multiple laser heads L1 and L2, laser light as a heat source is irradiated onto the coated sheet 10 from each of the laser heads L1 and L2.

[0025] Preferably, multiple laser heads are arranged above the conveyed coated sheet, spaced apart along a first direction. The spacing (distance between adjacent laser heads) may be the same or different. The laser heads typically incorporate optical lenses (not shown) having a predetermined curvature. The laser heads emit laser light from a laser oscillator (not shown) and irradiate the coated sheet with laser light through the optical lenses.

[0026] In this process, the positions of the coated and uncoated areas of the coated sheet are detected by a position detector, and the laser beam is switched ON / OFF at predetermined timings. Examples of position detectors for detecting the positions of the coated or uncoated areas of the coated sheet include laser displacement meters and image inspection devices.

[0027] Regarding the timing of ON / OFF of the laser light in this process, an example will be described where the coating sections 2a, 2b and the uncoated section 3a pass below the laser head L1 in Fig. 2. As shown in Figs. 2(a) and 2(b), with respect to the width W0 of the laser light irradiation area of the laser head L1, the width W α of the uncoated section 3a that has entered the laser light irradiation area satisfies 20% or more and 80% or less, and the laser light irradiated from the laser head L1 is switched from ON to OFF. Note that the laser light irradiation area is the irradiation area (laser spot) on the current collecting sheet of the laser light. Also, the above "width W of the uncoated section 3a that has entered the laser light irradiation area" α can be obtained, for example, by considering the conveyance speed of the coating sheet and the elapsed time since the end of the uncoated section 3a was detected by the position detector Z.

[0028] Thus, by switching the laser light to OFF at the timing when the above ratio (W α / W0) becomes a predetermined value or more, the coating section 2b can be sufficiently dried. On the other hand, by switching the laser light to OFF at the timing when the above ratio (W α / W0) becomes a predetermined value or less, for example, the laser light can be switched to OFF earlier than the timing when the end portion E T of the coating section 2b exits from the laser light irradiation area, and the laser light irradiation on the end portion E T of the coating section 2b can be made for a short time. Thereby, over-drying due to excessive laser irradiation can be suppressed at the end portion E T of the coating section 2b. Also, the end portion E T of the coating section 2b can be sufficiently dried by the residual heat. Note that the end portion of the coating section is the end portion on the upstream side in the conveyance direction (first direction) of the coating section.

[0029] Also, in this process, as shown in Figs. 2(c) and 2(d), with respect to the width W0 of the planned laser light irradiation area of the laser head L1 in the first direction D1, the width W of the coating section 2a that has entered the planned laser light irradiation area βThe laser light is switched from OFF to ON when the ratio of is between 20% and 80%. The laser light irradiation area is the area (laser spot) on the current collection sheet where the laser light is to be irradiated, and it usually has the same width as the laser light irradiation area. Also, the width W of the coated area that enters the laser light irradiation area is... β This is, in other words, the width of the coated area irradiated by the laser beam, assuming the laser beam is ON. This can be determined, for example, by considering the transport speed of the coated sheet and the elapsed time since the edge of the coated area was detected by the position detector Z.

[0030] Thus, the above proportion (W β By switching the laser beam ON at the timing when / W0) exceeds a predetermined value, for example, the starting end E of the coated portion 2a can be targeted to the area where the laser beam is to be irradiated. B Because the laser light is switched ON later than the timing when it enters, the starting end E of the coated portion 2a B The laser beam irradiation to the starting end E of the coated portion 2a can be kept short. B In this case, excessive drying due to excessive laser irradiation can be suppressed. On the other hand, the above ratio (W β By switching the laser beam ON at the timing when / W0) falls below a predetermined value, the coated area can be thoroughly dried.

[0031] As shown in Figure 1(a), in the first direction D1, the width of the coated portion 2 is W2 and the width of the uncoated portion 3 is W3. The ratio (W0 / W2) (%) of the width of the laser beam irradiation area to the width W2 of the coated portion 2 in the first direction is, for example, 1% or more, and may be 20% or more. On the other hand, the above ratio (W0 / W2) (%) is, for example, 100% or less, and may be 80% or less.

[0032] Furthermore, the ratio (W0 / W3)(%) of the width of the laser beam irradiation area to the width W3 of the uncoated area 3 in the first direction is, for example, 0.1% or more, and may be 10% or more. On the other hand, the above ratio (W0 / W3)(%) is, for example, 60% or less, and may be 50% or less.

[0033] The width W0 of the laser beam irradiation area and the width W0 of the area to be irradiated with laser beam in the first direction are, for example, 5 cm or more, may be 10 cm or more, or may be 20 cm or more. On the other hand, W0 may be, for example, 50 cm or less, or 40 cm or less.

[0034] The energy density of the laser light irradiated from the laser head onto the coated sheet is, for example, 0.1 W / cm². 2 The above is 0.2 W / cm². 2 The above values ​​may also be higher. On the other hand, the above energy density may be, for example, 1.0 W / cm². 2 The following is true: 0.5 W / cm² 2 The following is also acceptable.

[0035] 3. Other processes The method for manufacturing an electrode sheet in this disclosure may include a coating step in which coated portions, where the electrode material is applied, and uncoated portions, where the electrode material is not applied, are alternately formed on the second surface of the current collector sheet along a first direction. In this case, it is preferable to form the coated portions on the second surface at positions that overlap with the coated portions on the first surface in a plan view. Furthermore, the method may include a drying step after the coating step to dry the coated portions on the second surface. In this case, it is preferable to irradiate the second surface of the current collector sheet with laser light in the same way as the first surface.

[0036] The method for manufacturing an electrode sheet in this disclosure may include a pressurizing step in which the electrode sheet is pressed in the thickness direction. The pressurizing step causes the electrode layer to be pressed against the current collector sheet.

[0037] 4. Electrode Sheet Figure 3 is a schematic cross-sectional view showing an example of an electrode sheet manufactured in this disclosure. As shown in Figure 3(a), the electrode sheet 20 has a current collector sheet 1 and an electrode layer 4 intermittently formed on the first surface S1 of the current collector sheet 1. The electrode sheet 20 may also have an electrode layer 5 intermittently formed on the second surface S2 of the current collector sheet 1. That is, as shown in Figure 3(b), the electrode sheet may have electrode layers 4 and 5 on both the first and second surfaces of the current collector sheet.

[0038] Such electrode sheets are used in the manufacture of batteries and may be either positive electrode sheets or negative electrode sheets. When the electrode sheet in this disclosure is a positive electrode sheet, it is combined with a negative electrode sheet and a separator to form an electrode body. Similarly, when the electrode sheet in this disclosure is a negative electrode sheet, it is combined with a positive electrode sheet and a separator to form an electrode body. Furthermore, the electrode layer 4 shown in Figure 3(a) may be a positive electrode active material layer or a negative electrode active material layer. The electrode layers 4 and 5 shown in Figure 3(b) may both be positive electrode active material layers, both be negative electrode active material layers, or one may be a positive electrode active material layer and the other a negative electrode active material layer.

[0039] The type of battery using electrodes is not particularly limited, but lithium-ion secondary batteries are an example. Applications of the battery include powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline cars, and diesel cars. It is particularly preferable to use it as a power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or battery electric vehicles (BEVs). The battery may also be used as a power source for mobile devices other than vehicles (e.g., trains, ships, aircraft), or as a power source for electrical products such as information processing devices.

[0040] B. Manufacturing equipment for electrode sheets The electrode sheet manufacturing apparatus in this disclosure is an electrode sheet manufacturing apparatus that manufactures an electrode sheet by drying a coated sheet on which coated portions coated with an electrode material and uncoated portions not coated with the electrode material are alternately arranged along the first direction on the first surface of a current collector sheet having a longitudinal direction in the first direction, the apparatus comprising: a conveyor for transporting the coated sheet in the first direction; a laser beam irradiator equipped with a plurality of laser heads for irradiating the coated sheet with laser light; a position detector for detecting the position of the coated portion or the uncoated portion of the coated sheet; and a control device that controls the laser beam irradiator based on position information acquired by the position detector so as to switch the laser light irradiated from each laser head from ON to OFF in the following case (i) and from OFF to ON in the following case (ii). (i) When the ratio of the width of the uncoated portion that entered the laser light irradiation area to the width of the laser light irradiation area in the first direction is 20% or more and 80% or less. (ii) When the ratio of the width of the coated portion that has entered the laser light irradiation area to the width of the laser light irradiation area in the first direction is 20% or more and 80% or less.

[0041] According to the electrode sheet manufacturing apparatus of this disclosure, it is possible to manufacture an electrode sheet in which the decrease in peel strength between the electrode layer and the current collector sheet is suppressed.

[0042] The conveyor in this disclosure is not particularly limited as long as it is capable of conveying the coated sheet, and examples include conveyor rollers. The laser light irradiator comprises a plurality of the laser heads described above. The number of laser heads included in the laser light irradiator may be, for example, two or more, five or more, or ten or more. Furthermore, the laser light irradiator may also be equipped with a laser oscillator. Examples of position detectors include a laser displacement meter and an image inspection device. It is preferable that the position detector be positioned upstream of the laser light irradiator in the conveying direction (first direction).

[0043] The control device controls the laser beam irradiator so that, based on the position information of the coated or uncoated area acquired by the position detector, the laser beam emitted from each laser head is switched from ON to OFF in the case of (i) above, and from OFF to ON in the case of (ii) above. The timing of the switching has been described in detail above, so it will not be explained here. [Examples]

[0044] The present disclosure will be further explained below with reference to examples and comparative examples.

[0045] (Example 1) (Preparation process for coated sheets) A negative electrode material containing a negative electrode active material (graphite), a binder (styrene-butadiene rubber), a conductive material (carbon nanotubes), and a thickener (carboxymethylcellulose) was intermittently coated onto the first surface of a copper foil sheet having a longitudinal direction in the first direction. This prepared a coated sheet in which coated areas with the negative electrode material and uncoated areas without the negative electrode material were alternately arranged along the first direction on the first surface of the copper foil sheet.

[0046] (drying process) Next, the coated sheet was transported and irradiated with laser light by passing it under multiple laser heads. At this time, based on the position information obtained by detecting the coated edge of the coated sheet with a laser displacement meter, the timing of switching the laser light from each laser head ON to OFF and OFF to ON was determined as shown in Table 1 W α / W0 and W β The settings were controlled to be equal to / W0. Furthermore, the energy density and irradiation width of the laser beam were set to the values ​​shown in Table 1. Specifically, for each laser head, the width W of the uncoated area that entered the laser beam irradiation area was set relative to the width W0 of the laser beam irradiation area in the first direction. α The ratio W α When / W0 reaches 20%, the laser light is switched from ON to OFF, and the width W of the coated area that has entered the laser light irradiation area is calculated relative to the width W0 of the laser light irradiation area in the first direction.β The ratio W β / W0 switched the laser beam from OFF to ON at a timing of 20%.

[0047] (Examples 2-8, Comparative Examples 1-7) In the drying process, the energy density of the laser light, the irradiation width, and the timing of switching from ON to OFF (the above ratio W) α / W0), timing of switching from OFF to ON (the above percentage W) β The electrode sheets were manufactured in the same manner as in Example 1, except that the value of / W0) was set to the value shown in Table 1.

[0048] [evaluation] (Measurement of peel strength) Using the electrode sheets obtained above, the peel strength when the electrode layer was peeled from the copper foil sheet was measured according to the method compliant with "JIS K 6854-1 (Adhesives - Test method for peel strength - Part 1: 90-degree peel)". A value of 0.12 N / cm or higher was evaluated as OK, and a value of less than 0.12 N / cm was evaluated as NG.

[0049] (Temperature measurement of the current collector sheet) The temperature of the current collector sheet of the electrode sheet obtained above was measured and evaluated as NG if it was 150°C or higher, and OK if it was below 150°C. The results are shown in Table 1.

[0050] [Table 1]

[0051] As shown in Table 1, the width W of the uncoated area that entered the laser light irradiation area is relative to the width W0 of the laser light irradiation area. α The ratio W α The laser light is switched from ON to OFF when / W0 is between 20% and 80%, and the ratio W of the width of the coated area that enters the laser light irradiation area to the width W0 of the laser light irradiation area. βIt was confirmed that by switching the laser beam from OFF to ON when / W0 is between 20% and 80%, the temperature rise near the edges of the coated portion of the current collector sheet can be suppressed, thereby suppressing the reduction in peel strength (Examples 1-8).

[0052] On the other hand, in Comparative Example 1, the irradiation time was too long at the beginning of the coated area, resulting in over-drying and a decrease in peel strength. Also, in Comparative Example 2, the laser irradiation time was too short at the beginning of the coated area, and in Comparative Example 3, the laser irradiation time was too short at the end of the coated area, resulting in insufficient drying and a decrease in peel strength. In Comparative Example 4, the irradiation time was too long at the end of the coated area, resulting in over-drying and a decrease in peel strength. In Comparative Example 5, the irradiation time was too long at the beginning of the coated area, resulting in over-drying and a decrease in peel strength. In Comparative Example 6, the laser irradiation time was too short at the beginning of the coated area, resulting in insufficient drying and a decrease in peel strength. In Comparative Example 7, the irradiation time was too long at the beginning of the coated area, resulting in over-drying and a decrease in peel strength.

[0053] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Explanation of symbols]

[0054] 1 ... Current collection sheet 2 ... Coating section 3…Unpainted section 10…Coated sheet 20… Electrode sheet

Claims

1. A preparation step of preparing a coated sheet having a longitudinal direction in the first direction, wherein coated portions coated with electrode material and uncoated portions not coated with electrode material are alternately arranged along the first direction on the first surface of the current collector sheet having a longitudinal direction in the first direction, The process includes a drying step in which the coated sheet is dried by irradiating it with laser light from a plurality of laser heads while the coated sheet is being transported in the first direction, A method for manufacturing an electrode sheet, wherein, in the drying step, the laser light emitted from each laser head is controlled by detecting the position of the coated portion or the uncoated portion of the coated sheet, and switching it from ON to OFF when (i) below and from OFF to ON when (ii) below. (i) When the ratio of the width of the uncoated portion that entered the laser light irradiation area to the width of the laser light irradiation area in the first direction is 20% or more and 80% or less. (ii) When the ratio of the width of the coated portion that has entered the laser light irradiation area to the width of the laser light irradiation area in the first direction is 20% or more and 80% or less.

2. The method for manufacturing an electrode sheet according to claim 1, wherein in the drying step, the position of the coated portion or the uncoated portion of the coated sheet is detected by a laser displacement meter or an image inspection device.

3. A method for manufacturing an electrode sheet according to claim 1 or claim 2, wherein the laser light is irradiated such that the width of the laser light irradiation area and the width of the area to be irradiated with laser light are 10 cm or more and 40 cm or less.

4. An electrode sheet manufacturing apparatus for producing an electrode sheet, wherein coated portions coated with an electrode material and uncoated portions not coated with the electrode material are alternately arranged along the first direction on the first surface of a current collector sheet having a longitudinal direction in the first direction, and the coated sheet is dried to produce an electrode sheet, A conveying machine for conveying the coated sheet in the first direction, A laser beam irradiator equipped with multiple laser heads for irradiating the coated sheet with laser light, A position detector for detecting the position of the coated portion or the uncoated portion of the coated sheet, An electrode sheet manufacturing apparatus comprising: a control device that controls the laser beam irradiator to switch the laser beam emitted from each laser head from ON to OFF when (i) below and from OFF to ON when (ii) below, based on position information acquired by the position detector; (i) When the ratio of the width of the uncoated portion that entered the laser light irradiation area to the width of the laser light irradiation area in the first direction is 20% or more and 80% or less. (ii) When the ratio of the width of the coated portion that has entered the laser light irradiation area to the width of the laser light irradiation area in the first direction is 20% or more and 80% or less.

5. The electrode sheet manufacturing apparatus according to claim 4, wherein the position detector is a laser displacement meter or an image inspection device.

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