Method and apparatus for manufacturing strip-shaped electrode plates

Abstract

A method and an apparatus for manufacturing a strip-shaped electrode plate, which can efficiently heat an undried protective layer, are provided. [Solution] A method for manufacturing a strip-shaped electrode plate (1, 1a, 11, 11a) comprising a strip-shaped current collecting foil (3) extending in a longitudinal direction (LH), active material layers (5, 15) provided on surfaces (3A, 3B) of the current collecting foil, leaving only a foil exposed portion (3E) where the current collecting foil is exposed, and a protective layer (7) provided between the foil exposed portion and the active material layer, includes a protective layer drying step (S3, S7) for drying an undried protective layer (7x) provided on the current collecting foil (3) that will become the protective layer (7) upon drying, and the protective layer drying step (S3, S7) includes a protective layer heating step (S31, S71) for heating each irradiated portion (7xp) included in the undried protective layer (7x) by irradiating it with linear P-polarized laser light (LLP, LLP1, LLP2, LLP3, LLP4) that is linearly polarized and P-polarized at an incident angle θi of 20 to 67 degrees.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a strip-shaped electrode plate in which an active material layer and a protective layer are provided on a strip-shaped current collector foil, and to an apparatus for manufacturing the strip-shaped electrode plate. [Background technology]

[0002] Patent Document 1 discloses a method for manufacturing a strip-shaped electrode plate having a strip-shaped active material layer and a strip-shaped protective layer on a strip-shaped current collector foil. Specifically, it discloses a method for drying the wet active material layer and protective layer coated on the current collector foil using hot air. Meanwhile, Patent Document 2 discloses a method for manufacturing a strip-shaped electrode plate having an active material layer on a strip-shaped current collector foil, in which the wet active material layer coated on the current collector foil is dried using laser light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-174619 [Patent Document 2] Japanese Patent Application Publication No. 2023-169591 Summary of the Invention [Problem to be solved by the invention]

[0004] When applying an undried active material layer and an undried protective layer to a current collector foil, the solids content of the protective layer paste must often be lower than that of the active material paste, considering factors such as ease of application. Therefore, in terms of unit volume, drying the undried protective layer requires evaporating a larger amount of dispersion medium than drying the undried active material layer. Furthermore, light-colored ceramic powders such as alumina powder are often used for the protective layer. This makes the protective layer less likely to absorb infrared rays and be heated. For these reasons, when hot air drying is performed as described in Patent Document 1, it often takes longer to dry the protective layer than the active material layer.

[0005] Therefore, Patent Document 1 discloses a method for accelerating the drying of the protective layer by increasing the flow rate of the second hot air for drying the wet protective layer compared to the flow rate of the first hot air for drying the wet active material layer. However, there is a limit to how much hot air can accelerate the drying of the protective layer. Furthermore, this method uses a large amount of hot air, which results in low energy efficiency, and improvements have been sought.

[0006] On the other hand, in Patent Document 2, a wet active material layer is dried using a laser beam. However, even when a wet protective layer is dried with a laser beam in addition to the wet active material layer, it often takes longer to dry the protective layer than the active material layer.

[0007] The present invention has been made in view of the above circumstances, and provides a method and an apparatus for manufacturing a strip-shaped electrode plate that can efficiently heat an undried protective layer. [Means for solving the problem]

[0008] (1) One aspect of the present invention for solving the above-mentioned problems is a method for manufacturing a strip-shaped electrode plate including a strip-shaped current collecting foil extending in a longitudinal direction, an active material layer provided on a surface of the current collecting foil, leaving a foil exposed portion where the current collecting foil is exposed, and a protective layer provided between the foil exposed portion and the active material layer, the method including a protective layer drying step of drying a wet protective layer that is provided on the current collecting foil and becomes the protective layer by drying, the protective layer drying step including a protective layer heating step of irradiating a protective layer-irradiated portion included in the wet protective layer with linear P-polarized laser light that is linearly polarized and P-polarized at an incident angle of 20 to 67 degrees to heat the protective layer.

[0009] The wet protective layer is irradiated with linear P-polarized laser light at an incident angle ranging from 20 to 67 degrees. It has been found that this increases the laser light absorption rate in the wet protective layer compared to when the wet protective layer is irradiated with linearly polarized and S-polarized laser light, and also increases the absorption rate compared to when linearly polarized or unpolarized (randomly polarized) laser light is vertically incident at an incident angle of 0 degrees. Taking advantage of this, the protective layer drying step in the above-mentioned manufacturing method includes a protective layer heating step in which each irradiated portion of the wet protective layer is heated by irradiating it with linear P-polarized laser light at an oblique incidence angle ranging from 20 to 67 degrees. Therefore, in the above-mentioned manufacturing method, the wet protective layer can be efficiently heated in the protective layer heating step, contributing to the formation of the protective layer.

[0010] Among these, it is preferable that the method for manufacturing a strip-shaped electrode plate described in (1) be such that the active material layer is a strip-shaped active material layer extending in the longitudinal direction, the foil exposed portion is a strip-shaped foil exposed portion extending in the longitudinal direction, the protective layer is a strip-shaped protective layer extending in the longitudinal direction, and the protective layer drying step is performed while transporting the undried strip-shaped electrode plate provided with the strip-shaped undried protective layer in a transport direction that coincides with the longitudinal direction.

[0011] (2) Furthermore, in the method for manufacturing a strip-shaped electrode plate described in (1), the current collecting foil may be made of aluminum, and the protective layer heating step may be a step of irradiating and heating an exposed portion of the foil exposed portion, at least an exposed portion adjacent to the undried protective layer, with the linear P-polarized laser light at an incident angle of 25 degrees to 88 degrees. When the current collecting foil is made of copper, the incident angle of the linear P-polarized laser light should be set in the range of 30 degrees to 86 degrees.

[0012] (3) In the method for manufacturing a strip-shaped electrode plate described in (1) or (2), the protective layer drying process may also include a protective layer hot air drying process, which is performed in parallel with the protective layer heating process, to apply hot air to a hot air heating portion of the undried protective layer including the protective layer irradiated portion to heat and dry the undried protective layer.

[0013] (4) Furthermore, in the method for manufacturing a strip-shaped electrode plate according to any one of (1) to (3), the wet strip-shaped electrode plate may be formed by providing, on the current collecting foil, in addition to the wet protective layer, a wet active material layer that will become the active material layer upon drying, and the protective layer drying step may be a step of drying the wet active material layer as well.

[0014] (5) A method for manufacturing a strip-shaped electrode plate according to (4), wherein the protective layer heating step is a step of heating the irradiated portion of the active material layer contained in the wet active material layer by irradiating the linear P-polarized laser light.

[0015] In the method for manufacturing a strip-shaped electrode plate according to (6) or (4), the protective layer drying step may preferably include a laser heating step in which the wet active material layer is heated by irradiating it with a laser beam other than the linear P-polarized laser beam, in parallel with the protective layer heating step.

[0016] (7) Yet another solution is a manufacturing apparatus for a strip-shaped electrode plate, the manufacturing apparatus for a strip-shaped electrode plate including a strip-shaped current collecting foil extending in the longitudinal direction, an active material layer provided on the surface of the current collecting foil leaving a foil exposed portion where the current collecting foil is exposed, and a protective layer provided between the foil exposed portion and the active material layer, the manufacturing apparatus for a strip-shaped electrode plate including a conveying unit that conveys, in a conveying direction that coincides with the longitudinal direction, a wet-dried strip-shaped electrode plate having a wet-dried protective layer provided on the current collecting foil that will become the protective layer after drying, and a protective layer drying unit that dries the wet-dried protective layer, the protective layer drying unit having a protective layer heating unit that irradiates a protective layer-irradiated portion included in the wet-dried protective layer with linear P-polarized laser light that is linearly polarized and P-polarized at an incident angle of 20 to 67 degrees to heat the wet-dried protective layer. The protective layer drying unit of the manufacturing apparatus described above has a protective layer heating unit that irradiates each irradiated portion with a linear P-polarized laser beam that is obliquely incident at an incident angle in the range of 20 to 67 degrees to heat the wet protective layer. Therefore, in this manufacturing apparatus, the protective layer heating unit can efficiently heat the wet protective layer, which contributes to drying the protective layer.

[0017] (8) Furthermore, in the manufacturing apparatus for a strip-shaped electrode plate described in (7), the current collecting foil may be made of aluminum, and the protective layer heating unit may irradiate and heat each of the irradiated portions included in at least adjacent exposed portions of the foil exposed portion that are adjacent to the undried protective layer with the linear P-polarized laser light at an incident angle of 25 degrees to 88 degrees.

[0018] (9) Furthermore, in the manufacturing apparatus for a strip-shaped electrode plate described in (7) or (8), the protective layer drying unit may also have a protective layer hot air drying unit that applies hot air to a hot air heating portion of the undried protective layer including the protective layer irradiated portion to heat and dry the protective layer, in parallel with the irradiation of the linear P-polarized laser light in the protective layer heating unit.

[0019] In the manufacturing apparatus for a strip-shaped electrode plate described in (10) or (9), the protective layer hot air drying unit may be configured such that a hot air delivery unit that delivers the hot air is disposed on one side of the hot air heating portion of the undried protective layer in the conveying direction, and a hot air suction unit that sucks in the hot air that is delivered from the hot air delivery unit and has heated the hot air heating portion of the undried protective layer is disposed on the other side of the hot air heating portion in the conveying direction.

[0020] (11) Furthermore, in the apparatus for manufacturing a strip-shaped electrode plate according to any one of (7) to (10), the wet strip-shaped electrode plate may also have a wet active material layer formed on the current collecting foil, the wet active material layer being the active material layer upon drying, and the protective layer drying unit may also dry the wet active material layer.

[0021] (12) In the manufacturing apparatus for a strip-shaped electrode plate described in (11), the protective layer heating unit may be configured to heat the irradiated portion of the active material layer included in the wet active material layer by irradiating the linear P-polarized laser light at an incident angle of 20 degrees to 67 degrees.

[0022] In the manufacturing apparatus for a strip-shaped electrode plate described in (13) or (11), the protective layer drying unit may have a laser heating unit that irradiates the wet active material layer with a laser beam different from the linear P-polarized laser beam to heat it in parallel with the heating of the wet protective layer by the protective layer heating unit. [Brief explanation of the drawings]

[0023] [Figure 1] 1A to 1C are explanatory diagrams of strip-shaped electrode plates according to first to third embodiments and first to third modified embodiments. [Figure 2] 1 is a flowchart showing the steps of manufacturing a strip-shaped electrode plate according to first to third embodiments and first to third modified embodiments. [Figure 3] FIG. 1 is an explanatory diagram showing a schematic configuration of a manufacturing apparatus for a strip-shaped electrode plate according to the first and second embodiments and the first to third modified embodiments. [Figure 4] 1 is an explanatory diagram of a cross section in the conveying direction of a drying device according to a first embodiment and a first modified embodiment. [Figure 5] 1 is an explanatory diagram of a top view of a drying device according to a first embodiment and a first modified embodiment. [Figure 6] FIG. 10 is an explanatory diagram of a cross section in the conveying direction of a drying device according to a second modified embodiment. [Figure 7] FIG. 10 is an explanatory diagram of a top view of a drying device according to a second modified embodiment. [Figure 8] FIG. 11 is an explanatory diagram of a cross section in the conveying direction of a drying device according to a third modified embodiment. [Figure 9] FIG. 11 is an explanatory diagram of a top view of a drying device according to a third modified embodiment. [Figure 10] FIG. 10 is an explanatory view of a widthwise cross section of a drying device according to a second embodiment. [Figure 11] FIG. 10 is an explanatory diagram of a top view of a drying device according to a second embodiment. [Figure 12] FIG. 10 is an explanatory diagram showing a schematic configuration of a manufacturing apparatus for a strip-shaped electrode plate according to a third embodiment. [Figure 13] FIG. 10 is an explanatory diagram of a cross section in the conveying direction of a drying device according to a third embodiment. [Figure 14] FIG. 10 is an explanatory diagram of a top view of a drying device according to a third embodiment. [Figure 15] 10 is a graph showing the relationship between the angle of incidence θi and the absorptance when aluminum is irradiated with P-polarized light and S-polarized light. [Figure 16] 10 is a graph showing the relationship between the angle of incidence θi and the absorptance when copper is irradiated with P-polarized light and S-polarized light. [Figure 17] 10 is a graph showing the relationship between the angle of incidence θi and the absorptance when alumina is irradiated with P-polarized light and S-polarized light.

[0024] (Embodiment 1) Hereinafter, the manufacture of a strip-shaped electrode plate 1 extending in a longitudinal direction LH and a manufacturing apparatus 100 for the strip-shaped electrode plate 1 according to a first embodiment of the present invention will be described with reference to the drawings. The strip-shaped electrode plate 1 shown in FIG. 1 is used as an electrode body for an electricity storage device such as a secondary battery. The strip-shaped electrode plate 1 is used to manufacture a rectangular sealed lithium-ion secondary battery to be installed in vehicles such as HVs, PHEVs, and BEVs. Specifically, the strip-shaped electrode plate 1 is a strip-shaped positive electrode plate used to manufacture a flat wound or stacked electrode body that constitutes a battery.

[0025] The strip-shaped electrode plate 1 of the first embodiment includes a strip-shaped current collecting foil 3 made of aluminum and extending in the longitudinal direction LH; strip-shaped active material layers 5 provided on the first surface 3A and the second surface 3B of the current collecting foil 3, each extending in the longitudinal direction LH; and a strip-shaped protective layer 7 also extending in the longitudinal direction LH. Both end edge portions of the current collecting foil 3 in the width direction WH, which is perpendicular to the longitudinal direction LH, are strip-shaped foil exposed portions 3E where the current collecting foil 3 is exposed. The protective layer 7 is provided between the foil exposed portions 3E and the active material layer 5. The active material layer 5 contains lithium transition metal composite oxide particles as active material particles, acetylene black as conductive particles, and polyvinylidene fluoride (PVDF) as a binder. The protective layer 7 contains alumina particles as insulating ceramic particles and PVDF as a binder.

[0026] The active material layer 5 is formed by applying an active material paste 5Px onto the current collector foil 3 and then drying it (see FIG. 3). This active material paste 5Px is formed by dispersing active material particles, conductive particles, and a binder in N-methylpyrrolidone (NMP) as a dispersion medium. In the present embodiment 1, the solid content of this active material paste 5Px is adjusted to approximately 55 to 60%.

[0027] On the other hand, the protective layer 7 is formed by applying a protective paste 7Px onto the current collector foil 3 and then drying it (see FIG. 3). This protective paste 7Px is made by dispersing insulating ceramic particles and a binder in NMP, which is a dispersion medium. However, the solid content of the insulating paste 7Px is approximately 25 to 30 wt%. That is, the proportion of dispersion medium contained in the protective paste 7Px is higher than that of the active material paste 5Px, and the amount of dispersion medium contained per unit volume in the wet protective layer 7x formed by applying the protective paste 7Px to the current collector foil 3 is higher than that in the wet active material layer 5x formed by applying the active material paste 5Px to the current collector foil 3.

[0028] Therefore, the wet protective layer 7x is more difficult to dry than the wet active material layer 5x. Moreover, the protective paste 7Px using alumina particles used in the first embodiment and the wet protective layer 7x applied thereto are bright white and do not easily absorb infrared rays. For this reason, the wet protective layer 7x is more difficult to heat and dry than the wet active material layer 5x. Therefore, if the wet protective layer 7x is dried in parallel with the wet active material layer 5x using hot air or laser light, only the wet protective layer 7x is likely to be insufficiently dried.

[0029] Incidentally, when a flat surface of a metal (e.g., aluminum or copper) is irradiated with linearly polarized laser light (wavelength λ = 1064 nm), it is known that the change in absorptance with respect to the incident angle θi (θi = 0 to 90 degrees) differs between P-polarized light parallel to the incident surface and S-polarized light perpendicular to the incident surface. Specifically, when S-polarized laser light is incident on aluminum, the absorptance is 5% at normal incidence (incident angle θi = 0 degrees). As the incident angle θi increases, the absorptance gradually decreases, reaching 0 at an incident angle θi of 90 degrees. On the other hand, when P-polarized laser light is incident on aluminum, the absorptance is the same as S-polarized light at normal incidence (incident angle θi = 0 degrees). As the incident angle θi increases, the absorptance gradually increases, reaching a maximum of 22% at an incident angle θi of approximately 84 degrees. Thereafter, the absorptance rapidly decreases with increasing incident angle, reaching 0 at an incident angle θi of 90 degrees (see Figure 15). Furthermore, when the incident angle θi is in the range of approximately 25 to 88 degrees, the absorption rate is better than that of normal incidence or oblique incidence of S-polarized light. Incidentally, when S-polarized or P-polarized light is incident on copper, the absorption rate is lower than that of aluminum, but generally similar characteristics are shown (see Figure 16). Furthermore, when the incident angle θi is in the range of approximately 30 to 86 degrees, the absorption rate is better than that of normal incidence or oblique incidence of S-polarized light. These results show that when P-polarized laser light is incident obliquely on the irradiated area of ​​aluminum or copper, the laser light can be absorbed more efficiently than when S-polarized or randomly polarized (unpolarized) laser light is used.

[0030] Furthermore, when P-polarized laser light is incident obliquely on a flat alumina surface, it is more easily absorbed than when S-polarized or randomly polarized (unpolarized) laser light is used (see Figure 17). That is, when P-polarized laser light is irradiated onto a flat alumina surface at an oblique incidence angle θi of 20 to 67 degrees, the laser light can be absorbed more efficiently than when S-polarized or randomly polarized (unpolarized) laser light is irradiated obliquely. It was also found that when laser light is irradiated onto a wet protective layer 7x containing a large number of ceramic particles, such as alumina particles, a difference in absorption rate occurs between P-polarized and S-polarized light. That is, when P-polarized laser light is irradiated onto a wet protective layer 7x at an oblique incidence angle θi of 20 to 67 degrees, it is more easily absorbed and dried than when S-polarized or randomly polarized (unpolarized) laser light is irradiated obliquely. The incident angle of the laser light incident on each ceramic particle varies, but when the incident angles on each ceramic particle are averaged, it is thought that this depends on the incident angle θi on the wet protective layer 7x.

[0031] Therefore, in the present embodiment 1, when the wet active material layer 5x and the wet protective layer 7x formed on the current collector foil 3 are dried with hot air, laser light is irradiated onto at least the irradiated portions 7xp of the wet protective layer 7x to promote drying. Furthermore, the laser light irradiated onto the irradiated portions 7xp is linearly polarized and P-polarized at each portion of the irradiated portions 7xp. Note that in Figure 4 and other figures, the polarization direction of the laser light irradiated onto the irradiated portions 7xp and other areas is indicated by a bold double-headed arrow.

[0032] First, an outline of a method for manufacturing the strip-shaped electrode plates 1a,1 using the manufacturing apparatus 100 will be described with reference to Figures 2 and 3. In a first unwinding step S1, the current collecting foil 3 wound around the reel 111 is unwound by the unwinding device 110A and input into the coating device 120.

[0033] In the first electrode formation step S2, a coating device 120 uses the active material paste 5Px contained in a first tank 121 and the protective paste 7Px contained in a second tank 122 to form a wet strip electrode plate 1xa having a wet strip active material layer 5x and a wet strip protective layer 7x provided on the first surface 3A of the current collector foil 3. As described above, the wet active material layer 5x becomes the active material layer 5 after drying. Furthermore, the wet protective layer 7x becomes the protective layer 7 after drying.

[0034] In the first embodiment, the coating device 120 is specifically a die coater, which simultaneously and continuously discharges and applies the active material paste 5Px and the protective paste 7Px onto the first surface 3A of the current collector foil 3 being transported in the longitudinal direction LH, thereby simultaneously forming a band-shaped wet active material layer 5x and a wet insulating protective layer 7x along it. Note that a foil exposed portion 3E where the current collector foil 3 is exposed is left on the outer side WHO in the width direction of the current collector foil 3. As described above, the wet insulating protective layer 7x contains a larger amount of solvent (NMP) per unit volume than the wet active material layer 5x.

[0035] Next, in the first drying step S3, the wet active material layer 5x and the wet insulating protective layer 7x of the wet strip-shaped electrode plate 1xa are dried using a drying device 130, the details of which will be described later, to form a strip-shaped electrode plate 1a having an active material layer 5 and an insulating protective layer 7 on the first surface 3A.

[0036] Then, in a first winding step S4, the winding device 140A temporarily winds the strip-shaped electrode plate 1a onto a reel 141. Then, in a second unwinding step S5, the unwinding device 110B unwinds the strip-shaped electrode plate 1a from the reel 141. Furthermore, the current collecting foil 3 is reversed by a reversing roll 112 so that the second surface 3B becomes the surface to be coated, and the current collecting foil 3 is fed into the coating device 120 similar to the above.

[0037] In the second electrode formation process S6, in a coating device 120, an active material paste 5Px and a protective paste 7Px are successively applied to the second surface 3B of the collector foil 3 of the strip-shaped electrode plate 1a being transported in the longitudinal direction LH, to form a wet strip-shaped electrode plate 1x having a strip-shaped wet active material layer 5x and a wet insulating protective layer 7x.

[0038] Next, in the second drying step S7, the wet active material layer 5x and the wet insulating protective layer 7x of the wet strip-shaped electrode plate 1x are dried using a drying device 130, the details of which will be described later, to form a strip-shaped electrode plate 1 having an active material layer 5 and an insulating protective layer 7 on the first surface 3A and the second surface 3B, respectively.

[0039] Thereafter, in the pressing process S8, a pressing device 150 (specifically, a roll press) is used to roll-press the above-mentioned strip-shaped electrode plate 1 in the thickness direction TH while conveying it in the longitudinal direction LH, thereby increasing the density of the active material layer 5 and the insulating protective layer 7 and completing the strip-shaped electrode plate 1.

[0040] Furthermore, in a cutting step S9, a cutting blade 161 is used to cut the strip-shaped electrode plate 1 (see FIG. 1) in half in the width direction WH to form divided electrode plates 2. In the subsequent second winding step S10, a winding device 140B is used to wind the divided electrode plates 2 onto reels 142, respectively.

[0041] Next, the first drying step S3 and the second drying step S7, and the drying device 130 used therein will be described with reference to Figures 2, 4, and 5. Note that the second drying step S7 is almost the same as the first drying step S3, so the first drying step S3 will be mainly described.

[0042] The first drying step S3 and the second drying step S7 are examples of protective layer drying steps for drying the wet protective layer 7x that will become the protective layer 7. The first drying step S3 includes a first heating step S31 (an example of a protective layer heating step) for irradiating and heating irradiated portions 7xp of the wet protective layer 7x, which are provided on both sides of the wet protective layer 7x in the width direction WH (shown by solid lines in FIG. 2), with linear P-polarized laser beams LLP1 and LL2 that are linearly polarized and P-polarized at an oblique incidence angle θi of 20 to 67 degrees. Similarly, the second drying step S7 also includes a second heating step S71 for irradiating and heating the irradiated portions 7xp of the wet protective layer 7x with linear P-polarized laser beams LLP1 and LLP2. Therefore, in the first heating step S31 and the second heating step S71, the wet protective layer 7x can be efficiently heated and dried, contributing to the formation of the protective layer 7.

[0043] Moreover, the protective layer 7 and the wet protective layer 7x (see FIG. 1) are strip-shaped extending in the longitudinal direction LH, and in the first drying step S3 and the second drying step S7, the wet strip-shaped electrode plates 1xa, 1x provided with the wet protective layer 7x are dried while being transported in the transport direction CH that coincides with the longitudinal direction LH. Therefore, the strip-shaped wet protective layer 7x transported in the transport direction CH can be easily and continuously irradiated with the linear P-polarized laser beams LLP1, LLP2, and the wet protective layer 7x can be continuously heated.

[0044] In addition, the first drying step S3 of the first embodiment also includes a first hot air drying step S32, which is an example of a protective layer hot air drying step, in which the undried protective layer 7x is heated and dried with hot air HA, in parallel with the first heating step S31, as shown by the dashed line in Fig. 2. Similarly, the second drying step S7 includes a second hot air drying step S72 in which the undried protective layer 7x is heated and dried with hot air HA. Thus, the first drying step S3 and the second drying step S7 include, in addition to the first heating step S31 and the second heating step S71, heating the irradiated portion 7xp of the wet protective layer 7x using the linear P-polarized laser beams LLP1 and LLP2, a first hot air drying step S32 and a second hot air drying step S72, in which the hot air heating portion 7xw is heated and dried with hot air HA. This allows the wet protective layer 7x to be dried more efficiently. Moreover, by using the hot air HA, the hot air HA containing a large amount of evaporated dispersion medium (NMP in the first embodiment) can be removed from the vicinity of the wet protective layer 7x, facilitating the drying of the wet protective layer 7x.

[0045] Furthermore, as described above, in the present embodiment 1, in addition to the wet protective layer 7x, a wet active material layer 5x that will become the active material layer 5 upon drying is provided on the current collecting foil 3. Therefore, the first drying step S3 and the second drying step S7 are steps for drying the wet active material layer 5x as well. Specifically, in the present embodiment 1, the wet active material layer 5x is also heated and dried in the first hot air drying step S32 and the second hot air drying step S72, in which the wet protective layer 7x is dried with hot air HA. This allows the strip-shaped electrode plates 1a, 1 to be manufactured in a shorter process than when the wet active material layer 5x is dried separately from the first drying step S3 and the second drying step S7.

[0046] In the first embodiment, a drying device 130 shown in FIGS. 4 and 5 is used to perform the first drying step S3, which includes the first heating step S31 and the first hot air drying step S32, or the second drying step S7, which includes the second heating step S71 and the second hot air drying step S72. The drying device 130 includes a conveying section 131 that conveys the wet strip-shaped electrode plates 1xa, 1x, each having a wet protective layer 7x and a wet active material layer 5x provided on a current collecting foil 3, in a conveying direction CH (the left-right direction in FIGS. 4 and 5) that coincides with the longitudinal direction LH. In the first embodiment, the conveying section 131 is specifically a number of conveying rollers. The drying device 130 further includes a drying section 132, which is an example of a protective layer drying section, that dries the wet protective layer 7x. In the first embodiment, the drying section 132 also dries the wet active material layer 5x, as described below.

[0047] The drying unit 132 includes a heating unit 133, which is an example of a protective layer heating unit, that irradiates each irradiated portion 7xp of the wet protective layer 7x with linear P-polarized laser beams LLP1 and LLP2 at an oblique incidence angle θi to heat the wet protective layer 7x. The incidence angle θi with respect to the wet protective layer 7x varies depending on each irradiated portion 7xp, but is set within the range of 20 to 67 degrees as described with reference to FIG. 17 . Therefore, in the manufacturing method of the first embodiment, the oblique incidence of the linear P-polarized laser beams LLP1 and LLP2 in the first heating step S31 and the second heating step S71 can efficiently heat the wet protective layer 7x, thereby contributing to the formation of the protective layer 7. Furthermore, in the drying device 130, the oblique incidence of the linear P-polarized laser beams LLP1 and LLP2 within the aforementioned range by the heating unit 133 can efficiently heat the wet protective layer 7x, thereby contributing to the formation of the protective layer 7.

[0048] Additionally, the heating unit 133 of the first embodiment also heats each irradiated portion 3Erp included in the adjacent exposed portion 3Er adjacent to at least the wet protective layer 7x of the exposed foil portion 3E of the current collecting foil 3 by irradiating the linear P-polarized laser beams LLP1 and LLP2 at an oblique incidence angle θi. The incidence angle θi for the adjacent exposed portion 3Er also varies depending on the irradiated portion 3Erp, but is set within the range of 25 to 88 degrees as described with reference to FIG. 15 . Therefore, the oblique incidence of the linear P-polarized laser beams LLP1 and LLP2 by the heating unit 133 within the aforementioned range can efficiently heat each irradiated portion 3Erp of the adjacent exposed portion 3Er. Thus, the wet protective layer 7x adjacent to the adjacent exposed portion 3Er can be indirectly heated to promote drying of the protective layer 7. Furthermore, by irradiating the linear P-polarized laser light LLP1, LLP2 in the first heating step S31 and the second heating step S71, each irradiated portion 3Erp of the adjacent exposed portion 3Er can also be efficiently heated, and the undried protective layer 7x adjacent thereto can be indirectly heated, thereby accelerating the drying of the protective layer 7.

[0049] The linear P-polarized laser beams LLP1 and LLP2 are generated by a linear P-polarized laser beam source 134 constituting the heating unit 133. The linear P-polarized laser beam source 134 is composed of a laser beam source 134L, which is a fiber laser that generates unpolarized laser beams, and a polarization optical system 134P. The polarization optical system 134P converts the unpolarized laser beam into linearly polarized laser beams using multiple wavelength plates and DOEs. The converted laser beam is then split into two beams: a linear P-polarized laser beam LLP1 that travels from the upstream side CHU in the conveying direction CH toward one side WH1 in the width direction WH (upper left in FIG. 5 ) and is shaped like a rectangle; and a linear P-polarized laser beam LLP2 that travels from the upstream side CHU in the conveying direction CH toward the other side WH2 in the width direction WH (lower left in FIG. 5 ) and is shaped like a rectangle. In the first embodiment, the linear P-polarized laser beams LLP1 and LLP2 are irradiated from the downstream side CHD in the conveying direction CH toward the upstream side CHU. However, instead of this, linear P-polarized laser beams LLP1 and LLP2 may be emitted from the upstream CHU toward the downstream CHD.

[0050] The drying section 132 of the drying device 130 of the present embodiment 1 has a hot air drying section 136 in addition to the heating section 133. The hot air drying section 136 is an example of a protective layer hot air drying section, and in parallel with the irradiation of the linear P-polarized laser beams LLP1 and LLP2 using the heating section 133, hot air HA is applied to a hot air heating section 7xw including the irradiated section 7xp of the undried protective layer 7x to heat and dry it. Note that the hot air drying section 136 of the present embodiment 1 dries not only the hot air heating section 7xw of the undried protective layer 7x, but also the hot air heating section 5xw of the undried active material layer 5x.

[0051] The hot air drying section 136 comprises a hot air delivery section 137 and a hot air suction section 138. The hot air delivery section 137 is disposed upstream of the hot air heating areas 7xw and 5xw in the conveyance direction CH (on the left side in FIG. 4 ). As indicated by the white arrows in FIGS. 4 and 5 , hot air HA is blown out along the upper surfaces of the hot air heating areas 7xw and 5xw over an air blowing width HAw in the width direction WH toward the downstream side CHD in the conveyance direction CH (on the right side in FIGS. 4 and 5 ). Therefore, the hot air HA heats and dries the hot air heating areas 7xw and 5xw. Meanwhile, the hot air suction section 138 is disposed downstream of the hot air heating areas 7xw and 5xw in the conveyance direction CH. Then, after heating the hot air heating areas 7xw and 5xw over the transport direction distance LCH, the hot air HA containing the vapor of the dispersion medium (NMP in the first embodiment) is sucked in and discharged to the outside.

[0052] As described above, the drying device 130 includes a hot air drying section 136 in the drying section 132 that applies hot air HA to the hot air heating section 7xw to heat and dry it in parallel with the heating of the irradiated section 7xp by irradiating it with laser beams LLP1 and LLP2 in the heating section 133. This allows the wet protective layer 7x to be dried efficiently in a shorter time. Furthermore, a hot air delivery section 137 is disposed on either the upstream side CHU or the downstream side CHD in the conveyance direction CH (the upstream side CHU in the first embodiment) relative to the hot air heating section 7xw of the wet protective layer 7x, and a hot air suction section 138 is disposed on the other side CH2 in the conveyance direction CH (the downstream side CHD in the first embodiment). Therefore, regardless of the width dimension (dimension in the width direction WH) W3 of the current collecting foil 3, the hot air heated portion of the undried protective layer 7x can be dried with hot air HA over a transport direction distance LCH longer than this width dimension W3, and the transport direction distance LCH of the hot air heated portions 7xw, 5xw that are exposed to and heated by the hot air HA can be freely set.

[0053] Moreover, in the drying device 130 of this manufacturing apparatus 100, the wet active material layer 5x as well as the wet protective layer 7x is dried in the drying section 132. Therefore, the strip-shaped electrode plates 1a, 1 can be manufactured in a shorter time than when the wet active material layer 5x is not dried.

[0054] In the manufacturing method of the first embodiment described above, the strip-shaped electrode plate 1a is temporarily wound around the reel 141 in the first winding step S4. Then, in the second unwinding step S5, the reel 141 around which the strip-shaped electrode plate 1a is wound is set in the unwinding device 110B, and the strip-shaped electrode plate 1a is unwound from the reel 141 and fed into the coating device 120. However, as shown by the two-dot chain line in FIG. 2, the first winding step S4 and the second unwinding step S5 may be skipped. That is, the strip-shaped electrode plate 1a obtained after the first drying step S3 may be turned over and fed into the coating device 120 without being wound around the reel 141, and the second electrode forming step S6 and subsequent steps may be performed.

[0055] In addition, in the manufacturing apparatus 100 of the first embodiment, a single drying device 130 shown in FIGS. 4 and 5 is used to dry the wet protective layer 7x and wet active material layer 5x of the wet strip-shaped electrode plate 1xa, 1x, thereby obtaining the strip-shaped electrode plate 1a, 1 having the dried protective layer 7 and active material layer 5. However, if a long time or a long transport distance is required to dry the wet protective layer 7x and the wet active material layer 5x, multiple drying devices 130 may be arranged in the transport direction CH to dry the wet protective layer 7x and the wet active material layer 5x. Alternatively, the drying device 130 may have multiple stages of heating units 133 and hot air drying units 136 each having a linear P-polarized laser light source 134 arranged in the transport direction CH.

[0056] Furthermore, in this embodiment 1, only the irradiated portion 7xp and the irradiated portion 3Erp were heated with the linear P-polarized laser light LLP1, LLP2, but in order to dry the undried protective layer 7x more quickly, in addition to the irradiated portion 7xp and the irradiated portion 3Erp, the portion of the undried active material layer 5x adjacent to the irradiated portion 7xp may also be heated with the linear P-polarized laser light LLP1, LLP2.

[0057] (Variation 1) Next, a first modified embodiment of embodiment 1 will be described. In embodiment 1, one linear P-polarized laser light source 134 is used that splits and generates two linear P-polarized laser beams LLP1 and LLP2, as shown by the solid line in Fig. 5. In contrast, in this modified embodiment 1, two linear P-polarized laser light sources 134A and 134B are used that each generate one linear P-polarized laser beam LLP1 or one linear P-polarized laser beam LLP2, as shown by the dashed line in Fig. 5.

[0058] In the drying device 130 of this modified form 1, it is necessary to use two linear P-polarized laser light sources 134A and 134B, but the output of each of the linear P-polarized laser light sources 134A and 134B can be reduced to about half, and there is no need to generate two branched linear P-polarized laser beams LLP1 and LLP2, so the configuration of the polarization optical system used for the linear P-polarized laser light sources 134A and 134B can be simplified.

[0059] (Variation 2) Next, a second modified embodiment of the first embodiment will be described mainly with reference to Fig. 6 and Fig. 7. In the first embodiment, as shown by the solid lines in Fig. 5, two linear P-polarized laser beams LLP1 and LLP2 branched and generated from one linear P-polarized laser light source 134 are irradiated onto an irradiated portion 7xp of the wet protective layer 7x and an irradiated portion 3Erp of the adjacent exposed portion 3Er of the current collecting foil 3, thereby heating them.

[0060] In contrast, in the first drying step S3 and the second drying step S7 of the present modified embodiment 2, and in the drying apparatus 230 that performs these steps S3 and S7 of the manufacturing apparatus 200, a linear P-polarized laser light source 234 that generates linear P-polarized laser light LLP, as shown in FIG. 7 , is used as the heating section 233 of the drying section 232. Similar to the linear P-polarized laser light source 134 of the first embodiment, the linear P-polarized laser light source 234 irradiates the irradiated portion 7xp of the wet protective layer 7x and the irradiated portion 3Erp of the adjacent exposed portion 3Er of the current collecting foil 3 with the linear P-polarized laser light LLP to heat them. In addition, the linear P-polarized laser light source 234 also irradiates the irradiated portion 5xp of the wet active material layer 5x with the linear P-polarized laser light LLP at an oblique incidence, thereby heating the irradiated portion 5xp as well.

[0061] That is, in the drying device 230 used in the first heating step S31 and the second heating step S71, the irradiated portion 5xp of the wet active material layer 5x is also heated with the obliquely incident linear P-polarized laser light LLP, thereby making it possible to efficiently dry not only the wet protective layer 7x but also the wet active material layer 5x.

[0062] The intensity per unit area of ​​the linear P-polarized laser light LLP irradiated to the irradiated areas 7xp, 3Erp, and 5xp may be uniform, but it is preferable to increase the irradiation intensity of the irradiated areas 7xp and 3Erp compared to the irradiated area 5xp to heat these areas more.

[0063] In the second modified embodiment, the linear P-polarized laser light LLP generated by the single linear P-polarized laser light source 234 heats not only the irradiated portion 7xp and the irradiated portion 3Erp but also the irradiated portion 5xp of the wet active material layer 5x. However, as in the first embodiment, in addition to heating the irradiated portion 7xp and the irradiated portion 3Erp with the linear P-polarized laser light LLP1 and LLP2 generated by the linear P-polarized laser light source 134, it is also possible to heat the irradiated portion 5xp of the wet active material layer 5x using another linear P-polarized laser light source (not shown). Furthermore, in order to appropriately heat the irradiated portion 5xp of the wet active material layer 5x, which is wider than the irradiated portion 7xp, the irradiated portion 5xp may be divided, and multiple linear P-polarized laser light sources may be used as separate linear P-polarized laser light sources, and the divided irradiated portions 5xp may be heated by each linear P-polarized laser light source.

[0064] (Variation 3) In the heating section 233 of the drying section 232 of the above-mentioned modified embodiment 2, the linear P-polarized laser light LLP from the linear P-polarized laser light source 234 was also irradiated onto the irradiated portion 5xp of the wet active material layer 5x, thereby heating the irradiated portion 5xp as well (see Figure 7).

[0065] In contrast, the drying section 332 of the drying device 330 of Modified Example 3 shown in Figures 8 and 9 uses the same linear P-polarized laser light source 134 as the heating section 133 of Embodiment 1 to generate two linear P-polarized laser beams LLP1 and LLP2, which are irradiated onto an irradiated portion 7xp of the wet protective layer 7x and an irradiated portion 3Erp of the adjacent exposed portion 3Er of the current collecting foil 3 to heat them. In addition, the drying section 332 of Modified Example 3 has a laser heating section 339 that generates unpolarized laser light LR, separate from the linear P-polarized laser beams LLP1 and LLP2, and irradiates each irradiated portion 5xr within a rectangular area of ​​the wet active material layer 5x with the unpolarized laser beam LR to heat each irradiated portion 5xr and aid drying. This allows the drying device 330 to efficiently dry not only the wet protective layer 7x but also the wet active material layer 5x. In FIG. 9, the unpolarized laser light LR irradiated onto the irradiated portion 5xr is indicated by a symbol consisting of four double-headed arrows intersecting at an angle of 45 degrees.

[0066] 2, the first drying step S3 includes a first laser heating step S33 in which, in parallel with the first heating step S31 and the first hot-air drying step S32, an irradiated portion 5xr of the wet active material layer 5x is irradiated with unpolarized laser light LR, separate from the linear P-polarized laser light LLP1 and LLP2, to heat the irradiated portion 5xr. The second drying step S7 also includes a second laser heating step S73 in which, in parallel with the second heating step S71 and the second hot-air drying step S72, an irradiated portion 5xr is irradiated with unpolarized laser light LR, as shown by the dashed-dotted line. Thus, this manufacturing method can efficiently dry not only the wet protective layer 7x but also the wet active material layer 5x.

[0067] (Embodiment 2) Next, a manufacturing apparatus 500 according to a second embodiment will be described mainly with reference to Figures 10 and 11. In the drying devices 130 to 330 of the manufacturing apparatuses 100 to 300 of the first embodiment and the first to third modified embodiments described above, the linear P-polarized laser light sources 134, 134A, 134B, and 234 are arranged downstream CHD (to the right in Figures 3 to 8) in the conveyance direction CH from the irradiated portion 7xp of the wet protective layer 7x, and emit linear P-polarized laser light LLP1, LLP2, and LLP toward the upstream CHU in the conveyance direction CH and toward the downward THD in the thickness direction TH of the current collecting foil 3 (downward in Figures 3, 5, and 7).

[0068] In contrast, in drying device 530 of manufacturing apparatus 500 of this embodiment 2, linear P-polarized laser light source 534A, which is heating unit 533 of drying unit 532, is arranged on one side WH1 in the width direction WH (right side in FIG. 10, upper side in FIG. 11) of wet active material layer 5x and wet protective layer 7x. Also, linear P-polarized laser light source 534B is arranged on the other side WH2 in the width direction WH (left side in FIG. 10, lower side in FIG. 11) of wet active material layer 5x and wet protective layer 7x.

[0069] The two linear P-polarized laser light sources 534A and 534B emit linear P-polarized laser light LLP3 and LLP4, respectively, toward the inner side WHI in the width direction WH and toward the downward side THD (diagonally downward in FIG. 10) in the thickness direction TH of the current collecting foil 3. As a result, the linear P-polarized laser light LLP3 and LLP4 are irradiated onto the irradiated portion 7xp of the wet protective layer 7x and the irradiated portion 3Erp of the adjacent exposed portion 3Er of the current collecting foil 3 at an incident angle θi in the range of θi3 to θi4 within the range of 20 to 67 degrees, and these portions are heated.

[0070] In the drying device 530 of this embodiment 2, similar to the drying device 130 of embodiment 1, etc., the hot air HA blown out from the hot air blowing section 137 to the downstream side CHD in the conveying direction CH heats and dries the hot air heated portion 7xw of the undried protective layer 7x and the hot air heated portion 5xw of the undried active material layer 5x.

[0071] As described above, the drying device 530 of the second embodiment uses two linear P-polarized laser light sources 534A, 534B to irradiate and heat the irradiated portion 7xp of the undried protective layer 7x extending in the longitudinal direction LH (conveyance direction CH) and the irradiated portion 3Erp of the adjacent exposed portion 3Er of the current collecting foil 3 with linear P-polarized laser light LLP3, LLP4 from the outer side WHO in the width direction WH of the current collecting foil 3. Therefore, compared to the drying device 130 of the first embodiment and the like that irradiates the linear P-polarized laser light LLP1, LLP2 from the downstream side CHD in the conveyance direction CH, it is easier to uniformly irradiate the irradiated portion 7xp and the irradiated portion 3Erp.

[0072] The steps S1 to S10 of the method for manufacturing the strip-shaped electrode plate 1 of the second embodiment are the same as those of the first embodiment (see FIG. 2).

[0073] In the drying device 530 of the second embodiment, of the two wet protective layers 7x extending in the longitudinal direction LH (transport direction CH), the wet protective layer 7x on one side WH1 in the width direction WH is irradiated with linear P-polarized laser light LLP3 from a linear P-polarized laser light source 534A disposed on the other side WH1. The wet protective layer 7x on the other side WH2 is irradiated with linear P-polarized laser light LLP4 from a linear P-polarized laser light source 534B disposed on the other side WH2. However, to increase the incident angle θi, the two linear P-polarized laser light beams LLP3 and LLP4 may be irradiated in a crossed manner. That is, the wet protective layer 7x on one side WH1 may be irradiated with linear P-polarized laser light LLP4 from the linear P-polarized laser light source 534B disposed on the other side WH2, and the wet protective layer 7x on the other side WH2 may be irradiated with linear P-polarized laser light LLP3 from the linear P-polarized laser light source 534A disposed on the other side WH1.

[0074] (Embodiment 3) Next, a manufacturing method and manufacturing apparatus 600 for strip-shaped electrode plates 11a, 11 according to a third embodiment will be described mainly with reference to Figures 12 to 14. In the above-described first embodiment and the like, in manufacturing the strip-shaped electrode plates 1a, 1, the protective layer 7 is formed by drying the wet protective layer 7x formed by applying the protective paste 7Px to the current collecting foil 3, and the active material layer 5 is formed by drying the wet active material layer 5x formed by applying the active material paste 5Px to the current collecting foil 3.

[0075] In contrast, in the present embodiment 3, the protective layer 7 is formed by applying a protective paste 7Px to the current collector foil 3, and then drying the resulting wet protective layer 7x, as in the first embodiment etc. However, the active material layer 15 is different in that the active material layer 15 is completed on the current collector foil 3 using an active material material 15P that does not require drying. Furthermore, due to this difference, in the present embodiment 3, among the steps S1 to S10 of the method for manufacturing the strip-shaped electrode plates 11a, 11 and the split electrode plates 12, the first electrode-forming step S2, the first drying step S3, the second electrode-forming step S6, and the second drying step S7 are different (see FIGS. 2 and 12).

[0076] That is, in manufacturing the strip-shaped electrode plates 11a, 11, in the first electrode forming step S2 and the second electrode forming step S6, a coating device 620 uses active material material 15P contained in a first tank 621 to form a strip-shaped active material layer 15 on the first surface 3A of the current collector foil 3. In addition, a protective paste 7Px contained in a second tank 122 is used to form a strip-shaped undried protective layer 7x adjacent to the active material layer 15 on the first surface 3A of the current collector foil 3.

[0077] The active material material 15P may be, for example, a mixed powder obtained by mixing active material particles, conductive particles, and resin particles such as PTFE, some of which can be fibrillated. A method for forming the active material layer 15 on the surfaces 3A and 3B of the current collector foil 3 using this mixed powder active material material 15P includes, for example, mixing the mixed powder to fibrillate some of the resin particles to form a network connecting the active material particles, and then rolling the mixed powder into a sheet to form the self-supporting active material layer 15. Next, the active material layer 15 is bonded to the current collector foil 3.

[0078] Furthermore, a protective paste 7Px is applied by, for example, die coating to form a strip-shaped wet protective layer 7x between the strip-shaped active material layer 15 formed on the surfaces 3A and 3B of the current collector foil 3 and the exposed foil portion 3E of the current collector foil 3. In this way, a wet strip-shaped electrode plate 1xa having two strip-shaped wet protective layers 7x is formed (see FIG. 1).

[0079] In the first drying step S3 and the second drying step S7, a drying device 630, the details of which will be described later, is used to dry only the undried insulating protective layer 7x, thereby forming a strip-shaped electrode plate 11a having an active material layer 5 and an insulating protective layer 7 on the first surface 3A, or a strip-shaped electrode plate 11 having an active material layer 5 and an insulating protective layer 7 on both surfaces 3A and 3B, respectively.

[0080] Next, the drying device 630 of the manufacturing apparatus 600 of the present embodiment 3 will be described. In the drying device 130 of the embodiment 1 (see FIGS. 4 and 5), not only the hot air heated portion 7xw of the undried protective layer 7x but also the hot air heated portion 5xw of the undried active material layer 5x was dried using the hot air delivery portion 137 and the hot air suction portion 138 that constitute the hot air drying section 136. For this reason, as shown by the white arrow in FIG. 5, hot air HA was blown out from the hot air delivery portion 137 in a band shape spreading in the width direction WH.

[0081] In contrast, in the third embodiment, the hot air blowing section 637 of the hot air drying unit 636 is configured to blow out two streams of hot air HA that hit the hot air heated areas 7xw including the irradiated areas 7xp of the two strip-shaped wet protective layers 7x formed on the transported wet strip electrode plates 1xa, 1x. This configuration prevents the hot air HA from hitting the active material layer 15 that does not require drying, and allows the wet protective layer 7x to be dried efficiently. Note that in the drying device 630 of the third embodiment, in addition to the hot air heated areas 7xw, the two streams of hot air HA also heat the areas of the adjacent exposed portion 3Er of the foil exposed portion 3E of the current collecting foil 3 that are adjacent to the hot air heated areas 7xw, thereby facilitating heating of the hot air heated areas 7xw.

[0082] In the third embodiment, an example has been shown in which an active material layer 15 that does not require drying is formed on the current collector foil 3. However, the present invention may also be applied to a case in which an active material paste 5Px is applied to the current collector foil 3 in advance, dried to form an active material layer 5, and then a protective paste 7Px is applied using the drying device 630 described above to form a wet protective layer 7x.

[0083] The present invention has been described above in accordance with Embodiments 1 to 3 and Modifications 1 to 3. However, it goes without saying that the present invention is not limited to the embodiments, etc., and can be appropriately modified and applied without departing from the spirit of the present invention. For example, as the strip-shaped electrode plate 1 formed in the first embodiment, an example has been shown in which strip-shaped active material layers 5, 15 extending in the longitudinal direction LH are formed on a strip-shaped current collector foil 3 (see FIG. 1 ). However, in addition to this, a strip-shaped electrode plate may be formed in which a large number of independent island-shaped active material layers having a planar shape such as a rectangular shape and provided intermittently in the longitudinal direction LH on the strip-shaped current collector foil 3. In such a strip-shaped electrode plate having independent active material layers, an independent protective layer having a shape such as a linear segment, an L-shape, a U-shape, or a rectangular ring shape may be provided in a required portion between the independent active material layer and the surrounding exposed foil portion. In addition, in each of the first and second embodiments, an example has been shown in which the current collector foil 3 made of aluminum is used. However, the present invention can also be applied to the case in which a strip-shaped electrode plate is manufactured using a current collector foil made of copper. [Explanation of symbols]

[0084] CH Conveying direction CH1 (conveying direction) one side CH2 (conveying direction) other side LH Long arm direction WH amplitude direction WH1 (width direction) one side WH2 (width direction) other side 1,1a,11,11a Belt-shaped electrode plates 1x,1xa,11x,11xa Undried belt-shaped electrode plates 3. Current collector foil 3A (Foil Collector) First Surface (Surface) 3B (Foil Collector) Second Surface (Surface) 3E foil exposed part 3Er adjacent to the exposed part 3Erp Irradiated area (exposed area irradiated) 5.15 Living Matter Layer (Living Matter Layer) 5x Undried living material layer 5xp irradiated area (irradiated area of ​​the living mass layer) 5xr irradiated area (irradiated area of ​​the living mass layer) 5xw hot air heating element 7. Protective layer 7x Undried protective layer 7xp Irradiated area (protective layer irradiated area) 7xw hot air heating element Manufacturing equipment 100, 200, 300, 500, 600 Drying devices 130, 230, 330, 530, 630 131 Transport Department 132,232,332,532,632 Drying section (protective layer drying section) 133,233,533 Heating section (protective layer heating section) 134,134A,134B,234,534A,534B linear P polarized light source LLP1,LLP2,LLP,LLP3,LLP4 linear P polarized light θi, θi1, θi2, θi3, θi4 (Linear P-polarized light) incident angle 134L, 234L laser light source 134P,234P polarization optical system 136,636 Hot air drying section (protective layer hot air drying section) 137,637 Hot air outlet section 138,638 Hot air suction section HA hot air 339 Laser heating section LR Unpolarized laser light (another laser light) S2 First electrode formation process S3 1st drying process (protective layer drying process) S31 1st heating process (protective layer heating process) S32 1st hot air drying process (protective layer hot air drying process) S33 First laser heating process (laser heating process) S6 Second electrode formation process S7 2nd drying process (protective layer drying process) S71 2nd heating process (protective layer heating process) S72 2nd hot air drying process (protective layer hot air drying process) S73 Second laser heating process (laser heating process)

Claims

1. a strip-shaped current collecting foil extending in the longitudinal direction; an active material layer provided on a surface of the current collecting foil, leaving a foil exposed portion where the current collecting foil is exposed; a protective layer provided between the foil exposed portion and the active material layer. A method for manufacturing a strip-shaped electrode plate, a protective layer drying step of drying a wet protective layer that is provided on the current collecting foil and becomes the protective layer by drying, The protective layer drying step includes: a protective layer heating step of irradiating a protective layer irradiated portion included in the undried protective layer with linear P-polarized laser light that is linearly polarized and P-polarized at an incident angle of 20 to 67 degrees to heat the protective layer. Manufacturing method of strip-shaped electrode plate.

2. A method for manufacturing a strip-shaped electrode plate according to claim 1, The current collecting foil is made of aluminum, The protective layer heating step includes: a step of irradiating the exposed portion of the foil exposed portion, at least an exposed portion adjacent to the undried protective layer, with the linear P-polarized laser light at an incident angle of 25 degrees to 88 degrees to heat the exposed portion. Manufacturing method of strip-shaped electrode plate.

3. A method for manufacturing a strip-shaped electrode plate according to claim 1 or 2, comprising: The protective layer drying step includes: In parallel with the protective layer heating step, The method also includes a protective layer hot air drying step of applying hot air to a hot air heating portion of the undried protective layer, including the protective layer irradiated portion, to heat and dry the protective layer. Manufacturing method of strip-shaped electrode plate.

4. A method for manufacturing a strip-shaped electrode plate according to claim 1 or 2, comprising: The undried strip electrode plate is a wet active material layer that will become the active material layer upon drying is provided on the current collecting foil in addition to the wet protective layer, The protective layer drying step includes: a step of drying the undried active material layer. Manufacturing method of strip-shaped electrode plate.

5. A method for manufacturing a strip-shaped electrode plate according to claim 4, The protective layer heating step includes: a step of irradiating the irradiated portion of the active material layer included in the wet active material layer with the linear P-polarized laser light to heat it. Manufacturing method of strip-shaped electrode plate.

6. A method for manufacturing a strip-shaped electrode plate according to claim 4, The protective layer drying step includes: In parallel with the protective layer heating step, a laser heating step of irradiating the wet active material layer with a laser beam different from the linear P-polarized laser beam to heat the wet active material layer; Manufacturing method of strip-shaped electrode plate.

7. a strip-shaped current collecting foil extending in the longitudinal direction; an active material layer provided on a surface of the current collecting foil, leaving a foil exposed portion where the current collecting foil is exposed; a protective layer provided between the foil exposed portion and the active material layer. A manufacturing apparatus for a strip-shaped electrode plate, a conveying unit that conveys, in a conveying direction that coincides with the longitudinal direction, a wet strip-shaped electrode plate having a wet protective layer that becomes the protective layer by drying provided on the current collecting foil; a protective layer drying unit that dries the undried protective layer, The protective layer drying section a protective layer heating unit that heats the wet protective layer by irradiating a protective layer irradiated portion included in the wet protective layer with linear P-polarized laser light that is linearly polarized and P-polarized at an incident angle of 20 to 67 degrees; Manufacturing equipment for strip-shaped electrode plates.

8. The manufacturing apparatus for a strip-shaped electrode plate according to claim 7, The current collecting foil is made of aluminum, The protective layer heating unit includes: The linear P-polarized laser beam is irradiated at an incident angle of 25 degrees to 88 degrees to heat an exposed portion of the foil exposed portion, which is included in at least an adjacent exposed portion adjacent to the undried protective layer. Manufacturing equipment for strip-shaped electrode plates.

9. The manufacturing apparatus for a strip-shaped electrode plate according to claim 7 or 8, The protective layer drying section The protective layer heating unit also includes a protective layer hot air drying unit that applies hot air to a hot air heating portion of the undried protective layer including the irradiated portion of the protective layer, in parallel with the irradiation of the linear P-polarized laser light by the protective layer heating unit, to heat and dry the undried protective layer. Manufacturing equipment for strip-shaped electrode plates.

10. The manufacturing apparatus for a strip-shaped electrode plate according to claim 9, The protective layer hot air drying unit includes: a hot air blowing section for blowing the hot air, on one side of the hot air heating portion of the undried protective layer in the conveying direction; a hot air suction section for suctioning the hot air that has been delivered from the hot air delivery section and has heated the hot air heating section of the undried protective layer, the hot air suction section being disposed on the other side of the hot air heating section in the conveying direction; Manufacturing equipment for strip-shaped electrode plates.

11. The manufacturing apparatus for a strip-shaped electrode plate according to claim 7 or 8, the wet strip-shaped electrode plate also has a wet active material layer provided on the current collecting foil, the wet active material layer being formed by drying; The protective layer drying section The undried active material layer is also dried. Manufacturing equipment for strip-shaped electrode plates.

12. The manufacturing apparatus for a strip-shaped electrode plate according to claim 11, The protective layer heating unit includes: The irradiated portion of the active material layer included in the wet active material layer is also heated by irradiating it with the linear P-polarized laser light at an incident angle of 20 degrees to 67 degrees. Manufacturing equipment for strip-shaped electrode plates.

13. The manufacturing apparatus for a strip-shaped electrode plate according to claim 11, The protective layer drying section In parallel with the heating of the wet protective layer by the protective layer heating unit, a laser heating unit that irradiates the wet active material layer with a laser beam different from the linear P-polarized laser beam to heat the wet active material layer; Manufacturing equipment for strip-shaped electrode plates.

Images