Laser drying device

Abstract

[Problem] The present disclosure aims to provide a laser drying device with high drying efficiency capable of uniformly drying an electrode composite layer. [Solution] A laser drying device (100) for drying an electrode composite layer, wherein the laser drying device (100) comprises a laser light source (120) and a furnace body (110), and the laser-transmitting protective plate laminate (112) of the furnace body (110) has a multilayer structure in which a protective plate (upper layer) (112-1) and a protective plate (lower layer) (112-2) are laminated, and the protective plate (upper layer) (112-1) and the protective plate (lower layer) (112-2) are formed by arranging a protective plate piece (upper layer) (112-1A) and a protective plate piece (lower layer) (112-2A) in a planar direction, respectively, and when the laser-transmitting protective plate laminate (112) is viewed in the lamination direction, the boundary portion between a plurality of protective plate pieces (upper layer) (112-1A) and the boundary portion between a plurality of protective plate pieces (lower layer) (112-2A) are A laser drying device (100) that does not match.

Description

Technology Field

[0001] The present disclosure relates to a laser drying device. Background Technology

[0002] Laser drying is known as a drying method for an electrode composite layer coated on a current collector layer. Compared to hot air drying, laser drying is characterized by lower energy consumption and a lower environmental burden. Various proposals have been made to improve drying efficiency and quality regarding laser drying.

[0003] Patent Document 1 discloses a method for manufacturing an electrode body, comprising a conveying process in which an electrode body coated with at least one electrode material is conveyed by a conveying unit, and a drying process in which the electrode material is dried while the electrode body is conveyed by the conveying unit, wherein the drying process comprises an irradiation process in which the electrode material is dried by irradiating a laser onto the electrode material when the electrode body is conveyed to at least one first position in the conveying direction of the conveying unit, and a recovery process in which steam generated due to the laser irradiation onto the electrode material is recovered by a steam recovery unit provided at least one second position adjacent to the first position in the conveying direction. Patent Document 1 states that, according to the disclosure of Patent Document 1, when drying the electrode material by a laser, the decrease in drying efficiency can be suppressed.

[0004] Patent document 2 discloses a method for manufacturing an electrode for a battery in which an active material is fixed on a current collection substrate, comprising a first step of preparing the active material in a powder form to a predetermined thickness, and a second step of laser scanning from the side of the active material in a powder form and binding the active materials in a powder form to each other and fixing the active material to the current collection substrate by the heat of irradiation of the laser light, wherein the first and second steps are repeated until the active material on the current collection substrate reaches a predetermined thickness. According to the disclosure of Patent document 2, it is stated that, after securing production efficiency, it is possible to improve the chargeability of the active material and the electrical resistance, and at the same time, the porosity of the active material can be adjusted according to the particle size of the powder or heating conditions, thereby improving the permeability of lithium ions.

[0005] Patent document 3 discloses a method for manufacturing an electrode sheet, comprising a preparation process for preparing a coated sheet having a coated portion coated with an electrode material on a first surface of a current collection sheet having a longitudinal direction in a first direction, and a drying process for obtaining an electrode sheet by drying the coated portion by irradiating laser light from a plurality of laser heads arranged in a row in the first direction while conveying the coated sheet in the first direction, wherein the drying process supplies hot air with a temperature of 50°C or higher and a wind speed of 5 m / s or higher to a laser irradiation portion of the conveyed coated sheet, where laser light is irradiated from each laser head, during the period until the next laser irradiation. Patent document 3 states that, according to the disclosure of patent document 3, it is possible to manufacture an electrode sheet in which the decrease in peel strength between the electrode layer and the current collection sheet is suppressed while suppressing the increase in drying time. Prior art literature

[0006] Japanese Patent Publication No. 2023-169591, Japanese Patent Publication No. 2007-52934, Japanese Patent Publication No. 2023-20819 The problem to be solved

[0007] The furnace body is equipped with a protective plate having laser transparency, and by irradiating a laser light from a laser light source outside the furnace through the protective plate onto an electrode composite layer inside the furnace body, it is not necessary to place the laser light source inside the high-temperature furnace body, and the laser light source and the furnace body can be insulated.

[0008] In addition, in this case, by reducing the distance between the protective plate and the electrode composite layer, the size of the furnace body can be reduced, thereby increasing drying efficiency. On the other hand, in this case, the distance between the protective plate and the laser light source increases, and since the irradiation area of ​​the laser light on the protective plate increases, it is necessary to prepare a large-area protective plate.

[0009] However, it is difficult to prepare a protective plate composed of materials such as quartz glass as a large-area single sheet. In contrast, while it is conceivable to construct a protective plate by arranging multiple protective plate pieces in parallel in the planar direction, uneven drying of the electrode composite layer may occur because the transmittance of laser light differs between the protective plate pieces themselves and the boundaries between the multiple protective plate pieces.

[0010] Accordingly, the present disclosure aims to provide a laser drying device capable of suppressing drying non-uniformity of the electrode composite layer even when a large-area protective plate is formed by arranging a plurality of protective plate pieces in a planar direction. means of solving the problem

[0011] The present disclosure achieves the above objective by means of the following.

[0012] <Mode 1>

[0013] As a laser drying device for drying an electrode composite layer,

[0014] The above laser drying device comprises a laser light source and a furnace body, and

[0015] The above laser light source irradiates laser light onto the electrode composite layer through a laser-transmitting protective plate laminate of the furnace body, thereby heating and drying the electrode composite layer, and also

[0016] The above protective plate laminate is a multilayer structure in which a plurality of protective plates are laminated, and

[0017] The above protective plate is formed by arranging a plurality of protective plate pieces in a planar direction, and

[0018] A laser drying device in which, when the above-mentioned protective plate laminate is viewed in the lamination direction, the boundary between a plurality of protective plate pieces forming one of the above-mentioned protective plates and the boundary between a plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide.

[0019] <Mode 2>

[0020] The device described in Embodiment 1, wherein two adjacent protective plates are bonded to each other via a fluoropolymer film.

[0021] <Mode 3>

[0022] An apparatus described in Embodiment 1 or 2 that satisfies the following relationship when the distance between the laser light source and the electrode composite layer is x and the distance between the protective plate laminate and the electrode composite layer is y:

[0023] y / x≤0.15.

[0024] <Mode 4>

[0025] The above furnace body is additionally equipped with a hot air supply device, as described in any one of embodiments 1 to 3.

[0026] <Mode 5>

[0027] A method for manufacturing an electrode laminate using an apparatus described in any one of embodiments 1 to 4, wherein

[0028] A method for manufacturing an electrode laminate, comprising irradiating the laser light from the above laser light source through the above laser-transmitting protective plate laminate to the above electrode composite layer coated on the current collector layer. Effects of the invention

[0029] According to the present disclosure, a laser drying device capable of suppressing drying non-uniformity of the electrode composite layer can be provided even when a large-area protective plate is formed by arranging a plurality of protective plate pieces in a planar direction. Brief explanation of the drawing

[0030] FIG. 1 is a schematic diagram for explaining a laser drying apparatus of the present disclosure. FIG. 2 is a schematic diagram for explaining a laser drying apparatus of the present disclosure. FIG. 3 is a schematic diagram for explaining a laser drying apparatus of the present disclosure. FIG. 4 is a schematic diagram for explaining a laser drying apparatus of the present disclosure. FIG. 5 is a schematic diagram illustrating embodiments and comparative examples of the present disclosure. Specific details for implementing the invention

[0031] Laser Drying Device

[0032] As a laser drying device for drying an electrode composite layer,

[0033] The above laser drying device comprises a laser light source and a furnace body, and

[0034] The above laser light source irradiates laser light onto the electrode composite layer through a laser-transmitting protective plate laminate of the furnace body, thereby heating and drying the electrode composite layer, and also

[0035] The above protective plate laminate is a multilayer structure in which a plurality of protective plates are laminated, and

[0036] The above protective plate is formed by arranging a plurality of protective plate pieces in a planar direction, and

[0037] A laser drying device in which, when the above-mentioned protective plate laminate is viewed in the lamination direction, the boundary between a plurality of protective plate pieces forming one of the above-mentioned protective plates and the boundary between a plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide.

[0038] According to the present disclosure, a laser drying device capable of suppressing drying non-uniformity of the electrode composite layer can be provided even when a large-area protective plate is formed by arranging a plurality of protective plate pieces in a planar direction.

[0039] The present inventors considered placing a protective plate in the furnace body to insulate the laser light source from the inside of the furnace body when laser drying an electrode composite layer, thereby allowing laser light from the laser light source to irradiate the electrode composite layer through the protective plate, and reducing the distance between the protective plate and the electrode composite layer to increase drying efficiency. However, when a large-area protective plate with multiple protective plate pieces arranged in parallel was used to reduce the distance between the protective plate and the electrode composite layer, the transmittance of the laser light differed at the protective plate piece itself and at the boundary between the multiple protective plate pieces, and consequently, a variation occurred in the intensity of the laser light irradiated onto the electrode composite layer, resulting in non-uniform drying of the electrode composite layer.

[0040] In this regard, the present inventors have discovered that drying non-uniformity of the electrode composite layer can be suppressed by using a laser-transmitting protective plate laminate having a multilayer structure in which a plurality of protective plates are stacked. Specifically, according to the laser drying apparatus of the present disclosure, when the protective plate laminate is viewed in the stacking direction, the boundary between a plurality of protective plate pieces forming one protective plate and the boundary between a plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide, so the variation in the intensity of the laser light irradiated onto the electrode composite layer is reduced, and accordingly, drying non-uniformity can be suppressed. Furthermore, according to the laser drying apparatus of the present disclosure, the distance between the laser-transmitting protective plate laminate and the electrode composite layer within the furnace can be reduced, thereby increasing drying efficiency.

[0041] Specifically, for example, as shown in FIG. 1, the laser drying device (100) is equipped with a furnace body (110) and a laser light source (120). In addition, the laser drying device (100) has a conveying device (130), and by rotating the conveying roller (132), the electrode composite layer placed on the conveying belt (131) can be moved in a conveying direction at a constant speed. Thus, it is possible to bring the electrode composite layer into the furnace body (110) from outside the furnace body (110) and to take out the electrode composite layer from inside the furnace body (110) to outside the furnace body (110).

[0042] The furnace body (110) is composed of an outer substrate (111) and a laser-transmitting protective plate laminate (112). The electrode composite layer brought into the furnace body (110) by the conveying device (130) is irradiated with laser light (200) through the laser-transmitting protective plate laminate (112) from a laser light source (120) positioned outside the furnace body (110).

[0043] The laser-transmitting protective plate laminate (112) is a multilayer structure in which a protective plate (upper layer) (112-1) and a protective plate (lower layer) (112-2) are stacked in the stacking direction. The protective plate (upper layer) (112-1) is formed by a plurality of protective plate pieces (upper layer) (112-1A) being arranged in parallel in the plane direction, and the protective plate (lower layer) (112-2) is formed by a plurality of protective plate pieces (lower layer) (112-2A) being arranged in parallel in the plane direction. When looking at the laser-transmitting protective plate laminate (112) from the stacking direction (height direction), the boundary of the protective plate piece (upper layer) (112-1A) constituting the protective plate (upper layer) (112-1) and the boundary of the protective plate piece (lower layer) (112-2A) constituting the protective plate (lower layer) (112-2) do not coincide with each other, so the variation in the irradiation intensity of the laser light on the electrode composite layer is suppressed, and the electrode composite layer is dried uniformly.

[0044] Additionally, the laser drying device (100) has a hot air supply device (140), and the hot air supply device (140) is composed of a hot air generator (141), a supply air duct (142), and a supply air nozzle (143). The hot air supply device (140) supplies hot air generated by the hot air generator (141) into the furnace body (110) via the supply air duct (142) and the supply air nozzle (143). Additionally, the hot air is supplied in the direction of return and in the direction opposite to the return direction. Steam near the surface of the electrode composite layer generated by laser irradiation is removed by the hot air and is also discharged outside the furnace body (110) by the exhaust device (150). Accordingly, the drying efficiency of the electrode composite layer can be increased.

[0045] Additionally, although the inside of the furnace body (110) is heated to a high temperature by the hot air, a laser-transmitting protective plate laminate (112) exists between the laser light source (120) and the inside of the furnace body (110), so the laser light source (120) is protected from heat transfer from the inside of the furnace body (110).

[0046] Embodiments of the present disclosure are described in detail below. Furthermore, the present disclosure is not limited to the embodiments described below and may be implemented with various modifications within the scope of the gist of the present disclosure.

[0047] The laser drying device of the present disclosure is a laser drying device for drying an electrode composite layer.

[0048] In relation to the present disclosure, "electrode composite" refers to a composition that can form an electrode active material layer as is or by additionally including other components. And, "electrode composite layer" refers to a layer that includes a dispersion medium in addition to the "electrode composite" and can form an electrode active material layer by coating and drying accordingly.

[0049] The laser drying device of the present disclosure comprises a furnace body and a laser light source. Additionally, the laser drying device may further comprise a hot air supply device, a conveying device, and an exhaust device.

[0050] When the distance between the laser light source and the electrode composite layer is x and the distance between the laser-transmitting protective plate and the electrode composite layer is y, y / x ≤ 0.15, 0.14, 0.13, 0.12, 0.10, 0.08, or 0.05 may be satisfied. By satisfying the above relationship, the drying efficiency of the electrode composite layer increases. In addition, y / x ≥ 0.01, 0.02, 0.03, or 0.04 may be satisfied.

[0051] Specifically, for example, as shown in FIG. 2, the electrode composite layer (300) is placed on a conveyor belt (131) and irradiated with laser light. The x is the shortest distance from the laser light irradiation section of the laser light source (120) to the electrode composite layer (300) in the height direction. Also, the y is the shortest distance from the laser-transmitting protective plate laminate (112) to the electrode composite layer (300) in the height direction.

[0052] The distance (x) between the laser light source and the electrode composite layer is not specifically limited and may be appropriately determined by considering the irradiation area of ​​the laser light, etc. The distance (x) may, for example, be 300 mm or more, 500 mm or more, 1000 mm or more, 1500 mm or more, 2000 mm or more, or 5000 mm or less, 4000 mm or less, or 3000 mm or less. In addition, the laser light source may be placed inside the furnace body or outside the furnace body.

[0053] The distance (y) between the laser-transmitting protective plate laminate and the electrode composite layer is not specifically limited and may be appropriately determined by considering y / x or the thickness of the electrode composite layer. The distance (y) may, for example, be 5 mm or more, 10 mm or more, 30 mm or more, 50 mm or more, or 100 mm or more, or 750 mm or less, 500 mm or less, 400 mm or less, or 300 mm or less.

[0054] Noche

[0055] The furnace body is provided with a laser-transmitting protective plate laminate. As shown in FIG. 1, the furnace body has an outer substrate and a laser-transmitting protective plate laminate. At least a portion of the outer surface of the furnace body may be a laser-transmitting protective plate laminate. The placement position of the laser-transmitting protective plate laminate may be a position where laser light generated from a laser light source can be irradiated onto the electrode composite layer without omission through the laser-transmitting protective plate laminate.

[0056] The material of the outer casing is not particularly limited and may be, for example, steel, stainless steel, aluminum, etc. The outer casing may be surface-treated, such as by galvanizing or powder coating. The size of the furnace body is not particularly limited and may be appropriately determined by considering the dimensions of the electrode composite layer, etc.

[0057] The dimensions of the furnace body are not specifically limited and may be appropriately determined by considering the dimensions of the electrode composite layer, etc. Additionally, the furnace body may have an opening for introducing and removing the electrode composite layer by means of a conveying device.

[0058] In order to increase the drying efficiency of the electrode composite layer, it is desirable for the furnace body to have high thermal insulation properties, and it may have an insulating material on the outer side of the outer substrate. Examples of insulating materials include fire brick, ceramic fiber, glass wool, etc.

[0059] (Laser-transmitting protective plate laminate)

[0060] The laser protection plate laminate is a multilayer structure in which a plurality of protection plates are laminated. The number of laminated protection plates is not particularly limited, but it is desirable that the number be such that the position of the boundary portion of each protection plate constituting each protection plate is not offset when the laser protection plate laminate is observed in the lamination direction. The number of laminated protection plates may be, for example, 2 or more, 3 or more, 4 or more, or 5 or more, or 10 or fewer, 9 or fewer, 8 or fewer, or 7 or fewer.

[0061] Two adjacent protective plates may be bonded together with a fluoropolymer film interposed therebetween. By placing a fluoropolymer film in between, the thermal insulation of the laser protective plate laminate can be improved. In addition, since the laser transmittance of the fluoropolymer film is high, the effect on drying efficiency is minimal.

[0062] Fluoropolymer films are thin films of resins containing fluorine, and materials such as fluoroethylene propylene (FEP) and polytetrafluoroethylene (PTFE) can be used.

[0063] The thickness of the fluoropolymer film is not particularly limited and may be appropriately determined considering the thermal insulation performance or drying efficiency of the laser protection plate laminate. The thickness may, for example, be 10 μm or more, 50 μm or more, or 100 μm or more, or 300 μm or less, 250 μm or less, or 200 μm or less.

[0064] Two adjacent protective plates may be bonded together using an adhesive. As for the adhesive, an adhesive with high laser light transmittance and high heat resistance that can be applied to optical devices is preferred. The adhesive may be, for example, a UV-curing adhesive, an epoxy-based adhesive, etc.

[0065] An air gap may be provided between two adjacent protective plates. By having an air gap, the thermal insulation of the laser protective plate laminate can be improved.

[0066] A protective plate is formed by arranging a plurality of protective plate pieces in a plane direction. In relation to the present disclosure, the "plane direction" of the protective plate pieces refers to a direction parallel to the main surface (largest surface) of the protective plate pieces. Specifically, for example, it is any direction perpendicular to the height direction in FIG. 1, and as in FIG. 3, the protective plate pieces may be arranged in the width direction and the return direction. In addition, the laser-transmitting protective plate laminate (112) of FIG. 3 is a top view of the laser-transmitting protective plate laminate (112) of FIG. 1, and is composed by stacking a protective plate (upper layer) (112-1) and a protective plate (lower layer) (112-2). The boundary of the six protective plate pieces constituting the protective plate (upper layer) (112-1) is indicated by a solid line, and the boundary of the twelve protective plate pieces constituting the protective plate (lower layer) (112-2) is indicated by a dashed line.

[0067] The number of protective plate pieces is not specifically limited and may be appropriately determined by considering the positional relationship of the boundary portions of the protective plates, the dimensions of the protective plate pieces, and the irradiation area of ​​the laser-transmittable protective plate laminate.

[0068] When the protective plate laminate is viewed in the stacking direction, the boundary between the plurality of protective plate pieces forming one protective plate and the boundary between the plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide. "Stacking direction" refers to the height direction in FIG. 1, and FIG. 3 is a view of the laser-transmitting protective plate laminate (112) in the stacking direction. "The boundary between the plurality of protective plate pieces forming one protective plate and the boundary between the plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide" means that in FIG. 3, the boundary of the protective plate piece in the upper layer does not coincide with the boundary of the protective plate piece constituting the lower layer, at least partially. That is, in FIG. 3, it means that there is a dashed line that does not overlap with the solid line.

[0069] The boundary surface of two protective plate pieces adjacent to each other in the plane direction may be parallel to the height direction as in FIG. 4 (a), or it may be inclined rather than parallel to the height direction as in FIG. 4 (b). By being inclined, the boundary surface of the two protective plate pieces can be made non-parallel to the irradiation direction of the laser light (200) even directly below the laser light source (120), thereby mitigating the influence of the boundary and suppressing uneven drying.

[0070] Two protective plate pieces adjacent to each other in the plane direction may be bonded together by an adhesive. As for the adhesive, an adhesive with high laser light transmittance and high heat resistance that can be applied to optical devices is preferred. The adhesive may be, for example, a UV-curing adhesive, an epoxy-based adhesive, etc.

[0071] The transmittance of the laser light of the protective plate may be 95.0% or more, 96.0% or more, 97.0% or more, 98.0% or more, 99.0% or more, 99.5% or more, or 99.8% or more with respect to the laser light irradiated from the laser light source, or it may be 100.0% or less or 99.9% or less. By having a high transmittance of the laser light, the light energy generated from the laser light source can be supplied to the electrode composite layer without waste.

[0072] The transmittance of the laser light is the transmittance at that wavelength when the laser light is of a single wavelength, and the transmittance at the wavelength with the highest intensity when the laser light is of multiple wavelengths. The transmittance of the laser light can be measured by spectrophotometry using an ultraviolet-visible-near-infrared spectrophotometer (Solid Spec-3700DUV manufactured by Shimadzu Corporation).

[0073] The material of the protective plate may be glass. Glass may be, for example, quartz glass, soda-lime glass, lead glass, borosilicate glass, alkali glass, etc.

[0074] The protective plate may be double-pane glass. By being double-pane glass, thermal insulation performance is improved. The double-pane glass may have air, argon gas, krypton gas, etc. sealed between the multiple panes of glass.

[0075] The thickness of the protective plate is not specifically limited and may be appropriately determined according to the material of the laser-transmitting protective plate. The thickness of the laser-transmitting protective plate may be, for example, 1 mm or more, 3 mm or more, 5 mm or more, 7 mm or more, or 10 mm or more, or 30 mm or less, 25 mm or less, 20 mm or less, or 15 mm or less.

[0076] The dimensions of the protective plate are not particularly limited and may be dimensions such that when a plurality of transparent plate pieces are combined, the laser light generated from the laser light source can pass through the interior of the furnace without omission.

[0077] The thermal conductivity of the protective plate is not particularly limited and may be 1.50 W / (M·K) or less, 1.40 W / (M·K) or less, 1.38 W / (M·K) or less, 1.35 W / (M·K) or less, 1.30 W / (M·K) or less, 1.20 W / (M·K) or less, 1.10 W / (M·K) or less, or 1.00 W / (M·K) or less, or may be 0.10 W / (M·K) or more, 0.30 W / (M·K) or more, or 0.50 W / (M·K) or more. As the thermal conductivity is low, the laser light source becomes less susceptible to the influence of the temperature inside the furnace body.

[0078] Thermal conductivity can be measured by the heat flow meter method according to ASTM-E-1530.

[0079] Laser light source

[0080] A laser light source irradiates laser light onto an electrode composite layer through a laminate of laser-transmitting protective plates of a furnace body, thereby heating and drying the electrode composite layer.

[0081] The energy density of the laser light irradiated from a laser light source onto the electrode composite layer inside the drying oven is not particularly limited, and, for example, 0.1 W / cm² 2 Above, 0.5W / cm² 2 Above, 1.0W / cm² 2 Above, 2.0W / cm² 2 Above, or 3.0W / cm² 2 It can be higher, 20.0 W / cm² 2 Below, 10.0W / cm² 2 Below, 7.0W / cm² 2 Less than, or 4.0W / cm² 2 It is acceptable to do the following.

[0082] The laser light source may be placed outside the furnace. If the inside of the furnace is at a high temperature, the laser light source can be protected from high heat by placing an insulated laser light source outside the furnace.

[0083] The type of laser light source is not particularly limited and may be, for example, a Yb fiber laser, a YAG laser, a carbon dioxide laser, etc. The wavelength of the laser light may be 0.5 µm or more, 0.6 µm or more, 0.7 µm or more, 0.8 µm or more, or 0.9 µm or more, and may be 1.5 µm or less, 1.4 µm or less, 1.3 µm or less, 1.2 µm or less, or 1.1 µm or less. The laser light may be of a single wavelength or multiple wavelengths.

[0084] The output of the laser light source is not specifically limited and may be appropriately determined according to the laser light irradiation area, the laser light irradiation time, etc. The output of the laser light source may be, for example, 0.1 kW or more, 1 kW or more, 5 kW or more, 10 kW or more, 15 kW or more, 20 kW or more, or 30 kW or more, or 100 kW or less, 70 kW or less, or 50 kW or less.

[0085] The number of laser light sources is not specifically limited and may be appropriately determined according to the laser light irradiation area, the laser light irradiation time, etc. The number of laser light sources may, for example, be 1 or more, 2 or more, 3 or more, 5 or more, or 10 or more, or 30 or fewer, or 20 or fewer.

[0086] The shape of the irradiation area of ​​the laser light on the electrode composite layer may be, for example, rectangular. In addition, the size of the irradiation area is not particularly limited and may be appropriately determined according to the dimensions of the electrode composite layer.

[0087] Hot air supply device

[0088] The hot air supply device supplies hot air into the furnace body. By supplying hot air to the electrode composite layer, steam on the surface of the electrode composite layer can be removed, thereby increasing drying efficiency.

[0089] The temperature of the hot air supplied from the hot air supply device may be 50°C or higher, 100°C or higher, 130°C or higher, 150°C or higher, 160°C or higher, 180°C or higher, 200°C or higher, 220°C or higher, 240°C or higher, 260°C or higher, 280°C or higher, or 300°C or higher, or 500°C or lower, 450°C or lower, 400°C or lower, or 350°C or lower.

[0090] The hot air supply device is not particularly limited and may supply air heated by, for example, gas combustion, oil combustion, electric heating, etc., to the electrode composite layer via a blower fan, blower duct, and blower nozzle. From the perspective of drying the electrode composite layer, it is preferable that the hot air has low humidity.

[0091] The direction of hot air supply is not particularly limited; for example, when the electrode composite layer is conveyed within the furnace body, the direction may be opposite to the conveying direction. Additionally, multiple blower nozzles may be arranged, and each may be positioned to have a different supply direction.

[0092] The speed of the hot air is not specifically limited and may be, for example, 5 m / s or more, 10 m / s or more, 15 m / s or more, or 20 m / s or more. If the air speed is high, the drying efficiency of the electrode composite layer increases. In addition, the speed of the hot air may be 60 m / s or less, 50 m / s or less, 40 m / s or less, or 30 m / s or less.

[0093] Exhaust equipment

[0094] The laser drying device may be equipped with an exhaust device. By having an exhaust device, steam generated from the electrode composite layer can be recovered, thereby increasing drying efficiency. Furthermore, the steam is water vapor or other gases.

[0095] The exhaust device may be configured to draw steam from an exhaust port, for example by an exhaust fan, and discharge the steam to the outside of the furnace body via an exhaust duct. The output of the exhaust fan and the dimensions of the exhaust port and exhaust duct may be appropriately determined by taking into account the amount of steam generated, the internal pressure of the furnace body, etc.

[0096] It is desirable for the exhaust port to be positioned above the electrode composite layer and in a location that does not interfere with laser irradiation, from the perspective of increasing drying efficiency. The distance between the exhaust port and the electrode composite layer may be sufficient to allow for the suction of steam. The number of exhaust ports is not particularly limited.

[0097] <Return Device>

[0098] The conveying device is not particularly limited and may be, for example, a roller conveyor, a belt conveyor, etc. The electrode composite layer may be, for example, placed on a conveying path, brought into the furnace body, and taken out of the furnace body.

[0099] The electrode composite layer may be irradiated with laser light while being conveyed into the furnace body by a conveying device. In this case, the conveying speed may be appropriately determined by considering the output of the laser light source, the amount of energy required for drying the electrode composite layer, etc. The conveying speed may be, for example, 0.1 m / s or more, 0.3 m / s or more, 0.5 m / s or more, or 1.0 m / s or more, or 3.0 m / s or less, 2.5 m / s or less, or 2.0 m / s or less.

[0100] The conveying device may be connected to other devices, such as a coating device for the electrode composite layer and a winding device for the electrode laminate.

[0101] Method for manufacturing an electrode laminate

[0102] A method for manufacturing an electrode laminate using the laser drying apparatus of the present disclosure,

[0103] A method for manufacturing an electrode laminate, comprising irradiating the laser light from the above laser light source through the above laser-transmitting protective plate laminate to the above electrode composite layer coated on the current collector layer.

[0104] According to the present disclosure, a method for manufacturing an electrode laminate can be provided that suppresses drying non-uniformity of the electrode composite layer even when a large-area protective plate is formed by arranging a plurality of protective plate pieces in a planar direction.

[0105] The method of the present disclosure is a method for manufacturing an electrode laminate using the laser drying apparatus of the present disclosure. For the laser drying apparatus, reference may be made to the description of the laser drying apparatus above.

[0106] The method of the present disclosure comprises irradiating a laser light from a laser light source through a laser-transmitting protective plate laminate onto an electrode composite layer coated on a current collector layer. For the laser light source, the laser-transmitting protective plate laminate, the electrode composite layer, and the laser light, reference may be made to the description of the laser drying apparatus above. By irradiating the electrode composite layer with laser light, the dispersion medium contained in the electrode composite layer volatilizes, and an electrode active material layer is formed.

[0107] The dispersion medium contained in the electrode composite layer is not particularly limited and may be, for example, a nonpolar solvent such as heptane, xylene, and toluene, and a polar solvent such as water, a tertiary amine solvent, an ether solvent, a thiol solvent, a ketone solvent (e.g., diisobutyl ketone) and an ester solvent (e.g., butyl butyrate).

[0108] The content of the dispersion medium is not particularly limited, and, for example, may be an amount in which the solid content of the electrode composite layer is 30% or more, 35% or more, 40% or more, 45% or more, or 50% or more, or an amount in which it is 80% or less, 75% or less, 70% or less, 65% or less, or 60% or less.

[0109] The method of coating the electrode composite layer is not particularly limited and may include the doctor blade method, die coating method, gravure coating method, spray coating method, electrostatic coating method, bar coating method, etc.

[0110] The irradiation time of the laser light is not particularly limited and may be irradiated, for example, until the rate drying period of the electrode composite layer is reached. The irradiation time of the laser light may, for example, be 30 seconds or more, 1 minute or more, or 2 minutes or more, or 30 minutes or less, 20 minutes or less, or 10 minutes or less.

[0111] Electrode stack

[0112] The electrode laminate may have an electrode active material layer and a current collector layer. The electrode active material layer may be a positive electrode active material layer or a negative electrode active material layer. Additionally, the electrode laminate may be a bipolar electrode laminate having a positive electrode active material layer and a negative electrode active material layer.

[0113] (Electrode active material layer)

[0114] When the electrode active material layer of the present disclosure is a positive electrode active material layer, the positive electrode active material layer comprises at least a positive electrode active material. Additionally, when the electrode active material layer is a negative electrode active material layer, the negative electrode active material layer comprises at least a negative electrode active material. The electrode active material layer may optionally further comprise a binder, a solid electrolyte, and a conductive additive, etc. The electrode active material layer may also comprise various other additives. The respective contents of the positive electrode active material, negative electrode active material, binder, solid electrolyte, conductive additive, etc. in the electrode active material layer may be appropriately determined according to the intended battery performance.

[0115] The material of the positive electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium ions. Examples of positive electrode active materials include lithium cobaltate (LiCoO2), lithium nickelate (LiNiO2), lithium manganate (LiMn2O4), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), and nickel-cobalt-manganese oxide (NCM: LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2), nickel, cobalt, and lithium aluminum (LiNi 0.8 (CoAl) 0.2 O2), Li 1+x Mn 2-x-y M y It may be a heterogeneous element-substituted Li-Mn spinel with a composition represented by O4 (where M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn), but is not limited to these.

[0116] The shape of the positive electrode active material is not particularly limited, as long as it is a shape common for a positive electrode active material of a battery. The positive electrode active material may, for example, be in the form of particles. The positive electrode active material may be primary particles or secondary particles formed by the aggregation of multiple primary particles. Average particle size D of the positive electrode active material 50 Silver, for example, may be 1 nm or more, 5 nm or more, or 10 nm or more, and may also be 500 µm or less, 100 µm or less, 50 µm or less, or 30 µm or less. In addition, the average particle size D 50 The particle size (median diameter) at 50% of the cumulative value in the volume-based particle size distribution obtained by laser diffraction and scattering methods.

[0117] As a negative electrode active material, various materials may be employed in which the potential for absorbing and releasing lithium ions (charge / discharge potential) is a lower potential compared to the positive electrode active material of the present disclosure. The material of the negative electrode active material is not particularly limited and may be metallic lithium, or may be a material capable of absorbing and releasing metal ions such as lithium ions. Examples of materials capable of absorbing and releasing metal ions such as lithium ions include alloy-based negative electrode active materials, carbon materials, or lithium titanate (Li4Ti5O2). 12 Examples include ), but are not limited to these.

[0118] As for alloy-based negative electrode active materials, they are not particularly limited and, for example, Si alloy-based negative electrode active materials or Sn alloy-based negative electrode active materials may be used. Si alloy-based negative electrode active materials include silicon, silicon oxide, silicon carbide, silicon nitride, or solid solutions thereof. In addition, Si alloy-based negative electrode active materials may include metal elements other than silicon, for example, Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. Sn alloy-based negative electrode active materials include tin, tin oxide, tin nitride, or solid solutions thereof. In addition, Sn alloy-based negative electrode active materials may include metal elements other than tin, for example, Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0119] Carbon materials are not particularly limited and, for example, hard carbon, soft carbon, graphite, etc.

[0120] The shape of the negative electrode active material is not particularly limited, but any shape common to negative electrode active materials of a battery is sufficient. The negative electrode active material may, for example, be in the form of particles or sheets.

[0121] The material of the binder is not particularly limited. The binder may be, for example, polyvinylidene fluoride (PVdF), butadiene rubber (BR), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), etc., but is not limited to these. The binder is not particularly limited, but may be used as a single type or as a combination of two or more types.

[0122] The material of the solid electrolyte is not particularly limited and may be, for example, a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer electrolyte.

[0123] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, or azirodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include the Li2S-P2S5 system (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2 (Li 13 GeP3S 16 , Li 10 GeP2S 12 etc.), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x PS 6-x Cl x Etc.; or combinations thereof, but are not limited to these.

[0124] As an example of an oxide solid electrolyte, Li7La3Zr2O 12 , Li 7-x La3Zr 1-x Nb x O 12 , Li 7-3x La3Zr2Al x O 12 , Li 3x La 2 / 3-x TiO3, Li 1+x Al x Ti2-x (PO4)3, Li 1+x Al x Ge 2-x (PO4)3, Li3PO4, or Li 3+x PO 4-x N x (LiPON) etc.; or combinations thereof may be cited, but are not limited to these.

[0125] Sulfide solid electrolytes and oxide solid electrolytes may be glass or crystallized glass (glass ceramic).

[0126] Examples of polymer electrolytes include polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof, but are not limited to these.

[0127] The conductive agent is not particularly limited. The conductive agent may be, for example, vapor-grown carbon fiber (VGCF), acetylene black (AB), Ketjen black (KB), carbon nanotubes (CNT), carbon nanofibers (CNF), etc., but is not limited to these. The conductive agent may be, for example, in the form of particles or fibers, and its size is not particularly limited. The conductive agent is not particularly limited, but may be used alone or may be used in combination of two or more types.

[0128] (All floors of the house)

[0129] The material of the current collector layer is not particularly limited, but any material commonly used as a conductor for the electrode of a battery may be appropriately adopted. Examples of materials for the conductor layer include Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, etc., but are not limited to these. Furthermore, the current collector layer may be a metal foil or a substrate on which the above metals are plated or deposited.

[0130] The shape of the current collector layer is not particularly limited, but examples include a thin film shape, a plate shape, or a mesh shape. Among these, a thin film shape is preferred.

[0131] The thickness of the current collector layer is not particularly limited, but may be 0.1 μm or more, or 1 μm or more, or 1 mm or less, or 100 μm or less.

[0132] [Example]

[0133] The present invention will be specifically explained by examples and comparative examples, but the present invention is not limited thereto.

[0134] Evaluation of Uniform Drying

[0135] Laser Drying Device

[0136] As shown in FIG. 5 (a) and (b), a protective plate (upper layer) (112-1) and a protective plate (lower layer) (112-2) (thickness 1.5 mm each) were bonded with a fluoropolymer film (112-3) with a thickness of 100 μm interposed to produce a protective plate laminate (width direction 1200 mm × transport direction 1500 mm × thickness 3.1 mm).

[0137] Here, as shown in FIG. 5(a), the protective plate (upper layer) (112-1) consists of two quartz glass plates arranged side by side, and the protective plate (lower layer) (112-2) consists of three quartz glass plates arranged side by side, and this is referred to as the protective plate laminate of Example 1. In addition, the boundary surface of adjacent protective plate plates is perpendicular to the conveying direction.

[0138] As shown in FIG. 5(b), the protective plate (upper layer) (112-1) consists of two quartz glass plates placed side by side, and the protective plate (lower layer) (112-2) consists of five quartz glass plates placed side by side, and this is referred to as the protective plate laminate of Example 2. In addition, the boundary surface of adjacent protective plate pieces is not perpendicular to the conveying direction but is oblique.

[0139] As shown in Fig. 5(c), a protective plate having two pieces of protective plate placed side by side instead of a laminated protective plate was referred to as the protective plate of Comparative Example 1.

[0140] In addition, a laser drying apparatus having the configuration of FIG. 1, having a protective plate laminate or protective plate of Examples 1 and 2 and Comparative Example 1, was referred to as the laser drying apparatus of Examples 1 and 2 and Comparative Example 1. Furthermore, the laser light source has an output of 20 kW and is positioned so as to irradiate laser light onto the protective plate laminate or protective plate of Examples 1 and 2 and Comparative Example 1 in an irradiation area of ​​1300 mm in the conveying direction and 1000 mm in the width direction. In addition, the hot air supply device can supply hot air at 120°C into the furnace body. Furthermore, the protective plate laminate or protective plate is positioned so that the distance from the electrode composite layer is 200 mm.

[0141] Measurement of Drying Time

[0142] In the laser drying apparatus of Examples 1 and 2 and Comparative Example 1, the electrode composite layer (solid content 55%, basis weight: 35 mg / cm² 2 The electrode composite layer was dried, and the drying time was measured at positions A and B in Fig. 5. The results are shown in Table 1. In addition, the temperatures at positions A and B were continuously measured using a radiation thermometer, and the timing at which the rate of drying began was defined as the drying time.

[0143]

[0144] From Table 1, it can be understood that although Comparative Example 1 shows a significant discrepancy in drying time between position A and position B, the discrepancy is resolved when a laser-transmitting protective plate laminate with a multilayer structure in which a plurality of protective plates are stacked is used, as in Examples 1 and 2, and when the protective plate laminate is viewed in the stacking direction, the boundary between the plurality of protective plate pieces forming one protective plate and the boundary between the plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide. Accordingly, the laser drying apparatus of the present disclosure can uniformly dry the electrode composite layer.

[0145] Evaluation of Drying Efficiency

[0146] Laser Drying Device

[0147] A laser drying apparatus was prepared as Reference Examples 1 to 5 and Reference Comparative Example 1, with the same configuration as in FIG. 1 except that the laser-transmitting protective plate laminate was a single-plate protective plate, and the distance (y) between the protective plate and the electrode composite layer was adjusted as shown in Table 2. In addition, the distance (x) between the laser light source and the electrode composite layer was 1500 mm. In addition, the material of the protective plate was quartz glass, and the transmittance of the laser light generated from a laser light source with an output of 20 kW was 99.8% at a wavelength of 970 nm. The transmittance of the laser light was measured by spectrophotometry using an ultraviolet-visible-near-infrared spectrophotometer (Solid Spec-3700DUV manufactured by Shimadzu Corporation). The temperature of the hot air supplied from the hot air supply device was 120°C.

[0148] <Measurement of Drying Time>

[0149] Electrode composite layer (solid content 55%, basis weight: 35 mg / cm²) using the laser drying apparatus of Reference Examples 1 to 5 and Reference Comparative Example 1 2The electrode composite layer was dried, and the drying time was measured. The results are shown in Table 2. In addition, the temperature of the center of the electrode composite layer was continuously measured using a radiation thermometer, and the timing at which the center of the electrode composite layer entered falling rate drying was defined as the drying time.

[0150]

[0151] From Reference Examples 1 to 5 and Reference Comparative Example 1, it can be understood that the drying time is shortened as y / x is reduced. Therefore, by using a large-area laser-transmitting protective plate to reduce y / x, the drying efficiency can be increased. Explanation of the symbols

[0152] 100 Laser Drying Device 110 Noche 111 External Equipment 112 Laser-transmitting protective plate laminate 112-1 Protective plate (upper layer) 112-1A Protective plate piece (upper layer) 112-2 Protective plate (lower layer) 112-2A Protective plate piece (lower layer) 112-3 Fluoropolymer film 120 laser light source 130 return devices 131 Return Belt 132 Return Roller 140 hot air supply device 141 Hot Air Generator 142 supply air duct 143 Supply Nozzle 150 exhaust devices 200 laser beams 300 electrode composite layer

Claims

Claim 1 A laser drying device for drying an electrode composite layer, wherein the laser drying device comprises a laser light source and a furnace body, wherein the laser light source irradiates laser light onto the electrode composite layer through a laser-transmitting protective plate laminate of the furnace body to heat and dry the electrode composite layer, wherein the protective plate laminate is a multilayer structure in which a plurality of protective plates are laminated, and wherein the protective plate is formed by a plurality of protective plate pieces being arranged in parallel in a planar direction, and wherein, when the protective plate laminate is viewed from the lamination direction, the boundary between a plurality of protective plate pieces forming one protective plate and the boundary between a plurality of protective plate pieces forming another protective plate adjacent thereto do not coincide. Claim 2 A device according to claim 1, wherein two adjacent protective plates are bonded to each other via a fluoropolymer film. Claim 3 An apparatus according to claim 1 or 2, satisfying the following relationship when the distance between the laser light source and the electrode composite layer is x and the distance between the protective plate laminate and the electrode composite layer is y: y / x ≤ 0.

15. Claim 4 A device according to claim 1 or 2, wherein the furnace body further comprises a hot air supply device. Claim 5 A method for manufacturing an electrode laminate using the apparatus described in claim 1 or 2, comprising irradiating the laser light from the laser light source through the laser-transmitting protective plate laminate to the electrode composite layer coated on the current collector layer.

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