Method for manufacturing electrode for battery and battery electrode manufacturing system

Abstract

To provide a battery electrode manufacturing method capable of suppressing the formation of air bubbles in an active material layer formed on a current collector and improving the uniformity of the active material layer.SOLUTION: A battery electrode manufacturing method includes the steps of: removing gas inside a powdery active material 25 by placing the active material under reduced pressure; sending a degassed active material 25v to a supply device 3 arranged inside a chamber 2 whose pressure is reduced below atmospheric pressure; and supplying the active material to a strip-shaped base film 23 by a supply device inside the chamber.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an electrode for a battery and a battery electrode manufacturing system.

Background Art

[0002] A lithium-ion battery generally includes a positive electrode having a positive electrode active material layer formed on the surface of a positive electrode current collector, and a negative electrode having a negative electrode active material layer formed on the surface of a negative electrode current collector, which are laminated via a separator. As a process for manufacturing this lithium-ion battery, for example, as described in Patent Document 1, it is known to have an electrode manufacturing process in which an active material is supplied onto a current collector and then the active material is compressed.

[0003] Further, Patent Document 2 describes a manufacturing process of a lithium-ion battery in which a positive electrode frame and a negative electrode frame are formed, a positive electrode active material layer and a negative electrode active material layer are formed inside the positive electrode frame and the negative electrode frame, and then a positive electrode current collector and a negative electrode current collector are arranged so as to cover the positive electrode frame and the positive electrode active material layer and the negative electrode frame and the negative electrode active material layer, respectively.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, when manufacturing an electrode for a battery, the battery electrode may be molded with bubbles remaining in the active material layer. If bubbles remain in the active material layer, for example, when compressing the active material layer formed on the current collector as described in Patent Document 1, there is a risk that the active material may fly off or irregularities may be formed on the surface of the active material. Further, if bubbles remain in the active material layer, it becomes difficult to uniformly form the active material layer inside the frame body described in Patent Document 2, for example. As a result, problems may also occur when taking a step of manufacturing a battery by disposing a current collector on the surface of the active material layer (for example, the manufacturing step described in Patent Document 2).

[0006] An object of the present invention is to provide a method for manufacturing an electrode for a battery and a battery electrode manufacturing system that can suppress the generation of bubbles in the active material layer formed on the current collector and improve the uniformity of the active material layer.

Means for Solving the Problems

[0007] The method for manufacturing an electrode for a battery according to the present invention includes a step of removing gas inside the active material by placing the powdery active material under reduced pressure, a step of sending the active material from which the gas has been removed to a supply device disposed inside a chamber that is depressurized from atmospheric pressure, and a step of supplying the active material to a strip-shaped base material film by the supply device inside the chamber.

Effects of the Invention

[0008] According to the present invention, it is possible to suppress the generation of bubbles in the active material layer formed on the current collector and improve the uniformity of the active material layer.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0010] Hereinafter, a battery electrode manufacturing method and a battery electrode manufacturing system according to embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, the components in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[0011] [Embodiment] An embodiment will be described with reference to FIGS. 1 to 5. The present embodiment relates to a battery electrode manufacturing method and a battery electrode manufacturing system. FIG. 1 is a schematic configuration diagram of a lithium-ion single battery, FIG. 2 is a schematic configuration diagram of a battery electrode manufacturing system according to the embodiment, FIG. 3 is a diagram showing a part of the battery electrode manufacturing system, FIG. 4 is a diagram showing a degassing device of the embodiment, and FIG. 5 is a diagram of a sealed pressure-resistant container.

[0012] The battery electrode manufacturing method and the battery electrode manufacturing system of the present embodiment are applied, for example, to the manufacture of lithium-ion batteries. Lithium-ion batteries are used in the form of assembled batteries in which a plurality of lithium-ion single batteries (battery cells) are combined and modularized, or battery packs in which such assembled batteries are combined in a plurality to adjust the voltage and capacity.

[0013] FIG. 1 is a schematic configuration diagram of a lithium-ion single battery 10. In the lithium-ion single battery 10, a positive electrode current collector layer 111, a positive electrode active material layer 113, a separator 130, a negative electrode active material layer 123, and a negative electrode current collector layer 121 are laminated in the order shown in FIG. 1. That is, the positive electrode current collector layer 111 and the negative electrode current collector layer 121 are disposed on the outermost layers. Further, a frame body 140 seals the edges of the positive electrode current collector layer 111 and the negative electrode current collector layer 121 (the outer peripheries of the positive electrode active material layer 113 and the negative electrode active material layer 123). An electrolytic solution is enclosed in the positive electrode active material layer 113 and the negative electrode active material layer 123.

[0014] As the positive electrode current collector layer 111, a current collector used in a known lithium-ion single battery can be used. For example, a resin current collector composed of a known metal current collector and a conductive material and a resin (such as the resin current collector described in JP-A-2012-150905 and International Publication No. 2015-005116, etc.) can be used. From the viewpoint of battery characteristics and the like, the positive electrode current collector layer 111 is preferably a resin current collector.

[0015] The positive electrode active material layer 113 is preferably a non-binder body of a mixture containing a positive electrode active material. Here, the non-binder body means that the position of the positive electrode active material in the positive electrode active material layer is not fixed, and the positive electrode active materials and the positive electrode active materials and the positive electrode active material and the current collector are not irreversibly fixed. When the positive electrode active material layer 113 is a non-binder body, since the positive electrode active materials are not irreversibly fixed, the interface between the positive electrode active materials can be separated without mechanically breaking it, and even when stress is applied to the positive electrode active material layer 113, the positive electrode active material can move to prevent the positive electrode active material layer 113 from being broken, which is preferable. The non-binder positive electrode active material layer 113 can be obtained by a method such as making the positive electrode active material layer 113 a positive electrode active material layer containing a positive electrode active material and an electrolytic solution and not containing a binder.

[0016] Examples of the positive electrode active material include, but are not particularly limited to, composite oxides of lithium and transition metals, composite oxides having two transition metal elements, and composite oxides having three or more metal elements.

[0017] The positive electrode active material layer 113 may contain an electrolytic solution including an electrolyte and a non-aqueous solvent. As the electrolyte, those used in known electrolytic solutions and the like can be used.

[0018] As the negative electrode current collector layer 121, those similar to the configurations described for the positive electrode current collector layer 111 can be appropriately selected and used, and can be obtained by the same method. From the viewpoint of battery characteristics and the like, the negative electrode current collector layer 121 is preferably a resin current collector.

[0019] The negative electrode active material layer 123 is preferably a non-binder of a mixture containing a negative electrode active material. The reason why the negative electrode active material layer is preferably a non-binder, and the method for obtaining the non-binder negative electrode active material layer 123 and the like are the same as the reason why the positive electrode active material layer 113 is preferably a non-binder and the method for obtaining the non-binder positive electrode active material layer 113.

[0020] As the negative electrode active material, for example, carbon-based materials, silicon-based materials, and mixtures thereof can be used, but are not particularly limited.

[0021] The negative electrode active material layer 123 contains an electrolytic solution including an electrolyte and a non-aqueous solvent. As the composition of the electrolytic solution, an electrolytic solution similar to the electrolytic solution contained in the positive electrode active material layer 113 can be preferably used.

[0022] Examples of the separator 130 include porous films made of polyethylene or polypropylene, but are not particularly limited.

[0023] The lithium ion single battery 10 has a structure in which the electrolytic solution is sealed by sealing the edges of the positive electrode current collector layer 111 and the negative electrode current collector layer 121 with a frame body 140. The frame body 140 is disposed between the positive electrode current collector layer 111 and the negative electrode current collector layer 121 and has a function of sealing the outer peripheries of the positive electrode active material layer 113, the negative electrode active material layer 123, and the separator 130.

[0024] The frame 140 is not particularly limited as long as it is a material durable against the electrolytic solution, but a polymer material is preferable, and a thermosetting polymer material is more preferable. Specifically, examples thereof include epoxy resins, polyolefin resins, polyurethane resins, and polyvinylidene fluoride resins, and epoxy resins are preferable because of their high durability and ease of handling.

[0025] As shown in FIG. 2, the battery electrode manufacturing system 100 according to the present embodiment includes a battery electrode manufacturing apparatus 1, a degassing apparatus 7, and a film supply apparatus 32. The film supply apparatus 32 supplies a strip-shaped base film 23 to the battery electrode manufacturing apparatus 1. The film supply apparatus 32 sends out, for example, the base film 23 wound around a roll. Examples of the strip-shaped base film 23 include a current collector, a separator, and a transfer film. When the base film 23 is a transfer film, a lithium-ion battery electrode can be obtained by, for example, transferring an active material layer (electrode composition layer) formed on the transfer film onto a current collector.

[0026] As shown in FIG. 2, the battery electrode manufacturing apparatus 1 includes a chamber 2, a supply apparatus 3, a roll press 5, a tank 6, and a frame supply apparatus 15. The chamber 2 is a room that can maintain the inside in a state of reduced pressure from atmospheric pressure. The chamber 2 has a housing 20 that forms a closed space. The internal space 20a of the chamber 2 is reduced in pressure from atmospheric pressure by a decompression pump (not shown). The pressure of the internal space 20a may be an arbitrary value as long as it is reduced in pressure from atmospheric pressure. For example, it may be adjusted to a low vacuum environment from atmospheric pressure to 1×10 -1 ~1×10 -2 Pa, or it may be adjusted to a high vacuum environment of 1×10 -6 ~1×10 -7 Pa, or it may be an ultra-high vacuum higher than that, or an extremely high vacuum at the 10 -8 ~10 -9 Pa level. Note that the standard atmospheric pressure is about 1013 hPa (about 10 5 Pa).

[0027] The housing 20 has a slit 20s. The slit 20s is disposed on one side wall 20w of the housing 20. The illustrated slit 20s penetrates the side wall 20w along the conveyance direction X of the base film 23. The conveyance direction X is, for example, a direction orthogonal to the vertical direction Z. The base film 23 is conveyed from the external space 20b of the housing 20 into the internal space 20a through the slit 20s.

[0028] The frame supply device 15 is disposed in the internal space 20a of the housing 20. The illustrated frame supply device 15 is disposed between the side wall 20w and the supply mechanism 3. The frame supply device 15 supplies the frame 140 to the conveyed base film 23 and installs the frame 140 on the base film 23. The frame 140 is conveyed along the conveyance direction X together with the base film 23.

[0029] The supply device 3 is disposed in the internal space 20a of the housing 20. The supply device 3 supplies the powdery active material 25 to the conveyed base film 23. More specifically, the supply device 3 supplies the active material 25 to the frame 140 installed on the base film 23. The powdery active material 25 is stored in a tank 6 disposed in the external space 20b. The supply device 3 fills the inside of the frame 140 with the active material 25 sent from the tank 6 and applies the active material 25 to the base film 23.

[0030] The roll press 5 is disposed on the downstream side of the supply device 3 in the conveyance direction X. The roll press 5 press-molds the active material 25 applied to the base film 23. The roll press 5 has a role of fixing the active material 25 to the strip-shaped base film 23. The roll press 5 press-molds the active material 25 to form the positive electrode active material layer 113 or the negative electrode active material layer 123. For example, when the active material 25 applied to the base film 23 is a positive electrode active material, the positive electrode active material layer 113 is formed, and when the applied active material 25 is a negative electrode active material, the negative electrode active material layer 123 is formed.

[0031] As described below, in the battery electrode manufacturing system 100 according to the present embodiment, the active material 25 that has been previously degassed is sent to the supply device 3. In this specification, the previously degassed active material 25 is simply referred to as "degassed active material 25v". By degassing the active material 25 before supplying it to the supply device 3, it is possible to suppress the mixing of unnecessary gas and air into the active material at the stage before supplying the active material to the base film 23. As a result, for example, when the base film 23 is a current collector, the degassed active material 25v is applied to the current collector, so the generation of bubbles in the positive electrode active material layer 113 and the negative electrode active material layer 123 formed on the current collector is suppressed, and the uniformity of the active material layer is improved.

[0032] Furthermore, the battery electrode manufacturing apparatus 1 of the present embodiment performs both the steps of applying and press-molding the active material 25 in the internally depressurized space 20a. Thereby, when supplying the active material 25 to the base film 23, it is possible to eliminate the mixing of unnecessary gas and air into the degassed active material 25v. As a result, the generation of bubbles in the active material layer formed on the current collector can be further suppressed, and the uniformity of the active material layer can be further improved.

[0033] Note that the supply device 3 may supply the active material 25 to the transfer film. In this case, the active material 25 transferred to the transfer film is transferred to the current collector. According to the present embodiment, it is possible to suppress the mixing of unnecessary gas and air into the active material at the stage before supplying the active material to the transfer film. As a result, since the degassed active material 25v is transferred from the transfer film to the current collector, the generation of bubbles in the positive electrode active material layer 113 and the negative electrode active material layer 123 formed on the current collector is suppressed, and the uniformity of the active material layer is improved.

[0034] As shown in FIG. 3, the battery electrode manufacturing system 100 has a replenishing mechanism 4. The replenishing mechanism 4 is a mechanism for sending the degassed active material 25v to the supply device 3. The replenishing mechanism 4 includes a pressure-resistant container 40 and a tank 6.

[0035] The interior of the tank 6 may be depressurized by a vacuum pump to a pressure lower than atmospheric pressure. The tank 6 has an inlet 61 for receiving the degassed active material 25v. The illustrated inlet 61 is disposed at the top of the tank 6. The inlet 61 communicates the interior space of the tank 6 with the external space. The pressure-resistant container 40 is a container having rigidity capable of maintaining a hollow shape in a depressurized state inside. The pressure-resistant container 40 is attached to the inlet 61. A sealing member for hermetically sealing between the pressure-resistant container 40 and the tank 6 is disposed at the inlet 61. The interior of the pressure-resistant container 40 is maintained at a pressure lower than atmospheric pressure and contains the degassed active material 25v. The pressure-resistant container 40 is attached to the tank 6 with the opening facing downward.

[0036] The degassed active material 25v is sent into the tank 6 through the opening of the pressure-resistant container 40. The degassed active material 25v falls into the tank 6, for example, by its own weight. The degassed active material 25v may move from the pressure-resistant container 40 to the tank 6 due to the differential pressure between the internal pressure of the pressure-resistant container 40 and the internal pressure of the tank 6. The supply device 3 supplies the active material 25 sent from the tank 6 to the strip-shaped base material film 23. That is, the active material 25 applied to the base material film 23 is the degassed active material 25v.

[0037] The degassed active material 25v has been sufficiently degassed so that no gas such as air remains inside. Therefore, even if the positive electrode active material layer 113 and the negative electrode active material layer 123 after the pressing are placed under normal pressure, the generation of bubbles in the active material layers 113, 123 formed on the current collector is suppressed, and the uniformity of the active material layers 113, 123 is improved. Further, the degassed active material 25v is less likely to crack when press-molded. Therefore, the battery electrode manufacturing system 100 according to the present embodiment can improve the performance of the lithium-ion single battery 10 and improve the reliability of the lithium-ion single battery 10.

[0038] The degassing device 7 shown in FIG. 4 is a device for removing the gas inside the active material 25. The degassing device 7 includes a pump 71, a nozzle 72, and a pressure-resistant container 40. The nozzle 72 is fixed to the opening 41 of the pressure-resistant container 40. The pump 71 is connected to the nozzle 72 and sucks the gas inside the pressure-resistant container 40. The nozzle 72 is attached to the pressure-resistant container 40 filled with the active material 25 in advance. The active material 25 filled in the pressure-resistant container 40 is prepared by stirring and mixing the materials.

[0039] The degassing device 7 reduces the internal pressure of the pressure-resistant container 40 to a first pressure PA1 lower than the atmospheric pressure. The first pressure PA1 is, for example, a pressure equivalent to the internal pressure PB1 of the tank 6. The first pressure PA1 may be a pressure equivalent to the internal pressure PC1 of the chamber 2. The first pressure PA1 may be higher than the internal pressures PB1 and PC1. The degassing device 7 removes the gas inside the active material 25 by placing the active material 25 under reduced pressure. The degassing device 7 maintains the internal pressure of the pressure-resistant container 40 at the first pressure PA1 so that the gas contained inside the active material 25 can be sufficiently purged. The degassing time is, for example, several hours.

[0040] When the degassing of the active material 25 is completed, as shown in FIG. 5, the opening 41 of the pressure-resistant container 40 is closed by a plug 42. The plug 42 seals the opening 41 and encloses the degassed active material 25v inside the pressure-resistant container 40. The pressure-resistant container 40 is transported to the tank 6 in a sealed state and attached to the tank 6 as shown in FIG. 3. The opening 41 is opened, for example, after the attachment of the pressure-resistant container 40 to the tank 6 is completed.

[0041] When the transfer of the active material 25 from the pressure-resistant container 40 to the tank 6 is completed, the pressure-resistant container 40 is removed from the tank 6. For the removed pressure-resistant container 40, a filling process of filling the prepared active material 25 and a degassing process of degassing the active material 25 are performed. The battery electrode manufacturing system 100 may have a plurality of pressure-resistant containers 40. In this case, when one pressure-resistant container 40 is attached to the tank 6, the filling process and the degassing process are performed on another pressure-resistant container 40.

[0042] As described above, the method for manufacturing an electrode for a battery according to the present embodiment includes a removing step, a feeding step, and a supplying step. In the removing step, the degassing device 7 removes the gas inside the powdery active material 25 by placing the powdery active material 25 under reduced pressure. By degassing the active material 25 before supplying it to the supply device 3, it is possible to suppress the mixing of unnecessary gas and air into the active material 25 at the stage before supplying the active material to the base material film 23. In the feeding step, the replenishing mechanism 4 feeds the degassed active material 25v to the supply device 3 disposed inside the chamber 2. In the supplying step, the supply device 3 supplies the degassed active material 25v to the strip-shaped base material film 23. The base material film 23 is, for example, a current collector, but is not limited thereto, and may be a separator or a film for transfer. That is, the supply device 3 may directly supply the active material to the current collector, or may indirectly supply the active material to the current collector via a separator or a film for transfer. According to the method for manufacturing an electrode for a battery according to the present embodiment, by supplying the degassed active material 25v to the base material film 23, it is possible to suppress the generation of bubbles in the active material layers 113 and 123 formed on the current collector, and to improve the uniformity of the active material layers 113 and 123.

[0043] The battery electrode manufacturing system 100 according to the present embodiment includes a tank 6, a chamber 2, and a supply device 3. The tank 6 stores the degassed active material 25v. The chamber 2 is a room in which the internal space 20a is depressurized compared to the atmospheric pressure. The supply device 3 is disposed inside the chamber 2 and supplies the active material 25 sent from the tank 6 to the strip-shaped base material film 23. According to the battery electrode manufacturing system according to the present embodiment, by supplying the degassed active material 25v to the base material film 23, it is possible to suppress the generation of bubbles in the active material layers 113 and 123 formed on the current collector, and to improve the uniformity of the active material layers 113 and 123.

[0044] Note that the frame supply device 8 may install the frame 140 on the base film 23 on the downstream side of the supply mechanism 3. For example, the frame supply device 8 may be disposed between the supply mechanism 3 and the roll press 5, may be disposed on the downstream side of the roll press 5, or may be disposed outside the housing 2 on the downstream side of the roll press 5. Further, the battery electrode manufacturing system or the battery electrode manufacturing method according to the present embodiment may not include the frame supply device or the frame supply step. For example, when a transfer film is used as the base film 23, after the active material layer (electrode composition layer) is formed on the transfer film (that is, after the electrode manufacturing process is completed), the frame may be disposed on the current collector onto which the electrode composition layer is transferred, or on the current collector before the electrode composition layer is transferred.

[0045] Instead of supplying the frame 140 to the base film 23 inside the housing 2, the frame 140 may be installed on the base film 23 outside the housing 2. In this case, the base film 23 with the frame 140 attached is conveyed into the housing 2 through the slit 20s.

[0046] [First Modification of the Embodiment] Referring to FIG. 6, the first modification of the embodiment will be described. FIG. 6 is a diagram showing a degassing device according to the first modification of the embodiment. In the first modification of the embodiment, the difference from the above embodiment is that the degassing device 8 prepares the active material 25 under reduced pressure.

[0047] The degassing device 8 degasses the active material 25 while preparing the active material 25 under reduced pressure. The degassing device 8 includes a pump 80, a preparation tank 81, and a stirrer 82. The preparation tank 81 is a container having the same pressure resistance performance as the pressure-resistant container 40 of the embodiment. The preparation tank 81 has supply paths 81a and 81b. The materials M1 and M2 of the active material 25 are respectively supplied into the preparation tank 81 through the supply paths 81a and 81b. The pump 80 sucks the gas inside the preparation tank 81. That is, the inside of the preparation tank 81 is depressurized to a pressure lower than the atmospheric pressure by the pump 80.

[0048] The stirrer 82 has a motor 83, a stirring blade 84, and a rotating shaft 85. The stirring blade 84 is disposed inside the blending tank 81. The motor 83 is disposed outside the blending tank 81. The rotating shaft 85 penetrates the bottom wall of the blending tank 81 and connects the motor 83 and the stirring blade 84. The degassing device 8 stirs the materials M1 and M2 by rotating the stirring blade 84 and performs blending such as surface treatment of the active material 25. The degassing device 8 degasses the active material 25 inside the blending tank 81 to generate the degassed active material 25v. That is, the degassing device 8 simultaneously executes the blending process and the degassing process by blending the active material 25 under reduced pressure.

[0049] The degassed active material 25v is supplied to the tank 6 of the battery electrode manufacturing apparatus 1. For example, the blending tank 81 may be attached to the tank 6. In this case, it is preferable that the blending tank 81 is provided with an opening connected to the tank 6. In the blending process of blending the active material 25, the opening of the blending tank 81 is closed by a plug.

[0050] The degassed active material 25v may be transferred from the blending tank 81 to the pressure-resistant container 40 in a reduced-pressure environment. In this case, similar to the above embodiment, the pressure-resistant container 40 is attached to the tank 6. The blending tank 81 may be connected to the tank 6 via a pipe or the like. In this case, the degassed active material 25v is sent from the blending tank 81 to the tank 6 via a pipe or the like.

[0051] [Second Modified Example of Embodiment] Referring to FIG. 7, a second modified example of the embodiment will be described. FIG. 7 is a diagram showing a degassing device according to the second modified example of the embodiment. As shown in FIG. 7, the degassing device 9 according to the second modified example of the embodiment has a pump 90, a first degassing tank 91, a second degassing tank 92, and a third degassing tank 93. The first degassing tank 91, the second degassing tank 92, and the third degassing tank 93 are containers having pressure-resistant performance.

[0052] The first degassing tank 91 is connected to the tank 6 via the first passage 94. A valve 94a for opening and closing the first passage 94 is provided in the first passage 94. Further, the first degassing tank 91 is connected to the pump 90 via the first suction passage 97. A valve 97a for opening and closing the first suction passage 97 is provided in the first suction passage 97.

[0053] The second degassing tank 92 is connected to the tank 6 via the second passage 95. A valve 95a for opening and closing the second passage 95 is provided in the second passage 95. The second degassing tank 92 is connected to the pump 90 via the second suction passage 98. A valve for opening and closing the second suction passage 98 is provided in the second suction passage 98.

[0054] The third degassing tank 93 is connected to the tank 6 via the third passage 96. A valve 96a for opening and closing the third passage 96 is provided in the third passage 96. The third degassing tank 93 is connected to the pump 90 via the third suction passage 99. A valve 99a for opening and closing the third suction passage 99 is provided in the third suction passage 99.

[0055] The first degassing tank 91, the second degassing tank 92, and the third degassing tank 93 are each filled with the active material 25. The filled active material 25 is one that has been prepared with surface treatment or the like. When degassing of the active material 25 is performed, the degassing tank is connected to the pump 90 and blocked from the tank 6. For example, in FIG. 7, the degassing process is being executed in the first degassing tank 91 and the second degassing tank 92. In this case, the valves 97a, 98a are opened and the valves 94a, 95a are closed. The pump 90 sucks the gas inside the first degassing tank 91 and the second degassing tank 92. Therefore, the active material 25 stored in the first degassing tank 91 and the second degassing tank 92 is placed under reduced pressure, and the gas inside the active material 25 is removed.

[0056] Inside the third degassing tank 93, the degassed active material 25v is stored. That is, FIG. 7 shows the third degassing tank 93 after the degassing process is completed. When the degassed active material 25v is sent to the tank 6, the degassing tank is connected to the tank 6 and disconnected from the pump 90. For example, in FIG. 7, in the third degassing tank 93, the process of sending the degassed active material 25v to the tank 6 is being executed. In this case, the valve 96a is opened and the valve 99a is closed. Thus, the degassed active material 25v moves from the third degassing tank 93 to the tank 6, for example, by its own weight.

[0057] When the transfer of the active material 25 from the third degassing tank 93 to the tank 6 is completed, the valve 96a is closed. Thereafter, the active material 25 is replenished in the third degassing tank 93, and the degassing process is executed in the third degassing tank 93. When the degassing process is being executed in the third degassing tank 93, the degassed active material 25v is sent from the first degassing tank 91 or the second degassing tank 92 to the tank 6. Thus, in the degassing device 9 according to the second modification of the embodiment, in the plurality of degassing tanks 91, 92, 93, the degassing process and the process of sending the active material 25 from which gas has been removed to the tank 6 are alternately executed.

[0058] Note that the number of degassing tanks included in the degassing device 9 is not limited to three. For example, the degassing device 9 may have two degassing tanks or may have four or more degassing tanks.

[0059] The contents disclosed in the above embodiments and modifications can be executed in appropriate combinations.

Explanation of Reference Numerals

[0060] 1: Battery electrode manufacturing apparatus, 2: Chamber, 3: Supply apparatus 4: Refilling mechanism, 5: Roll press, 6: Tank, 7, 8, 9: Degassing device 10: Lithium ion single battery, 15: Frame supply apparatus 20: Housing, 20a: Internal space, 20b: External space, 20s: Slit 23: Base film, 24: Member sheet, 25: Active material, 25v: Degassed active material 32: Film supply device 40: Pressure-resistant container, 41: Opening, 42: Plug 61: Inlet 71: Pump, 72: Nozzle 80: Pump, 81: Mixing tank, 81a, 81b: Supply paths, 82: Stirrer 83: Motor, 84: Stirring blade, 85: Rotating shaft 90: Pump, 91: First degassing tank, 92: Second degassing tank, 93: Third degassing tank 94: First passage, 95: Second passage, 96: Third passage 97: First suction path, 98: Second suction path, 99: Third suction path 94a, 95a, 96a, 97a, 98a, 99a: Valves 100: Battery electrode manufacturing system 111: Positive current collector layer, 113: Positive active material layer, 121: Negative current collector layer 123: Negative active material layer, 130: Separator, 140: Frame M1, M2: Materials PA1: First pressure, PB1: Internal pressure of the tank, PC1: Internal pressure of the chamber X: Conveying direction, Z: Vertical direction

Claims

1. A step of removing gas inside the active material by placing the powdery active material under reduced pressure; A step of sending the active material from which gas has been removed to a supply device disposed inside a chamber that is under reduced pressure compared to atmospheric pressure; A step of supplying the active material to a strip-shaped base material film by the supply device inside the chamber; A method for manufacturing an electrode for a battery, including the above steps.

2. The removing step is performed by sucking gas from a mixing tank that mixes the active material. The method for manufacturing an electrode for a battery according to Claim 1.

3. A tank for storing a powdery active material that has been degassed in advance; A chamber whose internal space is under reduced pressure compared to atmospheric pressure; A supply device disposed inside the chamber for supplying the active material sent from the tank to a strip-shaped base material film; A manufacturing system for an electrode for a battery, comprising the above components.

4. Furthermore, it is provided with a degassing device that removes gas inside the active material while mixing the active material. The tank stores the active material degassed by the degassing device. The manufacturing system for an electrode for a battery according to Claim 3.

5. Furthermore, it is provided with a degassing device that removes gas inside the active material. The degassing device includes a plurality of degassing tanks in which the active material is stored, a pump for sucking gas from the degassing tanks, a plurality of passages individually connecting the plurality of degassing tanks and the tank, and valves for opening and closing the plurality of passages. The manufacturing system for an electrode for a battery according to Claim 3.

Images