JP2023119248A - Battery electrode manufacturing device and battery electrode manufacturing method - Google Patents

Abstract

To maintain a reduced pressure state in a chamber with a simple configuration.SOLUTION: A battery electrode manufacturing device includes a chamber whose interior is depressurized below atmospheric pressure, a conveying unit that conveys a strip-shaped base film into the chamber through a slit provided in the chamber by rotating two rollers while sandwiching the strip-shaped base film between the rollers provided outside the chamber, a first suppressing portion that is provided in a gap between the roller and the outer surface of the chamber and suppresses air from flowing into the chamber, and a second suppressing portion provided in a gap between the roller and the first suppressing portion and suppressing air from flowing into the chamber.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD The present invention relates to a battery electrode manufacturing apparatus and a battery electrode manufacturing method.

Lithium ion batteries are high-capacity secondary batteries and have been used in various applications in recent years. An electrode of a lithium ion battery is composed of an active material layer, a current collector layer, a separator, a frame enclosing the active material layer, and the like (see, for example, Patent Document 1). An active material layer in a lithium ion battery can be formed, for example, by supplying an electrode composition to a strip-shaped base film and compressing it by roll press or the like.

Here, by performing various steps such as supplying the electrode composition to the base film and roll pressing in a chamber whose interior is evacuated below atmospheric pressure, air remains inside the electrode composition. can be prevented, and the uniformity of the active material layer can be improved. For this reason, a slit is provided in the chamber, and the substrate film is conveyed into the chamber through the slit.

Japanese Patent No. 6633866 JP 2010-174264 A JP-A-62-23982

In order to maintain a decompressed state in the chamber while providing the slit in the chamber, it is conceivable to configure the slit narrow so as not to create a gap (clearance) between the substrate film and the slit. However, when there is no clearance, it is assumed that the base film may be worn or caught when passing through the slit.

As a technique for maintaining the reduced pressure state in the chamber, Patent Literature 2 describes sequential pressure reduction to high vacuum in a plurality of stages. Further, Patent Document 3 describes that ventilation resistance is increased by providing a long slit in the movement path of a belt-shaped body that continuously moves between the outside of the vacuum chamber. According to the configurations described in Patent Documents 2 and 3, it is possible to provide a clearance between the slit and the base film, but there is a problem in that a large-scale configuration is required.

By the way, rollers for conveying the base film are provided outside the chamber. The roller is in close contact with the base film, and it can be said that air hardly passes between the roller and the base film. Therefore, it is conceivable to suppress the inflow of air into the chamber by providing a member that fills the gap between the roller and the outer surface of the chamber. However, even in such a configuration, since a clearance is required for rotating the roller, the inflow of air into the chamber cannot be blocked.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery electrode manufacturing apparatus and a battery electrode manufacturing method capable of maintaining a reduced pressure state in a chamber with a simple configuration. do.

In order to achieve the above object, the battery electrode manufacturing apparatus according to the present invention includes a chamber in which the inside pressure is reduced below atmospheric pressure, and two rollers provided outside the chamber to sandwich a strip-shaped base film. provided in a gap between the roller and the outer surface of the chamber; A first suppressing portion that suppresses inflow of air into the chamber, and a second suppressing portion that is provided in a gap between the roller and the first suppressing portion and suppresses inflow of air into the chamber.

According to the battery electrode manufacturing apparatus and the battery electrode manufacturing method of the present invention, it is possible to maintain the reduced pressure state in the chamber with a simple configuration.

FIG. 1 is a schematic cross-sectional view of a single cell of a battery manufactured using the battery electrode manufacturing apparatus of the embodiment. FIG. 2 is a schematic diagram of the battery electrode manufacturing apparatus of the embodiment. FIG. 3 is a diagram for explaining a roller and a first suppressing portion according to the embodiment; FIG. 4 is a diagram for explaining a roller and a first suppressing portion according to the embodiment; FIG. 5 is a diagram illustrating an example of a second suppression unit according to the embodiment; FIG. 6 is a diagram illustrating an example of a second suppression unit according to the embodiment; FIG. 7 is a diagram illustrating an example of a second suppression unit according to the embodiment; FIG. 8A is a diagram illustrating an example of a second suppression unit according to the embodiment; 8B is a diagram illustrating an example of a second suppressing unit according to the embodiment; FIG. FIG. 9 is a diagram for explaining a roller and a first suppressing portion according to the embodiment; FIG. 10 is a diagram illustrating an example of a second suppression unit according to the embodiment; 11 is a diagram illustrating an example of a second suppressing unit according to the embodiment; FIG. 12 is a diagram illustrating an example of a second suppressing unit according to the embodiment; FIG. 13 is a diagram illustrating an example of a second suppressing unit according to the embodiment; FIG. 14 is a diagram illustrating an example of a second suppressing unit according to the embodiment; FIG.

(embodiment)
Embodiments to which the present invention is applied will be described below with reference to the drawings. In addition, in the drawings used in the following explanations, characteristic parts may be enlarged for the sake of convenience for the purpose of emphasizing the characteristic parts, and the dimensional ratios, etc. of each component may not necessarily be the same as the actual ones. do not have. Also, for the same purpose, some parts may be omitted from the drawings.

<Assembled battery (secondary battery)>
The battery electrode manufacturing apparatus and the battery electrode manufacturing method of the embodiments are applied, for example, to the manufacture of lithium ion batteries. Lithium ion batteries are assembled batteries that are modularized by combining a plurality of lithium ion single cells (also referred to as single cells or battery cells), or battery packs that are made by combining multiple such assembled batteries and adjusting the voltage and capacity. used in the form.

<Single cell (battery cell)>
FIG. 1 is a schematic cross-sectional view of a single cell 10. FIG. By combining a plurality of unit cells 10, the above assembled battery can be produced. For example, the single cell 10 has a positive electrode 20 a and a negative electrode 20 b as two electrodes 20 (battery electrodes) and a separator 30 .

The separator 30 is arranged between the positive electrode 20a and the negative electrode 20b. In the assembled battery, the plurality of unit cells 10 are stacked with the positive electrode 20a and the negative electrode 20b directed in the same direction.

The separator 30 holds an electrolyte. Thereby, the separator 30 functions as an electrolyte layer. The separator 30 is arranged between the electrode active material layers 22 of the positive electrode 20a and the negative electrode 20b to prevent them from coming into contact with each other. Thereby, the separator 30 functions as a partition wall between the positive electrode 20a and the negative electrode 20b.

The electrolyte held in the separator 30 includes, for example, an electrolytic solution or a gel polymer electrolyte. High lithium ion conductivity is ensured by using these electrolytes. Examples of the form of the separator include porous sheet separators and non-woven fabric separators made of polymers or fibers that absorb and retain the electrolyte.

The positive electrode 20 a and the negative electrode 20 b each have a current collector 21 , an electrode active material layer 22 and a frame 35 . The electrode active material layer 22 and the current collector 21 are arranged in this order from the separator 30 side. The frame 35 is frame-shaped (annular). The frame 35 surrounds the electrode active material layer 22 . The frame 35 of the positive electrode 20a and the frame 35 of the negative electrode 20b are welded together and integrated. In the following description, when distinguishing between the electrode active material layers 22 of the positive electrode 20a and the negative electrode 20b, they are referred to as a positive electrode active material layer 22a and a negative electrode active material layer 22b, respectively.

<Specific example of positive electrode current collector>
As the positive electrode current collector constituting the positive electrode current collector layer 21a, a known current collector used for a lithium ion single battery can be used. A resin current collector (such as the resin current collector described in JP-A-2012-150905 and WO 2015/005116) can be used. The positive electrode current collector constituting the positive electrode current collector layer 21a is preferably a resin current collector from the viewpoint of battery characteristics and the like.

Metal current collectors include, for example, copper, aluminum, titanium, nickel, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, alloys containing one or more of these metals, and the group consisting of stainless alloys. and one or more metal materials selected from These metal materials may be used in the form of thin plates, metal foils, or the like. Alternatively, a metal current collector formed by forming the above metal material on the surface of a base material other than the above metal material by sputtering, electrodeposition, coating, or the like may be used.

The resin current collector preferably contains a conductive filler and a matrix resin. Examples of the matrix resin include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP) and the like, but are not particularly limited. Also, the conductive filler is not particularly limited as long as it is selected from materials having conductivity. The conductive filler may be a conductive fiber having a fibrous shape.

The resin current collector may contain other components (dispersant, cross-linking accelerator, cross-linking agent, colorant, ultraviolet absorber, plasticizer, etc.) in addition to the matrix resin and the conductive filler. Also, a plurality of resin current collectors may be laminated and used, or a resin current collector and a metal foil may be laminated and used.

Although the thickness of the positive electrode current collector layer 21a is not particularly limited, it is preferably 5 to 150 μm. When a plurality of resin current collectors are laminated and used as the positive electrode current collector layer 21a, the total thickness after lamination is preferably 5 to 150 μm. The positive electrode current collector layer 21a can be obtained, for example, by molding a conductive resin composition obtained by melt-kneading a matrix resin, a conductive filler, and a dispersing agent for a filler used if necessary into a film by a known method. can be done.

<Specific example of positive electrode active material>
The positive electrode active material layer 22a is preferably a non-bound mixture containing a positive electrode active material. Here, the non-bound body means that the position of the positive electrode active material is not fixed in the positive electrode active material layer, and the positive electrode active materials and the positive electrode active material and the current collector are not irreversibly fixed. means When the positive electrode active material layer 22a is a non-bound body, the positive electrode active materials are not irreversibly fixed to each other. Even when stress is applied to the material layer 22a, the positive electrode active material moves, which is preferable because the destruction of the positive electrode active material layer 22a can be prevented. The positive electrode active material layer 22a, which is a non-binder, can be obtained by a method such as changing the positive electrode active material layer 22a into a positive electrode active material layer 22a containing a positive electrode active material and an electrolytic solution but not containing a binder. can. In this specification, the binder means an agent that cannot reversibly fix the positive electrode active materials together and the positive electrode active material and the current collector, and includes starch, polyvinylidene fluoride, polyvinyl alcohol, carboxyl Known solvent-drying type binders for lithium ion batteries such as methylcellulose, polyvinylpyrrolidone, tetrafluoroethylene, styrene-butadiene rubber, polyethylene and polypropylene can be used. These binders are used by dissolving or dispersing them in a solvent, and by volatilizing and distilling off the solvent, the surface solidifies without exhibiting stickiness. cannot be reversibly fixed.

Examples of the positive electrode active material include, but are not particularly limited to, a composite oxide of lithium and a transition metal, a composite oxide containing two transition metal elements, and a composite oxide containing three or more metal elements. .

The positive electrode active material may be a coated positive electrode active material in which at least part of the surface is coated with a coating material containing a polymer compound. When the positive electrode active material is covered with the coating material, the volume change of the positive electrode is moderated, and the expansion of the positive electrode can be suppressed.

As the polymer compound constituting the coating material, those described as active material coating resins in JP-A-2017-054703 and WO 2015/005117 can be preferably used.

The coating material may contain a conductive agent. As the conductive agent, the same conductive filler as contained in the positive electrode current collector layer 21a can be preferably used.

The positive electrode active material layer 22a may contain an adhesive resin. As the adhesive resin, for example, a non-aqueous secondary battery active material coating resin described in JP-A-2017-054703 is mixed with a small amount of an organic solvent to adjust its glass transition temperature to room temperature or lower. Also, those described as adhesives in JP-A-10-255805 can be preferably used. In addition, adhesive resin is a resin that does not solidify even if the solvent component is volatilized and dried, and has adhesiveness (the property of adhering by applying a slight pressure without using water, solvent, heat, etc.) means On the other hand, a solution-drying type electrode binder used as a binder is one that dries and solidifies by volatilizing a solvent component, thereby firmly adhering and fixing active materials to each other. Therefore, the binder (solution-drying type electrode binder) and the adhesive resin described above are different materials.

The positive electrode active material layer 22a may contain an electrolytic solution containing an electrolyte and a non-aqueous solvent. As the electrolyte, those used in known electrolytic solutions can be used. As the non-aqueous solvent, those used in known electrolytic solutions (eg, phosphate esters, nitrile compounds, mixtures thereof, etc.) can be used. For example, a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) or a mixture of ethylene carbonate (EC) and propylene carbonate (PC) can be used.

The positive electrode active material layer 22a may contain a conductive aid. As the conductive aid, a conductive material similar to the conductive filler contained in the positive electrode current collector layer 21a can be preferably used.

Although the thickness of the positive electrode active material layer 22a is not particularly limited, it is preferably 150 to 600 μm, more preferably 200 to 450 μm, from the viewpoint of battery performance.

In the embodiment, the positive electrode composition supplied to form the positive electrode active material layer 22a is a wet powder containing a positive electrode active material and a non-aqueous electrolyte. Moreover, it is more preferable that the wet powder is in a pendular state or a funicular state.

The ratio of the non-aqueous electrolyte in the wet powder is not particularly limited, but in the case of the positive electrode, the ratio of the non-aqueous electrolyte to the entire wet powder is 0.5 to 0.5 to make the pendular state or funicular state. 15% by weight is desirable.

<Specific example of negative electrode current collector>
As the negative electrode current collector constituting the negative electrode current collector layer 21b, the same one as the positive electrode current collector can be appropriately selected and used, and can be obtained by the same method. The negative electrode current collector layer 21b is preferably a resin current collector from the viewpoint of battery characteristics and the like. Although the thickness of the negative electrode current collector layer 21b is not particularly limited, it is preferably 5 to 150 μm.

<Specific example of negative electrode active material>
The negative electrode active material layer 22b is preferably a non-bonded mixture containing a negative electrode active material. The reason why the negative electrode active material layer is preferably a non-binder, and the reason why the positive electrode active material layer 22a is preferably a non-binder , and the method for obtaining the positive electrode active material layer 22a which is a non-binder.

As the negative electrode active material, for example, a carbon-based material, a silicon-based material, a mixture thereof, or the like can be used, but the material is not particularly limited.

The negative electrode active material may be a coated negative electrode active material in which at least part of the surface is coated with a coating material containing a polymer compound. When the periphery of the negative electrode active material is covered with the coating material, the volume change of the negative electrode is moderated, and the expansion of the negative electrode can be suppressed.

As the coating material, the same coating material as that constituting the coated positive electrode active material can be suitably used.

The negative electrode active material layer 22b contains an electrolytic solution containing an electrolyte and a non-aqueous solvent. As for the composition of the electrolytic solution, an electrolytic solution similar to the electrolytic solution contained in the positive electrode active material layer 22a can be preferably used.

The negative electrode active material layer 22b may contain a conductive aid. As the conductive aid, a conductive material similar to the conductive filler contained in the positive electrode active material layer 22a can be preferably used.

The negative electrode active material layer 22b may contain an adhesive resin. As the adhesive resin, the same adhesive resin as an optional component of the positive electrode active material layer 22a can be preferably used.

Although the thickness of the negative electrode active material layer 22b is not particularly limited, it is preferably 150 to 600 μm, more preferably 200 to 450 μm, from the viewpoint of battery performance.

In the embodiment, the negative electrode composition supplied to form the negative electrode active material layer 22b is wet powder containing a negative electrode active material and a non-aqueous electrolyte. Moreover, it is more preferable that the wet powder is in a pendular state or a funicular state.

The ratio of the non-aqueous electrolyte in the wet powder is not particularly limited, but in the case of the negative electrode, the ratio of the non-aqueous electrolyte to the entire wet powder is 0.5 to 0.5 to make the pendular state or funicular state. 25% by weight is desirable.

<Specific example of separator>
Examples of the electrolyte held in the separator 30 include an electrolytic solution and a gel polymer electrolyte. By using these electrolytes, the separator 30 ensures high lithium ion conductivity. Examples of the form of the separator 30 include, but are not particularly limited to, polyethylene or polypropylene porous films.

<Specific example of frame>
The material for the frame 35 is not particularly limited as long as it is a material that is durable against the electrolytic solution. For example, a polymer material is preferable, and a thermosetting polymer material is more preferable. As a material for forming the frame 35, any material having insulating properties, sealing properties (liquid-tightness), heat resistance under the battery operating temperature, and the like may be used, and a resin material is preferably employed. More specifically, examples of the frame 35 include epoxy-based resins, polyolefin-based resins, polyurethane-based resins, and polyvinylidene fluoride resins. preferable.

<Battery Electrode Manufacturing Apparatus and Battery Electrode Manufacturing Method>
Next, a battery electrode manufacturing apparatus and a battery electrode manufacturing method (hereinafter abbreviated as a manufacturing method) of the present embodiment will be described. For example, in the battery electrode manufacturing apparatus and the battery electrode manufacturing method, the positive electrode 20a and the negative electrode 20b are first manufactured. The method of manufacturing the positive electrode 20 a and the method of manufacturing the negative electrode 20 b mainly differ in the electrode active material contained in the electrode active material layer 22 . Here, as a method for manufacturing the electrode 20, a method for manufacturing the positive electrode 20a and the negative electrode 20b will be collectively described.

FIG. 2 is a schematic diagram of the battery electrode manufacturing apparatus 1000. As shown in FIG. For example, the battery electrode manufacturing apparatus 1000 includes a chamber 100 , a conveying device 200 , an electrode composition supply device 300 , a frame body supply device 400 and a press device 500 . In addition, below, the case where the strip|belt-shaped base film is the strip|belt-shaped collector 21B is demonstrated as an example.

The chamber 100 is a room whose interior can be kept under a pressure lower than the atmospheric pressure. The pressure inside the chamber 100 is reduced below atmospheric pressure by a decompression pump (not shown). The standard atmospheric pressure is approximately 1013 hPa (approximately 105 Pa).

For example, a current collector roll 21R is arranged outside the chamber 100, and a strip-shaped current collector 21B pulled out from the current collector roll 21R is transported into the chamber 100 through a slit. Hereinafter, the strip-shaped current collector 21B may be referred to as the current collector 21B. The current collector 21B is the current collector 21 before being cut into a predetermined shape. The current collector 21B is transported at a predetermined speed along the transport direction Da. Hereinafter, the direction in which the current collector 21B is conveyed will be described as the downstream side Da1, and the opposite direction as the upstream side Da2. The external space of the chamber 100 in which the current collector roll 21R is arranged may be at normal pressure, or may be decompressed by a chamber different from the chamber 100 .

As shown in FIG. 2, the upper side in the vertical direction Db is Db1, and the lower side in the vertical direction Db is Db2. A direction orthogonal to the transport direction Da and the vertical direction Db corresponds to the width direction of the current collector 21B and the electrode composition 22c placed on the current collector 21B.

The transport device 200 transports the current collector 21B to the downstream side Da1 in the transport direction Da. For example, outside the chamber 100, the transport device 200 transports the current collector 21B to the downstream side Da1 in the transport direction Da by rotating the two rollers while sandwiching the current collector 21B. Thereby, the transport device 200 transports the current collector 21B into the chamber 100 through the slit. Further, inside the chamber 100, the transport device 200 transports the current collector 21B to the downstream side Da1 in the transport direction Da by a belt conveyor that supports the current collector 21B from below. After the electrode composition 22c is supplied by the electrode composition supply device 300, which will be described later, the transport device 200 transports the current collector 21B on which the electrode composition 22c is placed. Further, after the frame body 35 is supplied by the frame body supply device 400, which will be described later, the transport device 200 transports the current collector 21B on which the frame body 35 and the electrode composition 22c are placed. The transport device 200 is an example of a transport unit.

The electrode composition supply device 300 supplies the electrode composition 22c onto the current collector 21B transported within the chamber 100, as shown in FIG. For example, the electrode composition supply device 300 is composed of a hopper and a shutter. In this case, the electrode composition supply device 300 holds the electrode composition 22c inside the hopper 1 having an opening on the lower side Db2 in the vertical direction Db, and by opening and closing the opening of the hopper with a shutter, a predetermined supply is performed. A predetermined amount of electrode composition 22c can be applied to the location.

In the embodiment, the electrode composition 22c (positive electrode composition, negative electrode composition ) is a wet powder containing an electrode active material (positive electrode active material, negative electrode active material) and an electrolytic solution (non-aqueous electrolytic solution). Moreover, in the embodiment, it is more preferable that the wet powder as the electrode composition 22c is in a pendular state or a funicular state. Moreover, the electrode active material is a coated electrode active material coated with a coating material containing a polymer compound. Since the electrode active material contained in the electrode composition 22c is a coated electrode active material, it is necessary to keep the electrode composition 22c in a soft state in the step of supplying it onto the current collector 21B.

The frame supply device 400 supplies the frame 35 to the conveyed current collector 21B. For example, the frame supply device 400 has a robot arm and places the prefabricated frame 35 at a predetermined position on the conveyed current collector 21B. Alternatively, the frame supply device 400 may manufacture the frame 35 on the current collector 21B. As an example, the current collector 21B is used as a base material, and a predetermined material is discharged or applied in a predetermined shape onto the current collector 21B using a dispenser, a coater, or the like, thereby forming the frame 35 on the current collector 21B. can be formed.

The pressing device 500 compresses the electrode composition 22c supplied to the current collector 21B. For example, the press device 500 has an upper roller 501 and a lower roller 502 as shown in FIG. The pressing device 500 sandwiches and compresses the electrode composition 22c supplied to the current collector 21B between the upper roller 501 and the lower roller 502. As shown in FIG. That is, the press device 500 roll-presses the electrode composition 22c.

After the compression process by the pressing device 500, the separator 30 shown in FIG. 1 is further supplied to fabricate the single cell 10. The supply of the separator 30 may be performed continuously with respect to the current collector 21B and the electrode composition 22c transported along the transport direction Da, or the current collector 21B and the electrode composition 22c may be supplied in predetermined units. After dividing, it may be performed on a sheet.

In FIG. 2, an example in which the frame body 35 is supplied by the frame body supply device 400 after the electrode composition 22c is supplied by the electrode composition supply device 300 has been described. However, embodiments are not so limited. For example, after the frame 35 is supplied by the frame supply device 400 , the electrode composition 22 c may be supplied by the electrode composition supply device 300 to a position inside the frame 35 .

Next, the configuration near the slits provided in the chamber 100 will be described with reference to FIG. In FIG. 3, the upstream side Da2 from the slit indicates the outside of the chamber 100, and the downstream side Da1 from the slit indicates the inside of the chamber 100. As shown in FIG.

As shown in FIG. 3, rollers 211 and 212 are provided near the slit. The rollers 211 and 212 convey the current collector 21B by rotating. That is, the conveying device 200 conveys the current collector 21B into the chamber 100 through the slit by rotating the rollers 211 and 212 provided outside the chamber 100 while sandwiching the current collector 21B.

Further, in the vicinity of the slit, members 611 and 612 are provided in the gaps between the rollers 211 and 212 and the outer surface of the chamber 100 to suppress the inflow of air into the chamber 100 . The member 611 and the member 612 are examples of the first suppressing portion. That is, the slit of the chamber 100 is covered with the current collector 21B, the roller 211, the roller 212, the member 611 and the member 612, and the inflow of air into the chamber 100 is suppressed.

Although the rollers 211 and 212 are in close contact with the current collector 21B, depending on the surface roughness of the current collector 21B, air may escape from between the rollers 211 and 212 and the current collector 21B. A case of inflow is also assumed. Therefore, instead of the rollers 211 and 212, the conveying device 200 may convey the current collector 21B using rollers whose surfaces are made of an elastic material.

For example, as shown in FIG. 4, the conveying device 200 uses a roller 221 composed of a base 221a and an elastic body 221b, and a roller 222 composed of a base 222a and an elastic body 222b. may be transported. The elastic bodies 221b and 222b are made of, for example, rubber or elastomer. By forming the side surface of the roller with the elastic bodies 221b and 222b, the degree of close contact with the current collector 21B is improved, and the inflow of air from between the roller and the current collector 21B is suppressed.

In addition, in FIG. 4, the example in which the side surfaces of both the two rollers sandwiching the current collector 21B are made of an elastic material has been described. However, the embodiment is not limited to this, and the side surface of only one of the two rollers sandwiching the collector 21B may be made of an elastic material. In addition, FIG. 4 illustrates an example of covering the periphery of the base 221a and the base 222a with the elastic bodies 221b and 222b as a method of forming the side surface of the roller with the elastic body. However, the embodiment is not limited to this, and for example, the entire roller may be made of an elastic material.

Here, as shown in FIG. 3, there are gaps between the roller 211 and the member 611 and between the roller 212 and the member 612 . Similarly in FIG. 4 , there are gaps between the roller 221 and the member 611 and between the roller 222 and the member 612 . This gap is a clearance for a roller such as roller 211 to rotate. A case can be assumed in which air flows into the chamber 100 through such a gap and the decompressed state cannot be sufficiently maintained.

Therefore, the battery electrode manufacturing apparatus 1000 may further include a second suppressing section that suppresses the inflow of air from the gap between the roller such as the roller 211 and the first suppressing section such as the member 611 . Examples of the second suppression unit will be described below with reference to FIGS. 5 to 14. FIG. 5 to 14, an example in which a roller 221 and a roller 222 whose side surfaces are made of an elastic material are provided as rollers for conveying the current collector 21B will be described.

In FIG. 5, valves 711 and 712 are illustrated as an example of the second suppression unit. For example, the valve 711 is attached to the member 611 and configured to contact the side of the roller 221 that is parallel to the axis of rotation. In addition, below, the side surface parallel to the rotating shaft in the roller 221 is also simply described as the side surface of the roller 221 . That is, the valve 711 is configured to be in contact with the side surfaces of the member 611 and the roller 221 and suppress the inflow of air from between the member 611 and the roller 221 . Similarly, the valve 712 is configured to contact the sides of the member 612 and the roller 222 to restrict the inflow of air from between the member 612 and the roller 222 .

FIG. 6 illustrates the valves 721 and 722 as an example of the second suppression unit. Similar to the valve 711 of FIG. 5, the valve 721 is configured to contact the sides of the member 611 and the roller 221 to restrict the inflow of air from between the member 611 and the roller 221 . Also, similar to valve 712 of FIG. 5 , valve 722 is configured to contact the side of member 612 and roller 222 to restrict the inflow of air from between member 612 and roller 222 .

Here, as shown in FIGS. 5 and 6, the position of the valve for suppressing the inflow of air is not particularly limited. For example, the valve 711 in FIG. 5 is mounted inside a recess provided in the member 611 according to the shape of the roller 221, whereas the valve 721 in FIG. installed.

According to various valves shown in FIGS. 5 and 6, it is possible to maintain the reduced pressure state in the chamber 100 with a simple configuration. However, since friction occurs between the roller and the valve, a case is assumed in which the roller such as the roller 221 is worn.

Therefore, the battery electrode manufacturing apparatus 1000 may include a ring-shaped member 731a in contact with the side surface of the roller 221 and a ring-shaped member 732a in contact with the side surface of the roller 222, as shown in FIG. Here, the ring-shaped member 731a rotates while meshing with the rotation of the roller 221, as indicated by the arrow in FIG. That is, the position where the ring-shaped member 731a contacts the roller 221 and the position where the roller 221 contacts the ring-shaped member 731a move in the same direction at the same speed. The ring-shaped member 731 a may be driven by a motor (not shown) or the like, or may be driven by the roller 221 . Similarly, the ring-shaped member 732a rotates while meshing with the rotation of the roller 222. As shown in FIG.

As shown in FIG. 7, the battery electrode manufacturing apparatus 1000 further includes a ring member 731a and a valve 731b in contact with the member 611, and a ring member 732a and a valve 732b in contact with the member 612. As shown in FIG. In FIG. 7, current collector 21B, roller 221, roller 222, ring member 731a, ring member 732a, valve 731b, valve 732b, member 611 and member 612 cover the slit of chamber 100, allowing air to flow into chamber 100. Inflow is suppressed. Further, in FIG. 7, valves 731b and 732b do not contact rollers 221 and 222, avoiding wear on these rollers. The ring-shaped member 731a, the ring-shaped member 732a, the valve 731b, and the valve 732b are examples of the second suppressing portion.

8A and 8B illustrate an example in which an air inflow suppressing roller 741a and an air inflow suppressing roller 742a are provided instead of the ring-shaped members 731a and 732a of FIG. In addition, FIG. 8B is a perspective view, whereas FIG. 8A is a view from the width direction orthogonal to the conveying direction Da and the vertical direction Db.

The air inflow suppressing roller 741a rotates in mesh with the rotation of the roller 221 . The air inflow suppression roller 741 a may be driven by a motor (not shown) or the like, or may be driven by the roller 221 . Similarly, the air inflow suppressing roller 742a rotates while meshing with the rotation of the roller 222. As shown in FIG. 8A and 8B, the slit of the chamber 100 is covered by the current collector 21B, the roller 221, the roller 222, the air inflow suppression roller 741a, the air inflow suppression roller 742a, the valve 741b, the valve 742b, the member 611 and the member 612. , the inflow of air into the chamber 100 is suppressed. Further, in FIGS. 8A and 8B, valves 741b and 742b do not contact rollers 221 and 222, avoiding wear on these rollers. The air inflow suppressing roller 741a, the air inflow suppressing roller 742a, the valve 741b, and the valve 742b are examples of the second suppressing portion.

It is possible to suppress the inflow of air from the side surface parallel to the rotation axis of the roller such as the roller 221 by the various second suppressing portions described above. Here, in order to more sufficiently maintain the decompressed state in the chamber 100, it is preferable to suppress the inflow of air from the bottom surface of the roller such as the roller 221, which is perpendicular to the rotation axis.

FIG. 9 shows the configuration (roller 221, etc.) in the vicinity of the slit from the upper side Db1 in the vertical direction Db. Note that FIG. 9 omits the member 611 and various second suppressing portions shown in FIGS. 5 to 8B. As shown in FIG. 9 , the battery electrode manufacturing apparatus 1000 includes members 621 and 622 that are provided in the gap between the roller 221 and the outer surface of the chamber 100 to suppress the inflow of air into the chamber 100 . The member 621 and the member 622 are examples of the first suppressing portion. The members 611 and 612 shown in FIGS. 3 to 8B and the members 621 and 622 shown in FIG. 9 may be different members, respectively, or may be integrated.

As described below, the battery electrode manufacturing apparatus 1000 includes, as the second suppressing portion, a bottom surface orthogonal to the rotation axis of the roller such as the roller 221 and a bottom surface member such as the member 621 that is in contact with the first suppressing portion. You may prepare. As examples of such bottom members, FIG. 10 illustrates members 751a and 751b.

As shown in FIG. 10, the member 751a is a bush that is fitted to the rotating shaft of the roller 221. As shown in FIG. The member 751a fills the gap between the bottom surface of the roller 221 and the member 622 shown in FIG. Similarly, the member 751 b fills the gap between the bottom surface of the roller 222 and the member 622 to suppress the inflow of air from the bottom surface of the roller 222 . Even if the member 751a and the member 751b cannot completely block the inflow of air from the bottom surface of the roller 221, the flow of the air flowing in from the bottom surface can be made turbulent instead of laminar. Viscous resistance can be increased and inflow can be reduced.

Although not shown in FIG. 10, members similar to the members 751a and 751b are fitted to the bottom surface on the opposite side of the rollers 221 and 222 as well. The members 751a and 751b are made of felt, for example.

FIG. 10 illustrates an example in which the member 751a is fitted to the rotating shaft of the roller 221 and the member 751b is fitted to the rotating shaft of the roller 222. As shown in FIG. That is, FIG. 10 illustrates an example in which members are fitted individually for each roller. However, rollers 221 and 222 may be configured such that a single member is fitted.

For example, the battery electrode manufacturing apparatus 1000 may include a blade 752 shown in FIG. 11 instead of the members 751a and 751b shown in FIG. That is, the blade 752 is an example of the bottom member. As shown in FIG. 11, the blade 752 is a corrugated plate having ridges radiating from the rotation axis of each roller. As a result, while filling the gap between the bottom surfaces of the rollers 221 and 222 and the member 622 to suppress the inflow of air, the contact area with the rollers 221 and 222 is reduced, and the rollers 221 and 222 rotate. can be prevented.

Alternatively, the battery electrode manufacturing apparatus 1000 may include a blade 753 shown in FIG. 12 as a bottom member. The blade 753 is a corrugated plate having ridges parallel to the vertical direction. Alternatively, the battery electrode manufacturing apparatus 1000 may include a blade 754 shown in FIG. 13 as a bottom member. The blade 754 is a corrugated plate having many ridges parallel to the vertical direction. The blade 753 or the blade 754 fills the gap between the bottom surfaces of the rollers 221 and 222 and the member 622 to suppress the inflow of air, while reducing the contact area with the rollers 221 and 222. The rotation of the roller 222 can be made unhindered.

Alternatively, the battery electrode manufacturing apparatus 1000 may include a member 755 shown in FIG. 14 as a bottom member. The member 755 has villi on the surface on the side contacting the rollers 221 and 222 . The villus fills the gap between the bottom surfaces of the rollers 221 and 222 and the member 622 to suppress the inflow of air, while reducing the friction with the rollers 221 and 222 and allowing the rollers 221 and 222 to rotate. can be prevented.

In addition, in the above-described embodiment, only one pair of rollers such as the roller 221 and the roller 222 is illustrated and described. However, the embodiment is not limited to this, and a plurality of pairs of rollers may be provided. In such a case, the above-described first suppressing portion and second suppressing portion may be provided for each pair of rollers. That is, in contrast to the above-described embodiment, a plurality of front chambers may be provided to reduce the pressure in stages.

Further, in the above-described embodiment, the strip-shaped base film on which the electrode composition 22c is placed is described as the strip-shaped current collector 21B, but it is not limited to this. For example, instead of the strip-shaped current collector 21B shown in FIG. 2, a strip-shaped separator sheet or a strip-shaped release film may be used as the base film. The strip-shaped separator sheet can be trimmed later to form the separator 30 shown in FIG.

For example, when the separator sheet is used as the base film, the electrode composition 22c is supplied on the separator sheet, the current collector 21B is supplied to the surface of the electrode composition 22c opposite to the separator sheet, and the separator sheet and the current collector are supplied. The positive electrode 20a or the negative electrode 20b can be manufactured by trimming the body 21B into a predetermined shape and further supplying the frame 35. FIG.

Further, when the release film is used as the base film, the electrode composition 22c is supplied on the release film, the current collector 21B is supplied to the surface of the electrode composition 22c opposite to the release film, and the release film is After collecting the film, a separator sheet is supplied to the surface opposite to the current collector 21B, the current collector 21B and the separator sheet are trimmed into a predetermined shape, and a frame 35 is supplied to obtain the positive electrode 20a. Alternatively, the negative electrode 20b can be manufactured. Instead of supplying a separator sheet and then trimming, the separator 30 may be supplied to the electrode composition 22c.

Alternatively, the electrode composition 22c is supplied on the release film, the separator sheet is supplied to the surface of the electrode composition 22c opposite to the release film, the release film is recovered, and then the surface opposite to the separator sheet The positive electrode 20a or the negative electrode 20b can be produced by supplying the current collector 21B to , trimming the separator sheet and the current collector 21B into a predetermined shape, and further supplying the frame 35 . Instead of supplying the current collector 21B and then trimming it, the current collector 21 trimmed into a predetermined shape may be supplied to the electrode composition 22c.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment. is also included. Furthermore, it goes without saying that the configurations shown in the respective embodiments can be used in combination as appropriate.

10: Single cell 20: Electrode 20a: Positive electrode 20b: Negative electrode 21: Current collector 21a: Positive electrode current collector layer 21b: Negative electrode current collector layer 21B: Strip-shaped current collector 21R: Current collector roll 22: Electrode active material Layer 22a: Positive electrode active material layer 22b: Negative electrode active material layer 22c: Electrode composition 30: Separator 35: Frame 100: Chamber 200: Conveying device 211, 212, 221, 222: Rollers 221a, 222a: Base 221b, 222b : Elastic body 300: Electrode composition supply device 400: Frame supply device 500: Press device 501: Upper roller 502: Lower roller 611, 612, 621, 622, 751a, 751b, 755: Member 711, 712, 721, 722 , 731b, 732b, 741b, 742b: valves 731a, 732a: annular members 741a, 742a: air inflow suppression rollers 752, 753, 754: blades 1000: battery electrode manufacturing apparatus Da: conveying direction Da1: downstream side Da2: upstream side Db: vertical direction Db1: upper side Db2: lower side

Claims (12)

a chamber whose interior is evacuated below atmospheric pressure;
A transport unit that transports a strip-shaped base film into the chamber through a slit provided in the chamber by rotating the two rollers provided outside the chamber while sandwiching the strip-shaped base film. and,
a first suppressing portion provided in a gap between the roller and the outer surface of the chamber to suppress inflow of air into the chamber;
A battery electrode manufacturing apparatus, comprising: a second suppressing section provided in a gap between the roller and the first suppressing section to suppress inflow of air into the chamber. 2. The battery electrode manufacturing apparatus according to claim 1, wherein said second suppressing portion includes a side surface of said roller parallel to a rotation axis and a valve in contact with said first suppressing portion. The second suppressing portion includes a ring-shaped member that contacts a side surface of the roller parallel to the rotation axis and rotates in mesh with the rotation of the roller, and a valve that contacts the ring-shaped member and the first suppressing portion. The battery electrode manufacturing apparatus according to claim 1, comprising: The second suppressing portion includes an air inflow suppressing roller that contacts a side surface of the roller parallel to the rotation axis and rotates in mesh with the rotation of the roller, and the air inflow suppressing roller and the first suppressing portion. 2. The battery electrode manufacturing apparatus according to claim 1, comprising a contacting valve. The battery electrode manufacturing apparatus according to any one of claims 1 to 4, wherein the second restraint part includes a bottom surface perpendicular to the rotation axis of the roller and a bottom surface member in contact with the first restraint part. 6. The battery electrode manufacturing apparatus according to claim 5, wherein said bottom surface member is a bush that is fitted onto the rotating shaft of said roller. 7. The battery electrode manufacturing apparatus according to claim 5, wherein said bottom member is made of felt. 7. The battery electrode manufacturing apparatus according to claim 5, wherein said bottom surface member is a wavy blade having ridges radiating from the rotating shaft of said roller. 7. The battery electrode manufacturing apparatus according to claim 5, wherein said bottom member is a wavy blade having ridges parallel to the vertical direction. 7. The battery electrode manufacturing apparatus according to claim 5, wherein said bottom member includes villi in contact with said roller. The battery electrode manufacturing apparatus according to any one of claims 1 to 10, wherein at least one of the two rollers has a side surface parallel to the rotation axis of the roller made of an elastic material. A belt-shaped base film is sandwiched between two rollers provided outside a chamber whose interior is evacuated below atmospheric pressure, and the rollers are rotated to allow the belt-shaped base film to pass through a slit provided in the chamber. conveying into the chamber;
suppressing the inflow of air into the chamber by a first suppressing portion provided in the gap between the roller and the outer surface of the chamber;
A method for manufacturing a battery electrode, comprising: suppressing an inflow of air into the chamber by a second suppressing portion provided in a gap between the roller and the first suppressing portion.

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