JP2023065919A - Electrode manufacturing device for batteries and electrode manufacturing method for batteries - Google Patents

Abstract

To provide an electrode manufacturing device for batteries and an electrode manufacturing method for batteries with which it is possible to increase the efficiency of shaping an electrode composition before compaction.SOLUTION: The electrode manufacturing device for batteries comprises: an inclined plate 310 which is inclined downward toward a downstream side D1 in a conveyance direction D of a belt-like base film and a frame body 35 placed on the base film; a first supply unit 320 for supplying to the inclined plate an electrode composition 22c, which is a wet powder substance including an active material and an electrolytic solution; an adjustment unit 330 for adjusting the thickness of the electrode composition supplied to the inclined plate; and a second supply unit 342 for supplying the electrode composition, the thickness of which has been adjusted, to the base film and in the inside of the frame body. The inclined plate includes a first inclined part, and a second inclined part which is located downstream of the first inclined part in the conveyance direction, and the inclination of which is smaller than that of the first inclined part.SELECTED DRAWING: Figure 3

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 produced, for example, by compressing an electrode composition together with a current collector and a separator by roll pressing or the like. More specifically, the electrode composition is supplied inside the frame, shaped into a predetermined shape, and then compressed.

As a method for supplying the electrode composition to the inside of the frame, a method using a hopper is conceivable. Specifically, the electrode composition is supplied to the inside of the frame positioned below the opening of the hopper by holding the electrode composition inside the hopper and opening and closing the opening of the hopper with a shutter. be able to. Further, for example, as described in Patent Document 1, by conveying the electrode composition to the opening of the hopper using an endless belt, the electrode composition is applied to the inside of the frame positioned below the opening of the hopper. can be supplied.

JP 2020-161303 A Japanese Patent No. 6067636

When the electrode composition is supplied to the inside of the frame by the above method, it is necessary to shape the electrode composition inside the frame before compression by roll press or the like. Here, the electrode composition may be wet powder containing an active material and an electrolytic solution. Such an electrode composition has a characteristic of sticking when pressure is applied, and in relation to the frame surrounding the electrode composition, it is easy to shape the electrode composition inside the frame. isn't it.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery electrode manufacturing apparatus and a battery electrode manufacturing method that can efficiently shape the electrode composition before compression. do.

In order to achieve the above object, a battery electrode manufacturing apparatus according to the present invention includes a strip-shaped base film and a frame placed on the base film, which is inclined downward toward the downstream side in the conveying direction. a slanted plate, a first supply section for supplying an electrode composition, which is a wet powder containing an active material and an electrolytic solution, to the slanted plate, and a thickness of the electrode composition supplied on the slanted plate and a second supply unit that supplies the electrode composition with the adjusted thickness onto the base film and inside the frame, wherein the inclined plate is the first and a second inclined portion that is positioned downstream in the conveying direction from the first inclined portion and has a smaller inclination than the first inclined portion.

According to the battery electrode manufacturing apparatus and the battery electrode manufacturing method of the present invention, it is possible to efficiently shape the electrode composition before compression.

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 showing an example of the electrode composition supply device of the embodiment. FIG. 4A is a diagram showing an example of an inclined plate according to the embodiment; FIG. 4B is a diagram illustrating an example of the inclined plate of the embodiment; FIG. 5 is a diagram showing an example of an electrode composition supply device according to a first modified example. FIG. 6 is a diagram showing an example of a belt conveyor according to the first modified example. FIG. 7 is a diagram showing an example of an electrode composition supply device according to a second modification. FIG. 8 is a diagram showing an example of the second inclined portion of the second modified example.

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 (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 a polymer or fiber that absorbs and retains 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 that constitutes the positive electrode current collector layer 21a, a known current collector used in 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 methyl cellulose, 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 adhesiveness, so that the positive electrode active material and the positive electrode active material and the current collector are solidified. 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 is the method for obtaining the negative electrode active material layer 22b which is 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 suitably 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 proportion of the non-aqueous electrolyte in the wet powder is not particularly limited, but in the case of the negative electrode, the proportion of the non-aqueous electrolyte in 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.

<Manufacturing apparatus and method for manufacturing battery electrode>
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 frame supply device 200 , an electrode composition supply device 300 , a compression device 400 and a transfer device 500 . As an example, a case where the strip-shaped base film is the strip-shaped current collector 21B will be described below.

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 10 ⁵ 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 along the transport direction D. As shown in FIG. For example, the current collector 21B is transported by the transport device 500 at a predetermined speed. Hereinafter, the direction in which the current collector 21B is conveyed will be described as the downstream side D1, and the opposite direction as the upstream side D2. 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 .

The transport device 500 transports the current collector 21B along the transport direction D. As shown in FIG. For example, the transport device 500 is a belt conveyor including a belt and a drive mechanism for driving the belt. In this case, the current collector 21B is conveyed to the downstream side D1 in the conveying direction D while being placed on the belt of the conveying device 500 .

The frame supply device 200 supplies the frame 35 to the conveyed current collector 21B. Although FIG. 2 shows the case where the frame supply device 200 is arranged inside the chamber 100 , the frame supply device 200 may be arranged outside the chamber 100 . For example, the frame supply device 200 has a robot arm, and places the pre-manufactured frame 35 at a predetermined position on the transported current collector 21B. After placing the frame 35 on the current collector 21B, the current collector 21B and the frame 35 may be compressed by a roll press so as to be sandwiched between them.

In addition, in FIG. 2, the prefabricated frame 35 is described as being placed on the current collector 21B, but the embodiment is not limited to this. For example, the frame 35 may be manufactured 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 electrode composition supply device 300 shapes the electrode composition 22c and supplies it to the inside of the current collector 21B and the frame 35 . The electrode composition supply device 300 supplies the electrode composition 22c in the chamber 100, as shown in FIG.

As described above, in the embodiment, the electrode composition 22c (positive electrode composition A material, a 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.

Here, the details of the electrode composition supply device 300 will be described with reference to FIG. FIG. 3 is a diagram showing an example of the electrode composition supply device 300 of the embodiment. For example, the electrode composition supply device 300 includes an inclined plate 310 , a supply device 320 , a squeegee 330 , a shutter 341 and a vibrator 342 . The inclined plate 310 is an example of an inclined plate. Supply device 320 is an example of a first supply unit. Squeegee 330 is an example of an adjustment unit. The shutter 341 and vibrator 342 are examples of a second supply unit.

The inclined plate 310 is arranged so as to be inclined downward toward the downstream side D1 in the transport direction D of the current collector 21B and the frame 35, as shown in FIG. The shape of the inclined plate 310 will be described in more detail with reference to FIGS. 4A and 4B. 4A and 4B are diagrams showing an example of the inclined plate 310 of the embodiment.

FIG. 4A is a diagram showing the inclined plate 310 from a direction perpendicular to the transport direction D and the vertical direction. As shown in FIG. 4A, the inclined plate 310 has a first inclined portion 311 and a second inclined portion 312 . The second inclined portion 312 is located on the downstream side D<b>1 in the transport direction D of the first inclined portion 311 and has a smaller inclination than the first inclined portion 311 .

4B is a cross-sectional view showing an arbitrary position on the inclined plate 310 from the downstream side D1 in the transport direction D. FIG. As shown in FIG. 4B, the inclined plate 310 includes a fence 313a and a fence 313b. Here, the inclined plate 310 has a fence 313a and a fence 313b at each position along the transport direction D. As shown in FIG. That is, the inclined plate 310 has rails on two sides parallel to the transport direction D. As shown in FIG. The interval between the fences 313a and 313b is adjusted to be substantially the same as the width inside the frame 35. As shown in FIG.

As shown in FIG. 3, the supply device 320 supplies the electrode composition 22c to the inclined plate 310. As shown in FIG. For example, the supply device 320 supplies the electrode composition 22c to the first inclined portion 311 of the inclined plate 310 while reciprocating between the fences 313a and 313b.

Note that FIG. 3 is only an example, and the method of supplying the electrode composition 22c to the inclined plate 310 is not particularly limited. For example, the supply device 320 may include a hopper and a shutter, and the electrode composition 22c held inside the hopper may be supplied to the inclined plate 310 by opening and closing the opening of the hopper with the shutter.

The squeegee 330 adjusts the thickness of the electrode composition 22c provided on the inclined plate 310. FIG. Here, the width of the electrode composition 22c supplied on the inclined plate 310 is restricted by the fences 313a and 313b. That is, the width and thickness of the electrode composition 22c can be adjusted to desired values by the squeegee 330, the fence 313a and the fence 313b.

The electrode composition 22c slides down the inclined plate 310 while being shaped by the squeegee 330, the fences 313a and 313b, and flows downstream D1 in the transport direction D. As shown in FIG. Here, the shutter 341 controls the supply of the electrode composition 22c to the inside of the frame 35 by controlling the drop of the electrode composition 22c from the end of the inclined plate 310 on the downstream side D1.

Specifically, the shutter 341 is controlled to open when the inner space of the frame 35 is located below the end of the inclined plate 310 on the downstream side D1, and to close otherwise. That is, as shown in FIG. 3, while the shutter 341 is open, the electrode composition 22c drops from the end of the inclined plate 310 on the downstream side D1 and is supplied to the inside of the frame . On the other hand, while the shutter 341 is closed, the electrode composition 22c is dammed at the downstream D1 end of the inclined plate 310 and accumulates on the inclined plate 310 .

When the electrode composition 22c is wet powder, the fluidity is low, and when the inclination is small, the electrode composition 22c may not flow and may clog the inclined plate 310. FIG. On the other hand, at the end of the inclined plate 310 on the downstream side D1, the angle difference between the inclined plate 310 and the current collector 21B and the frame 35 is preferably small.

On the other hand, the inclined plate 310 has a first inclined portion 311 with a large inclination and a second inclined portion 312 with a small inclination. Since the inclination of the first inclined portion 311 is large, sufficient force for flowing downstream D1 in the transport direction D can be applied to the electrode composition 22c on the inclined plate 310 . In addition, the inclination of the second inclined portion 312 is small, and the angle difference between the current collector 21B and the frame 35 can be made small.

The vibration exciter 342 can assist the flow of the electrode composition 22c on the inclined plate 310 by vibrating the inclined plate 310 . That is, by providing the vibration exciter 342, clogging of the electrode composition 22c on the inclined plate 310 can be more reliably prevented, and the electrode composition 22c can be supplied to the inside of the frame 35 more accurately. can. Although FIG. 3 shows the electrode composition supply device 300 including the vibration exciter 342, the vibration exciter 342 may be omitted as appropriate.

The inclined plate 310 may be provided with a treated layer by roughening treatment or fluorine coating (for example, Teflon (registered trademark) treatment). As a result, clogging of the electrode composition 22c on the inclined plate 310 can be more reliably prevented, and the electrode composition 22c can be supplied to the inside of the frame 35 with higher accuracy.

The compressing device 400 compresses the electrode composition 22c supplied on the current collector 21B and inside the frame 35, thereby forming the electrode active material layer 22 shown in FIG. Here, the shaping of the electrode composition 22c has been completed at the stage of being supplied from the electrode composition supply device 300, and the compression step by the compression device 400 can be performed without requiring an additional step.

Alternatively, even if the electrode active material layer 22 supplied from the electrode composition supply device 300 is subjected to more precise shaping before the compression step by the compression device 400, the shaping can be performed in a small width, which is simple. It is possible to set it as a process.

For example, compression device 400 is a pair of rollers as shown in FIG. In this case, the compression device 400 can manufacture the positive electrode 20a or the negative electrode 20b by sandwiching and compressing the current collector 21B, the frame 35, and the electrode composition 22c.

Although FIG. 1 shows only a pair of rollers as the compression device 400, the embodiment is not limited to this. For example, the battery electrode manufacturing apparatus 1000 may be provided with a plurality of pairs of rollers as the compressing device 400 to compress the current collector 21B, the frame 35 and the electrode composition 22c step by step. Alternatively, the electrode composition 22c may be compressed while a release film is interposed between the roller and the electrode composition 22c. Thereby, it is possible to prevent a part of the electrode composition 22c from adhering to the roller, and to make the surface of the electrode composition 22c smoother. Alternatively, the electrode composition 22c may be compressed with the separator 30 sandwiched between the roller and the electrode composition 22c. As a result, the surface of the electrode composition 22c can be made smoother, and the step of supplying the separator 30 to the positive electrode 20a or the negative electrode 20b can be omitted.

As described above, the electrode composition supply device 300 shapes the electrode composition 22c on the inclined plate 310 and then supplies it to the current collector 21B and the frame 35 . As a result, the step of shaping the electrode composition 22c inside the frame 35 before compression by the compression device 400 can be omitted or simplified. That is, the electrode composition supply device 300 can efficiently shape the electrode composition 22c before compression, and thus improve the manufacturing efficiency of the electrode 20 .

In addition, in the embodiment, each step of supplying the electrode composition 22c by the electrode composition supply device 300 and compressing the electrode composition 22c by the compression device 400 is performed in the chamber 100 whose inside is reduced in pressure below atmospheric pressure. do. As a result, air can be prevented from remaining inside the electrode composition 22c, and the uniformity of the electrode active material layer 22 can be improved.

In order to more accurately control the behavior of the electrode composition 22c on the inclined plate 310, the electrode composition supply device 300 may further include a belt conveyor 343 shown in FIGS. FIG. 5 is a diagram showing an example of the electrode composition supply device 300 of the first modified example. Moreover, FIG. 6 is a figure which shows an example of the belt conveyor 343 of a 1st modification. For example, as shown in FIG. 6, the belt conveyor 343 includes a ring-shaped belt 343a and rollers 343b to 343m. The rollers 343b-343m are an example of a driving mechanism that rotates the belt 343a. That is, the belt 343a is an endless moving belt driven by rollers 343b to 343m.

As shown in FIG. 5, the belt conveyor 343 is arranged such that the lower surface of the belt 343a is in contact with the upper surface of the electrode composition 22c located on the second inclined portion 312. As shown in FIG. With the lower surface of the belt 343a in contact with the electrode composition 22c, the belt 343a is rotated so that the lower surface of the belt 343a moves to the downstream side D1 in the conveying direction D, whereby the electrode composition inside the frame 35 is moved. A supply of goods 22c can be provided.

Hereinafter, the rotation direction in which the lower surface of the belt 343a moves to the downstream side D1 in the transport direction D is defined as a first rotation direction, and the rotation direction opposite to the first rotation direction is defined as a second rotation direction. For example, when the inner space of the frame 35 is located below the end of the inclined plate 310 on the downstream side D1, the belt conveyor 343 rotates the belt 343a in the first rotation direction to change the electrode composition. The object 22 c can be dropped from the end of the inclined plate 310 on the downstream side D<b>1 and supplied to the inside of the frame 35 . In addition, the belt conveyor 343 can stop the supply of the electrode composition 22c by stopping or decelerating the rotation of the belt 343a. Although FIG. 3 shows the electrode composition supply device 300 including the shutter 341 and the vibrator 342, the shutter 341 and the vibrator 342 may be omitted as appropriate.

In addition, the belt conveyor 343 can be configured to compact the contacting electrode composition 22c to some extent. As a result, when the electrode composition 22c drops from the inclined plate 310 into the frame 35, it is possible to prevent the electrode composition 22c from losing its shape.

Also, the distance (gap) between the lower surface of the belt conveyor 343 and the second inclined portion 312 is configured to be substantially constant. For example, the distance between the lower surface of the belt conveyor 343 and the second inclined portion 312 is configured to be constant in a predetermined section on the second inclined portion 312 along the conveying direction D. Thereby, the thickness of the electrode composition 22c after coming into contact with the belt conveyor 343 can be adjusted with higher accuracy.

Also, the rotation speed of the belt 343a may be variable. For example, the belt conveyor 343 rotates the belt 343a in the first rotation direction at the first rotation speed at the start of supplying the electrode composition 22c to the inside of the frame 35 . Here, the first rotation speed is a rotation speed at which the moving speed of the lower surface of the belt 343a toward the downstream side D1 is higher than the moving speed of the frame body 35 toward the downstream side D1. Next, the belt conveyor 343 reduces the rotation speed of the belt 343a so that the moving speed of the lower surface of the belt 343a toward the downstream side D1 and the moving speed of the frame body 35 toward the downstream side D1 match. Rotate 343a. Then, the belt conveyor 343 reduces the rotation speed of the belt 343a so that the moving speed of the lower surface of the belt 343a toward the downstream side D1 is lower than the moving speed of the frame 35 toward the downstream side D1, and The supply of the electrode composition 22c to the inside of 35 is finished. Thereby, it is possible to avoid the formation of a gap in the transport direction D between the frame 35 and the electrode composition 22c.

According to the belt conveyor 343, it is possible not only to start and stop the supply of the electrode composition 22c into the frame 35 but also to adjust the supply pace. That is, according to the belt conveyor 343, it is possible to supply the electrode composition 22c in accordance with the moving speed of the frame 35. As shown in FIG. Thus, for example, when supplying the electrode composition 22c, it is not necessary to stop the transport of the current collector 21B and the frame 35 by the transport device 500, and the manufacturing efficiency of the electrode 20 can be improved.

In order to more accurately control the behavior of the electrode composition 22c on the inclined plate 310, the electrode composition supply device 300 may further include a belt conveyor 344 shown in FIGS. FIG. 7 is a diagram showing an example of an electrode composition supply device 300 of a second modified example. Moreover, FIG. 8 is a figure which shows an example of the belt conveyor 344 of a 2nd modification. For example, the belt conveyor 344 includes a ring-shaped belt 344a and rollers 344b to 344g, as shown in FIG. The rollers 344b-344g are an example of a drive mechanism that rotates the belt 344a. That is, the belt 344a is an endless moving belt driven by rollers 344b to 344g. Belt 344a is an example of a lower belt.

As shown in FIG. 7, the second inclined portion 312 of the inclined plate 310 is configured by the belt 344a. That is, in the second modification, the inclined plate 310 is integrated with the belt conveyor 344, and the second inclined portion 312 is configured to be drivable.

As shown in FIG. 8, the belt conveyor 344 may further include a flat plate 344h. The flat plate 344h is a reinforcing member arranged so that the upper surface of the belt 344a is flat. That is, the flat plate 344h is arranged so that the second inclined portion 312 in the second modified example is flat. Further, a cover may be attached to cover the belt 344a so that the electrode composition 22c adhering to the belt 344a does not scatter.

The belt conveyor 344 controls so that the lower surface of the belt 343a included in the belt conveyor 343 and the upper surface of the belt 344a move synchronously. For example, when supplying the electrode composition 22c to the inside of the frame 35, the belt conveyor 343 rotates the belt 343a so that the lower surface of the belt 343a moves to the downstream side D1, and the belt conveyor 344 moves the belt 344a. The belt 344a is rotated so that the upper surface moves downstream D1 at the same speed as the lower surface of the belt 343a. Further, when stopping the supply of the electrode composition 22c to the inside of the frame 35, the belt conveyor 343 and the belt conveyor 344 stop the rotation of the belts 343a and 344a. Alternatively, when stopping the supply of the electrode composition 22c to the inside of the frame 35, the belt conveyor 343 decelerates the rotation of the belt 343a, and the belt conveyor 344 rotates the upper surface of the belt 344a and the lower surface of the belt 343a at the same speed. The rotation of the belt 344a is decelerated so that

The belt conveyor 343 and the belt conveyor 344 can control the behavior of the electrode composition 22c on the inclined plate 310 from both the top surface and the bottom surface. As a result, the behavior of the electrode composition 22c on the inclined plate 310 can be controlled more accurately than when only the belt conveyor 343 is provided, and shear force is applied to the electrode composition 22c to cause cracking. Such situations can be avoided.

In the above-described embodiment and each modified example, the strip-shaped base film on which the electrode composition 22c is placed is described as the strip-shaped current collector 21B, but the present invention 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 frame 35 and the electrode composition 22c are 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 By trimming the separator sheet and current collector 21B into a predetermined shape, the positive electrode 20a or the negative electrode 20b can be produced.

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

Alternatively, the frame 35 and the electrode composition 22c are 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 separator sheet and The positive electrode 20a or the negative electrode 20b can be produced by supplying the current collector 21B to the opposite surface and trimming the separator sheet and the current collector 21B into a predetermined shape. 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 embodiments and modifications of the present invention have been described in detail with reference to the drawings. However, the specific configurations are not limited to these. Deletion etc. are also included. Furthermore, it goes without saying that the configurations shown in each embodiment and each modified example can be appropriately combined and used.

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: Frame supply device 300: Electrode composition supply device 310: Inclined plate 311: First inclination Part 312: Second Inclined Part 313a: Fence 313b: Fence 320: Supply Device 330: Squeegee 341: Shutter 342: Vibrator 343: Belt Conveyor 343a: Belt 344: Belt Conveyor 344a: Belt 400: Compressor 500: Conveyor 1000: Battery electrode manufacturing apparatus D: Conveying direction D1: Downstream side D2: Upstream side

Claims (11)

a slant plate that is inclined downward toward the downstream side in the conveying direction of the strip-shaped base film and the frame placed on the base film;
a first supply unit that supplies an electrode composition, which is a wet powder containing an active material and an electrolytic solution, to the inclined plate;
an adjustment unit that adjusts the thickness of the electrode composition supplied onto the inclined plate;
A battery electrode manufacturing apparatus comprising: a second supply unit that supplies the electrode composition with an adjusted thickness onto the base film and inside the frame,
The slanted plate includes a first slanted portion and a second slanted portion located downstream of the first slanted portion in the conveying direction and having a smaller slant than the first slanted portion. Device. The second supply unit includes a belt conveyor including a ring-shaped belt and a drive mechanism for rotating the belt,
The belt conveyor moves the belt so that the lower surface of the belt moves downstream in the conveying direction while the lower surface of the belt is in contact with the upper surface of the electrode composition positioned on the second inclined portion. The battery electrode manufacturing apparatus according to claim 1, wherein the electrode composition is supplied onto the base film and into the frame by rotating. 3. The battery electrode manufacturing apparatus according to claim 2, wherein the distance between the lower surface of said belt and said second inclined portion is substantially constant. 4. The battery electrode manufacturing apparatus according to claim 2, wherein the rotation speed of said belt is variable. The second supply unit supplies the electrode composition onto the base film and into the frame by rotating the belt so that the lower surface of the belt moves downstream in the conveying direction. 5. The battery electrode manufacturing apparatus according to any one of claims 2 to 4, wherein the supply of the electrode composition is stopped by stopping or decelerating the rotation of the belt. The battery electrode manufacturing apparatus according to any one of claims 2 to 5, wherein the second inclined portion is composed of a lower belt arranged below the belt, unlike the belt. 7. The battery electrode manufacturing apparatus according to claim 6, wherein said lower belt is a ring-shaped member that is rotated by a drive mechanism, and is controlled such that the lower surface of said belt and the upper surface of said lower belt move synchronously. The second supply unit according to any one of claims 1 to 7, wherein the second supply unit includes a shutter for stopping the supply of the electrode composition, which is positioned at the end of the inclined plate on the downstream side in the transport direction. The battery electrode manufacturing apparatus described. The battery electrode manufacturing apparatus according to any one of claims 1 to 8, wherein the second supply section includes a vibrator that vibrates the inclined plate. The battery electrode manufacturing apparatus according to any one of claims 1 to 9, wherein said inclined plate includes a treated layer by roughening treatment or fluorine coating. A wet powder containing an active material and an electrolytic solution is applied to a belt-shaped base film and an inclined plate inclined downward toward the downstream side in the conveying direction of a frame placed on the base film. supplying an electrode composition;
adjusting the thickness of the electrode composition supplied on the inclined plate;
A method for manufacturing a battery electrode, comprising: supplying the electrode composition having an adjusted thickness on the base film and inside the frame,
The slanted plate includes a first slanted portion and a second slanted portion located downstream of the first slanted portion in the conveying direction and having a smaller slant than the first slanted portion. Method.

Images