Battery electrode material application device

Abstract

To obtain a battery electrode material application device which can apply a powder to an application object uniformly.SOLUTION: A battery electrode material application device 10 includes: a transport part 12 which transports a conductive base material 14; a hopper 18 configured to house a powder P; a conductive screen 17 disposed between the base material 14 transported by the transport part 12 and the hopper 18; a voltage application part 16 which can apply a voltage to an area between the transport part 12 and the screen 17; and an inclined plate 22 extending from the screen 17 in an oblique downward direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electrode material application device for a battery. [Background technology]

[0002] Patent Document 1 discloses a powder / granular material supplying device in which a screen is disposed under a hopper. In particular, the device disclosed in Patent Document 1 has a structure in which a plurality of vibration plates are provided inside the hopper below the screen, and an ultrasonic vibrator is attached to a vibration connecting rod that connects these vibration plates, thereby applying vibrations uniformly to the powder / granular material in the hopper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-109031 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device described in Patent Document 1, the powder may hit the vibrating connecting rod before being discharged, which may result in the powder not being applied uniformly to the object to be coated.

[0005] An object of the present invention is to provide a battery electrode material application device capable of uniformly applying powder to an object to be applied. [Means for solving the problem]

[0006] The battery electrode material application device of claim 1 comprises a conveying unit that conveys a conductive base material, a hopper configured to store powder, a conductive screen arranged between the base material conveyed by the conveying unit and the hopper, a voltage application unit that can apply a voltage between the conveying unit and the screen, and an inclined plate extending diagonally downward from the screen.

[0007] In the battery electrode material application device according to claim 1, a conductive base material is conveyed by a conveying unit. The hopper is configured to be able to accommodate powder. A conductive screen is disposed between the base material conveyed by the conveying unit and the hopper. A voltage application unit is configured to be able to apply a voltage between the conveying unit and the screen. As a result, a predetermined amount of powder is supplied from the hopper through the screen to the base material conveyed by the conveying unit, so that the powder is applied to the base material. Here, an inclined plate is extended obliquely downward from the screen. As a result, the powder that has passed through the screen is dispersed in the process of sliding on the inclined plate, and the powder can be applied uniformly to the base material.

[0008] A battery electrode material applying device according to a second aspect of the present invention is the battery electrode material applying device according to the first aspect, wherein the inclined plate extends to the vicinity of the base material transported by the transport section.

[0009] In the battery electrode material application device according to claim 2, since the inclined plate extends to the vicinity of the base material, it is possible to prevent the powder that falls from the inclined plate from scattering.

[0010] The battery electrode material applying device according to claim 3 is the same as claim 1, in which a plurality of the inclined plates are provided along the transport direction of the base material.

[0011] In the battery electrode material application device according to claim 3, since a plurality of inclined plates are provided, even if the screen is long, the powder can be applied uniformly to the base material.

[0012] The battery electrode material applying device according to claim 4 is the same as claim 1, wherein the inclined plate is set at an angle of 45 degrees or more and 80 degrees or less with respect to the screen.

[0013] In the battery electrode material application device according to claim 4, by setting the angle of the inclined plate to 45 degrees or more with respect to the screen, the powder can be prevented from stagnating on the inclined plate, compared to when the inclination angle is smaller than 45 degrees. Also, by setting the angle of the inclined plate to 80 degrees or less with respect to the screen, the powder can be prevented from falling without contacting the inclined plate, compared to when the inclination angle is larger than 80 degrees.

[0014] The battery electrode material application device of claim 5 is, in any one of claims 1 to 4, characterized in that a frame body holding the screen is provided below the hopper, and an ultrasonic vibrator is connected to a side wall of the frame body.

[0015] In the battery electrode material application device according to claim 5, a frame holding the screen is provided below the hopper. An ultrasonic vibrator is connected to a side wall of the frame, so that ultrasonic vibration can be applied to the powder passing through the screen. Effect of the Invention

[0016] As described above, the battery electrode material application device according to the present invention can apply powder uniformly to an object to be applied. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram showing an overall configuration of a battery electrode material application device according to an embodiment of the present invention; [Diagram 2] FIG. 13 is a diagram illustrating an overall configuration of a battery electrode material application device according to a modified example. [Diagram 3] FIG. 2 is a diagram illustrating an overall configuration of a battery electrode material application device according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A battery electrode material application apparatus 10 according to an embodiment will be described with reference to the drawings.

[0019] Fig. 1 is a diagram showing a schematic overall configuration of a battery electrode material application apparatus 10 according to the present embodiment. As shown in Fig. 1, the battery electrode material application apparatus 10 according to the present embodiment is a coater for manufacturing an electrode plate for a battery, and includes a conveying section 12, a frame 15, a screen 17, a hopper 18, a power source 16 as a voltage application section, an ultrasonic vibrator 20, and an inclined plate 22.

[0020] The conveying section 12 includes a supply side roller 12A and a collection side roller 12B. The supply side roller 12A and the collection side roller 12B are configured to rotate by the operation of a motor (not shown).

[0021] A conductive base material 14 is wound between the supply side roller 12A and the recovery side roller 12B. A metal foil or the like is used as the base material 14, and for example, a copper foil or an aluminum foil is used in a rolled state.

[0022] A pre-coated substrate 14A before being coated with powder is wound in a roll around the supply roller 12A, and a post-coated substrate 14C after being coated with powder is wound in a roll around the recovery roller 12B. By operating a motor (not shown), the supply roller 12A and the recovery roller 12B rotate, and the substrate 14 is transported from the supply roller 12A to the recovery roller 12B. The substrate 14B is then coated with powder P during transport between the supply roller 12A and the recovery roller 12B.

[0023] A frame 15 is provided above the substrate 14B being transported. The frame 15 is formed in a substantially box-like shape including a bottom wall 15A and a side wall 15B, and is open at the top. A screen 17 is held on the bottom wall 15A of the frame 15, and the screen 17 is located below a hopper 18, which will be described later. In other words, the screen 17 is disposed between the substrate 14 being transported by the transport section 12 and the hopper 18.

[0024] The screen 17 is conductive and has a predetermined pattern formed thereon. For example, the screen 17 may be a conductive screen in which the pattern portion is formed of a mesh material. The powder P passes through the screen 17 and is applied onto the substrate 14, whereby the powder P is applied onto the substrate 14 in a desired pattern.

[0025] There are no particular limitations on the mesh material of the screen 17 as long as it is conductive. For example, wire materials such as stainless steel containing iron as the main component, zinc-plated iron, brass, and copper may be used. There are no particular limitations on the size of the mesh, and it may be changed appropriately depending on the pattern.

[0026] A hopper 18 is disposed above the screen 17. The hopper 18 is formed in a shape that is open at both the top and bottom ends and gradually narrows downward. The hopper 18 of this embodiment is disposed with its longitudinal direction perpendicular to the direction in which the substrate 14 is conveyed by the conveying section 12. That is, the hopper 18 is disposed with its longitudinal direction extending in the depth direction of the paper surface in FIG. 1. For example, the longitudinal length of the hopper 18 may be slightly shorter than the width of the substrate 14 being conveyed.

[0027] Powder P is supplied from a supply hole at the upper end of the hopper 18. As the powder P, an active material constituting an electrode material, a binder, and the like are used. For example, in the case of a negative electrode material of a lithium ion battery, a composite material of graphite, which is an active material, and a binder is used as the powder P. As the binder, for example, at least one material selected from polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-HEP), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyacrylic acid (PAA), polyamideimide (PAI), and polyimide (PI) may be used.

[0028] Here, the side wall 15B of the frame 15 and the transport section 12 are each electrically connected to a power source 16, and a voltage can be applied between the screen 17 and the transport section 12 by the power source 16. When powder passes through the screen 17 with a voltage applied, the mesh comes into contact with the powder P and charges the powder P.

[0029] An ultrasonic vibrator 20 is connected to the side wall 15B of the frame 15. The structure and type of the ultrasonic vibrator 20 are not particularly limited as long as it is a vibrator that can apply ultrasonic vibrations to the powder in the hopper 18.

[0030] In the present embodiment, as an example, the ultrasonic vibrator 20 is connected to the lower end of the side wall 15B of the frame 15, and is configured to be able to directly apply ultrasonic vibrations to the bottom wall 15A as well. From the viewpoint of applying ultrasonic vibrations evenly to the powder P contained in the hopper 18, the ultrasonic vibrator 20 is preferably connected to a central portion in the longitudinal direction of the hopper 18.

[0031] An inclined plate 22 is attached to the screen 17. The inclined plate 22 extends obliquely downward from the lower surface of the screen 17, and in this embodiment, as an example, is inclined in the conveying direction from the screen 17 toward the substrate 14 (downward).

[0032] In the present embodiment, as an example, three inclined plates 22 are attached to the screen 17. The three inclined plates 22 are attached at equal intervals along the transport direction of the base material 14, and extend to the vicinity of the base material 14.

[0033] Furthermore, each of the three inclined plates 22 is set at an angle of 45 degrees or more and 80 degrees or less with respect to the screen 17. In this embodiment, as an example, the three inclined plates 22 are set at an angle of 70 degrees with respect to the screen 17. The angle of the inclined plates 22 may be changed depending on the material of the powder to be supplied.

[0034] (action) Next, the operation of the battery electrode material application device 10 according to this embodiment will be described.

[0035] In the battery electrode material application device 10 according to this embodiment, a conductive base material 14 is conveyed by a conveying unit 12. A hopper 18 is configured to be capable of containing powder P. A conductive screen 17 is disposed between the base material 14 conveyed by the conveying unit 12 and the hopper 18. A voltage can be applied between the conveying unit 12 and the screen 17. As a result, a predetermined amount of powder P is supplied from the hopper 18 through the screen 17 to the base material 14 conveyed by the conveying unit 12, whereby the powder P is applied to the base material 14.

[0036] In addition, an inclined plate 22 is attached to the screen 17, and the inclined plate 22 extends obliquely downward from the screen 17. As a result, the powder P that has passed through the screen 17 is dispersed as it slides along the inclined plate 22, and the powder P can be applied uniformly to the substrate 14.

[0037] In particular, in this embodiment, since the inclined plate 22 extends to the vicinity of the substrate 14B being transported, it is possible to prevent the powder P that falls from the inclined plate 22 from scattering. In other words, it is possible to prevent the powder P from being unevenly applied.

[0038] In this embodiment, a plurality of inclined plates 22 are provided along the conveying direction. Therefore, even if the length of the screen 17 is long in the conveying direction, the powder P can be uniformly applied to the substrate 14.

[0039] Furthermore, in this embodiment, the angle of the inclined plate 22 is set to an angle of 45 degrees or more and 80 degrees or less with respect to the screen. This makes it possible to suppress the powder P from stagnating on the inclined plate 22, compared to when the inclination angle of the inclined plate 22 is smaller than 45 degrees. In other words, the smaller the angle of the inclined plate 22, the more difficult it is for the powder P to slide, and the more likely it is that the powder will stagnate on the inclined plate 22. In this embodiment, by setting the inclination angle of the inclined plate 22 to 45 degrees or more, the powder can be smoothly slid on the inclined plate 22 regardless of the type of powder to be applied.

[0040] On the other hand, if the angle of the inclined plate 22 with respect to the screen 17 is too large, there is a possibility that the powder P will fall from the screen 17 onto the substrate 14 without contacting the inclined plate. Also, in order to reliably bring the powder P into contact with the inclined plate 22, the pitch between adjacent inclined plates 22 needs to be narrowed, which increases the number of inclined plates 22. In this embodiment, by setting the inclination angle of the inclined plate 22 to 80 degrees or less, it is possible to prevent the powder P from falling without contacting the inclined plate 22.

[0041] Furthermore, in this embodiment, an ultrasonic vibrator 20 is connected to the side wall 15B of the frame 15, and is configured to be able to apply ultrasonic vibrations to the screen 17. This makes it possible to pass the powder P in a dispersed state through the screen 17 and slide it on the inclined plate 22 without the need to print the powder P with a dedicated roller or squeegee.

[0042] In particular, in this embodiment, since the ultrasonic transducer 20 is connected to the lower part of the side wall 15B of the frame body 15, ultrasonic vibration can be applied to the screen 17 in an adjustable manner.

[0043] In this embodiment, the screen 17 is held by the frame 15, but the present invention is not limited to this. For example, a modified structure shown in FIG. 2 may be used.

[0044] (Modification) 2 is a diagram showing an overall configuration of a modified battery electrode material application apparatus 30. As shown in FIG. 2, the modified battery electrode material application apparatus 30 is different from the embodiment in that it does not have a frame 15.

[0045] In this modified example, a hopper 32 is disposed above the substrate 14B being transported. The hopper 32 is formed in a shape that is open at both the upper and lower ends and gradually narrows toward the lower side, and is formed to have a shorter length along the transport direction than the hopper 18 of the embodiment.

[0046] A screen 34 is provided at the lower end of the hopper 32. The screen 34 is attached to a discharge hole of the hopper 32, and is disposed between the substrate 14B being transported and the hopper 32. An inclined plate 22 is attached to the screen 34, and the inclined plate 22 extends obliquely downward from the lower surface of the screen 34. Note that, in this embodiment, as an example, the inclined plate 22 is inclined in the transport direction from the screen 34 toward the substrate 14 (downward), and one inclined plate 22 is attached.

[0047] The ultrasonic transducer 20 is connected to a side wall of the hopper 32. The ultrasonic transducer 20 is connected to a part of the side wall of the hopper 32 that is lower than the center in the up-down direction.

[0048] In this modified example, as in the embodiment, the inclined plate 22 extends downward from the screen 34, so that the powder P that passes through the screen 34 is dispersed as it slides along the inclined plate 22, allowing the powder P to be applied uniformly to the substrate 14.

[0049] (Example) Hereinafter, a description will be given of the evaluation results of the battery electrode material application apparatus 10 according to the present invention and the comparative battery electrode material application apparatus 100. First, the comparative battery electrode material application apparatus 100 will be described, and then the evaluation procedure will be described.

[0050] 3 is a diagram showing a schematic overall configuration of a battery electrode material application apparatus 100 according to a comparative example. As shown in FIG. 3, the battery electrode material application apparatus 100 according to the comparative example includes a substrate holder 102, a hopper 108, a screen 112, a power source 106, and an ultrasonic transducer 20.

[0051] In the structure of the comparative example, a frame 110 is disposed below a hopper 108, and a conductive screen 112 is disposed on a bottom wall 110A of this frame 110. In addition, in the structure of the comparative example, a power source 106 is provided so that a voltage can be applied between the frame 110 and the substrate holder 102.

[0052] Furthermore, in the structure of the comparative example, the ultrasonic vibrator 20 is connected to the side wall 110B of the frame body 110, and by attaching the ultrasonic vibrator to the frame body 110, the ultrasonic vibrator is applied to the screen 112 via the frame body 110. Here, in the structure of the comparative example, the inclined plate 22 is not provided. Therefore, the powder P supplied from the hopper 108 to the frame body 110 is subjected to ultrasonic vibration when passing through the screen 112, and falls as it is to be applied to the substrate 104 placed on the substrate holder 102.

[0053] The evaluation procedure is as follows.

[0054] (1) Composite negative electrode materials Graphite and PVDF were added to an MP mixer (manufactured by Nippon Coke and Engineering Co., Ltd.) as the powders to be applied, and the composite process was carried out at 10,000 rpm for 2 min. The average particle size of the graphite was 10 to 20 μm, and the composition ratio of graphite to PVDF was 97.5 / 2.5 wt%.

[0055] (2) Film formation In the battery electrode material application device 10 shown in FIG. 1, the composite-treated powder P was supplied to a hopper 18, and the powder P was applied to the substrate 14 in an area of ​​100 mm × 50 mm from a screen 17 set to 300 mesh. On the other hand, in the battery electrode material application apparatus 100 shown in FIG. 3, the composite-treated powder P was supplied to a hopper 108, and the powder P was applied to the substrate 104 in an area of ​​100 mm x 50 mm from a screen 112 set to 300 mesh.

[0056] (3) Fixation and densification Using a flat press, pressure is applied at 150[℃] and 5[kN] for 1 minute to fix the powder P to the substrate 14, thereby producing an electrode. Using the same procedure, the powder P is fixed to the substrate 104, thereby producing an electrode.

[0057] (4) Measurement of electrode weight The produced electrode was punched out at 12 locations, and the weight was measured using an electronic balance. Table 1 below shows the calculated weight variation at 12 locations.

[0058] [Table 1]

[0059] The results in Table 1 show that coating with the battery electrode material coating apparatus 10 according to the embodiment can reduce the variation in weight during electrode fabrication, compared to the case where the battery electrode material coating apparatus 100 of the comparative example is used. Since the weight of the electrode depends on the amount of powder P to be coated per unit area, it can be seen that the embodiment can coat the powder P more uniformly than the comparative example.

[0060] In this embodiment, as shown in FIG. 1, the ultrasonic transducer 20 is connected to the side wall 15B of the frame 15. However, the present invention is not limited to this, and the ultrasonic transducer 20 may not be provided.

[0061] In addition, in this embodiment, the ultrasonic transducer 20 is connected to the lower part of the side wall 15B of the frame body 15, but is not limited to this. For example, the ultrasonic transducer 20 may be connected to the center part of the side wall 15B in the vertical direction.

[0062] Furthermore, in this embodiment, three inclined plates 22 are provided, but the present invention is not limited to this, and the number and angles of the inclined plates 22 may be changed. For example, the number of inclined plates 22 may be increased and arranged so that adjacent inclined plates 22 overlap when the screen 17 is viewed from the top and bottom.

[0063] Furthermore, in this embodiment, the angles of the three inclined plates 22 are the same, but this is not limiting, and the inclination angle may be changed for each inclined plate 22. For example, the angle of the inclined plate 22 farther from the side wall 15B to which the ultrasonic transducer 20 is connected may be made larger, and the angle of the inclined plate 22 closer to the side wall 15B to which the ultrasonic transducer 20 is connected may be made smaller. In this way, by adjusting the angle of the inclined plate 22 according to the attenuation of the ultrasonic vibration, it is possible to drop the same amount of powder P from all the inclined plates 22 per unit time.

[0064] In the present embodiment, the conveying unit 12 includes the supply-side roller 12A and the recovery-side roller 12B, but is not limited thereto, and other structures may be adopted as long as they are capable of conveying the substrate 14. For example, when the substrate is in a sheet shape rather than a roll shape, the substrate may be conveyed by a belt or the like.

[0065] Regarding the above embodiment, the following notes are disclosed.

[0066] (Appendix 1) A conveying unit that conveys a conductive base material; A hopper configured to accommodate powder; a conductive screen disposed between the substrate conveyed by the conveying section and the hopper; a voltage application unit capable of applying a voltage between the transport unit and the screen; An inclined plate extending obliquely downward from the screen; The battery electrode material coating device has (Appendix 2) 2. The battery electrode material application device according to claim 1, wherein the inclined plate is extended to a vicinity of the substrate transported by the transport section. (Appendix 3) 3. The battery electrode material application device according to claim 1, wherein the inclined plate is provided in a plurality of inclined plates along a transport direction of the base material. (Appendix 4) 4. The battery electrode material application device according to any one of claims 1 to 3, wherein the inclined plate is set at an angle of 45 degrees or more and 80 degrees or less with respect to the screen. (Appendix 5) A frame that holds the screen is provided below the hopper, 5. The battery electrode material application device according to claim 1, wherein an ultrasonic vibrator is connected to a side wall of the frame. [Explanation of symbols]

[0067] 10, 30 Battery electrode material coating device 12 Conveyor section 14 Base material 15 Frame 15B Side wall 16 Power supply (voltage application part) 17,34 screen 18,32 Hopper 20 Ultrasonic transducer 22 Inclined plate P powder

Claims

1. A conveying unit that conveys a conductive base material; A hopper configured to accommodate powder; a conductive screen disposed between the substrate conveyed by the conveying section and the hopper; a voltage application unit capable of applying a voltage between the transport unit and the screen; An inclined plate extending obliquely downward from the screen; The battery electrode material coating device has

2. The battery electrode material applying device according to claim 1 , wherein the inclined plate is extended to a vicinity of the substrate transported by the transport section.

3. The battery electrode material applying device according to claim 1 , wherein the inclined plate is provided in a plurality of positions along a transport direction of the substrate.

4. 2. The battery electrode material coating device according to claim 1, wherein the inclined plate is set at an angle of 45 degrees or more and 80 degrees or less with respect to the screen.

5. A frame that holds the screen is provided below the hopper, 5. The battery electrode material coating device according to claim 1, wherein an ultrasonic vibrator is connected to a side wall of the frame.

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