CN114797534A

CN114797534A - Stirring device

Info

Publication number: CN114797534A
Application number: CN202210674971.9A
Authority: CN
Inventors: 大畠积; 森安信彦; 和仁崇行; 古市尚
Original assignee: Primix Corp
Current assignee: Primix Corp
Priority date: 2018-05-21
Filing date: 2019-05-17
Publication date: 2022-07-29
Also published as: CN114797533A; WO2019225502A1

Abstract

The invention provides a stirring device, which comprises a container for accommodating stirring objects and a rotating component rotating on the inner side of the inner wall surface of the container. When the stirring device is operated, a film-like stirring object is present between the rotating member and the inner wall surface, and the stirring object is stirred. The rotating member and/or the inner wall surface of the container are formed with concave and convex portions by grooves, recesses, or projections arranged at predetermined intervals. The container has: the mixing device comprises a first input port for inputting a powder component constituting the mixing object, a second input port for inputting a liquid-containing component constituting the mixing object, and a discharge port for discharging a mixing object obtained by mixing the powder component and the liquid-containing component. According to the present invention, the coating material for a battery electrode to be stirred can be highly dispersed.

Description

Stirring device

The application is a divisional application of patent applications with application date of 2019, 05 and 17, application number of 201980034003.8 and invention name of 'stirring device'.

Technical Field

The present invention relates to a stirring apparatus. In particular, the present invention relates to a stirring apparatus for producing a coating material containing an electrode material for a battery.

Background

In addition to a power source for portable electronic devices, there is expected to be an increasing demand for batteries represented by lithium ion secondary batteries and fuel cells, such as power sources for electric vehicles and storage of electric power generated by wind power and solar power generation devices. Further, not only are there demands for further improvement in characteristics such as miniaturization, weight reduction, and safety of the battery itself, but also for efficient and low-cost production of a battery having these characteristics.

As an effective means for solving the above problems, the inventors of the present application have proposed a method for producing a coating material for a battery electrode using a stirring device system disclosed in the following patent document 1. A stirring device included in this stirring device system is a so-called high-speed stirrer including a vessel and a rotating member that rotates at a high speed slightly inside the inner wall surface of the vessel. In the high-speed mixer, a stirring target is continuously supplied, and the stirring target is stirred in a film shape between a rotating member and an inner wall surface of a vessel by a centrifugal force generated by the rotating member. When the stirring device is used for manufacturing the coating for the battery electrode, the coating for the battery electrode which is suitable for improving the battery performance while maintaining high battery safety can be efficiently manufactured.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2010/018771.

Disclosure of Invention

Problems to be solved by the invention

In recent years, there has been a growing demand for efficient and low-cost production of electrode coating materials. In view of such current situation, the inventors of the present application have earnestly studied a method of improving the agitation apparatus system disclosed in patent document 1 and further efficiently manufacturing a coating material for an electrode suitable for improving the battery performance while maintaining the battery safety at a high level, and have completed the present invention.

In addition, in recent years, demands for high efficiency and low cost in battery production have further increased, and all-solid-state batteries have attracted attention as batteries that satisfy these demands. Since all-solid batteries do not use a flammable organic electrolyte, they can ensure high safety. Further, the all-solid battery has a simple structure in which the layered solid electrolyte is sandwiched between the positive electrode and the negative electrode, and therefore has an advantage that it can be manufactured efficiently and at low cost. The inventors have examined the stirring device system disclosed in patent document 1 in order to further improve the battery performance while utilizing the advantages of such an all-solid battery, to complete the present invention.

In the above-described stirring device system, since the stirring target to be supplied to the high-speed stirrer needs to be mixed with all the materials in advance to equalize the mixing state, a preliminary stirring step is provided as a preliminary step. In the preliminary stirring step, for example, when manufacturing a coating material for an electrode for a lithium ion secondary battery, it is necessary to mix a stirring target containing a plurality of constituent components such as a powder, a solvent, and a binder as an active material and to average the mixed state of all the materials, and therefore, it takes time to handle the process using a relatively expensive large-sized apparatus. Therefore, the method of manufacturing the battery electrode coating material or the like using the above-described stirring device system has a problem in terms of cost. As a method for solving this problem, it is effective to adopt a method of directly charging the powder component contained in the stirring object into the high-speed stirrer without a preliminary stirring step, thereby simplifying the apparatus structure. However, when the method of directly charging all the components included in the stirring target into the high-speed mixer is used, there is a problem that the components to be charged into the high-speed mixer may remain in the charging route or agglomerate in the stirring vessel to prevent continuous supply of the stirring target, and thus the processing efficiency is significantly reduced. In order to solve the above problem, the inventors have conducted extensive studies and have found that the above problem can be solved by redesigning the shape and arrangement of the inlet of the high-speed mixer to be stirred.

In addition, in the case of using a method in which all the components included in the stirring target are directly charged into the high-speed stirrer, it is effective to charge the components into the container from the top plate of the high-speed stirrer by gravity drop and to discharge the components from the bottom side of the container. However, when the above-described feeding and discharging method is applied to the case where stirring is performed in a state where the stirring is present in a film shape between the rotating member and the inner wall surface due to the centrifugal force generated by the rotating member, there is a problem in that continuous supply of the stirring target is hindered, and the processing efficiency is significantly reduced. In order to solve the problem, the inventors have conducted extensive studies and found that the above problem can be solved by redesigning the structure and arrangement of the discharge mechanism of the stirring object in the high-speed mixer, and have completed the present invention.

Means for solving the problems

Specifically, the stirring device of the present invention includes a container and a rotating member that rotates inside an inner wall surface of the container, and is configured to stir an object to be stirred that is present in a film shape between the rotating member and the inner wall surface due to a centrifugal force generated by the rotating member, wherein the container includes a concave-convex portion formed by grooves, recesses, or projections arranged at predetermined intervals on a surface of the rotating member and/or the inner wall surface that faces the object to be stirred that is present in the film shape, and the container includes: a first inlet for introducing a powder component constituting the object to be stirred; a second inlet for introducing a liquid-containing component (e.g., slurry) constituting the object to be stirred; and a discharge port for discharging a mixing object obtained by mixing the powder component and the liquid-containing component.

Preferably, the container is defined in a vertical direction as a plurality of dispersion tanks, the rotary members are housed in the plurality of dispersion tanks, and the uneven portions are formed by grooves, recesses, or projections arranged at predetermined intervals on the rotary members and a surface of a part of the inner wall surface of each of the dispersion tanks facing the stirring target in the form of a film.

More preferably, the first inlet and the second inlet are formed in a dispersion tank disposed at the uppermost layer among the plurality of dispersion tanks, and the discharge port is formed in a dispersion tank disposed at the lowermost layer.

A stirring apparatus according to the present invention for producing a battery electrode coating material includes a container and a rotating member that rotates inside an inner wall surface of the container, and is configured to stir an intermediate material of a battery electrode coating material as a stirring target that is present in a film shape between the rotating member and the inner wall surface due to a centrifugal force generated by the rotating member, wherein the container includes a concave-convex portion formed by grooves, recesses, or protrusions arranged at predetermined intervals on a surface of the rotating member and/or the inner wall surface that faces the stirring target present in the film shape, and the container includes: a first inlet for introducing a powder component containing an active material to be stirred; a second inlet for introducing a liquid-containing component of the slurry containing the conductive material to be stirred; and a discharge port for discharging a mixing object obtained by mixing the powder component and the liquid-containing component.

Preferably, the stirring device for producing a coating material for a battery electrode is applied to an intermediate material of a coating material for a battery electrode in which the conductive material is any one of carbon black, carbon nanotubes, and graphene.

Preferably, the above stirring apparatus for producing a coating material for a battery electrode is applied to an intermediate material of a coating material for a battery electrode containing an active material for a nonaqueous electrolyte secondary battery as an active material.

In addition, the present invention provides a stirring apparatus for producing an all-solid-state battery electrode paint, the stirring apparatus including a container and a rotating member rotating inside an inner wall surface of the container, the stirring apparatus being configured to stir an intermediate material of the battery electrode paint, which is a stirring target, existing in a film shape between the rotating member and the inner wall surface due to a centrifugal force generated by the rotating member, wherein the container includes a concave-convex portion formed by grooves, recesses, or protrusions arranged at predetermined intervals on a surface of the rotating member and/or the inner wall surface facing the stirring target existing in the film shape, and the container includes: an inlet for introducing an active material, a solid electrolyte and a solvent to be stirred; and a discharge port for discharging a mixed object to be stirred, wherein the mixing of the active material, the solid electrolyte and the solvent constituting the object to be stirred is performed in the container.

Preferably, in the stirring apparatus for producing the coating material for all-solid-state battery electrodes, the active material constituting the object to be stirred is particles covered with a lithium ion conductive coating film.

Further, a stirring device of the present invention includes a container and a rotating member that rotates inside an inner wall surface of the container, and is configured to stir an object to be stirred that is present in a film shape between the rotating member and the inner wall surface due to a centrifugal force generated by the rotating member, the container including: a first inlet for introducing a powder component constituting the object to be stirred; a second inlet for introducing a liquid-containing component constituting the object to be stirred; and a discharge port for discharging a mixing object obtained by mixing the powder component and the liquid-containing component, wherein the first inlet is connected to a cylindrical first path that is arranged at the center of the container and penetrates from the outside of the container into the container, and the second inlet is connected to a cylindrical second path that is arranged adjacent to the outer periphery of the first path and penetrates from the outside of the container into the container.

Preferably, the rotating member has a cylindrical portion disposed with a gap from an inner wall surface of the container, and a horizontal portion horizontally rotating inside the cylindrical portion.

Preferably, a front end of the first path is closer to the horizontal portion than a front end of the second path.

The cylindrical portion has a plurality of holes penetrating therethrough in the inward and outward direction.

Preferably, in the stirring target to be put into the stirring apparatus of the present invention, the liquid-containing component includes a solute component, and an average particle diameter of the solute component is smaller than an average particle diameter of the powder component.

Further, a stirring device of the present invention includes a container and a rotating member that rotates inside an inner wall surface of the container, and is configured to stir an object to be stirred that is present in a film shape between the rotating member and the inner wall surface due to a centrifugal force generated by the rotating member, the container including: a first inlet for introducing a powder component constituting the object to be stirred; a second inlet for introducing a liquid-containing component constituting the object to be stirred; and a discharge mechanism for discharging a mixing object obtained by mixing the powder component and the liquid-containing component, the discharge mechanism including: a discharge groove disposed adjacent to a bottom of the container; a first discharge port for communicating the bottom of the container with the discharge groove; and a second discharge port for communicating the discharge groove with the outside.

Preferably, the first discharge port has a discharge blade for transferring the stirring object in the container to the discharge groove.

Preferably, the second discharge vane has the same rotation axis as the rotation member, and has a surface groove that is spiral with respect to the rotation axis.

Preferably, the bottom of the container is horizontal with respect to the axis of rotation of the rotating member.

Preferably, the cylindrical portion has a plurality of holes penetrating therethrough in the inward and outward direction.

Effects of the invention

According to the stirring device of the present invention, the coating material for the battery electrode to be stirred can be highly dispersed. Thus, when the above-described coating material is used to manufacture a battery electrode, an electrode having a high bulk density and reduced resistance can be obtained. Further, since the stirring device of the present invention adopts a mode in which the powder component to be stirred is input from the first input port and the liquid-containing component to be stirred is input from the second input port, the device can be simplified as compared with the stirring device system of patent document 1. This can reduce the production cost of the battery electrode coating material. As described above, it is possible to efficiently produce an electrode coating material suitable for improving the performance of a battery while maintaining high safety of the battery.

Further, when a battery electrode coating material containing a conductive material is produced using the stirring apparatus system disclosed in patent document 1, although it is not usual, a problem occasionally occurs that aggregates of the conductive material generated in the preliminary stirring step are not dispersed but are directly mixed into the battery electrode coating material, and when the battery electrode coating material is produced by using the stirring apparatus for producing a battery electrode coating material of the present invention, it is possible to suppress the occurrence of the above-mentioned problem and further suppress the reagglomeration of the conductive material for a long time.

The above effects can be obtained by the synergistic effects of the following modes (a) to (C).

(A) A powder component containing an active material and a liquid-containing component containing a slurry of a conductive material, which are to be stirred, are introduced into a container through a first inlet and a second inlet, respectively.

(B) The stirring target charged into the container is treated in a film-like state by a centrifugal force generated by the rotating member between the container and the rotating member rotating at a high speed slightly inside the inner wall surface of the container.

(C) The inner wall surface of the container and/or the rotating member facing the stirring target to be treated in a film-like state has concave and convex portions formed by grooves, recesses, or projections arranged at predetermined intervals.

Further, a battery manufactured by using a highly dispersed coating material for a battery electrode containing no aggregate of a conductive material can achieve high safety. Therefore, an agitation device suitable for producing a coating material for battery electrodes of batteries requiring extremely high safety, for example, a nonaqueous electrolyte secondary battery such as a lithium ion battery used as a power source for electric vehicles, is used in a state where a plurality of batteries are connected in series in order to obtain an appropriate voltage, and even when one of the batteries has an electrode defect, the risk of ignition increases.

Further, according to the above-described stirring apparatus for producing a coating material for an all-solid battery electrode, it is possible to obtain a coating material for an all-solid battery electrode in which active material particles and solid electrolyte particles are highly uniformly mixed without subjecting a stirring object to preliminary stirring treatment as in the stirring apparatus system disclosed in patent document 1. Thus, a high-performance all-solid-state battery can be manufactured efficiently and at low cost. Further, when the active material constituting the object of agitation is particles coated with a lithium ion conductive film, it is possible to highly uniformly mix the active material particles and the solid electrolyte particles without impairing the performance of the film. As a result, an all-solid-state battery having particularly excellent electrode conductivity can be obtained.

The above-described effects can be obtained by the synergistic effects of the following modes (D) to (F).

(D) An active material, a solid electrolyte and a solvent to be stirred are put into a container, and they are mixed in the container of a stirring apparatus.

(E) The stirring target put into the container of the stirring apparatus is treated in a film-like state by a centrifugal force generated by the rotating member between the container and the rotating member rotating at a high speed slightly inside the inner wall surface of the container.

(F) The uneven portion is formed by grooves, dimples, or protrusions arranged at predetermined intervals on the inner wall surface of the container and/or the rotating member facing the stirring target to be treated in a film-like state.

As described above, when the first inlet is connected to the cylindrical first path which is disposed at the center of the container and penetrates from the top plate portion of the container into the container, and the second inlet is connected to the cylindrical second path which is disposed adjacent to the outer periphery of the first path and penetrates from the outside of the container into the container, the powder component and the liquid-containing component which constitute the object to be stirred can be accurately positioned and respectively injected into the specific positions in the stirring container. This not only solves the problem that the components to be stirred remain in the feed path or the agglomerated matter is generated in the stirring vessel, but also improves the effect of stirring in which the treatment is performed in a film-like state between the rotating member and the inner wall surface due to the centrifugal force generated by the rotating member.

In this case, the powder component charged into the stirring vessel is scattered in the horizontal direction by the rotation of the horizontal portion before coming into contact with the liquid-containing component, so that the powder component and the liquid-containing component can be mixed in an ideal state, and the effect of suppressing the retention in the charging path and the formation of the lump-like substance can be further enhanced, and the effect of stirring in a state of a film between the rotating member and the inner wall surface due to the centrifugal force generated by the rotating member can be further enhanced. Further, when the front end of the first path is closer to the horizontal portion than the front end of the second path, most of the liquid-containing component discharged from the front end of the second path is in contact with the horizontal portion, and is not dispersed in the radial direction (horizontal direction) of the rotation shaft, and is immediately transferred to the vicinity of the cylindrical portion of the rotating member. This can further enhance the effect of stirring the object to be stirred in a film-like state between the rotating member and the inner wall surface by the centrifugal force generated by the rotating member. Further, since the cylindrical portion of the rotating member has a plurality of holes penetrating in the inward and outward direction, the mixed stirring target can be directly fed from the inside of the cylindrical portion to between the rotating member and the inner wall surface by the centrifugal force of the rotating member. In this way, the powder component and the liquid-containing component that have been introduced as described above can be immediately fed between the rotating member and the inner wall surface, and the stirring treatment can be performed in a state in which the stirring target is in a film shape, and the effect of stirring in a state in which the stirring target is in a film shape between the rotating member and the inner wall surface can be further improved. In addition, in the case where the liquid-containing component contains a solute component and the average particle size of the solute component is smaller than the average particle size of the powder component, when a stirring processing object containing these components is processed by a high-speed stirrer, the effect of stirring in a state where the stirring object is formed into a film shape between the rotating member and the inner wall surface due to the centrifugal force generated by the rotating member can be further remarkably obtained.

As described above, when the container is provided with the first inlet and the second inlet, and the powder component and the liquid-containing component to be stirred are respectively introduced into the stirring container, not only the problems that the components to be stirred stay in the introduction path and form lumps in the stirring container can be solved, but also the effect of stirring in a state where the components are formed into a film between the rotating member and the inner wall surface by the centrifugal force generated by the rotating member can be further improved. Further, as described above, the container has a discharge mechanism for discharging a stirring target obtained by mixing the powder component and the liquid-containing component, and the discharge mechanism includes: a discharge groove disposed adjacent to the bottom of the container; a first discharge port for communicating the bottom of the container with the discharge groove; and a second discharge port for communicating the discharge groove with the outside, wherein the stirring object rotated at a high speed by the centrifugal force of the rotating member is decelerated after being transferred to the discharge groove without being decelerated in the container, so that the stirring effect performed in a state where the stirring object is present in a film form between the rotating member and the inner wall surface is not impaired, and the stirring object can be smoothly discharged to the outside of the container. Further, as described above, when the first discharge port has the discharge blade for transferring the agitation object in the container to the discharge tank, the agitation object is smoothly transferred from the container to the discharge tank, and the effect of agitation performed in a state where the agitation object is present in a film shape between the rotating member and the inner wall surface can be more reliably exhibited while suppressing unnecessary retention of the agitation object in the container. Further, as described above, when the second discharge blade has the same rotation axis as the rotation member and has the surface groove that is spiral with respect to the rotation member, the agitation target can be transferred to the discharge groove while suppressing the deceleration of the agitation target that rotates at a high speed by the centrifugal force generated by the rotation member in the container, and the effect of agitation performed in a state where the agitation target is present in a film shape between the rotation member and the inner wall surface can be more reliably exhibited. Further, as described above, when the bottom of the container is horizontal with respect to the rotation axis of the rotating member, the stirring target can be easily maintained in a state of being present in a film shape between the rotating member and the inner wall surface by the centrifugal force of the rotating member, and the effect of stirring in a state of being present in a film shape between the rotating member and the inner wall surface can be more reliably exhibited. Further, when the cylindrical portion has the plurality of holes penetrating in the inward and outward direction as described above, the powder component and the liquid-containing component put into the container can be immediately fed between the rotating member and the inner wall surface as described above, and the stirring treatment can be performed with the stirring object existing in a film shape, whereby the effect of stirring the stirring object existing in a film shape between the rotating member and the inner wall surface can be further improved. In addition, when the liquid-containing component includes a solute component and the average particle size of the solute component is smaller than the average particle size of the powder component, when a stirring target containing these components is treated by a high-speed stirrer, the effect of stirring the stirring target in a film state between the rotating member and the inner wall surface due to the centrifugal force generated by the rotating member can be more remarkably exhibited.

Other features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings.

Drawings

Fig. 1 is an external perspective view showing a stirring device of the present invention.

Fig. 2 is a sectional view of the stirring device shown in fig. 1.

Fig. 3 is an overall configuration diagram of a conventional paint manufacturing apparatus.

Fig. 4 is a schematic diagram showing active material particles as a stirring object.

Fig. 5 is a schematic diagram showing a state after mixing active material particles and solid electrolyte particles as objects of agitation.

Fig. 6 is a configuration diagram showing the stirring device of the present invention.

Fig. 7 is a structural diagram of a conventional paint manufacturing apparatus.

Fig. 8 is a configuration diagram showing the stirring device of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. Fig. 1 to 2 show an example of the stirring device of embodiment 1.

As shown in fig. 1 and 2, the stirring device 1 has a vessel 2 and

rotating members

31, 41. The rotating

members

31 and 41 rotate at high speed around the rotating shaft 8 extending in the vertical direction through the center of the container 2. The container 2 has a substantially cylindrical inner wall surface, and a cylindrical space having a predetermined length in the vertical direction is defined by the inner wall surface. The rotary shaft 8 is rotated at a high speed by a high torque motor (not shown) connected thereto, and the

rotary members

31, 41 are correspondingly rotated at a high speed. The rotating

members

31 and 41 are cylindrical members having outer circumferential surfaces facing the inner wall surface of the container 2 with a small gap of about 1 to 10 mm. When the stirring target is supplied to the stirring device 1, the stirring target is pressed against the inner wall surface of the container 2 by the centrifugal force generated by the rotating

members

31 and 41 rotating at a high speed, and spreads in the gap between the outer peripheral surfaces of the

rotating members

31 and 41 and the inner wall surface of the container 2 to become a thin film. The stirring target in the form of a film rotates at a high speed in the container with the rotation of the

rotating members

31 and 41. As a result, the stirring target in the form of a film continues to receive a strong shearing force between the outer peripheral surfaces of the

rotating rotary members

31 and 41 and the inner wall surface of the stationary container 2, and the stirring target is highly dispersed by its strong energy.

Although not shown, grooves, recesses, or projections are formed at regular intervals on the outer circumferential surfaces of the

rotating members

31 and 41 and the inner wall surface of the container 2, respectively, to form concave and convex portions. In the stirring device 1, the inside of the container 2 is defined into a plurality of dispersion tanks in the vertical direction. In the example shown in the figure, the inside of the container 2 is defined into two dispersion tanks 3, 4, and the

rotating members

31, 41 are respectively housed in the dispersion tanks 3, 4, but the present invention is not limited to this configuration.

The rotating

members

31 and 41 are both connected to the rotating shaft 8 and each rotate at high speed integrally with the rotating shaft 8. In the first dispersion tank 3 located on the upper side of the vessel, a second inlet 6 for introducing a liquid-containing component (for example, slurry) constituting an object to be stirred is disposed together with a first inlet 5 for introducing a powder component constituting an object to be stirred. On the other hand, a discharge port 7 for mixing the powder component and the liquid-containing component and discharging the object to be stirred after the dispersion treatment from the container 2 to the outside is disposed at the lower portion of the second dispersion tank 4 located on the lower side of the container. In the first dispersion tank 3, the respective components fed from the first inlet 5 and the second inlet 6 are mixed and subjected to a dispersion treatment. The stirring target mixed and subjected to the dispersion treatment in the first dispersion tank 3 is sent to the second dispersion tank 4 through a connection port provided in the lower part of the first dispersion tank 3, and the dispersion treatment is performed again.

The stirring target subjected to the above-described processing is discharged from the discharge port 7 to the outside of the container 2.

When the inventors manufactured and evaluated an electrode for a lithium secondary battery using a stirring object treated by the stirring apparatus 1, the electrode was improved in terms of bulk density and resistance as compared with an electrode manufactured using a high-speed stirring apparatus shown in patent document 1.

Further, it was confirmed that, in the case where the multistage treatment is performed by the dispersing tank defined in plural as in the stirring apparatus 1, the above-mentioned improvements in bulk density and resistance are more remarkable than in the case where the treatment is performed in a single dispersing tank.

As is apparent from the above description, the stirring device 1 can efficiently produce the electrode coating material suitable for improving the performance of the battery while maintaining the high safety of the battery.

On the other hand, as shown in fig. 3, when a battery electrode coating material containing a conductive material is produced using the stirring apparatus system disclosed in patent document 1, although it is not common, there occasionally occurs a problem that aggregates of the conductive material generated in the preliminary stirring step are not dispersed but are directly mixed into the battery electrode coating material. In contrast, when the battery electrode coating material is produced using the stirring apparatus 1, the above-described problems can be suppressed, and the suppressed state can be maintained for a long period of time. These will be described in detail below.

First, a stirring device system a (fig. 3) disclosed in patent document 1 is configured to mix materials including powder and a solvent to generate a slurry-like coating material. For this purpose, the system comprises a preliminary stirring tank 100, a storage tank 200, a high-speed stirrer 300, treatment tanks 501 to 503, and a transfer means (a conduit 491, etc.). A predetermined material is charged into the preliminary stirring tank 100, and the charged material is preliminary stirred in a batch manner as an intermediate material. The intermediate material is supplied to the storage tank 200. The storage tank stores the intermediate material while stirring the intermediate material by the stirring blade 202. The intermediate material is continuously supplied from the storage tank 200 to the high-speed mixer 300. The high-speed mixer 300 includes a vessel 310 and a rotating member 330 rotating at a high speed slightly inside an inner wall surface 311 of the vessel, and continuously mixes the intermediate material between the rotating member and the inner wall surface by a centrifugal force of the rotating member. The stirred material obtained by the high-speed stirrer 300 is supplied to the treatment tanks 501 to 503 and stirred by the respective stirring blades 511. Thus, the material after completion of the stirring was subjected to a vacuum defoaming treatment. The material subjected to the vacuum defoaming treatment in the treatment tanks 501 to 503 is transferred to a coating step by a transfer unit and used as a coating material.

The preliminary mixing tank 100 is provided to pre-mix the materials to some extent before the materials are completely mixed in the high-speed mixer 300. In the mode shown in fig. 3, the method includes: a small-diameter stirring blade 102 rotating at high speed around a vertical rotating shaft 101; and a large-diameter stirring blade 104 rotating at a low speed around a rotating shaft 103 also vertical. The materials fed from the

hoppers

120, 130 are gathered and the two

stirring blades

102, 104 are rotated to pre-stir the materials. The materials are mixed by rotating the small-diameter stirring blade 102 at a high speed, and the entire materials are stirred by rotating the large-diameter stirring blade 104, thereby averaging the mixing states.

However, when the aforementioned preliminary agitation tank 100 is used to manufacture an intermediate material containing a slurry of an active material for a lithium ion battery and a conductive material, aggregates of the conductive material are occasionally generated in the intermediate material, although not commonly. Even if the aggregate of the conductive material is processed by the high-speed mixer 300 in a subsequent process, the aggregate may not be sufficiently removed, and further improvement is required in the production of a coating material for an electrode of a battery having an extremely high safety requirement.

In contrast, in the stirring apparatus 1 shown in fig. 1 and 2, the slurry of the active material for a lithium ion battery and the conductive material is directly charged into the stirring apparatus 1 without a step of stirring all the materials with a preliminary stirring tank to prepare an intermediate material having an averaged mixture state, and immediately after the charging, the slurry is processed in a state where a film is formed by a centrifugal force generated by the rotating member between the container and the rotating member rotating at a high speed slightly inside the inner wall surface of the container. The concave-convex portion is formed by grooves, recesses, or projections arranged at predetermined intervals on the rotating member facing the film-like stirring object and/or the inner wall surface of the container.

When a battery electrode coating material containing a slurry of an active material for a lithium ion battery and a conductive material is produced in the above manner, the formation of aggregates of the conductive material can be suppressed, and the re-aggregation of the conductive material can be suppressed for a long period of time, and an electrode coating material suitable for a battery requiring extremely high safety can be produced.

In addition, as the conductive material, any of carbon black, carbon nanotubes, and graphene can be used.

When the inventors manufactured a coating material for an all-solid battery electrode using the stirring device 1 described above, it was found that a coating material for an all-solid battery electrode in which the active material particles 50 and the solid electrolyte particles 52 (see fig. 5) were highly uniformly mixed could be obtained.

Specifically, LiCoO is used ₂ Particles are used as the active material particles 50, solid electrolyte particles composed of sulfide are used as the solid electrolyte particles 52, and they are put into the stirring apparatus 1 together with a solvent or the like to be treated.

As LiCoO ₂ Particles (fig. 4 (a)) covered with a lithium ion conductive oxide film 51 by performing an appropriate surface treatment (fig. 4 (b)) can be used, and in the present embodiment, covered with Li ₄ Ti ₅ O ₁₂ Formed oxide film LiCoO ₂ And (3) granules.

As a result, as schematically shown in fig. 5, it was confirmed that the active material particles 50 and the solid electrolyte particles 52 were highly uniformly mixed. Further, it was confirmed that even after the treatment by the stirring device 1 described above, the coverage of LiCoO was maintained ₂ Of particles consisting of Li ₄ Ti ₅ O ₁₂ The properties of the oxide film formed.

In addition, the active material particles and the solid electrolyte particles are not limited to the above particles as long as they function in an all-solid battery.

Fig. 6 is a schematic diagram showing the internal structure of a stirring device B1 of embodiment 2. As shown in fig. 6, stirring apparatus B1 includes vessel B2 and rotating member B7 that rotates at high speed about a rotating shaft B6 extending in the vertical direction through the center of vessel B2.

The container B2 defines a cylindrical space having a cylindrical inner wall surface B21 and a predetermined length in the vertical direction. The rotary shaft B6 is rotated at high speed by a high torque motor (not shown) of the rotary shaft B6 connected thereto, and the rotary member B7 is also rotated at high speed accordingly.

The rotating member B7 has a cylindrical portion B8 facing the inner wall surface 21 of the container 2 with a slight gap of about 1 to 10 mm.

A horizontal portion B9 that rotates horizontally is disposed inside the cylindrical portion B8. The horizontal portion B9 has a disk-like shape and is formed integrally with the cylindrical portion B8 so as to be concentric therewith. The horizontal portion B9 has a lower surface connected to a rotation shaft, and the horizontal portion B9 rotates at high speed around the rotation shaft B6 together with the rotation member B7.

A first inlet B3 and a second inlet B4 are provided above the ceiling of the container B2, respectively.

First inlet B3 is disposed on the central axis of vessel B2, and a tubular first path B31 penetrating from above the ceiling of vessel B2 to below vessel B2 is connected to first inlet B3.

Second inlet B4 is disposed adjacent to the outer periphery of first path B31, and a cylindrical second path B41 penetrating from above the ceiling of container B2 to below container B2 is connected to second inlet B4.

A discharge port B5 for discharging the processed objects to be stirred is provided in the lower portion of the container B2.

The stirring target was charged into the stirring apparatus B1 separately from the powder component containing no liquid and the component containing liquid.

The powder component containing no liquid is charged through the first charging port B3, and the charged powder component descends in the first path B31. The front end of the first path B31 extends to the vicinity of the horizontal portion B9 of the rotating member B7 in the container B2, and the charged powder component is discharged from the front end opening of the first path B31 toward the vicinity of the center of the horizontal portion B9 of the rotating member B7.

The powder component discharged from the tip of the first path B31 comes into contact with the horizontal portion B9 rotating at a high speed, and is scattered in the radial direction (horizontal direction) of the rotating shaft B6 by the action of the powder component.

The liquid-containing component is charged through the second charging port B4, and the charged liquid component descends in the second path B41.

The second path B4 is shorter than the first path B3, and the front end opening inside the container B2 is arranged at a relatively high position inside the container B2. Immediately below the front end opening inside the container B2, the inner peripheral surface B82 of the cylindrical portion B8 of the rotating member B7 is located. Accordingly, most of the liquid-containing components discharged from the front end opening inside the container B2 are not scattered in the radial direction (horizontal direction) of the rotation axis B6 due to contact with the horizontal portion B9, and are immediately transferred to the vicinity of the inner circumferential surface B82 of the cylindrical portion B8 of the rotating member B7.

The powder component and the liquid-containing component that have reached the vicinity of the inner peripheral surface B82 of the cylindrical portion B8 of the rotating member B7 are transferred to a small gap between the inner wall surface B21 of the container B2 and the cylindrical portion B8 of the rotating member B7 via a plurality of holes (not shown) that penetrate in the inward and outward directions of the cylindrical portion B8 by the centrifugal force applied by the cylindrical portion B8 of the rotating member B7 that rotates at a high speed.

In the minute gap between the inner wall surface B21 of the container B2 and the outer circumferential surface B81 of the rotating member B7, the stirring target is pressed against the inner wall surface B21 of the container B2 by the centrifugal force generated by the rotating member B7, and spreads in the gap between the outer circumferential surface B81 of the rotating member B7 and the inner wall surface of the container B2 to form a film shape. Further, the stirring target in the form of a film rotates at a high speed in the container B2 as the rotating member B7 rotates. At this time, the stirring target in the form of a film is continuously subjected to a strong shearing force between the outer peripheral surface B81 of the rotating rotary member B7 and the inner wall surface of the stationary container B2, and the stirring target is highly dispersed by its strong energy.

The stirring target thus treated successively descends into the space below vessel B2, and is discharged from discharge port B5 to the outside of vessel B2.

Next, an example in which the stirring device B1 of the second embodiment and the stirring device of the comparative example were applied to the manufacture of a coating material for an electrode of a lithium-ion secondary battery will be described.

Example 1:

in this example, a positive electrode active material (Ni — Co — Mn (NCM)) powder (average particle diameter 10.5 μm) for a lithium secondary battery as a powder component was fed from a first feeding port, and a conductive material slurry containing a conductive material (carbon black) and a binder (PVDF) as a liquid-containing component was fed from a second feeding port, and the treatment was performed while rotating a rotating member B7 and a horizontal portion B9 at a circumferential speed of 25m/sec, using a stirring device B1 shown in fig. 6.

Comparative example 1:

in this comparative example, a stirring device shown in fig. 7 (corresponding to the device disclosed in patent document 1) was used. The stirring apparatus of this comparative example includes a preliminary stirring tank C100 in which the objects to be stirred are mixed in advance to some extent before the treatment with the high-speed stirrer C300. The preliminary agitation tank C100 includes: a small-diameter stirring blade C102 rotating at high speed around a vertical rotating shaft C101; and a large-diameter stirring blade C104 rotating at a low speed around a rotating shaft C103 having the same vertical shape, wherein the materials fed from the hoppers C120 and C130 are gathered, and the two stirring blades C102 and C104 are rotated to pre-stir the stirring target. The objects to be stirred are mixed by rotating the small-diameter stirring blade C102 at a high speed, and the mixing state is averaged by rotating the large-diameter stirring blade C104.

The mixing state-averaged mixing target is transferred to the high-speed mixer C300 and processed.

The high-speed mixer C300 includes: a container C310; and a rotating member C330 that rotates at high speed around a rotating shaft C350 extending in the vertical direction through the center of the container C310. The container C310 defines a cylindrical space having a substantially cylindrical inner wall surface C311 and a predetermined length in the vertical direction. The rotary shaft C350 is rotated at a high speed by a high torque motor C351 mounted on the upper portion of the container C310. A material supply port C314 connected to the lower space is provided in the bottom of the container C310, and the stirring target having the averaged mixture state is supplied from the material supply port C314. A discharge port C315 connected to the upper space is provided at the upper part of the container C310, and the slurry-like stirred material is discharged to the outside.

In this comparative example, the Ni — Co — Mn-based (NCM) active material powder, the conductive material (carbon black), and the binder (PVDF) used in the examples were preliminarily stirred at the same mixing ratio as in the examples, and then treated by the high-speed stirrer C300 at the same peripheral speed of 25m/sec as in the examples.

When comparing the coatings for electrodes of the lithium-ion secondary batteries of example 1 and comparative example 1 manufactured as described above, it was confirmed that: the coating material of example 1 can suppress the formation of aggregates of the conductive material and the re-aggregation of the conductive material for a longer period of time than the coating material of comparative example 1, and can produce a coating material for an electrode suitable for a battery which requires extremely high safety.

In the above examples, the positive electrode active material (Ni — Co — Mn (NCM)) powder for a lithium secondary battery was used as the powder component, and the conductive material slurry containing the conductive material (carbon black) and the binder (PVDF) was used as the liquid-containing component, but the present invention is not limited to these, and similar effects can be obtained by using other active materials and additives.

Fig. 8 is a schematic diagram showing the internal structure of a stirring device D1 according to embodiment 3. As shown in fig. 8, the stirring device D1 includes: container D2; and a rotating member D7 that rotates at high speed around a rotating shaft D6 extending in the vertical direction through the center of the container D2. The container D2 defines a cylindrical space having a cylindrical inner wall surface D21 and a predetermined length in the vertical direction. The rotation shaft D6 is rotated at a high speed by a high torque motor (not shown) of the rotation shaft D6 connected thereto, and the rotation member D7 is also rotated at a high speed correspondingly thereto. The rotating member D7 has a cylindrical portion D8 facing the inner wall surface D21 of the container 2 with a small gap of about 1 to 10 mm. A horizontal portion D9 that rotates horizontally is disposed inside the cylindrical portion D8. The horizontal portion D9 has a disc shape and is formed integrally with the cylindrical portion D8 so as to be concentric therewith. The lower surface of the horizontal portion is connected to the rotation shaft, and the horizontal portion D9 rotates at high speed around the rotation shaft D6 together with the rotation member D7. A first inlet D3 and a second inlet D4 were provided above the ceiling of the container D2, respectively. The stirring target was charged into the stirring device D1 separately from the powder component containing no liquid and the component containing liquid. The powder component containing no liquid was charged through the first charging port D3, and the liquid component was charged through the second charging port D4.

As described above, each component to be stirred, which is put into the container D2, reaches the vicinity of the inner peripheral surface D82 of the cylindrical portion D8 of the rotating member D7 by the action of the rotating member D7 rotating at a high speed, and is transferred to the minute gap between the inner wall surface D21 of the container D2 and the cylindrical portion D8 of the rotating member D7 through the plurality of holes (not shown) penetrating in the inside-outside direction of the cylindrical portion D8 by the centrifugal force applied to the cylindrical portion D8 of the rotating member D7 rotating at a high speed. In the minute gap between the inner wall surface D21 of the container D2 and the outer peripheral surface D81 of the rotating member D7, the stirring target is pressed against the inner wall surface D21 of the container D2 by the centrifugal force generated by the rotating member D7, and spreads in the gap between the outer peripheral surface D81 of the rotating member D7 and the inner wall surface of the container D2 to form a film shape. Further, the stirring target in the form of a film rotates at a high speed in the container D2 as the rotating member D7 rotates. At this time, the stirring target formed in a film shape continues to receive a strong shearing force between the outer peripheral surface D81 of the rotating member D7 and the inner wall surface of the stationary container D2, and the stirring target is highly dispersed by its strong energy.

The stirring objects processed as described above sequentially descend in the container D2 and reach the bottom D22 of the container D2. Then, the stirring target was transferred to the discharge groove D51 through the first discharge port D54 disposed at the center of the bottom D22 and communicating the bottom D22 of the container with the discharge groove D51.

In order to maintain the film-like state of the stirring target by the centrifugal force of the rotating member D7, the bottom portion D22 of the container D2 is horizontal to the rotation axis D6 of the rotating member D7, and the stirring target rotating at a high speed on the bottom portion D22 is difficult to be efficiently discharged from the first discharge port D54 in the center of the bottom portion D22 in a normal state. Therefore, the second discharge blade D53 is disposed at the first discharge port D54, so that the stirring objects rotating at a high speed on the bottom D22 can be efficiently discharged from the first discharge port D54 at the center of the bottom D22.

The second discharge vane D53 has the same rotation shaft D6 as the rotation member D7, and rotates at high speed at the same angular speed as the rotation member D7. Further, a spiral surface groove is formed on the surface of the second discharge vane D53 with respect to the rotation shaft D6. With the above configuration, the stirring target rotating at a high speed on the bottom portion D22 can be efficiently transferred to the discharge groove D51 via the first discharge port D54 at the center of the bottom portion D22 while maintaining the membranization of the stirring target by the centrifugal force of the rotating member D7.

The stirring object transferred to the discharge groove D51 is discharged out of the container D2 through the second discharge port D55 with a reduced rotational speed in the discharge groove D51. The first discharge blade D52 having the same rotation axis D6 as the rotation member D7 is disposed in the discharge box D51. The first discharge blade D52 has a diameter sufficiently smaller than that of the rotating member D7, applies a centrifugal force smaller than that of the rotating member D7 to the mixing target, and has a function of facilitating the mixing target to be discharged from the second discharge port D55.

Next, an example in which the stirring device of the present invention and the stirring device of the comparative example were applied to the production of a coating material for an electrode of a lithium-ion secondary battery will be described.

Example 2:

in this example, using the stirring apparatus of embodiment 3 shown in fig. 8, a positive electrode active material (Ni — Co — Mn (NCM)) powder (average particle diameter 10.5 μm) for a lithium secondary battery as a powder component was fed from the first feeding port D3, and a conductive material slurry containing a conductive material (carbon black) and a binder (PVDF) as a liquid-containing component was fed from the second feeding port D4, and the treatment was performed while rotating the rotating member D7 and the horizontal portion D9 at a circumferential speed of 25 m/sec.

Comparative example 2:

in this comparative example, a stirring apparatus corresponding to patent document 1 shown in fig. 7 was used. The stirring apparatus of this comparative example includes a preliminary stirring tank C100 for mixing the objects to be stirred to some extent in advance before the treatment with the high-speed stirrer C300. The preliminary agitation tank C100 includes:

a small-diameter stirring blade C102 rotating at high speed around a vertical rotating shaft C101; and a large-diameter stirring blade C104 rotating at a low speed around a rotating shaft C103 having the same vertical shape, wherein the materials fed from the hoppers C120 and C130 are gathered, and the two stirring blades C102 and C104 are rotated to pre-stir the stirring target. The objects to be stirred are mixed by rotating the small-diameter stirring blade C102 at a high speed, and the mixing state is averaged by rotating the large-diameter stirring blade C104. Next, the mixing object whose mixing state is averaged is transferred to the high-speed mixer C300 and processed.

The high-speed mixer C300 includes: a container C310; and a rotating member C330 that rotates at high speed around a rotating shaft C350 extending in the vertical direction through the center of the container C310. The container C310 defines a cylindrical space having a substantially cylindrical inner wall surface C311 and a predetermined length in the vertical direction. The rotary shaft C350 is rotated at a high speed by a high torque motor C351 mounted on the upper portion of the container C310. A material supply port C314 connected to the lower space is provided at the bottom of the container C310, and the mixing target having the averaged mixing state is supplied from the material supply port C314. A discharge port C315 connected to the upper space is provided at the upper part of the container C310, and the slurry-like stirred material is discharged to the outside.

When comparing the coatings for electrodes of the lithium-ion secondary batteries of example 2 and comparative example 2 manufactured as described above, it was confirmed that: the coating material of example 2 can suppress the formation of aggregates of the conductive material and the re-aggregation of the conductive material for a longer period of time than the coating material of comparative example 2, and can produce a coating material for an electrode suitable for a battery which requires extremely high safety.

The stirring device of the present invention is not limited to the above-described embodiment. The specific structure of each part of the stirring device of the present invention can be freely designed and changed.

Description of the reference numerals

1, a stirring device; 2, a container; 3 a first dispersion tank; 4 a second dispersion tank; 5 a first input port; 6 a second input port; 7 an outlet; 8 rotating the shaft; 31. 41 a rotating member; 50 active substance particles; 51 an oxide film; 52 solid electrolyte particles; 100 a pre-stirring tank; 101. 103 a rotating shaft; 102. 104 stirring blades; 110 a housing; 120. 130 a hopper; 140 an exhaust port; 150 pumps; 200 storage tanks; 201 a rotating shaft; 202 stirring blades; 210 a housing; 220 pump; 300 high-speed stirrer; 310, a container; 311 an inner wall surface; 330 a rotating member; 350 a rotating shaft; 351 a high torque motor; 400 a buffer tank; 410 a catheter; 411 a cooling water circulation path; 420 a pump; a 422 filter; 450 a feed pipe; 451. 452, 453 manifold; 460 valves; 470 vacuum pumps; 480 pipes; 490 a pump; 491 a catheter; 501. 502, 503 treatment tank; 510 a rotation shaft; 511 stirring blades; 520 a housing;

b1 stirring device; a B2 container; b3 a first inlet; b4 a second inlet; b5 discharge port; b6 rotating shaft; b7 rotary member; b8 cylindrical part; a B9 horizontal part; b10 mechanical seal; b21 inner wall surface; b31 first path; b41 second path; b81 outer circumferential surface; b82 inner peripheral surface;

c100 pre-stirring tank; c101, C103 rotation axes; c102 and C104 stirring blades; a C110 housing; c120 and C130 hoppers; a C140 discharge port; a C150 pump; a C200 groove; a C201 rotating shaft; c202 stirring blades; a C210 housing; c220 pump C300 high speed mixer; a C310 container; c311 inner wall surface; a C314 material supply port; a C315 vent; a C330 rotating component; a C350 rotating shaft; c351 high torque motors; a C410 discharge path; a C411 cooling tube;

d1 stirring device; a D2 container; a first inlet port D3; a second inlet port D4; a D5 discharge mechanism; d6 rotating shaft; d7 rotating part; a D8 cylindrical portion; a D9 horizontal portion; d10 mechanical seal; bottom of D22; d51 discharge chute; d52 discharge vane; d53 second discharge vane; d54 first outlet; d55 second exhaust port; d81 outer circumferential surface; d82 inner peripheral surface.

Claims

1. A stirring device comprising a container and a rotating member that rotates inside an inner wall surface of the container, characterized in that:

the stirring device is configured to stir the stirring object existing in a film shape between the rotating member and the inner wall surface due to the centrifugal force generated by the rotating member,

the container has: a first inlet for introducing a powder component constituting the object to be stirred; a second inlet for introducing a liquid-containing component constituting the object to be stirred; and a discharge port for discharging a mixing object obtained by mixing the powder component and the liquid-containing component,

a cylindrical first path arranged at the center of the container and penetrating from the outside of the container to the inside of the container is connected to the first inlet,

a cylindrical second passage that penetrates from the outside of the container to the inside of the container and is disposed adjacent to the outer periphery of the first passage is connected to the second inlet.

2. The stirring device of claim 1, wherein:

the rotating member has a cylindrical portion disposed with a gap from an inner wall surface of the container, and has a horizontal portion that rotates horizontally inside the cylindrical portion.

3. The stirring device according to claim 1 or 2, wherein:

the front end of the first path is closer to the horizontal portion than the front end of the second path.

4. The stirring device according to claim 1 or 2, wherein:

5. The stirring device according to claim 1 or 2, wherein:

the liquid-containing component comprises a solute component,

the solute component has an average particle size smaller than an average particle size of the powder component.