JP2009161815A - Aerosol deposition apparatus, pole plate for electricity storage device, separator, and electricity storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aerosol deposition apparatus that forms a structure of a material powder on a substrate, by spraying an aerosol in which a powder formed of a brittle material is dispersed in a gas, onto the substrate. <P>SOLUTION: In an inner wall of a vessel 21 for stabilizing the aerosol concentration, arithmetic mean surface roughness Ra is controlled to 0.25 or less, in at least one wall surface among the inner wall in the vicinity of an inlet through which the aerosol is introduced, the inner wall in the vicinity of the face with which the aerosol collides at first, and the inner wall in the vicinity of an outlet from which the aerosol is discharged. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aerosol deposition apparatus in which an aerosol in which a powder made of a brittle material is dispersed in a gas is sprayed on a substrate to form a structure of material powder on the substrate.

  In recent years, as a method for manufacturing an electrode of a non-aqueous electrolyte secondary battery, which is a kind of power storage device, active material particles (powder) are dispersed in an air stream without being melted or evaporated, and this air stream is sprayed on a current collector. An electrode manufacturing method in which active material particles collide with a current collector and the active material particles are bonded to the current collector surface by an impact force has attracted attention. According to this manufacturing method, since the active material particles can be directly bonded to the current collector surface, the current collecting property can be improved, and the binder and the conductive material that do not contribute to the capacity of the electrode can be eliminated. An electrode having a high capacity can be obtained.

  One of the above-described electrode manufacturing methods is a manufacturing method called an aerosol deposition method. In the aerosol deposition method, powder consisting of brittle materials, which are active material particles, is dispersed in a gas to generate an aerosol, and the aerosol is sprayed from a nozzle onto a substrate of metal, glass, ceramic, plastic, etc. Is made to collide with the substrate. The powder made of a brittle material is deformed and crushed by an impact at the time of collision, thereby joining to the substrate and forming a powder structure on the substrate. A structure can be formed at room temperature that does not require heating means, and a structure having mechanical strength equivalent to that of the fired body can be obtained.

  In the aerosol deposition method, in order to form a uniform powder layer, it is important to stably generate aerosol over a long period of time. Therefore, in order to aerosolize the powder and supply it to a certain amount, at least one place of the inner wall of the aerosol generator, the inside of the pipe (path), the inner wall of the film forming film is subjected to fluororesin or conductive fluororesin coating, mirror finish, An aerosol deposition apparatus that prevents aggregation and clogging of material particles has been proposed (see, for example, Patent Document 1).

Similarly, in order to supply a certain amount of aerosol, an aerosol deposition apparatus that stabilizes the concentration of aerosol and provides an aerosol concentration stabilizing container (second chamber) in addition to the film formation chamber (first chamber). It has been proposed (see, for example, Patent Document 2).
JP 2005-89826 A JP 2006-200013 A

  The aerosol concentration can be stabilized to some extent by applying fluororesin or conductive fluororesin coating and mirror finishing to at least one place on the inner wall of the aerosol generator, the pipe, and the film forming chamber wall. However, when a fluororesin or conductive fluororesin coating is applied, the resin coating layer peeled off by friction with the powder is carried along with the aerosol and may be contained in the structure as an impurity. On the other hand, in the mirror finishing, there is no possibility of impurities being mixed in, but in the long term, there is an aerosol pressure fluctuation, etc., so it is difficult to stabilize the concentration of the aerosol and supply a certain amount of aerosol. Become.

Further, by providing an aerosol concentration stabilizing container in addition to the film formation chamber, the aerosol concentration can be stabilized to some extent over the long term. However, if the operation of the device is continued, the powder adheres to the inner wall of the aerosol concentration stabilization container, and the adhered powder forms an adhesion layer on the inner wall surface of the container to increase the thickness, resulting in an unstable aerosol concentration. Become. Furthermore, there is a problem that aggregated powder of the powder is generated from the adhesion layer, causing clogging of piping and nozzles to the film forming chamber.

  That is, in the conventional aerosol deposition apparatus, the aerosol cannot be stably generated for a long time, and the concentration of the powder in the aerosol is not stabilized. When forming, the forming speed becomes unstable and the thickness varies. If the operation of the apparatus is continued, the particle adhesion layer formed on the inner wall of the container becomes thick in the aerosol concentration stabilizer, making it difficult to stabilize the aerosol concentration. Part of the adhesion layer is sent as aggregated powder to the pipe connected to the nozzle, causing clogging of the pipe and nozzle, increasing the number of times the pipe and nozzle are cleaned by interrupting film formation and increasing productivity. The situation was impossible.

  In order to solve the above problems, an aerosol deposition apparatus of the present invention includes an aerosol generator that contains powder and introduces a gas to generate an aerosol of the powder, and an inside of the vicinity of an inlet to which the aerosol is introduced. At least one of the wall surface, the inner wall surface in the vicinity of the surface where the aerosol first collides, and the inner wall surface in the vicinity of the outlet from which the aerosol is discharged is configured by a surface having an arithmetic average surface roughness Ra of 0.25 or less. An aerosol concentration stabilizing container that stabilizes the concentration of the aerosol, a nozzle that sprays the aerosol supplied from the aerosol concentration stabilizer on a substrate, and a film forming chamber in which the nozzle is provided. To do.

  According to the present invention, since the powder can be prevented from adhering to the inner wall of the aerosol concentration stabilization container, the aerosol concentration can be stabilized. Furthermore, since generation | occurrence | production of the agglomerated powder of powder can be suppressed, clogging of piping and a nozzle is prevented, and it enables it to generate aerosol stably for a long term. As a result, when the powder structure is formed on the substrate, the formation speed can be kept constant, so that variations in the thickness of the structure can be suppressed and a good structure can be formed. Furthermore, since the number of cleanings of pipes and nozzles, which have been conventionally performed by interrupting film formation, can be reduced, productivity can be increased.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
<Configuration of aerosol deposition device 1>
FIG. 1 is a schematic diagram of an aerosol deposition apparatus 1 used in the first embodiment.

  The aerosol deposition apparatus 1 stabilizes the concentration of the aerosol generated by the gas generator 11 for supplying the gas for generating the aerosol, the aerosol generator 13 for storing the material particles 20 as powder, and the aerosol generator 20. An aerosol concentration stabilizing container 21 and a film forming chamber 14 which is a film forming chamber for forming a film (forming a structure) by spraying the generated aerosol onto the substrate. Moreover, the gas cylinder 11 is connected to the aerosol generator 13 through the pipe 12a. Further, it is connected to the aerosol concentration stabilizing container 21 through the pipe 12b. The concentration stabilizing container 21 and the film forming chamber 14 are connected by a pipe 12 c for sending aerosol to the nozzle 15. One end of the pipe 12c is exposed in the aerosol concentration stabilizing container 21, and the other end of the pipe 12c is connected to a nozzle 15 installed in the film forming chamber 14 for spraying aerosol. .

  The film forming chamber 14 includes a substrate holder 17 for installing the substrate 16 and an exhaust pump 18 connected via a pipe 12d. The substrate holder 17 includes a mechanism (not shown in detail) that moves in the horizontal direction or the vertical direction at a constant speed, and the nozzle 15 is disposed to face the substrate 16.

<Operation of the aerosol deposition apparatus 1>
Next, operation | movement of the aerosol deposition apparatus 1 in this Embodiment is demonstrated.

  A gas for generating aerosol from the gas cylinder 11 is opened to supply the aerosol generator 13 with a flow rate of several to several tens of liters per minute. The aerosol generator 13 winds up the contained material particles 20 with the supplied gas to generate an aerosol. The generated aerosol is sent to the aerosol concentration stabilization container 21, and after stabilizing the aerosol concentration, it is supplied to the nozzle 15 installed in the film forming chamber 14. At this time, the degree of vacuum in the film forming chamber 14 is adjusted by operating the exhaust pump 18. The aerosol is sprayed from the nozzle 15 toward the substrate 16 placed on the substrate holder 17 to form a structure made of the material particles 20 on the substrate 16.

<Configuration of aerosol concentration stabilizing container 21>
Next, the aerosol concentration stabilizing container 21 having a characteristic configuration in the present embodiment will be described in detail.

  2 and 3 show an XX sectional view of the aerosol concentration stabilizing container 21 in FIG. 1 and a YY sectional view of the aerosol concentration stabilizing container in FIG. 4 shows a ZZ cross-sectional view of the aerosol concentration stabilizing container 21 in FIG. In each figure, the flow of the aerosol is indicated by an arrow, and the portion where the arithmetic average surface roughness Ra of the inner wall surface (the surface roughness Ra is defined in Japanese Industrial Standard JIS0601-1994) is 0.25 or less is narrow. Shown with diagonal lines. In addition, the oblique line with a wide space | interval shows the cross section of another inner wall surface.

  As shown in FIGS. 2, 3, and 4, in the first embodiment, in the inner wall of the aerosol concentration stabilizing container 21, the inner wall B region in the vicinity of the aerosol inlet 211, the inner surface in the vicinity of the surface where the aerosol first collides The wall surface C region and the inner wall surface A region in the vicinity of the aerosol discharge port 212 are configured by surfaces having an arithmetic average surface roughness Ra of 0.25 or less.

  Next, the aerosol flow in the aerosol concentration stabilization container 21 will be described with reference to FIGS.

First, as shown in FIG. 3, the aerosol generated by the aerosol generator 13 is sent from the inlet 211 to the aerosol concentration stabilizing container 21. At this time, the aerosol is diffused in the aerosol concentration stabilizing container 21, and a turbulent flow is generated in the region B near the inlet 211. In addition, turbulence is generated even in the vicinity of the region C of the inner wall surface where the aerosol first hits because the flow direction of the aerosol changes. Further, as shown in FIG. 2, the turbulent flow is generated because the flow converges also in the area A in the vicinity of the discharge port 212 discharged to the pipe 12c. It seems that the stirring of the aerosol, which leads to stabilization and homogenization of the aerosol concentration, is performed by the generation of the turbulent flow described above. On the other hand, the material particles 20 collide violently on the inner wall surface in the vicinity of the turbulent flow generation location. Therefore, in the first embodiment, the inner wall surface in the vicinity of the introduction port 211 (B region), the vicinity that first hits the wall (C region), and the vicinity of the discharge port 212 (A region), which is the vicinity of the turbulent flow generation location. Is made smooth (arithmetic mean surface roughness Ra of 0.25 or less). Thereby, since the adhesion of the material particles to the inner wall can be suppressed, the concentration of the aerosol can be stabilized. Furthermore, since generation | occurrence | production of agglomerated powder can also be suppressed, generation | occurrence | production probability of the clogging by the agglomerated powder in piping 12a, 12b, 12c and the nozzle 15 can also be reduced. In addition, since it is possible to stably generate the aerosol for a long period of time, when forming the structure made of the material particles 20 on the substrate 16, the formation speed of the structure can be kept constant, and the thickness Thus, it is possible to form a favorable structure in which variations such as the above are suppressed. Furthermore, the number of times the film formation is interrupted and the piping and nozzles are cleaned is reduced, and the productivity can be increased.

  In addition, it is preferable that arithmetic mean surface roughness Ra is 0.25 or less from a viewpoint of suppressing adhesion to the inner wall of a material particle. Furthermore, since the effect of suppressing the adhesion of the material particles to the inner wall is exhibited when the surface is not rough, the arithmetic average surface roughness Ra is more preferably about 0.01 to 0.03. In addition, 0.01-0.03 arithmetic mean surface roughness Ra is obtained by mirror-polishing an inner wall surface.

  In addition, for locations where the arithmetic average surface roughness Ra is 0.25 or less, the inner wall surface B region in the vicinity of the aerosol introduction port 211, the inner wall surface C region in the vicinity of the surface where the aerosol first collides, and the aerosol discharge port 212 vicinity The effect of suppressing the adhesion of the material particles to the inner wall can be obtained not only at all but at least one of the three locations in the inner wall surface A region.

  Furthermore, in addition to the above-mentioned place, you may expand | deploy to another place. For example, as shown in FIG. 5, for the aerosol concentration stabilizing container 21, the upper and lower portions of the inner wall (the portions where the arithmetic average surface roughness Ra is 0.25 or less are indicated by diagonal lines), and further, the inner wall surface as shown in FIG. All (the portion where the arithmetic average surface roughness Ra is 0.25 or less is indicated by hatching) may be used. The flow of the aerosol generator 13 constituting the aerosol deposition apparatus 21 is also in a turbulent state, and the adhesion of material particles is also remarkable on the inner wall surface. The aerosol flow in the pipes 12a, 12b, and 12c is a laminar flow, but when the agglomerated powder is brought in, it adheres to the inside of the pipe. Therefore, the inner surfaces of the pipes 12b and 12c shown in FIG. 1, the inner wall surface of the aerosol generator 13 and the inner wall surface of the film forming chamber 14 can be made smooth (the arithmetic average surface roughness Ra is 0.25 or less). It is also effective to suppress the occurrence of this. In particular, it is preferable to make the surface roughness of the inner surface of the pipe 12 c close to the nozzle 15 smooth (the arithmetic average surface roughness Ra is 0.25 or less) because it is effective in suppressing clogging of the nozzle 15.

  The aerosol concentration stabilizing container 21 also has a function of classifying powder separately. Even if the aggregated powder is sent from the aerosol generator 13, it is dropped to the bottom of the container due to the weight difference. However, if there are adhering portions of the material particles in the concentration stabilizing container 21, the agglomerated powder sent from the aerosol generator 13 is trapped in the adhering portions and is not easily dropped to the bottom of the container. Further, when the condensed powder is trapped in the upper part of the aerosol concentration stabilizing container 21 (near the aerosol discharge port 212), it will leave the aerosol concentration stabilizing container 21 as it is, and is clogged by the nozzle 15 and the pipe 12c. Will be caused. That is, in order to obtain the function of classifying the aerosol concentration stabilizing container 21 better, it is important to make the inner wall surface of the aerosol concentration stabilizing container 21 particularly smooth so that particle adhesion does not occur.

The aerosol deposition apparatus 1 shown in the first embodiment can be used for forming an active material layer for a positive electrode or a negative electrode plate for a lithium ion battery, which is an electricity storage device, and for forming a porous electronic insulating layer in a separator. For example, the lithium-containing composite oxide used as the positive electrode active material material of the lithium ion battery that becomes the material particle 20 is particularly a brittle material, and more specifically, LiNi _0.81 Co _0.15 Al _0.04 O _2. In the case where LiNi _0.33 Co _0.33 Mn _0.33 O ₂ or the like is used, the aerosol deposition apparatus 1 according to the first embodiment indicates that the material particles 20 adhere to the inner wall of the aerosol concentration stabilizing container 21. Therefore, the aerosol concentration can be stabilized. As a result, variations such as the thickness of the structure can be suppressed, and a favorable structure can be formed. That is, when an electricity storage device is configured using a positive electrode, a negative electrode plate, and a separator manufactured by the aerosol deposition apparatus 1, an electricity storage device with stable charge / discharge characteristics can be obtained.

  Hereinafter, as an example of the present invention, when the arithmetic average surface roughness Ra of the inner wall of the aerosol concentration stabilizing container 21 is set to 0.25 and 0.40, the nozzle 15 is clogged within a certain time. Examples and comparative examples in which presence / absence was investigated will be described. The presence or absence of clogging of the nozzle 15 indicates that the film formation is interrupted and the piping and nozzle are cleaned, and is used as a guideline for productivity comparison. In addition, this invention is not limited to the structure of an Example.

Example 1
Using the aerosol deposition apparatus 1 shown in FIG. 1, an alumina film was produced by the following method.

  The film forming chamber 14 used was a modified sputtering system manufactured by Hitz High Technology. The aerosol generator 13 was made by Unicontrols (capacity 2 liters).

  Next, a pipe 12b having an inner diameter of 4 mm is drawn from the aerosol generator 13 into an aerosol concentration stabilizing container 21 (capacity 2 liters) manufactured by Hitz High Technology, and from there into the film forming chamber 14 via a pipe 12c having an inner diameter of 4 mm. The spray nozzle 15 (product made from spraying system Japan: YB1 / 8MSSP37) was installed in the front-end | tip. A commercially available slide glass was installed as the substrate 16 at a position 2 mm away from the spray nozzle 15. The substrate holder 17 is movable, and the spray nozzle 15 is movable so as to be movable in the vertical direction. As a result, the area for film formation could be determined. On the other hand, the aerosol generator 13 and the argon cylinder 11 were connected by a pipe 12a having an inner diameter of 4 mm.

200 g of alumina powder (manufactured by Wako Pure Chemical Industries, Ltd.) having an average particle diameter of 1 μm was charged into the aerosol generator 13 using the above apparatus. Next, the exhaust pump 18 was operated, and the vacuum was drawn from the film forming chamber 14 to the aerosol concentration stabilizing container 21 and the aerosol generator 13. Then, argon gas is sent into the aerosol generator 13, alumina particles are dispersed in the argon gas to generate an aerosol, and the aerosol is substrated from the injection nozzle 15 through the pipe 12b, the aerosol concentration stabilizing container 21, and the pipe 12c. Sprayed toward 16. At this time, the flow rate of argon gas was 10 to 20 liters / minute. The substrate holder 17 is moved 5 mm in the horizontal direction, and the spray nozzle is moved 10 mm in the vertical direction at a speed of 7 mm / min, and the structure is stacked on the slide glass of the substrate 16 in a rectangle with an area of 50 mm ^2. did. The film formation time was 3 hours, and the degree of vacuum in the film formation chamber 14 when forming the alumina film was about 50 Pa to 150 Pa. Here, the aerosol concentration stabilizing container 21 is made of stainless steel, the inner wall is subjected to electrolytic polishing, and the arithmetic average surface roughness Ra is set to 0.25.

(Comparative Example 1)
Using the same aerosol deposition apparatus 1 as in Example 1, except that the inner wall of the stainless steel aerosol concentration stabilizing vessel 21 is buffed to have an arithmetic average surface roughness Ra of 0.40, an alumina film is formed on the substrate 16. Was made.

(Evaluation)
In Example 1 and Comparative Example 1, the presence or absence of nozzle clogging within 3 hours of the film formation time was investigated and compared. In Example 1, the nozzle 15 was not clogged, and an alumina film having a thickness of 3 μm was obtained. On the other hand, in Comparative Example 1, the nozzle 15 was clogged after about 1 hour 30 minutes, and the thickness of the obtained alumina film was also less than 1 μm. After the film formation, the aerosol concentration stabilization container 21 of Comparative Example 1 was returned to the atmosphere, and the inner wall was observed. As a result, the inner wall C region in the vicinity of the inlet to which the aerosol was supplied and the inner surface in the vicinity of the surface to which the supplied aerosol first hit Alumina powder was deposited in layers near the wall surface B region and the inner wall surface A region near the outlet from which the aerosol was discharged. On the other hand, adhesion of alumina powder was not observed on the inner wall of the aerosol concentration stabilizing container 21 of Example 1.

  From the above, the effect of setting the arithmetic average surface roughness Ra of the inner wall of the aerosol concentration stabilizing container 21 to 0.25 was confirmed. That is, in the aerosol concentration stabilization container 21, the arithmetic mean surface roughness Ra of the inner wall near the inlet to which the aerosol is supplied, near the surface where the supplied aerosol first collides, and near the outlet from which the aerosol is discharged. It can be seen that the reduction of clogging of the nozzle 15 can be expected by reducing the value of.

  In the present invention, when forming a fine particle powder structure on a substrate, it is possible to stably generate an aerosol for a long period of time in order to keep the formation speed constant and suppress variations in thickness and the like. As an aerosol deposition apparatus, it can be used beneficially industrially.

Schematic showing an example of the aerosol deposition apparatus of the present invention XX sectional drawing of the aerosol concentration stabilization container in FIG. YY sectional view of the aerosol concentration stabilizing container in FIG. ZZ sectional view of the aerosol concentration stabilizing container in FIG. Schematic showing another form aerosol concentration stabilization container of the present invention Schematic showing another form aerosol concentration stabilization container of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aerosol deposition apparatus 11 Gas cylinder 12a Piping 12b Piping 12c Piping 13 Aerosol generator 14 Deposition chamber 15 Nozzle 16 Substrate 17 Substrate holder 18 Exhaust pump 19 Valve 20 Material particle 21 Aerosol concentration stabilization vessel 211 Aerosol inlet 212 Aerosol outlet

Claims (9)

An aerosol generator for containing powder and introducing gas to generate aerosol of the powder;
The arithmetic average surface roughness Ra is at least one of an inner wall surface near the inlet where the aerosol is introduced, an inner wall surface near the surface where the aerosol first collides, and an inner wall surface near the outlet where the aerosol is discharged. An aerosol concentration stabilizing container configured to stabilize the concentration of the aerosol, which is configured with a surface of 0.25 or less;
A nozzle that sprays the aerosol supplied from the aerosol concentration stabilizer on a substrate;
An aerosol deposition apparatus having a film forming chamber provided with the nozzle.   2. The aerosol deposition apparatus according to claim 1, wherein an arithmetic average surface roughness Ra of the entire inner wall surface of the aerosol stabilizer is 0.25 or less.   The aerosol deposition apparatus according to claim 1 or 2, further comprising a path connecting the aerosol concentration stabilizing container and the nozzle, wherein an arithmetic average surface roughness Ra of an inner surface through which the aerosol is circulated is 0.25 or less.   The aerosol according to any one of claims 1 to 3, further comprising a path connecting the aerosol generator and the aerosol concentration stabilizing container, wherein an arithmetic average surface roughness Ra of an inner surface through which the aerosol is circulated is 0.25 or less. Deposition device.   The aerosol deposition apparatus according to any one of claims 1 to 4, wherein an arithmetic average surface roughness Ra of the aerosol generator and the inner wall surface of the film forming chamber is 0.25 or less. The active material layer
An electrode plate for an electricity storage device configured by spraying the powder as an active material onto the substrate as a current collector using the aerosol deposition apparatus according to claim 1. Porous electronic insulation layer
The separator comprised by spraying the said powder which is an inorganic particle on the said board | substrate using the aerosol deposition apparatus in any one of Claim 1 to 5. A separator;
An electrical storage device provided with the electrode plate for electrical storage devices of Claim 6 in any one of a positive electrode and a negative electrode. A separator according to claim 7;
An electricity storage device comprising a positive electrode plate and a negative electrode plate.

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