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CN-116670073-B - Tungsten oxide powder slurry, method for producing same, and method for producing electrochromic element using same

CN116670073BCN 116670073 BCN116670073 BCN 116670073BCN-116670073-B

Abstract

A tungsten oxide powder slurry comprising a tungsten oxide powder and an aqueous solvent, wherein D 50 is 20nm to 10000nm in a particle size cumulative curve of the tungsten oxide powder in the slurry, D 90 is 100000nm or less, and a half value width of a strongest peak detected at 29 DEG + -1 DEG in X-ray diffraction analysis (2 [ theta ]) is 2 DEG or less.

Inventors

  • FUKUSHI DAISUKE

Assignees

  • 株式会社东芝
  • 东芝高新材料公司

Dates

Publication Date
20260512
Application Date
20220210
Priority Date
20210224

Claims (18)

  1. 1. A tungsten oxide powder slurry obtained by mixing a tungsten oxide powder with an aqueous solvent, wherein the tungsten oxide powder slurry is a slurry for manufacturing an electrochromic element, In the particle size cumulative curve of the tungsten oxide powder in the slurry, D 50 is 20nm to 10000nm, D 90 is 100000nm, When X-ray diffraction analysis (2 theta) is performed, the half-value width of the strongest peak detected at 29 DEG + -1 DEG is 2 DEG or less, The absorbance of the tungsten oxide powder slurry at a wavelength of 600nm is 1 or less.
  2. 2. The tungsten oxide powder slurry according to claim 1, wherein D 50 is 500nm or less and D 90 is 1000nm or less.
  3. 3. The tungsten oxide powder slurry according to any one of claims 1 to 2, wherein the tungsten oxide powder has a particle size frequency profile in the range of D 0 ～D 90 with one peak.
  4. 4. The tungsten oxide powder slurry according to any one of claims 1 to 2, wherein a content of the tungsten oxide powder in the slurry is in a range of 5 mass% or more and 50 mass% or less.
  5. 5. A tungsten oxide powder slurry according to claim 3, wherein the content of the tungsten oxide powder in the slurry is in a range of 5 mass% or more and 50 mass% or less.
  6. 6. The tungsten oxide powder slurry according to any one of claims 1 to 2, wherein the slurry contains 1 or 2 or more kinds selected from ammonia, potassium hydroxide and sodium hydroxide.
  7. 7. The tungsten oxide powder slurry according to claim 3, wherein the tungsten oxide powder slurry contains 1 or 2 or more kinds selected from the group consisting of ammonia, potassium hydroxide and sodium hydroxide.
  8. 8. The tungsten oxide powder slurry according to any one of claims 1 to 2, wherein an average particle diameter of the tungsten oxide powder is 20nm or less when the aqueous solvent is removed.
  9. 9. The tungsten oxide powder slurry according to claim 3, wherein an average particle diameter of the tungsten oxide powder is 20nm or less when the aqueous solvent is removed.
  10. 10. The tungsten oxide powder slurry according to any one of claims 1 to 2, wherein the tungsten oxide powder slurry contains tungsten oxide powder containing at least one of 0.01 mass% and 50 mass% or more of potassium, sodium, lithium, and magnesium.
  11. 11. The tungsten oxide powder slurry according to any one of claims 1 to 2, wherein absorbance at a wavelength of 350 nm/absorbance at a wavelength of 600nm is 3 or more.
  12. 12. A method for manufacturing an electrochromic element using the tungsten oxide powder slurry according to any one of claims 1 to 11.
  13. 13. The method for producing a tungsten oxide powder slurry according to any one of claim 1 to claim 11, comprising a step of crushing the tungsten oxide powder by a bead mill using beads containing zirconium oxide as a main component having a particle diameter of 0.05mm or more and 0.5mm or less, and a step of mixing the crushed tungsten oxide powder with the aqueous solvent, In the bead mill, the amount of beads added is set in a range of 40 to 90% by volume when the volume in the disperser is set to 100% by volume.
  14. 14. The method for producing a tungsten oxide powder slurry according to claim 13, wherein in the step of mixing the tungsten oxide powder with the aqueous solvent, when the volume in the disperser is set to 100% by volume, the total input amount of water and the tungsten oxide powder is set to be in a range of 10% by volume to 60% by volume.
  15. 15. The method for producing a tungsten oxide powder slurry according to claim 13 or 14, wherein in the step of crushing with the bead mill, an impact force generated by the bead mill is in a range of 100G to 500G.
  16. 16. The method for producing a tungsten oxide powder slurry according to claim 15, wherein a rotational speed of the disperser is 7m/sec or more.
  17. 17. The method for producing a tungsten oxide powder slurry according to claim 13 or 14, wherein in the step of crushing with the bead mill, the crushing time is 20 minutes or longer.
  18. 18. The method for producing a tungsten oxide powder slurry according to claim 15, wherein in the step of crushing with the bead mill, the crushing time is 20 minutes or longer.

Description

Tungsten oxide powder slurry, method for producing same, and method for producing electrochromic element using same Technical Field The embodiment described below relates to a tungsten oxide powder slurry, a method for producing the same, and a method for producing an electrochromic element using the same. Background Tungsten oxide powder is used in various fields such as electrochromic materials, electrode materials for batteries, photocatalysts, and sensors. For example, international publication No. 2018/199020 (patent document 1) discloses a tungsten oxide powder having an average particle diameter of 50nm or less. In patent document 1, a tungsten oxide powder having a predetermined value by spectroscopic ellipsometry is used. The tungsten oxide powder of patent document 1 shows an improvement in photocatalytic performance. Further, the response speed of the display electrochromic element increases. For example, electrochromic elements are light emitting elements that are switched transparent and colored by switching of electric charges. When the electrochromic element is formed using the tungsten oxide powder of patent document 1, there arises a problem of so-called reduction in transparency. As a result of this, it was found that the cohesiveness of the tungsten oxide powder was problematic. The electrode layer of the electrochromic element is formed using a coating process. The coating step uses a paste containing tungsten oxide powder. The paste is obtained by mixing an organic binder in an aqueous solvent. The paste was prepared by mixing tungsten oxide powder with an aqueous dispersion. The paste is prepared by mixing an organic substance such as a binder with the slurry. For example, japanese patent No. 5641926 (patent document 2) discloses a slurry in which the particle diameter D 50、D90 of tungsten oxide powder is controlled. Patent document 2 discloses a slurry obtained by mixing tungsten oxide powder with an aqueous solvent. Even when the slurry of patent document 2 is used, the problem of cohesiveness arises. Prior art literature Patent literature Patent document 1 International publication No. 2018/199020 Patent document 2 Japanese patent No. 5641926 Patent document 3 International publication No. 2020/196720 Disclosure of Invention Problems to be solved by the invention The slurry of patent document 2 controls the particle size distribution of the tungsten oxide powder. If the slurry obtained by mixing the tungsten oxide powder with the aqueous solvent is left for a long period of time, aggregation of the tungsten oxide powder is caused. As a result, there is caused a phenomenon that the particle size distribution of the tungsten oxide powder when added to the aqueous solvent cannot be maintained. The present invention is an invention for solving such problems, and provides a tungsten oxide powder slurry which can suppress aggregation even when left for a long period of time. Means for solving the problems The tungsten oxide powder slurry according to the embodiment is characterized in that the tungsten oxide powder is mixed with an aqueous solvent, and in the particle size accumulation curve of the tungsten oxide powder in the slurry, D 50 is 20nm to 10000nm, D 90 is 100000nm or less, and the half value width of the strongest peak detected at 29 DEG + -1 DEG is 2 DEG or less when X-ray diffraction analysis (2 theta) is performed. Drawings Fig. 1 is a view showing an example of a particle size distribution of a tungsten oxide powder slurry according to an embodiment. Fig. 2 is a view showing an example of X-ray diffraction (2θ) of the tungsten oxide powder slurry according to the embodiment. Fig. 3 is a diagram showing an example of absorbance of the tungsten oxide powder slurry according to the embodiment. Fig. 4 is a diagram showing an example of an electrochromic element. Detailed Description The tungsten oxide powder slurry according to the embodiment is characterized in that the tungsten oxide powder is mixed with an aqueous solvent, and in the particle size accumulation curve of the tungsten oxide powder in the slurry, D 50 is 20nm to 10000nm, D 90 is 100000nm or less, and the half value width of the strongest peak detected at 29 DEG + -1 DEG is 2 DEG or less when X-ray diffraction analysis (2 theta) is performed. The tungsten oxide powder is preferably a powder satisfying WO 3-x, 0≤x < 0.3. The tungsten oxide powder has properties that exhibit intercalation (Intercalation). Intercalation is the reversible reaction of electrons or ions into and out of the nano-metal compound particles. By actively performing the embedding reaction, the performance as a semiconductor improves. Further, movement of electrons generated by flowing electricity or irradiating light becomes active. Therefore, the tungsten oxide powder is suitable for various fields such as a photocatalyst, an electrochromic element, an electrode material for a battery, and a sensor. Further, when used in a material for elec