Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/11—Making porous workpieces or articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/18—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by using pressure rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
  • B22F5/006—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of flat products, e.g. sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
  • B22F7/002—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of porous nature
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
  • B22F2998/10—Processes characterised by the sequence of their steps

Definitions

• the invention is based on a method for producing a large-area current collector according to the preamble of claim 1.
• Titanium foils of limited dimensions for experimental purposes are Titanium foils of limited dimensions for experimental purposes
• the invention is based on the object of specifying an economical method for producing a current collector in the form of a porous plate or foil made of titanium, the area of which is not limited and the thickness and porosity of which are uniform over the entire area, the density or Porosity can be selectively reproduced within narrow limits with narrow tolerances.
• Fig. 3 is a Flie 'ssdiagramm the method.
• the diagram 1 shows the temperature profile as a function of time for the heat treatment of the titanium powder. posed.
• the diagram is self-explanatory. In deviation from the diagram, heating to 500 ° C. can also be carried out in the period from 30 to 90 minutes.
• the sintering temperature can be 900 to 1200 c.
• 1 is the support in the form of a flat plate (non-porous, non-sticky graphite).
• 2 represents the viscous, homogeneous paste consisting of titanium powder and terpineol (C .H Collector0).
• 3 is the coherent, uniform layer of this paste.
• a movable coating device 4 to be displaced in the direction of the arrow in the form of a container tapering downward can be used as a means for applying the paste.
• 2 and 3 represent the dry, free-flowing titanium powder or the upper layer thus produced on the carrier 1.
• Terpineol evaporated in air by heating to approx. 200 ° C.
• Layer 3 was then dried together with carrier substance 1 in a vacuum drying cabinet at approx. 200 ° C.
• the titanium powder was already compacted. Furthermore, the material was subjected to a multi-stage heat treatment. To this end, the layer
• the material was heated to a temperature of 500 C over a period of about 90 min and during
• the cold-rolled foil was then placed on a graphite powder-coated support 1 and subjected to a further heat treatment according to FIG. 1.
• the measured porosity was still 58%.
• a layer consisting of platinum was applied to the porous titanium foil in an electrochemical manner.
• the case was a mixture of ruthenium oxide
• the process steps of cold rolling and sintering can be carried out several times in succession until the desired targeted density or porosity of the film or plate has been reached.
• paste 2 can also be produced with the aid of a suitable liquid other than C.
• the application of the paste is also not bound to the coating device 4 for thin-layer plates, but can be carried out with the aid of any other suitable device.
• the condition is that a viscous, homogeneous paste is first produced and then applied as uniformly as possible to a non-adhesive substrate (carrier 1).
• a current collector * for an electrochemical ozone cell in the form of a porous titanium foil 1.45 mm thick was produced as follows: On one with graphite powder (KS 75 from Lonza) coated support 1 made of fine-grained graphite (ground plate, quality Ringsdorff EK 72) was dry, free-flowing titanium powder 2 (Sumitomo, Osaka) in the form of a uniform layer using a movable coating device 4 (Camag thin-layer apparatus for chromatography) 3 applied. The layer thickness was approximately 1.9 mm; the area was a square with a side length of 200 mm. The whole was then subjected to a multi-stage heat treatment in a vacuum oven in order to sinter the titanium powder.
• KS 75 from Lonza coated support 1 made of fine-grained graphite (ground plate, quality Ringsdorff EK 72) was dry, free-flowing titanium powder 2 (Sumitomo, Osaka) in the form of a uniform layer using a movable coating
• the mixture was first heated from room temperature to 500 ° C. over a period of about 90 minutes and this temperature was kept constant for a further 30 minutes. The mixture was then heated to 1000 ° C. for 30 minutes and this temperature was maintained for 3 hours. After cooling to room temperature, the pre-sintered in this way
• Titanium foil can be easily detached from the carrier 1, since the graphite powder had formed a protective layer.
• the thickness of the film after presintering was approx. 1.8 mm, the porosity 70%.
• the film was cold rolled in several passes in a roll stand with rolls of 130 mm in diameter.
• the decrease in height per stitch was approx. 0.1 mm, so that after 3 stitches a film thickness of approx. 1.5 was now achieved.
• the rolling speed was 1.2 m / min. Care must be taken that the total cross-sectional reduction before the next heat treatment does not exceed 30%, since otherwise the material could tear.
• the decrease in height per stitch should not exceed 15%.
• the rolling speed can advantageously be set to 1 to 30 m / min.
• the porosity had dropped to about 62% after cold rolling.
• the cold-rolled titanium foil was then subjected to a further sintering process in accordance with the heat treatment described above. * The thickness of the film was still after sintering approx.1.45 mm, the porosity approx. 59%.
• the porous titanium foil was now coated with platinum according to Example I. An additional layer consisting of PbO p in
• any desired film thickness and any porosity between 0 and that approximately corresponds to the loosely poured titanium powder can be achieved, which is primarily used for sintering heat treatment can be carried out under vacuum or protective gas.
• the porous titanium foil is provided with a thin layer of platinum, on which another layer made of at least one platinum metal or one
• Platinum metal oxide or PbO existing electrocatalyst layer is applied.
• the process according to the invention enables the economical production of current collectors in the form of porous titanium foils and titanium plates of 0.1 to approximately 5 mm constant thickness with uniform, targeted porosity and practically any surface area, such as that required for the construction of large industrial ones electrochemical devices, in particular electrolysis apparatus (individual parts and entire batteries constructed according to the filter press principle) are required.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electrochemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Composite Materials (AREA)
• Cell Electrode Carriers And Collectors (AREA)
• Catalysts (AREA)
• Powder Metallurgy (AREA)
• Inert Electrodes (AREA)
• Battery Electrode And Active Subsutance (AREA)
• Electrodes For Compound Or Non-Metal Manufacture (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 1982
  • 1982-03-05 CH CH1343/82A patent/CH653581A5/de not_active IP Right Cessation
• 1983
  • 1983-02-28 EP EP83900695A patent/EP0102966A1/de not_active Withdrawn
  • 1983-02-28 WO PCT/CH1983/000021 patent/WO1983003105A1/de not_active Ceased
  • 1983-03-04 IT IT19907/83A patent/IT1160493B/it active

Non-Patent Citations (1)

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