CN1212025A - Method of applying conductive coating - Google Patents

Method of applying conductive coating Download PDF

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Publication number
CN1212025A
CN1212025A CN97192455A CN97192455A CN1212025A CN 1212025 A CN1212025 A CN 1212025A CN 97192455 A CN97192455 A CN 97192455A CN 97192455 A CN97192455 A CN 97192455A CN 1212025 A CN1212025 A CN 1212025A
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CN
China
Prior art keywords
coating
substrate
coated
aforementioned
composition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN97192455A
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Chinese (zh)
Inventor
安德鲁·希尔
基思·戈登·埃利斯
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Atraverda Ltd
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Atraverda Ltd
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Publication date
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Publication of CN1212025A publication Critical patent/CN1212025A/en
Pending legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
    • C23C4/10—Oxides, borides, carbides, nitrides or silicides; Mixtures thereof
    • C23C4/11—Oxides
    • 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
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C25B11/093—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one noble metal or noble metal oxide and at least one non-noble metal oxide

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrochemistry (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • Coating By Spraying Or Casting (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)

Abstract

A titanium suboxide of the formula TiOx where x is 1.55 to 1.95, is applied to a substrate by a thermal process to form a coating of the same composition. The thermal process may be plasma spraying, and the formed article may be an electrode of enhanced corrosion resistance and electrical conductivity.

Description

The coating method of conductive coating
The present invention relates in a substrate, form the method for the conductive coating of erosion resistance.Described substrate can be an electrode, for example an electrochemical cell.
Known that titanium suboxide can be used as coating.Known equally, can in a substrate, form the coating of above-mentioned materials by flame plating or plasma spraying, for example GB-A-1438462; US-A-5225382; And GB-A-1595061 is described.In these open source literatures, with the precursor mixture of titanium suboxide in plasma spraying to a substrate under the condition of selected formation suboxide.Typical suboxide has formula TiO x, wherein x is 1.95-1.99, described in GB-A-1438462 and US-A-5225382.Yet when these suboxide had erosion resistance, their electroconductibility was bad.
US-A-4252629 discloses a kind of by agglomerating TiO xForm, wherein x is 0.25-1.5, and has a manganese bioxide coated erosion resistance carrier.This carrier can prepare by plasma spraying titanium oxide under argon gas.
EP-A-0047595 discloses the body titanium suboxide TiO with erosion resistance and electroconductibility x, wherein x is 1.55-1.95.The disclosure document points out that this material can be by pressurization or extrusion molding.
Find that now if the material of a known chemical metering is coated in the substrate, can obtain to have the coating of predetermined composition, this coating has special enhanced corrosion resistance and electroconductibility.
According to an aspect of the present invention, provide a kind of method that in substrate, forms the erosion resistance conductive coating, comprised forming a kind of formula TiO xPredetermined titanium suboxide, wherein x is 1.55-1.95, applies the material to then in the substrate so that form the coating that substantially the same stoichiometric this material is really arranged in this substrate.
Can adopt any suitable coating technology to apply described material, only otherwise influence the stoichiometry of this material.Such technology comprises plasma spraying and laser cladding.Also can consider detonation gun coating, that is, and the method by detonation flame spraying then with the material fusion, and other hot coating technology.
Because raw material is the known chemical metering, has required performance, therefore can obtain having required stoichiometric coating, thereby obtain required over-all properties, for example electroconductibility, erosion resistance etc.Can apply the mixture of suboxide or only apply a kind of suboxide.Most preferably, the plasma spraying of the titanium suboxide determined is carried out not influencing under its stoichiometric condition.For this reason, for example can for example apply under the protection of argon gas in vacuum or at a kind of suitable rare gas element.
Preferably pre-treatment is carried out on the surface of substrate, be coated with the adhesive power of the coating that applies with enhancing.Described pre-treatment can be mechanical, chemistry or electrochemical, and for example sand/coarse sand sandblast, deposition, laser ablation, etching, baking are coated with etc.
Method of the present invention can comprise a spot of doping agent of adding in coated material.The example of doping agent comprises eelctro-catalyst and other stablizer, Pt for example, Ir, Ta, Nb, Ru, V etc.; Oxide compound, for example stannic oxide, and their mixture.These doping agents can influence electroconductibility, adhesive power, erosion resistance.Usually, composition of the present invention should have specific forms, and is for example Powdered.The adding doping agent can be used as a kind of aftertreatment, for example, can be coated with or the further coating that applies an eelctro-catalyst of similar approach by plating, heat baking, to influence the chemical property of the finished product.
Coating device, for example plasma gun can be a known form, and is furnished with suitable optional equipment to guarantee an inert gas cover, for example GB-A-2281488 is described.
With the powder melts of using laser to make just to be applied in toward substrate, carrying out in vacuum more completely or purer inert gas atmosphere can be effective especially.In addition, can be by the surface of the coated substrate of laser surface ablation technology cleaning desire, wherein the moment before the fused powder arrives substrate, second laser treatment process can provide a high energy pulse (being generally per 20 nanosecond 35MW) the suprabasil oxide on surface of cleaning and other pollutent.
Coated object can be directly used in the electrode (both can be that anode also can be a negative electrode) under the low current density, or as mentioned above, is used for the occasion of high current density after having applied suitable eelctro-catalyst.Its surface can also be electroplated, and for example electroplates the electrically contacting or adhesive power with the active material in raising and the battery with metallic lead or zinc.Described electrode can be used for the electrolytic metallurgy, chlorine battery, water treatment of electrochemical cell, metal etc. and use.
Method of the present invention can make the thickness of coated coating far surpass the required thickness of erosion resistance, keeps good electroconductibility simultaneously.The thickness range of coating can be (50-1000) * 10 -3Mm.For very high erosion resistance, common coating or for the thickness rank be (200-500) * 10 -3The coating of mm, wherein the x in the stoichiometry is about 1.75-1.8, perhaps is thin coating, and thickness is about (100-200) * 10 -3Mm, wherein the x in the stoichiometry is about 1.85-1.9.For not really arduous environment for use, preferred thickness is about (100-200) * 10 -3Mm, the x in the stoichiometry are the high conductivity coating of 1.75-1.8.Coating of the present invention has the electroconductibility of 10 1 100S/cm.Even in not really arduous corrosive environment, also can add doping agent with further raising electroconductibility.
In order to understand the present invention better, describe referring now to the following example, these embodiment only are used to illustrate the present invention.Embodiment 1
The test electrode that has prepared the electrolytic metallurgy that is used for zinc by following method.All edges of the commercial grade aluminium flake of two thickness, the 230 * 80mm that is 2mm are filed gently to remove sharp edges and burr, afterwards to its grit-blast(ing).With a Metco rifle above-mentioned article are carried out plasma spraying then, be equipped with a wheel cap described in GB-A-2281488 on the Metco rifle, this wheel cap is being controlled to guarantee the even coating at whole surface and edge by a robot.Add the powder of prepared beforehand in the rifle, the stoichiometry of this powder is defined as formula TiO by X-ray diffraction xComposition, x=1.72 wherein.Its electroconductibility is 10S/cm.The thickness of coating is 120 microns, and tap density is 3.84gm/cc.Adjust the flow velocity and the pressure of argon gas and hydrogen subsequently, obtaining stoichiometry is TiO x, the composition of x=1.76 wherein, the tap density of its coating is 4.03gm/cc.(it has been generally acknowledged that, if tap density theoretical theoretical density 5% within, just do not have the hole of interconnection).
Eelctro-catalyst coating with a kind of mixed oxide based on tantalum and iridium is further handled coated anode.In the process that baking is coated with, because the thermal expansion of ceramics component and metal ingredient is different, a test electrode has lost most coating, therefore is dropped.Yet another electrode has stood up to about 400 ℃ temperature cycle with 30 coatings.As the anode in the test cell of electrodepositing zinc from a solution, described solution contains the Zn of 50g/l with this electrode 2+H with 180-200g/l 2SO 4, and the fluorochemical of trace (approximately 10mg/l), Mn 2+(5-8mg/l) and other the pollutent of in commercial zinc electrolytic metallurgy current, finding.Electrode of the present invention is at 450A/m 2Current density under can successfully use above 1000 hours.Be very significantly in this test, though after using for a long time, electrode potential raises to some extent compared with beginning (also being preferred) is low-level really, and the electromotive force of the Pb/Ag anode material that the electromotive force of this electrode still uses than tradition hangs down 250mV, and any MnO that forms on the electrode 2Can constantly break away from automatically or by means of once in a while ultrasonication and break away from.Embodiment 2
Method coating titanium metal plate with embodiment 1.Because this metal and to be coated with the difference of the coefficient of expansion of interlayer less, to dry by the fire with eelctro-catalyst when being coated with, coating is without any peeling off.Embodiment 3
Method with embodiment 1 is coated to conductivity ceramics on the solid piece and expansible metallic screen of aluminium and titanium, applies with plumbic oxide, platinum and antimony/stannum oxide coating in the temperature electropaining of gentleness then.Embodiment 4
Method with embodiment 1 is coated to the electroconductibility ceramic coating on steel, brass, copper, lead and KEVLAR (nonmetal) test film.

Claims (14)

1, in a substrate, forms the method for erosion resistance conductive coating, comprise forming a kind of formula TiO xPredetermined titanium suboxide, wherein x is 1.55-1.95, then this material is coated in the substrate to have substantially the same stoichiometric coating so that form in this substrate.
2, apply described material according to the process of claim 1 wherein with plasma spraying process.
3, apply described material according to the process of claim 1 wherein with the laser cladding method.
4, apply described material according to the process of claim 1 wherein with de-rifle coating technology.
5, according to claim 1,2,3 or 4 method, it comprises add a kind of doping agent in titanium suboxide, and the doping that will obtain composition be coated in the substrate.
6, according to the method for claim 5, wherein said doping agent is a kind of eelctro-catalyst and/or other stablizer.
7, according to the described method of aforementioned each claim, the applied thickness of its floating coat is 50-1000 * 10 -3Mm.
8,, before it also is included in and is coated to described composition in the substrate, anticipate the step of substrate surface with machinery, laser, chemistry or electrochemical method according to the described method of aforementioned each claim.
9, method according to Claim 8, wherein said pre-treatment are that sand-blast, chemical method or sedimentation, baking are coated with method.
10, according to the described method of aforementioned each claim, the coating of wherein said material is carried out under vacuum.
11, according to the method for claim 10, the coating of wherein said material is carried out under a kind of atmosphere, and this atmosphere comprises a kind of gas that is used for the composition that the eliminating meeting impacts described titanium suboxide.
12, according to the method for claim 11, wherein said gas is argon gas.
13, according to the described method of aforementioned each claim, it comprises the subsequent step that applies a kind of electrocatalyst materials, take this described surface and further applied a kind of eelctro-catalyst, described eelctro-catalyst comprises precious metal and composition thereof, its oxide compound and composition thereof, plumbic oxide, doped stannum oxide etc.
14, according to the described method of aforementioned each claim, wherein said substrate comprises an electrode that is used for electrochemical cell.
CN97192455A 1996-01-22 1997-01-22 Method of applying conductive coating Pending CN1212025A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB9601236.4A GB9601236D0 (en) 1996-01-22 1996-01-22 Conductive coating
GB9601236.4 1996-01-22

Publications (1)

Publication Number Publication Date
CN1212025A true CN1212025A (en) 1999-03-24

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CN (1) CN1212025A (en)
AU (1) AU1451497A (en)
CA (1) CA2244158A1 (en)
GB (2) GB9601236D0 (en)
WO (1) WO1997027344A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101292057B (en) * 2005-10-21 2012-06-13 奥图泰有限公司 Method for forming an electrocatalytic surface on an electrode and the electrode
CN104241655A (en) * 2014-07-04 2014-12-24 超威电源有限公司 Conductive ceramic battery grid
CN104321468A (en) * 2012-05-21 2015-01-28 德诺拉工业有限公司 Electrode for evolution of gaseous products and method of manufacturing thereof
CN105297073A (en) * 2015-10-30 2016-02-03 昆明理工大学 Preparation method of copper-based titanium black electrode plate
CN105776429A (en) * 2016-03-15 2016-07-20 中国矿业大学(北京) Circular tubular titanium black membrane electrode with electrochemical oxidation activity and preparation method of circular tubular titanium black membrane electrode
CN109457270A (en) * 2018-12-29 2019-03-12 西安泰金工业电化学技术有限公司 A kind of preparation method of ti-based coating Ni―Ti anode

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6517962B1 (en) 1999-08-23 2003-02-11 Ballard Power Systems Inc. Fuel cell anode structures for voltage reversal tolerance
DE10000979C1 (en) * 1999-10-01 2001-05-10 Daimler Chrysler Ag Coating powder used in plasma spraying, high speed flame spraying and detonation spraying of components of engines is based on a titanium sub-oxide
US6524750B1 (en) 2000-06-17 2003-02-25 Eveready Battery Company, Inc. Doped titanium oxide additives
US20070264564A1 (en) 2006-03-16 2007-11-15 Infinite Power Solutions, Inc. Thin film battery on an integrated circuit or circuit board and method thereof
US9793523B2 (en) 2002-08-09 2017-10-17 Sapurast Research Llc Electrochemical apparatus with barrier layer protected substrate
ITRM20020622A1 (en) * 2002-12-13 2004-06-14 Ct Sviluppo Materiali Spa PROCEDURE FOR PLASMA THERMAL SPRAYING OF DRY SEMICONDUCTIVE OXIDE-BASED COATINGS.
US7608358B2 (en) 2006-08-25 2009-10-27 Bdf Ip Holdings Ltd. Fuel cell anode structure for voltage reversal tolerance
KR20150128817A (en) 2007-12-21 2015-11-18 사푸라스트 리써치 엘엘씨 Method for sputter targets for electrolyte films
WO2009089417A1 (en) 2008-01-11 2009-07-16 Infinite Power Solutions, Inc. Thin film encapsulation for thin film batteries and other devices
JP2012500610A (en) 2008-08-11 2012-01-05 インフィニット パワー ソリューションズ， インコーポレイテッド Energy device with integrated collector surface and method for electromagnetic energy acquisition
JP5492998B2 (en) 2009-09-01 2014-05-14 インフィニット パワー ソリューションズ， インコーポレイテッド Printed circuit board with built-in thin film battery
WO2011076396A1 (en) * 2009-12-22 2011-06-30 Daimler Ag Fuel cell with selectively conducting anode component
JP2013528912A (en) 2010-06-07 2013-07-11 インフィニット パワー ソリューションズ， インコーポレイテッド Rechargeable high density electrochemical device
KR102061922B1 (en) 2012-02-23 2020-01-02 트레드스톤 테크놀로지스, 인크. Corrosion resistant and electrically conductive surface of metal
WO2019176956A1 (en) * 2018-03-12 2019-09-19 三菱マテリアル株式会社 Titanium base material, method for producing titanium base material, electrode for water electrolysis, and water electrolysis device

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3330707A (en) * 1963-10-07 1967-07-11 Varian Associates Method for reducing electron multipactor on a dielectric window surface
DE2300422C3 (en) * 1973-01-05 1981-10-15 Hoechst Ag, 6000 Frankfurt Method of making an electrode
GB1464375A (en) * 1974-05-22 1977-02-09 Ass Eng Ltd Abrading devices
US3962488A (en) * 1974-08-09 1976-06-08 Ppg Industries, Inc. Electrically conductive coating
GB1595061A (en) * 1976-11-22 1981-08-05 Atomic Energy Authority Uk Electrically conductive layers produced by plasma spraying
DE2714605A1 (en) * 1977-04-01 1978-10-05 Sigri Elektrographit Gmbh Lead di:oxide electrode having sub:oxide-coated titanium support - used in fuel and galvanic cells, for electrochemical reactions and for anticorrosion purposes
US4194022A (en) * 1977-07-25 1980-03-18 Ppg Industries, Inc. Transparent, colorless, electrically conductive coating
US4422917A (en) * 1980-09-10 1983-12-27 Imi Marston Limited Electrode material, electrode and electrochemical cell
DE3046757C2 (en) * 1980-12-12 1985-09-12 W.C. Heraeus Gmbh, 6450 Hanau Gravure cylinder
US4395432A (en) * 1981-12-16 1983-07-26 Westinghouse Electric Corp. β-Alumina coating
JPS59230773A (en) * 1983-06-14 1984-12-25 Kyocera Corp Thermal head
JPS60251291A (en) * 1984-05-29 1985-12-11 Ishifuku Kinzoku Kogyo Kk Anode for electrolyzing diluted chloride solution
DE3513892A1 (en) * 1985-04-17 1986-10-23 Plasmainvent AG, Zug CR (DOWN ARROW) 2 (DOWN ARROW) O (DOWN ARROW) 3 (DOWN ARROW) PROTECTIVE LAYER AND METHOD FOR PRODUCING THE SAME
US5538612A (en) * 1987-12-09 1996-07-23 Ngk Spark Plug Co., Ltd. Oxygen sensor element
US4861680A (en) * 1988-02-11 1989-08-29 Southwall Technologies Bronze-grey glazing film and window made therefrom
JPH0774470B2 (en) * 1990-03-20 1995-08-09 ダイソー株式会社 Manufacturing method of anode for oxygen generation
DE4421007A1 (en) * 1994-06-18 1995-12-21 Philips Patentverwaltung Electronic component and method for its production
US5521029A (en) * 1995-02-22 1996-05-28 At&T Corp. Current collecting elements

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101292057B (en) * 2005-10-21 2012-06-13 奥图泰有限公司 Method for forming an electrocatalytic surface on an electrode and the electrode
CN104321468A (en) * 2012-05-21 2015-01-28 德诺拉工业有限公司 Electrode for evolution of gaseous products and method of manufacturing thereof
CN104241655A (en) * 2014-07-04 2014-12-24 超威电源有限公司 Conductive ceramic battery grid
CN105297073A (en) * 2015-10-30 2016-02-03 昆明理工大学 Preparation method of copper-based titanium black electrode plate
CN105776429A (en) * 2016-03-15 2016-07-20 中国矿业大学(北京) Circular tubular titanium black membrane electrode with electrochemical oxidation activity and preparation method of circular tubular titanium black membrane electrode
CN109457270A (en) * 2018-12-29 2019-03-12 西安泰金工业电化学技术有限公司 A kind of preparation method of ti-based coating Ni―Ti anode

Also Published As

Publication number Publication date
AU1451497A (en) 1997-08-20
GB2309230A (en) 1997-07-23
GB9601236D0 (en) 1996-03-20
GB9701229D0 (en) 1997-03-12
CA2244158A1 (en) 1997-07-31
WO1997027344A1 (en) 1997-07-31

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