US20110177427A1 - Densification of ceria based electrolytes - Google Patents
Densification of ceria based electrolytes Download PDFInfo
- Publication number
- US20110177427A1 US20110177427A1 US13/076,761 US201113076761A US2011177427A1 US 20110177427 A1 US20110177427 A1 US 20110177427A1 US 201113076761 A US201113076761 A US 201113076761A US 2011177427 A1 US2011177427 A1 US 2011177427A1
- Authority
- US
- United States
- Prior art keywords
- electrolyte
- concentration
- mole
- cations
- electrode
- 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.)
- Abandoned
Links
- 239000003792 electrolyte Substances 0.000 title claims abstract description 86
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 title claims abstract description 15
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 title claims abstract description 15
- 238000000280 densification Methods 0.000 title description 13
- 150000001768 cations Chemical class 0.000 claims abstract description 99
- 239000000758 substrate Substances 0.000 claims description 28
- 239000000446 fuel Substances 0.000 claims description 14
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 239000001301 oxygen Substances 0.000 claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 abstract description 15
- 238000000034 method Methods 0.000 description 27
- 229910052751 metal Inorganic materials 0.000 description 20
- 239000002184 metal Substances 0.000 description 20
- 238000005245 sintering Methods 0.000 description 18
- 238000007792 addition Methods 0.000 description 16
- 230000008569 process Effects 0.000 description 16
- 239000008188 pellet Substances 0.000 description 10
- 230000003647 oxidation Effects 0.000 description 8
- 238000007254 oxidation reaction Methods 0.000 description 8
- 239000012300 argon atmosphere Substances 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- 238000011109 contamination Methods 0.000 description 5
- 230000002939 deleterious effect Effects 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- -1 transition metal cations Chemical class 0.000 description 5
- 239000011888 foil Substances 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 229910052723 transition metal Inorganic materials 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- OVSKIKFHRZPJSS-UHFFFAOYSA-N 2,4-D Chemical compound OC(=O)COC1=CC=C(Cl)C=C1Cl OVSKIKFHRZPJSS-UHFFFAOYSA-N 0.000 description 1
- 101150018759 CG10 gene Proteins 0.000 description 1
- 229910002484 Ce0.9Gd0.1O1.95 Inorganic materials 0.000 description 1
- DSEKYWAQQVUQTP-UHFFFAOYSA-N Cerin Natural products CC12CCC3(C)C4CC(C)(C)CCC4(C)CCC3(C)C2CCC2(C)C1CC(O)C(=O)C2C DSEKYWAQQVUQTP-UHFFFAOYSA-N 0.000 description 1
- 229910003265 NiCr2O4 Inorganic materials 0.000 description 1
- 229910003264 NiFe2O4 Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 238000012899 de-mixing Methods 0.000 description 1
- 230000003413 degradative effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 description 1
- 238000000462 isostatic pressing Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910000000 metal hydroxide Inorganic materials 0.000 description 1
- 150000004692 metal hydroxides Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- NQNBVCBUOCNRFZ-UHFFFAOYSA-N nickel ferrite Chemical compound [Ni]=O.O=[Fe]O[Fe]=O NQNBVCBUOCNRFZ-UHFFFAOYSA-N 0.000 description 1
- RJSRQTFBFAJJIL-UHFFFAOYSA-N niobium titanium Chemical compound [Ti].[Nb] RJSRQTFBFAJJIL-UHFFFAOYSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
- H01M8/124—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the process of manufacturing or by the material of the electrolyte
- H01M8/1246—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the process of manufacturing or by the material of the electrolyte the electrolyte consisting of oxides
- H01M8/126—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the process of manufacturing or by the material of the electrolyte the electrolyte consisting of oxides the electrolyte containing cerium oxide
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F17/00—Compounds of rare earth metals
- C01F17/10—Preparation or treatment, e.g. separation or purification
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/50—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on rare-earth compounds
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
- C04B2235/3206—Magnesium oxides or oxide-forming salts thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
- C04B2235/3229—Cerium oxides or oxide-forming salts thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3241—Chromium oxides, chromates, or oxide-forming salts thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
- C04B2235/3265—Mn2O3
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3272—Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3275—Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/658—Atmosphere during thermal treatment
- C04B2235/6582—Hydrogen containing atmosphere
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/658—Atmosphere during thermal treatment
- C04B2235/6583—Oxygen containing atmosphere, e.g. with changing oxygen pressures
- C04B2235/6584—Oxygen containing atmosphere, e.g. with changing oxygen pressures at an oxygen percentage below that of air
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/74—Physical characteristics
- C04B2235/77—Density
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Definitions
- the present invention relates to the densification of ceria based electrolytes as may be used in fuel cells and oxygen generators for example.
- EP-A-1000913 describes processes for producing dense (>97% of the theoretically achievable density) ceria electrolytes at relatively low temperatures ( ⁇ 1000° C.).
- This patent application demonstrates that when small amounts (1-2 mol %) of CuO, NiO or CoO are added to commercial ceria based electrolyte powders (eg supplied by Rhodia, France) then pellets pressed from these doped pellets can be sintered to densities greater than 97% of the theoretical achievable density at temperatures as low as 1000° C. compared to 1350° C. usually required for pellets without any transition metal cation additions.
- the ceria based electrolytes are impermeable and so significantly reduce gaseous leakage between the anode and cathode gases.
- transition metal cations is not without problems. EMF measurements have been carried out at 650° C. on thin ( ⁇ 1 mm) discs fabricated from the sintered powders. EMF values (910 mV) for electrolyte discs without additions of divalent cations were at least 100 m V higher than values recorded (800 mV) for thin discs containing 2 mole % Co 2+ or 1 mole % Mn 2+ using similar experimental conditions. Clearly additions of the transition metal cations has introduced significant electronic conductivity which is an undesirable side-effect as it would have a major impact on the performance characteristics of intermediate-temperature solid oxide fuel cell (IT-SOFC) stacks incorporating cerin based electrolytes with cation additives.
- IT-SOFC intermediate-temperature solid oxide fuel cell
- a method of determining the effective concentration of divalent cations in a fabricated electrolyte comprising
- This method enables the effective concentration of divalent actions in an electrolyte to be determined.
- the effective concentration of divalent actions may be optimised to ensure sufficient densification of the electrolyte under desired conditions, eg approximately 1000° C. It should be emphasised that the procedures described herein apply to deposited ‘green’ electrolyte layers having typical densities in the range 50-60%. Fabrication routes capable of attaining this requirement have been described in patent application GB 0205291, and a preferred method involves depositing the electrolyte powder by EPD followed by isostatic pressing.
- divalent and trivalent cations can be incorporated into an electrolyte film during the fabrication procedures, but it has been found that their roles are very different. Divalent cations can enhance the densification process whereas it has been found that the presence of trivalent cations have an adverse effect on the densification process. To ensure electrolyte densification at 1000° C. it has been found that the concentration of divalent cations should exceed the concentration of trivalent cations, and it can be necessary to deliberately add small quantities of divalent cations (eg Mn 2+ , Fe 2+ , Mg 2+ , etc) to overcome the deleterious effects of trivalent cations (eg Cr 3+ , Fe 3+ , Al 3+ , etc) in the electrolyte.
- divalent cations eg Mn 2+ , Fe 2+ , Mg 2+ , etc
- the concentration of divalent cations in a fabricated electrolyte may be determined by adding the concentration of divalent cations that were added to the electrolyte prior to completion of the fabrication process to the concentration of divalent cations determined to be in the electrolyte after the fabrication process, had there been no additions.
- Divalent cations present in the electrolyte after the fabrication process could have originated from a number of sources.
- Divalent cations can originate from the conversion or reduction of intrinsic trivalent cations into divalent cations.
- the processing conditions during the fabrication procedure can be modified to reduce the concentration of deleterious trivalent cations, for example Fe 3+ can be reduced to Fe 2+ by appropriate control of the oxygen or water partial pressure in a sintering furnace.
- Divalent cations in the electrolyte could have originated from vapours from a metal substrate and/or an oxide layer on a metal substrate.
- Divalent cations can be added to the electrolyte at an appropriate opportunity, eg prior to the sintering process.
- the magnitude and type of the various cation impurity levels in turn influence the sintering kinetics and determine whether adequate densification of the electrolyte (generally required to be greater than 97% of the achievable density for desirable results) can be achieved by 1000° C.
- an effective concentration of divalent cations concentration of divalent cations—adjusted concentration of trivalent cations
- concentration of divalent cations 0.1 mole % inclusive
- an effective concentration of divalent cations does not produce as severe a reduction in EMF as electrolytes containing greater concentrations of divalent cations.
- the effective concentration of divalent cations is between 0.02 mole % and 0.09 mole % inclusive.
- the effective concentration of divalent cations is between 0.03 mole % and 0.08 mole % inclusive.
- a method of preparing an electrolyte with a desired effective cation concentration comprising fabricating an electrolyte and before or during fabrication increasing the divalent cation concentration by one or more of the following:
- the desired range may include or be between 0.01% and 0.1 mole %, but is preferably between 0.02 mole % and 0.09 mole % inclusive and more preferably between 0.03 mole % and 0.08 mole % inclusive.
- an electrolyte with an effective concentration of divalent cations determined by subtracting an adjusted concentration of trivalent cations in the electrolyte from the concentration of divalent cations in the substrate.
- the effective cation concentration may be between 0.01 mole % and 0.1 mole % inclusive, but is preferably between 0.02 mole % and 0.09 mole % inclusive and is more preferably between 0.03 mole % and 0.08 mole % inclusive.
- a half cell comprising a substrate, an electrode and an electrolyte according to the third aspect of the present invention.
- a fuel cell comprising the half cell of the fourth aspect of the present invention provided with a further electrode on the opposite side of the electrolyte from the other electrode.
- an oxygen generator comprising the half cell of the fourth aspect with a further electrode on the opposite side of the electrolyte from the other electrode.
- FIG. 1 illustrates the sintering characteristics of ceria based electrolyte pellets for 0.1% and 2% addition of cations
- FIG. 2 illustrates the sintering characteristics of ceria based electrolyte pellets for 0 and 0.1% addition of cations
- FIG. 3 is a schematic representation of a metal foil supported thick film cell assembly.
- FIG. 1 Studies on the sintering characteristics of a ceria based electrolyte, Ce 0.9 Gd 0.1 O 1.95 , powder are summarised in FIG. 1 . Inspection of FIG. 1 reveals that 1-2 mole % cation additions of divalent cations (eg Co 2+ , Fe 2+ , Mn 2+ ) can produce technologically useful pellet densities around 97/98% of the theoretical achievable density, whereas the trivalent cations (Fe 3+ , Mn 3+ ) severely retard the sintering kinetics.
- divalent cations eg Co 2+ , Fe 2+ , Mn 2+
- the observed densification of the electrolyte thick films compared to pellets could be associated with the realisation that the sintering process is taking place within an oxygen partial pressure gradient.
- the associated oxygen flux contributes to oxidation of the metal substrate foil.
- a small but significant cation flux in the opposite direction influences the sintering kinetics which are controlled by cation transport as illustrated in FIG. 3 .
- Both anionic and cation fluxes can be produced when multi-component oxide phases are placed in oxygen chemical potential gradients, and the associated differential transport processes can be responsible for de-mixing phenomena.
- [M E 2+ ] represents the effective concentration of divalent cations (eg Mn 2+ , Fe 2+ , Mg 2+ , etc) in a specific electrolyte.
- minimum effective concentrations of divalent cations required to ensure densification are typically 0.01-0.1 mole % (200-1000 ppm), which are below values mentioned in earlier publications such as EP-A-1000913.
- the valence of selected cation impurities, e.g. Fe, Mn will depend upon the oxygen partial pressure established within the sintering furnace.
- [M A 2+ ] represents the concentration of divalent cations (eg, Mn 2+ , Fe 2+ , Mg 2+ , etc) that were added to electrolyte prior to the high temperature fabrication procedures.
- the divalent cations in the electrolyte after the fabrication process could have originated from vapours from the metal substrate, or oxide on the substrate or from reduction of trivalent cations in the electrolyte layer for example.
- [M E 3+ ] represents the concentration of trivalent cations (eg Fe 3+ , Cr 3+ , Al 3+ , etc) determined to be in the electrolyte after the fabrication processes.
- the concentration of impurities is determined as above for the determination of the concentration of divalent cations in the electrolyte after the fabrication processes without prior additions.
- Trivalent cations are deleterious for sintering enhancement at 1000° C.
- Y represents a multiplying factor (typically 5-10).
- the presence of trivalent cations is very deleterious for the sintering process and so their actual concentration has to be multiplied by the factor Y to take account of their severe impact on the sintering behaviour. It can also be necessary to vary the value of Y according to the nature and distribution of the trivalent cations. For example, the influence of Al 3+ in discrete Al 2 O 3 particles introduced during milling processes, differs from the role of Al 3+ interfacial species widely distributed over the surface of the CGO powder.
- FIG. 3 shows a schematic representation of a metal foil supported thick film cell assembly as used in some of the following examples.
- CGO is deposited directly onto 1.4509 metal substrate (no pre-oxidation Treatment).
- the COO is sintered at 1000° C. in a H 2 /H 2 O/argon atmosphere designed to establish a pO 2 value of 10 ⁇ 14 at 1000° C.
- [M E 2+ ] was determined to be +0.1% (Table 1) and dense electrolyte was produced.
- the Fe and Cr are transported into the electrolyte via the vapour phase species, eg: Fe(g), Fe(OH) 2 (g), Cr(g), Cr(OH) 3 (g).
- concentration of gaseous metal hydroxide species will be influenced by metal thermodynamic activity in the metal oxide coating, and the p (H 2 O) in sintering furnace (processing variable).
- a CGO electrolyte film is deposited directly onto 1.4509 metal substrate (pre-oxidation treatment) and sintered at 1000° C. in CO 2 /H 2 argon atmosphere designed to establish pO 2 value of 10 ⁇ 14 at 1000° C. [M E 2+ ] was found to be ⁇ 0.07% (Table 1) due to Al 3+ contamination. The electrolyte was not dense.
- a Ni-CGO anode is fabricated on top of a 1.4509 metal substrate (pre-oxidation treatment). A CGO film is next deposited on top of the anode (see FIG.
- a Ni-CGO anode is fabricated on top of a JS-3 metal substrate (pre-oxidation treatment). A CGO film is next deposited on top of the anode (see FIG. 3 ), and sintered at 1000° C. in a H 2 /H 2 O/argon atmosphere designed to establish pO 2 value of 10 ⁇ 14 at 1000° C.
- [M E 2+ ] was found to be +0.1% (Table 1) due to high Mn 3+ content in spite of Al 3+ contamination. A dense electrolyte was produced. 5.
- a Ni-CGO anode is fabricated on top of a JS-3 metal substrate (pre-oxidation treatment). Mn (0.1 cation %) was added to the COO powder, A COO film is next deposited on top of the anode (see FIG. 3 ), and sintered at 1000° C. in a H 2 /H 2 O/argon atmosphere designed to establish pO 2 value of 10 ⁇ 14 at 1000° C.
- [M E 2+ ] was found to be +0.1% (Table 1) due to high Mn 3+ content in spite of Al 3 contamination and Fe present as Fe 3+ .
- a dense electrolyte was produced. 6.
- a Ni-CGO anode is fabricated on top of a ZMG 232 metal substrate (pre-oxidation treatment).
- a CGO film is next deposited on top of the anode (see FIG. 3 ), and sintered at 1000° C. in a H 2 /H 2 O/argon atmosphere designed to establish pO 2 value of 10 ⁇ 14 at 1000° C., ⁇ M E 2+ ⁇ was found to be +0.08% (Table 1) due to high Mn 3+ content in spite of Al 3+ contamination.
- a dense electrolyte was produced.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Sustainable Energy (AREA)
- Structural Engineering (AREA)
- Sustainable Development (AREA)
- Analytical Chemistry (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Fuel Cell (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Conductive Materials (AREA)
- Inert Electrodes (AREA)
Abstract
The fabrication of ceria based electrolytes to densities greater than 97% of the theoretical achievable density at temperatures below 1200° C., preferably approximately 1000° C., is disclosed. The electrolyte has a concentration of divalent cations minus an adjusted concentration of trivalent cations of between 0.01 mole % and 0.1 mole %.
Description
- This application is a divisional application of U.S. application Ser. No. 10/552,476, filed Mar. 25, 2004, which application is the U.S. national stage of international application no. PCT/GB04/01293, filed Mar. 25, 2004, published in the English language, which application claims priority benefits of United Kingdom application no. 0308215.3, filed Apr. 9, 2003, each application of which is incorporated by reference herein in its entirety.
- The present invention relates to the densification of ceria based electrolytes as may be used in fuel cells and oxygen generators for example.
- Procedures are known for fabricating thick film solid oxide fuel cell (SOFC) structures onto porous ferritic stainless steel foil substrates. The metal supported single cells can then easily be assembled into arrays by laser welding the individual cells onto a metal bi-polar plate. Such technology is described in GB 2,368,450. It has also been demonstrated that ceria based electrolytes, eg Ceo.9Gd0.1O=1.95(CG10) could be sintered on a metallic substrate to provide a dense impermeable electrolyte film at lower temperatures than previously used. The ability to sinter electrolytes at lower temperatures, eg 1000° C. minimises degradative changes to the stainless steel microstructure, reduces fabrication costs and also reduces the concentration of transition metal cations in the electrolyte due to transport of gaseous metal species from the substrate and its protective oxide.
- EP-A-1000913 describes processes for producing dense (>97% of the theoretically achievable density) ceria electrolytes at relatively low temperatures (˜1000° C.). This patent application demonstrates that when small amounts (1-2 mol %) of CuO, NiO or CoO are added to commercial ceria based electrolyte powders (eg supplied by Rhodia, France) then pellets pressed from these doped pellets can be sintered to densities greater than 97% of the theoretical achievable density at temperatures as low as 1000° C. compared to 1350° C. usually required for pellets without any transition metal cation additions. It should be noted that at densities of 97% of the theoretical achievable density the ceria based electrolytes are impermeable and so significantly reduce gaseous leakage between the anode and cathode gases.
- However the addition of transition metal cations is not without problems. EMF measurements have been carried out at 650° C. on thin (−1 mm) discs fabricated from the sintered powders. EMF values (910 mV) for electrolyte discs without additions of divalent cations were at least 100 m V higher than values recorded (800 mV) for thin discs containing 2 mole % Co2+ or 1 mole % Mn2+ using similar experimental conditions. Clearly additions of the transition metal cations has introduced significant electronic conductivity which is an undesirable side-effect as it would have a major impact on the performance characteristics of intermediate-temperature solid oxide fuel cell (IT-SOFC) stacks incorporating cerin based electrolytes with cation additives.
- It is an object of the present invention to assist in overcoming one or more of the problems described above to enable the sintering of dense electrolytes without an excessive reduction in EMF.
- According to a first aspect of the present invention there is provided a method of determining the effective concentration of divalent cations in a fabricated electrolyte, the method comprising
- determining the concentration of divalent cations in a fabricated electrolyte;
- determining the concentration of trivalent cations in a fabricated electrolyte and subtracting the adjusted concentration of trivalent cations from the concentration of divalent cations to produce the effective concentration of divalent cations. Due to the deleterious effect of the trivalent cations it is necessary to multiply their measured concentration by a factor between 5 and 10 as described later.
- This method enables the effective concentration of divalent actions in an electrolyte to be determined. Once the effective concentration of divalent actions can be determined, it may be optimised to ensure sufficient densification of the electrolyte under desired conditions, eg approximately 1000° C. It should be emphasised that the procedures described herein apply to deposited ‘green’ electrolyte layers having typical densities in the range 50-60%. Fabrication routes capable of attaining this requirement have been described in patent application GB 0205291, and a preferred method involves depositing the electrolyte powder by EPD followed by isostatic pressing.
- Both divalent and trivalent cations can be incorporated into an electrolyte film during the fabrication procedures, but it has been found that their roles are very different. Divalent cations can enhance the densification process whereas it has been found that the presence of trivalent cations have an adverse effect on the densification process. To ensure electrolyte densification at 1000° C. it has been found that the concentration of divalent cations should exceed the concentration of trivalent cations, and it can be necessary to deliberately add small quantities of divalent cations (eg Mn2+, Fe2+, Mg2+, etc) to overcome the deleterious effects of trivalent cations (eg Cr3+, Fe3+, Al3+, etc) in the electrolyte.
- The concentration of divalent cations in a fabricated electrolyte may be determined by adding the concentration of divalent cations that were added to the electrolyte prior to completion of the fabrication process to the concentration of divalent cations determined to be in the electrolyte after the fabrication process, had there been no additions.
- Divalent cations present in the electrolyte after the fabrication process could have originated from a number of sources. Divalent cations can originate from the conversion or reduction of intrinsic trivalent cations into divalent cations. For example the processing conditions during the fabrication procedure can be modified to reduce the concentration of deleterious trivalent cations, for example Fe3+ can be reduced to Fe2+ by appropriate control of the oxygen or water partial pressure in a sintering furnace. Divalent cations in the electrolyte could have originated from vapours from a metal substrate and/or an oxide layer on a metal substrate. Divalent cations can be added to the electrolyte at an appropriate opportunity, eg prior to the sintering process. The magnitude and type of the various cation impurity levels in turn influence the sintering kinetics and determine whether adequate densification of the electrolyte (generally required to be greater than 97% of the achievable density for desirable results) can be achieved by 1000° C.
- The inventors of the present invention have surprisingly found that an effective concentration of divalent cations (concentration of divalent cations—adjusted concentration of trivalent cations) of between 0.01 mole % and 0.1 mole % inclusive can be used to produce an electrolyte with a density greater than 97% of the achievable density at approximately 1000° C. Furthermore such an effective concentration of divalent cations does not produce as severe a reduction in EMF as electrolytes containing greater concentrations of divalent cations.
- Preferably the effective concentration of divalent cations is between 0.02 mole % and 0.09 mole % inclusive.
- More preferably the effective concentration of divalent cations is between 0.03 mole % and 0.08 mole % inclusive.
- According to a second aspect of the present invention there is provided a method of preparing an electrolyte with a desired effective cation concentration, the method comprising fabricating an electrolyte and before or during fabrication increasing the divalent cation concentration by one or more of the following:
- receiving divalent cations from vapour produced by a metal substrate associated with the electrolyte or an oxide layer on the substrate;
- reducing trivalent cations in the substrate material into divalent cations; or
- specifically adding divalent cations to the electrolyte prior to or during fabrication;
- such that the effective concentration of divalent cations minus the adjusted concentration of trivalent cations in the fabricated electrolyte is within a desired range.
- The desired range may include or be between 0.01% and 0.1 mole %, but is preferably between 0.02 mole % and 0.09 mole % inclusive and more preferably between 0.03 mole % and 0.08 mole % inclusive.
- According to a third aspect of the present invention there is provided an electrolyte with an effective concentration of divalent cations determined by subtracting an adjusted concentration of trivalent cations in the electrolyte from the concentration of divalent cations in the substrate. The effective cation concentration may be between 0.01 mole % and 0.1 mole % inclusive, but is preferably between 0.02 mole % and 0.09 mole % inclusive and is more preferably between 0.03 mole % and 0.08 mole % inclusive.
- According to a fourth aspect of the present invention there is provided a half cell comprising a substrate, an electrode and an electrolyte according to the third aspect of the present invention.
- According to a fifth aspect of the present invention there is provided a fuel cell comprising the half cell of the fourth aspect of the present invention provided with a further electrode on the opposite side of the electrolyte from the other electrode.
- According to an sixth aspect of the present invention there is provided an oxygen generator comprising the half cell of the fourth aspect with a further electrode on the opposite side of the electrolyte from the other electrode.
- Preferred embodiments of the present invention will now be described herein below by way of example only with reference to the accompanying drawings, in which:
-
FIG. 1 illustrates the sintering characteristics of ceria based electrolyte pellets for 0.1% and 2% addition of cations; -
FIG. 2 illustrates the sintering characteristics of ceria based electrolyte pellets for 0 and 0.1% addition of cations and -
FIG. 3 is a schematic representation of a metal foil supported thick film cell assembly. - Experiments have been carried out using a titanium-niobium stabilised ferritic stainless steel substrate (˜18% Cr) with the designation 1.4509. Analysis of a sintered electrolyte on the substrate indicated cation impurity levels of Fe2+ (0.25 mole %) and Cr3+ (0.005 mole %). Subsequent investigations have shown that densification of the CG010 electrolyte can be accomplished using a variety of ferritic stainless steels with different initial compositions and oxidation characteristics. These different substrates together with processing variations can produce significant changes in the concentration and valence of the metal impurities incorporated into the CGO electrolyte.
- Studies on the sintering characteristics of a ceria based electrolyte, Ce0.9Gd0.1O1.95, powder are summarised in
FIG. 1 . Inspection ofFIG. 1 reveals that 1-2 mole % cation additions of divalent cations (eg Co2+, Fe2+, Mn2+) can produce technologically useful pellet densities around 97/98% of the theoretical achievable density, whereas the trivalent cations (Fe3+, Mn3+) severely retard the sintering kinetics.FIG. 2 shows that for cation additions at the 0.1% levels the density of fired pellets was about the same for each of the additions of Mn2+, Mg2+, Ca2+, and comparable to densities (˜93% of the theoretical achievable density) developed by the pellets without cation additions as mentioned earlier. Co2+ and Fe2+ reduced the sintering kinetics, and particularly noteworthy is the very large decrease in sintered density due to additions of Fe3+ and Cr3+, even for cation additions as low as 0.1%. - The studies summarised in
FIGS. 1 and 2 show that the addition of divalent cations enhances the densification process, whereas the presence of trivalent cations has an adverse effect on the densification process. However, these studies indicate that ceria based pellets require a divalent cation concentration of the order of 2% to produce densification of 97% of the theoretical achievable density. The studies summarised inFIGS. 1 and 2 highlight how surprising it is that dense electrolyte thick films can be produced with apparently lower divalent cation concentrations. - The observed densification of the electrolyte thick films compared to pellets could be associated with the realisation that the sintering process is taking place within an oxygen partial pressure gradient. The associated oxygen flux contributes to oxidation of the metal substrate foil. At the same time a small but significant cation flux in the opposite direction influences the sintering kinetics which are controlled by cation transport as illustrated in
FIG. 3 . Both anionic and cation fluxes can be produced when multi-component oxide phases are placed in oxygen chemical potential gradients, and the associated differential transport processes can be responsible for de-mixing phenomena. Whatever the details of the enhanced sintering mechanism its manifestation is an important technological innovation, and investigations by the applicants have provided information related to optimisation of the processing parameters to densify ceria electrolytes which may be used in SOFC structures supported on metal substrates, oxygen generators etc. - The following empirical equation has been developed to ensure high (>98% of the theoretical achievable density) electrolyte densities, and to optimise the processing conditions for a variety of metal substrates, anode compositions, and SOFC configurations.
-
└M E 2+ ┘=└M A 2+ ┘+└M 1 2+ ┘−Y└M 1 3+┘ (A) - [ME 2+] represents the effective concentration of divalent cations (eg Mn2+, Fe2+, Mg2+, etc) in a specific electrolyte. Experiments suggest that minimum effective concentrations of divalent cations required to ensure densification (>98% of the theoretical achievable density) are typically 0.01-0.1 mole % (200-1000 ppm), which are below values mentioned in earlier publications such as EP-A-1000913. It should be noted that the valence of selected cation impurities, e.g. Fe, Mn, will depend upon the oxygen partial pressure established within the sintering furnace.
[MA 2+] represents the concentration of divalent cations (eg, Mn2+, Fe2+, Mg2+, etc) that were added to electrolyte prior to the high temperature fabrication procedures. - [M1 2+] represents the concentration of divalent cations (eg Mn2+, Fe2+, etc) determined to be in the electrolyte after the fabrication processes (without prior additions). The concentration of impurities can be determined by dynamic SIMS or Glow Discharge Optical Emission Spectrography (GDOES). Divalent cations are beneficial for enhanced sintering at 1000° C.
NOTE: ideally |M1 2+| should not exceed 0.1% for Fe2+ and Mn2+ ions, to avoid significant electronic conductivity in the electrolyte - The divalent cations in the electrolyte after the fabrication process could have originated from vapours from the metal substrate, or oxide on the substrate or from reduction of trivalent cations in the electrolyte layer for example.
- [ME 3+] represents the concentration of trivalent cations (eg Fe3+, Cr3+, Al3+, etc) determined to be in the electrolyte after the fabrication processes. The concentration of impurities is determined as above for the determination of the concentration of divalent cations in the electrolyte after the fabrication processes without prior additions. Trivalent cations are deleterious for sintering enhancement at 1000° C.
- Y represents a multiplying factor (typically 5-10). The presence of trivalent cations is very deleterious for the sintering process and so their actual concentration has to be multiplied by the factor Y to take account of their severe impact on the sintering behaviour. It can also be necessary to vary the value of Y according to the nature and distribution of the trivalent cations. For example, the influence of Al3+ in discrete Al2O3 particles introduced during milling processes, differs from the role of Al3+ interfacial species widely distributed over the surface of the CGO powder.
-
FIG. 3 shows a schematic representation of a metal foil supported thick film cell assembly as used in some of the following examples.
1. CGO is deposited directly onto 1.4509 metal substrate (no pre-oxidation Treatment). The COO is sintered at 1000° C. in a H2/H2O/argon atmosphere designed to establish a pO2 value of 10−14 at 1000° C. [ME 2+] was determined to be +0.1% (Table 1) and dense electrolyte was produced. The Fe and Cr are transported into the electrolyte via the vapour phase species, eg: Fe(g), Fe(OH)2 (g), Cr(g), Cr(OH)3 (g). Note the concentration of gaseous metal hydroxide species will be influenced by metal thermodynamic activity in the metal oxide coating, and the p (H2O) in sintering furnace (processing variable).
2. A CGO electrolyte film is deposited directly onto 1.4509 metal substrate (pre-oxidation treatment) and sintered at 1000° C. in CO2/H2 argon atmosphere designed to establish pO2 value of 10−14 at 1000° C. [ME 2+] was found to be −0.07% (Table 1) due to Al3+ contamination. The electrolyte was not dense.
3. A Ni-CGO anode is fabricated on top of a 1.4509 metal substrate (pre-oxidation treatment). A CGO film is next deposited on top of the anode (seeFIG. 3 ), and sintered at 1000° C. in a CO2/H2/argon atmosphere designed to establish pO2 value of 10−14 at 1000° C. [ME 2+] was found to be −0.05% (Table 1) due to Al3+ contamination. The electrolyte was not dense.
4. A Ni-CGO anode is fabricated on top of a JS-3 metal substrate (pre-oxidation treatment). A CGO film is next deposited on top of the anode (seeFIG. 3 ), and sintered at 1000° C. in a H2/H2O/argon atmosphere designed to establish pO2 value of 10−14 at 1000° C. [ME 2+] was found to be +0.1% (Table 1) due to high Mn3+ content in spite of Al3+ contamination.
A dense electrolyte was produced.
5. A Ni-CGO anode is fabricated on top of a JS-3 metal substrate (pre-oxidation treatment). Mn (0.1 cation %) was added to the COO powder, A COO film is next deposited on top of the anode (seeFIG. 3 ), and sintered at 1000° C. in a H2/H2O/argon atmosphere designed to establish pO2 value of 10−14 at 1000° C. [ME 2+] was found to be +0.1% (Table 1) due to high Mn3+ content in spite of Al3 contamination and Fe present as Fe3+.
A dense electrolyte was produced.
6. A Ni-CGO anode is fabricated on top of a ZMG 232 metal substrate (pre-oxidation treatment). A CGO film is next deposited on top of the anode (seeFIG. 3 ), and sintered at 1000° C. in a H2/H2O/argon atmosphere designed to establish pO2 value of 10−14 at 1000° C., └ME 2+┘ was found to be +0.08% (Table 1) due to high Mn3+ content in spite of Al3+ contamination.
A dense electrolyte was produced. -
TABLE 1 Ferritic Stainless Steel Electrolyte Substrate Oxide Anode [MA 2+] % [MI 2+] % Y[MI 3+] % [ME 2+] % Result 1.4509 NT NP 0 0.15 0.05 +0.1 Dense 1.4509 T NP 0 0.03 0.1 −0.07 Not dense 1.4509 T Ni- CGO 0 0.05 0.1 −0.05 Not dense JS-3 T Ni- CGO 0 0.2 0.1 +0.1 Dense JS-3 T Ni-CGO 0.1 0.1 0.1 +0.1 Dense ZMG 232 T Ni- CGO 0 0.2 0.12 +0.08 Dense NT indicates no pre-treatment to form oxide layer
Presence of Ni-CGO reduces concentration of Cr and Fe in electrolyte (these species probably trapped as NiFe2O4, NiCr2O4). Unless there is sufficient divalent cations such as Mn2+ (eg then the electrolyte not dense.
Claims (20)
1. A half cell assembly comprising a substrate, an electrode and an electrolyte, wherein the electrolyte is a ceria based electrolyte with a density greater than 97% of the theoretical achievable density and with a concentration of divalent cations minus an adjusted concentration of trivalent cations of between 0.01 mole % and 0.1 mole % inclusive.
2. A half cell assembly as defined in claim 1 , wherein the concentration of divalent cations minus an adjusted concentration of trivalent cations is between 0.02 mole % and 0.09 mole % inclusive.
3. A half cell assembly as defined in claim 1 , wherein the concentration of divalent cations minus an adjusted concentration of trivalent cations is between 0.03 mole % and 0.08 mole % inclusive.
4. A half cell assembly as defined in claim 1 , wherein the concentration of trivalent cations is adjusted by multiplication by a number between 5 and 10.
5. A half cell assembly as defined in claim 1 , wherein the electrolyte is sintered.
6. A fuel cell assembly comprising:
a half cell assembly comprising a substrate, a first electrode and an electrolyte, wherein the electrolyte is a ceria based electrolyte with a density greater than 97% of the theoretical achievable density and with a concentration of divalent cations minus an adjusted concentration of trivalent cations of between 0.01 mole % and 0.1 mole % inclusive; and
a second electrode provided on the opposite side of the electrolyte from the first electrode.
7. A fuel cell assembly as defined in claim 6 , wherein the concentration of divalent cations minus an adjusted concentration of trivalent cations is between 0.02 mole % and 0.09 mole % inclusive.
8. A fuel cell assembly as defined in claim 7 , wherein the first electrode is an anode and the second electrode is a cathode.
9. A fuel cell assembly as defined in claim 6 , wherein the concentration of divalent cations minus an adjusted concentration of trivalent cations is between 0.03 mole % and 0.08 mole % inclusive.
10. A fuel cell as defined in claim 9 , wherein the first electrode is an anode and the second electrode is a cathode.
11. A fuel cell assembly as defined in claim 6 , wherein the concentration of trivalent cations is adjusted by multiplication by a number between 5 and 10.
12. A fuel cell as defined in claim 11 , wherein the first electrode is an anode and the second electrode is a cathode.
13. A fuel cell assembly as defined in claim 6 , wherein the electrolyte is sintered.
14. A fuel cell as defined in claim 13 , wherein the first electrode is an anode and the second electrode is a cathode.
15. A fuel cell assembly as defined in claim 6 , wherein the first electrode is an anode and the second electrode is a cathode.
16. An oxygen generator, comprising:
a half cell assembly comprising a substrate, a first electrode and an electrolyte, wherein the electrolyte is a ceria based electrolyte with a density greater than 97% of the theoretical achievable density and with a concentration of divalent cations minus an adjusted concentration of trivalent cations of between 0.01 mole % and 0.1 mole % inclusive; and
a second electrode provided on the opposite side of the electrolyte from the first electrode.
17. An oxygen generator as defined in claim 16 , wherein the concentration of divalent cations minus an adjusted concentration of trivalent cations is between 0.02 mole % and 0.09 mole % inclusive.
18. An oxygen generator as defined in claim 16 , wherein the concentration of divalent cations minus an adjusted concentration of trivalent cations is between 0.03 mole % and 0.08 mole % inclusive.
19. An oxygen generator as defined in claim 16 , wherein the concentration of trivalent cations is adjusted by multiplication by a number between 5 and 10.
20. An oxygen generator as defined in claim 16 , wherein the electrolyte is sintered.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/076,761 US20110177427A1 (en) | 2003-04-09 | 2011-03-31 | Densification of ceria based electrolytes |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0308215.3 | 2003-04-09 | ||
GB0308215A GB2400486B (en) | 2003-04-09 | 2003-04-09 | Densification of ceria based electrolytes |
PCT/GB2004/001293 WO2004089848A1 (en) | 2003-04-09 | 2004-03-25 | Densification of ceria based electrolytes |
US10/552,476 US7947212B2 (en) | 2003-04-09 | 2004-03-25 | Densification of ceria based electrolytes |
US13/076,761 US20110177427A1 (en) | 2003-04-09 | 2011-03-31 | Densification of ceria based electrolytes |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB2004/001293 Division WO2004089848A1 (en) | 2003-04-09 | 2004-03-25 | Densification of ceria based electrolytes |
US11/552,476 Division US20080096684A1 (en) | 2006-10-24 | 2006-10-24 | Golf Practice Mat |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110177427A1 true US20110177427A1 (en) | 2011-07-21 |
Family
ID=9956496
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/552,476 Active 2027-07-24 US7947212B2 (en) | 2003-04-09 | 2004-03-25 | Densification of ceria based electrolytes |
US13/076,761 Abandoned US20110177427A1 (en) | 2003-04-09 | 2011-03-31 | Densification of ceria based electrolytes |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/552,476 Active 2027-07-24 US7947212B2 (en) | 2003-04-09 | 2004-03-25 | Densification of ceria based electrolytes |
Country Status (16)
Country | Link |
---|---|
US (2) | US7947212B2 (en) |
EP (1) | EP1608605B1 (en) |
JP (1) | JP5048322B2 (en) |
KR (1) | KR101065949B1 (en) |
CN (1) | CN100381395C (en) |
AU (1) | AU2004228427B2 (en) |
BR (1) | BRPI0409093B1 (en) |
CA (1) | CA2521901C (en) |
DK (1) | DK1608605T3 (en) |
EA (1) | EA009103B1 (en) |
ES (1) | ES2444217T3 (en) |
GB (1) | GB2400486B (en) |
HK (1) | HK1069680A1 (en) |
MX (1) | MXPA05010789A (en) |
WO (1) | WO2004089848A1 (en) |
ZA (1) | ZA200508144B (en) |
Families Citing this family (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4937755B2 (en) * | 2004-10-15 | 2012-05-23 | パナソニック株式会社 | Fuel cell system |
WO2008003976A1 (en) | 2006-07-07 | 2008-01-10 | Ceres Intellectual Property Company Limited | Metal substrate for fuel cells |
US9162931B1 (en) * | 2007-05-09 | 2015-10-20 | The United States Of America As Represented By The Secretary Of The Air Force | Tailored interfaces between two dissimilar nano-materials and method of manufacture |
US9120245B1 (en) | 2007-05-09 | 2015-09-01 | The United States Of America As Represented By The Secretary Of The Air Force | Methods for fabrication of parts from bulk low-cost interface-defined nanolaminated materials |
US8617456B1 (en) | 2010-03-22 | 2013-12-31 | The United States Of America As Represented By The Secretary Of The Air Force | Bulk low-cost interface-defined laminated materials and their method of fabrication |
KR101478207B1 (en) * | 2007-11-23 | 2015-01-02 | 삼성전자주식회사 | Method and apparatus for indentifing equipments requesting javapush |
GB2461115A (en) | 2008-04-23 | 2009-12-30 | Ceres Power Ltd | Fuel Cell Module Support |
ES2387212T3 (en) | 2008-08-21 | 2012-09-18 | Ceres Intellectual Property Company Limited | Improved air flow of the flow hood of a fuel cell stacking using an air distribution device |
FR2948821B1 (en) | 2009-08-03 | 2011-12-09 | Commissariat Energie Atomique | ELECTROCHEMICAL METAL SUPPORT CELL AND METHOD OF MANUFACTURING THE SAME |
CN101654366B (en) * | 2009-09-10 | 2012-10-24 | 中国矿业大学(北京) | Composite sintering agent and method for preparing nano crystalline ceramics at low temperature |
DE102012211669A1 (en) * | 2012-07-04 | 2014-01-09 | Behr Gmbh & Co. Kg | air conditioning |
GB2517927B (en) | 2013-09-04 | 2018-05-16 | Ceres Ip Co Ltd | Process for forming a metal supported solid oxide fuel cell |
GB2517928B (en) | 2013-09-04 | 2018-02-28 | Ceres Ip Co Ltd | Metal supported solid oxide fuel cell |
EP3117477B1 (en) | 2014-03-12 | 2018-12-19 | Ceres Intellectual Property Company Limited | Fuel cell stack arrangement |
GB2534124B (en) | 2014-12-19 | 2017-04-19 | Ceres Ip Co Ltd | A swirl burner assembly and method |
US11527766B2 (en) | 2014-12-19 | 2022-12-13 | Ceres Intellectual Property Company Limited | Fuel cell system and tail gas burner assembly and method |
GB2563848B (en) | 2017-06-26 | 2022-01-12 | Ceres Ip Co Ltd | Fuel cell stack assembly |
GB201713141D0 (en) | 2017-08-16 | 2017-09-27 | Ceres Ip Co Ltd | Fuel cell unit |
GB201913907D0 (en) | 2019-09-26 | 2019-11-13 | Ceres Ip Co Ltd | Fuel cell stack assembly apparatus and method |
GB201915294D0 (en) | 2019-10-22 | 2019-12-04 | Ceres Ip Co Ltd | Alignment apparatus and methods of alignment |
GB201915438D0 (en) | 2019-10-24 | 2019-12-11 | Ceres Ip Co Ltd | Metal-supported cell unit |
GB2591462B (en) | 2020-01-27 | 2022-04-20 | Ceres Ip Co Ltd | Interlayer for solid oxide cell |
GB202009687D0 (en) | 2020-06-25 | 2020-08-12 | Ceres Ip Co Ltd | Layer |
WO2023078944A1 (en) | 2021-11-08 | 2023-05-11 | Rhodia Operations | Cerium-gadolinium composite oxide |
CN118201892A (en) | 2021-11-08 | 2024-06-14 | 罗地亚经营管理公司 | Cerium gadolinium composite oxide |
GB202304341D0 (en) | 2023-03-24 | 2023-05-10 | Ceres Ip Co Ltd | Solid oxide electrochemical cell |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5509189A (en) * | 1993-03-10 | 1996-04-23 | Massachusetts Institute Of Technology, A Ma Corp. | Method for making an electrochemical cell |
US5665482A (en) * | 1995-01-10 | 1997-09-09 | Tosoh Corporation | Fluorite structure type ceria type solid electrolyte |
US20010007381A1 (en) * | 1998-11-13 | 2001-07-12 | Christoph Kleinlogel | Process for the production of sintered ceramic oxide |
US20030027027A1 (en) * | 2001-04-27 | 2003-02-06 | Cutler Raymond Ashton | Ceria based solid elecrolytes |
US20030224234A1 (en) * | 2002-03-06 | 2003-12-04 | Steele Brian Charles Hilton | Forming an impermeable sintered ceramic electrolyte layer on a metallic foil substrate for solid oxide fuel cell |
US20040026668A1 (en) * | 2000-03-15 | 2004-02-12 | Mitsubishi Materials Corporation | Oxide ion conductor, manufacturing method therefor, and fuel cell using the same |
US20050048340A1 (en) * | 2000-03-10 | 2005-03-03 | Carsten Bagger | Solid oxide fuel cell as well as a method of manufacturing said solid oxide fuel cell |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB205291A (en) | 1922-09-07 | 1923-10-18 | Francis Mcnally | Improvements in thermometers |
JPH092873A (en) * | 1995-01-10 | 1997-01-07 | Tosoh Corp | Fluorite-type ceria-based solid electrolyte |
JPH10154523A (en) * | 1996-09-27 | 1998-06-09 | Tosoh Corp | Defective fluorite type ceria system solid electrolyte |
CN1150647C (en) * | 2000-02-16 | 2004-05-19 | 刘向荣 | Composite ceramic material for middle-temperature oxide fuel cell |
GB2368450B (en) | 2000-10-25 | 2004-05-19 | Imperial College | Fuel cells |
-
2003
- 2003-04-09 GB GB0308215A patent/GB2400486B/en not_active Expired - Lifetime
-
2004
- 2004-03-25 EP EP04723244.2A patent/EP1608605B1/en not_active Expired - Lifetime
- 2004-03-25 EA EA200501588A patent/EA009103B1/en not_active IP Right Cessation
- 2004-03-25 MX MXPA05010789A patent/MXPA05010789A/en active IP Right Grant
- 2004-03-25 BR BRPI0409093-4B1A patent/BRPI0409093B1/en not_active IP Right Cessation
- 2004-03-25 CA CA2521901A patent/CA2521901C/en not_active Expired - Lifetime
- 2004-03-25 CN CNB200480009486XA patent/CN100381395C/en not_active Expired - Lifetime
- 2004-03-25 US US10/552,476 patent/US7947212B2/en active Active
- 2004-03-25 KR KR1020057019309A patent/KR101065949B1/en active IP Right Grant
- 2004-03-25 JP JP2006506020A patent/JP5048322B2/en not_active Expired - Lifetime
- 2004-03-25 DK DK04723244.2T patent/DK1608605T3/en active
- 2004-03-25 AU AU2004228427A patent/AU2004228427B2/en not_active Ceased
- 2004-03-25 ES ES04723244.2T patent/ES2444217T3/en not_active Expired - Lifetime
- 2004-03-25 WO PCT/GB2004/001293 patent/WO2004089848A1/en active Application Filing
-
2005
- 2005-01-18 HK HK05100465A patent/HK1069680A1/en not_active IP Right Cessation
- 2005-10-10 ZA ZA200508144A patent/ZA200508144B/en unknown
-
2011
- 2011-03-31 US US13/076,761 patent/US20110177427A1/en not_active Abandoned
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5509189A (en) * | 1993-03-10 | 1996-04-23 | Massachusetts Institute Of Technology, A Ma Corp. | Method for making an electrochemical cell |
US5665482A (en) * | 1995-01-10 | 1997-09-09 | Tosoh Corporation | Fluorite structure type ceria type solid electrolyte |
US20010007381A1 (en) * | 1998-11-13 | 2001-07-12 | Christoph Kleinlogel | Process for the production of sintered ceramic oxide |
US20050048340A1 (en) * | 2000-03-10 | 2005-03-03 | Carsten Bagger | Solid oxide fuel cell as well as a method of manufacturing said solid oxide fuel cell |
US20040026668A1 (en) * | 2000-03-15 | 2004-02-12 | Mitsubishi Materials Corporation | Oxide ion conductor, manufacturing method therefor, and fuel cell using the same |
US20030027027A1 (en) * | 2001-04-27 | 2003-02-06 | Cutler Raymond Ashton | Ceria based solid elecrolytes |
US20030224234A1 (en) * | 2002-03-06 | 2003-12-04 | Steele Brian Charles Hilton | Forming an impermeable sintered ceramic electrolyte layer on a metallic foil substrate for solid oxide fuel cell |
Also Published As
Publication number | Publication date |
---|---|
CN100381395C (en) | 2008-04-16 |
GB2400486B (en) | 2006-05-10 |
AU2004228427B2 (en) | 2009-09-17 |
MXPA05010789A (en) | 2006-03-30 |
CA2521901A1 (en) | 2004-10-21 |
EP1608605B1 (en) | 2013-08-28 |
US20070020498A1 (en) | 2007-01-25 |
BRPI0409093B1 (en) | 2013-08-27 |
CA2521901C (en) | 2011-09-06 |
EP1608605A1 (en) | 2005-12-28 |
GB2400486A (en) | 2004-10-13 |
EA200501588A1 (en) | 2006-04-28 |
KR101065949B1 (en) | 2011-09-19 |
DK1608605T3 (en) | 2013-12-09 |
JP5048322B2 (en) | 2012-10-17 |
GB0308215D0 (en) | 2003-05-14 |
EA009103B1 (en) | 2007-10-26 |
AU2004228427A1 (en) | 2004-10-21 |
BRPI0409093A (en) | 2006-04-11 |
KR20060012271A (en) | 2006-02-07 |
WO2004089848A1 (en) | 2004-10-21 |
ZA200508144B (en) | 2006-10-25 |
CN1771212A (en) | 2006-05-10 |
HK1069680A1 (en) | 2005-05-27 |
ES2444217T3 (en) | 2014-02-24 |
US7947212B2 (en) | 2011-05-24 |
JP2006523002A (en) | 2006-10-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20110177427A1 (en) | Densification of ceria based electrolytes | |
US10008726B2 (en) | Metal supported solid oxide fuel cell | |
US6737186B2 (en) | Current collector for SOFC fuel cells | |
US8173328B2 (en) | Interconnects for solid oxide fuel cells and ferritic stainless steels adapted for use with solid oxide fuel cells | |
CA2922876C (en) | Process for forming a metal supported solid oxide fuel cell | |
AU2006259739B2 (en) | Interconnects for solid oxide fuel cells and ferritic stainless steels adapted for use with solid oxide fuel cells | |
US7842434B2 (en) | Interconnects for solid oxide fuel cells and ferritic stainless steels adapted for use with solid oxide fuel cells | |
CA2597997A1 (en) | Fuel cell cathodes | |
AU2004213893A1 (en) | Method for producing a protective coating for substrates that are subjected to high temperatures and form chromium oxide | |
Horita et al. | Cation diffusion in (La, Ca) CrO3 perovskite by SIMS | |
US8158057B2 (en) | Interconnects for solid oxide fuel cells and ferritic stainless steels adapted for use with solid oxide fuel cells | |
Sakai et al. | Material transport and degradation behavior of SOFC interconnects | |
Sata et al. | Protonic ceramic electrochemical cells in a metal supported architecture: challenges, status and prospects | |
CN105948747A (en) | Method for preparing dense diffusion barrier of limiting current type oxygen sensor with co-permeation method | |
AU2011244954B2 (en) | Interconnects for solid oxide fuel cells and ferritic stainless steels adapted for use with solid oxide fuel cells |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CERES POWER LIMITED, UNITED KINGDOM Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:STEELE, BRIAN CHARLES HILTON;LEWIS, GENE;OISHI, NAOKI;AND OTHERS;SIGNING DATES FROM 20051202 TO 20060109;REEL/FRAME:026082/0063 |
|
AS | Assignment |
Owner name: CERES INTELLECTUAL PROPERTY COMPANY LIMITED, UNITE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CERES POWER LIMITED;REEL/FRAME:026205/0533 Effective date: 20061221 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |